Simple Performance Tester for Superpave Mix Design: First-Article Development and Evaluation (2003)

Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

A-1 APPENDIX A FIRST-ARTICLE EQUIPMENT SPECIFICATIONS

A-2 NCHRP Project 9-29 Simple Performance Tester for Superpave Mix Design First-Article Equipment Specifications For The Simple Performance Test System LIMITED USE DOCUMENT The information contained in this Document is regarded as fully privileged. Dissemination of information included herein must be approved by the NCHRP. November 19, 2001 Includes Amendment 1 Advanced Asphalt Technologies, LLC 108 Powers Court, Suite 100 Sterling, Virginia 20166 ADVANCED ASPHALT TECHNOLOGIES ENGINEERING SERVICES FOR THE ASPHALT INDUSTRY NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-3 Table of Contents Table of Content ....................................................................................................................A-3 1.0 Summary .......................................................................................................................A-4 2.0 Definitions.......................................................................................................................A-8 3.0 Test Specimens ...............................................................................................................A-8 4.0 Simple Performance Test System ...................................................................................A-9 5.0 Compression Loading Machine ......................................................................................A-10 6.0 Loading Platens...............................................................................................................A-11 7.0 Load Measuring System .................................................................................................A-11 8.0 Deflection Measuring System.........................................................................................A-12 9.0 Specimen Deformation Measuring System ....................................................................A-12 10.0 Confining Pressure System...........................................................................................A-13 11.0 Environmental Chamber ...............................................................................................A-14 12.0 Computer Control and Data Acquisition ......................................................................A-14 13.0 Computations ................................................................................................................A-24 14.0 Calibration and Verification of Dynamic Performance ................................................A-31 15.0 Verification of Normal Operation.................................................................................A-32 16.0 Documentation..............................................................................................................A-33 17.0 Warranty .......................................................................................................................A-33 Annex A. NCHRP Project 9-19 Draft Test Protocol W1: Simple Performance Test for Permanent Deformation Based Upon Static Creep / Flow Time Strength of Asphalt Concrete Mixtures.......................A-34 Annex B. NCHRP Project 9-19 Draft Test Protocol W2: Simple Performance Test for Permanent Deformation Based Upon Repeated Load Test of Asphalt Concrete Mixtures..............................................A-51 Annex C. NCHRP Project 9-19 Draft Test Protocol X1: Simple Performance Test for Permanent Deformation Based Upon Dynamic Modulus of Asphalt Concrete Mixtures ................................................A-67 Annex D. Specification Compliance Tests Methods for the Simple Performance Test System ..................................................................................A-83

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-4 1.0 Summary 1.1 This specification describes the requirements for a testing system to conduct the following National Cooperative Highway Research Program (NCHRP) Project 9-19 simple performance tests: Protocol W1: Simple Performance Test for Permanent Deformation Based Upon Static Creep / Flow Time Strength of Asphalt Concrete Mixtures. Protocol W2: Simple Performance Test for Permanent Deformation Based Upon Repeated Load Test of Asphalt Concrete Mixtures. Protocol X1: Simple Performance Test for Permanent Deformation Based Upon Dynamic Modulus of Asphalt Concrete Mixtures. The Project 9-19 Draft Test Protocols are reproduced in Annex A, B and C of this equipment specification to provide manufacturers with a description of the proposed test procedure. Note: This equipment specification represents a revision of the equipment requirements contained in the Project 9-19 Draft Test Protocols. The requirements of this specification supersede those contained in Project 9-19 Draft Test Protocols. 1.2 The testing system shall be capable of performing three compressive tests on nominal 100 mm (4 in) diameter, 150 mm (6 in) high cylindrical specimens. The tests are briefly described below. 1.3 Flow Time Test. In this test, the specimen is subjected to a constant axial compressive load at a specific test temperature. The test may be conducted with or without confining pressure. The resulting axial strain is measured as a function of time and numerically differentiated to calculate the flow time. The flow time is defined as the time corresponding to the minimum rate of change of axial strain. This is shown schematically in Figure 1. 1.4 Flow Number Test. In this test, the specimen, at a specific test temperature, is subjected to a repeated haversine axial compressive load pulse of 0.1 sec every 1.0 sec. The test may be conducted with or without confining pressure. The resulting permanent axial strains are measured as a function of time and numerically differentiated to calculate the flow number. The flow number is defined as the number of load cycles corresponding to the minimum rate of change of permanent axial strain. This is shown schematically in Figure 2. NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-5 a. Axial Strain in Flow Time Test. b. Rate of Change of Axial Strain. Figure 1. Schematic of Flow Time Test Data. 0.000 0.005 0.010 0.015 0.020 0.025 0 100 200 300 400 Time, Sec A x i a l S t r a i n (  ) , m m / m m 0.0E+00 2.0E-05 4.0E-05 6.0E-05 8.0E-05 1.0E-04 0 100 200 300 400 Time, Sec d (  ) / d t

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-6 a. Permanent Axial Strain in Flow Number Test. b. Rate of Change of Permanent Axial Strain. Figure 2. Schematic of Flow Number Test Data. 0.0E+00 2.0E-06 4.0E-06 6.0E-06 8.0E-06 1.0E-05 0 500 1000 1500 2000 2500 3000 Load Pulse d (  p ) / d t 0.000 0.005 0.010 0.015 0.020 0.025 0 1000 2000 3000 Load Pulse P e r m a n e n t A x i a l S t r a i n (  p ) , m m / m m NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-7 1.5 Dynamic Modulus Test. In this test, the specimen, at a specific test temperature, is subjected to controlled sinusoidal (haversine) compressive stress of various frequencies. The applied stresses and resulting axial strains are measured as a function of time and used to calculate the dynamic modulus and phase angle. The dynamic modulus and phase angle are defined by Equations 1 and 2. Figure 3 presents a schematic of the data generated during a typical dynamic modulus test. o oE ε σ =* (1) )360( p i T T = Φ (2) Where: |E*| = dynamic modulus Φ = phase angle, degree σo = stress amplitude ε o = strain amplitude Ti = time lag between stress and strain Tp = period of applied stress Figure 3. Schematic of Dynamic Modulus Test Data. 0.00 0.05 0.10 0.15 TIME, SEC L O A D A X I A L S T R A I N TIME LAG, TI O O PERIOD, TP 2 σ ο 2  ο

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-8 2.0 Definitions 2.1 Flow Time. Time corresponding to the minimum rate of change of axial strain during a creep test. 2.2 Flow Number. The number of load cycles corresponding to the minimum rate of change of permanent axial strain during a repeated load test. 2.3 Dynamic Modulus. Ratio of the stress amplitude to the strain amplitude for asphalt concrete subjected to sinusoidal loading (Equation 1). 2.4 Phase Angle. Angle in degrees between a sinusoidally applied stress and the resulting strain in a controlled stress test (Equation 2). 2.5 Resolution. The smallest change of a measurement that can be displayed or recorded by the measuring system. When noise produces a fluctuation in the display or measured value, the resolution shall be one-half of the range of the fluctuation. 2.6 Accuracy. The permissible variation from the correct or true value. 2.7 Error. The value obtained by subtracting the value indicated by a traceable calibration device from the value indicated by the measuring system. 2.8 Confining Pressure. Stress applied to all surfaces in a confined test. 2.9 Deviator Stress. Difference between the total axial stress and the confining pressure in a confined test. 2.10 Dynamic Stress. Sinusoidal deviator stress applied during the Dynamic Modulus Test. 2.11 Dynamic Strain. Sinusoidal axial strain measured during the Dynamic Modulus Test. 3.0 Test Specimens 3.1 Test specimens for the Simple Performance Test System will be cylindrical meeting the following requirements. Item Specification Remarks Average Diameter 100 mm to 104 mm Standard Deviation of Diameter 1.0 mm See note 1 Height 147.5 mm to 152.5 mm End Flatness 0.3 mm See note 2 End Parallelism 1 degree See note 3 NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-9 Notes: 1. Measure the diameter at the center and third points of the test specimen along axes that are 90 degrees apart. Record each of the six measurements to the nearest 1 mm. Calculate the average and the standard deviation of the six measurements. The standard deviation shall be less than 1.0 mm. The average diameter, reported to the nearest 1 mm, shall be used in all material property calculations. 2. Check this requirement using a straight edge and feeler gauges. 3. Check this requirement using a machinists square and feeler gauges. Note: Test specimens will be fabricated using separate equipment. This information is provided for design of the Simple Performance Test system. 4.0 Simple Performance Test System 4.1 The Simple Performance Test System shall be a complete, fully integrated testing system meeting the requirements of these specifications and having the capability to perform the Flow Time, Flow Number, and Dynamic Modulus simple performance tests described in Annex A, B, and C, respectively. 4.2 Annex D summarizes the methods that will be used to verify that the Simple Performance Test System complies with the requirements of this specification. 4.3 The Simple Performance Test System shall include the following components: 1. Compression loading machine. 2. Loading platens. 3. Load measuring system. 4. Deflection measuring system. 5. Specimen deformation measuring system. 6. Confining pressure system. 7. Environmental chamber. 8. Computer control and data acquisition system. 4.4 The load frame, environmental chamber, and computer control system for the Simple Performance Test System shall occupy a foot-print no greater than 1.5 m (5 ft) by 1.5 m (5 ft) with a maximum height of 1.8 m (6 ft). A suitable frame, bench or cart shall be provided so that the bottom of the test specimen, and the computer keyboard and display are approximately 90 cm (36 in) above the floor. 4.5 The load frame, environmental chamber and computer control system for the Simple Performance Test System shall operate on single phase 115 or 230 VAC 60 Hz electrical power.

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-10 4.6 If a hydraulic power supply is required, it shall be air-cooled occupying a foot-print no larger than 1 m (3 ft) by 1.5 m (5 ft). The noise level 2 m (6.5 ft) from the hydraulic power supply shall not exceed 70 dB. The hydraulic power supply shall operate on single phase 115 of 230 VAC 60 Hz electrical power. 4.7 When disassembled, the width of any single component shall not exceed 76 cm (30 in). 4.8 Air supply requirements shall not exceed 0.005 m3/s (10.6 ft3/min) at 850 kPa (125 psi). 4.9 The Simple Performance Test System shall include appropriate limit and overload protection. 4.10 An emergency stop shall be mounted at an easily accessible point on the system. 5.0 Compression Loading Machine 5.1 The machine shall have closed-loop load control with the capability of applying constant, ramp, sinusoidal, and pulse loads. The requirements for each of the simple performance tests are listed below. Test Type of Loading Capacity Rate Flow Time Ramp, constant 10 kN (2.25 kips) 0.5 sec ramp Flow Number Ramp, constant, pulse 8 kN (1.80 kips) 10 Hz pulse with 0.9 sec dwell Dynamic Modulus Ramp, constant, sinusoidal 6 kN (1.35 kips) 0.1 to 25 Hz 5.2 For ramp and constant loads, the load shall be maintained within +/- 2 percent of the desired load. 5.3 For sinusoidal loads, the standard error of the applied load shall be less than 5 percent. The standard error of the applied load is a measure of the difference between the measured load data, and the best fit sinusoid. The standard error of the load is defined in Equation 3. ( )     – – = Σ = o n i ii xn xx Pse ˆ %100 4 ˆ )( 1 2 (3)     NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-11 Where: se(P) = Standard error of the applied load xi = Measured load at point i ixˆ = Predicted load at point i from the best fit sinusoid, See Equation 16 oxˆ = Amplitude of the best fit sinusoid n = Total number of data points collected during test. 5.4 For pulse loads, the peak of the load pulse shall be within +/- 2 percent of the specified value and the standard error of the applied load during the sinusoidal pulse shall be less than 10 percent. 5.5 For the Flow Time and Flow Number Tests, the loading platens shall remain parallel during loading. For the Dynamic Modulus Test, the load shall be applied to the specimen through a ball or swivel joint. 6.0 Loading Platens 6.1 The loading platens shall be fabricated from aluminum and have a Brinell Hardness Number HBS 10/500 of 95 or greater. 6.2 The loading platens shall be at least 25 mm (1 in) thick. The diameter of the loading platens shall not be less than 105 mm (4.125 in) nor greater than 108 mm (4.25 in). 6.3 The loading platens shall not depart from a plane by more than 0.0125 mm (0.0005 in) across any diameter. 7.0 Load Measuring System 7.1 The Simple Performance Test System shall include an electronic load measuring system with full scale range equal to or greater than the stall force for the actuator of the compression loading machine. 7.2 The load measuring system shall have an error equal to or less than +/- 1 percent for loads ranging from 2 to 100 percent of the capacity of the machine when verified in accordance with ASTM E4. 7.3 The resolution of the load measuring system shall comply with the requirements of ASTM E4.

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-12 8.0 Deflection Measuring System 8.1 The Simple Performance Test System shall include a electronic deflection measuring system that measures the movement of the loading actuator for use in the Flow Time and Flow Number Tests 8.2 The deflection measuring system shall have a range of at least 12 mm (0.5 in). 8.3 The deflection measuring system shall have a resolution equal to or better than 0.0025 mm (0.0001 in). 8.4 The deflection measuring system shall have an error equal to or less than 0.03 mm (0.001 in) over the 12 mm range when verified in accordance with ASTM D 6027. 8.5 The deflection measuring system shall be designed to minimize errors due to compliance and/or bending of the loading mechanism. These errors shall be less than 0.25 mm (0.01 in) at 8 kN (1.8 kips) load. 9.0 Specimen Deformation Measuring System 9.1 The Simple Performance Test System shall include an electronic system for measuring deformations on the specimen over a gauge length of 70 mm (2.76 in) at the middle of the specimen. This system will be used in the Dynamic Modulus Test, and shall include at least two transducers spaced equally around the circumference of the specimen. 9.2 The transducers shall have a range of at least 1 mm (0.04 in). 9.3 The transducers shall have a resolution equal to or better than 0.0002 mm (7.8 micro inch). 9.4 The transducers shall have an error equal to or less than 0.0025 mm (0.0001 in) over the 1 mm range when verified in accordance with ASTM D 6027. 9.5 The axial deformation measuring system shall be designed for rapid specimen installation and subsequent testing. Specimen instrumentation, installation, application of confining pressure, and temperature equilibration shall take no longer than 3 minutes over the complete range of temperatures. NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-13 10.0 Confining Pressure System 10.1 The confining pressure system shall be capable of providing a constant confining pressure up to 210 kPa (30 psi) to the test specimen. The system shall include a pressure cell with appropriate pressure regulation and control, a flexible specimen membrane, a device or method for detecting leaks in the membrane, a pressure transducer, and a temperature sensing device that is mounted internal to the cell. 10.2 Confining pressure shall be controlled by the computer control and data acquisition system. The confining pressure control system shall have the capability to maintain a constant confining pressure throughout the test within +/- 2 percent of the desired pressure. 10.3 The specimen shall be enclosed in an impermeable flexible membrane sealed against the loading platens. 10.4 The pressure inside the specimen membrane shall be maintained at atmospheric pressure through vents in the loading platens. The system shall include a device or method for detecting membrane leaks. 10.5 The confining pressure system shall include a pressure transducer for recording confining pressure during the test. The pressure transducer shall have a range of at least 210 kPa, (30 psi) and a resolution of 0.5 kPa (0.07 psi). The pressure transducer shall have an error equal to or less than ±1 percent of the indicated value over the range of 35 kPa (5 psi) to 210 kPa (30 psi) when verified in accordance with ASTM D5720. 10.6 A suitable temperature sensor shall be mounted at the mid-height of the specimen in the pressure cell between the specimen and the cell wall. This temperature sensor shall have a range of 20 to 60 °C (68 to 140 °F), and be readable and accurate to the nearest 0.25 °C. (0.5 °F). For confined tests this sensor shall be used to control the temperature in the chamber, and provide a continuous reading of temperature that will be sampled by the data acquisition system during the test. 10.7 The confining pressure system shall be designed for rapid installation of the test specimen in the confining cell and subsequent equilibration of the chamber temperature to the target test temperature. Specimen instrumentation, installation, application of confining pressure, and temperature equilibration shall take no longer than 3 minutes over the complete range of temperatures.

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-14 11.0 Environmental Chamber 11.1 The environmental chamber shall be capable of controlling temperatures inside the chamber over the range from 20 to 60 °C (68 to 140 °F) within +/- 0.5 °C (1 °F), when room temperature is between 15 and 27 °C (60 and 80 °F). 11.2 The environmental chamber need only be large enough to accommodate the test specimen. It is envisioned that specimens will be preconditioned in a separate chamber that is large enough to hold the number of specimens needed for a particular project along with one or more dummy specimens with internally mounted temperature sensors. 11.3 The Flow Time Test system shall be designed for rapid installation of the test specimen and subsequent equilibration of the environmental chamber temperature to the target test temperature. Specimen instrumentation, installation, application of confining pressure, and temperature equilibration shall take no longer than 3 minutes over the complete range of temperatures. 11.4 A suitable temperature sensor shall be mounted in the environmental chamber within 25 mm (1 in) of the specimen at the mid-height of the specimen. This temperature sensor shall have a range of 20 to 60 °C (68 to 140 °F), and be readable and accurate to the nearest 0.25 °C (0.5 °F). This sensor shall be used to control the temperature in the chamber, and provide a continuous reading of temperature that will be sampled by the data acquisition system during the test. 12.0 Computer Control and Data Acquisition 12.1 The Simple Performance Test System shall be controlled from a Personal Computer operating software specifically designed to conduct the Flow Time, Flow Number, and Dynamic Modulus Tests described in Annex A, B, and C, and to analyze data in accordance with Section 13. 12.2 The Simple Performance Test System Software shall provide the option for user selection of SI or US Customary units. 12.3 Flow Time Test Control and Data Acquisition 12.3.1 The control system shall control the deviator stress, and the confining pressure within the tolerances specified in Sections 5 and 10.2 12.3.2 The control system shall ramp the deviator stress from the contact stress condition to the creep stress condition in 0.5 sec. NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-15 12.3.3 Zero time for data acquisition and zero strain shall be defined as the start of the ramp from contact stress to creep stress. Using this time as a reference, the system shall provide a record of deviator stress, confining pressure, axial strain, and temperature at zero time and a user specified sampling interval, t, between (0.5 and 10 sec). The axial strains shall be based on the user provided specimen length and the difference in deflection at any time and the deflection at zero time. 12.3.4 The control system shall terminate the test and return the deviator stress and confining pressure to zero when the axial strain exceeds 5 percent or the maximum user specified test duration time is exceeded. Note: in Project 9-19, flow time criteria will be developed for mixtures as a function of climate, and traffic level. These criteria will be used by the user to determine the maximum duration of the test. 12.3.5 Figure 4 presents a schematic of the specified loading and data acquisition. Figure 4. Schematic of Loading and Data Acquisition. 0.5 0 t CREEP DEVIATOR STRESS +/- 2% CONFINING PRESSURE +/- 2% CONTACT DEVIATOR STRESS +/- 2% TIME, SEC S T R E S S , k P a 2t 3t t = sampling interval

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-16 12.3.6 The Flow Time Test Software shall include a screen to input test and file information including: 1. Project Name 2. Operating Technician 3. Specimen Identification 4. File Name 5. Specimen Diameter 6. Specimen Height 7. Target Test Temperature 8. Target Confining Stress 9. Target Contact Deviator Stress 10. Target Creep Deviator Stress 11. Specimen Conditioning Time 12. Sampling Interval 13. Test Duration 14. Remarks 12.3.7 The Flow Time Test Software shall prompt the operator through the Flow Time Test. 1. Test and file information screen. 2. Insert specimen. 3. Apply confining pressure and contact stress. 4. Wait for temperature equilibrium, check for confining system leaks. 5. Ramp to creep stress and collect and store data. 6. Post test remarks. 7. Remove tested specimen. 12.3.8 During the creep loading portion of the test, the Flow Time Test Software shall provide a real-time display of the time history of the deviator stress, the axial strain, and the rate of change of axial strain. The rate of change of axial strain shall be computed in accordance with the algorithm presented in Section 13. 12.3.9 If at any time during the creep loading portion of the test, the deviator stress, confining pressure, or temperature exceed the tolerances listed below, the Flow Time Test Software shall display a warning and indicate the parameter that exceeded the control tolerance. The test shall continue and the software shall include this warning in the data file and the hard copy output. Response Tolerance Deviator stress +/- 2 percent of target Confining pressure +/- 2 percent of target Temperature +/- 0.5 °C of target NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-17 12.3.10 Data files shall include the following information: 1. Test information supplied by the user in Section 12.3.6. 2. Date and time stamp. 3. Computed flow time. 4. Axial strain at the flow time. 5. Average temperature during the test. 6. Average confining stress during the test. 7. Time and corresponding measured deviator stress, measured confining pressure, measured temperature, measured axial strain, and computed rate of change of strain. 8. Warnings 9. Post test remarks. 12.3.11 The Flow Time Test Software shall provide the capability of retrieving data files and exporting them to an ASCII comma delimited file for further analysis. 12.3.12 The Flow Time Test Software shall provide a one page hard copy output with the following: 1. Test information supplied by the user in Section 12.3.6. 2. Date and time stamp. 3. Computed flow time. 4. Axial strain at the flow time. 5. Average temperature during the test. 6. Average confining stress during the test. 7. Warnings 8. Post test remarks 9. Plot of axial strain versus time. 10. Plot of rate of change of axial strain versus time with the flow time indicated. 12.4 Flow Number Test Control and Data Acquisition 12.4.1 The control system shall control the deviator stress, and the confining pressure within the tolerances specified in Sections 5 and 10.2 12.4.2 The control system shall be capable of applying an initial contact stress, then testing the specimen with the user specified cyclic deviator stress. 12.4.3 The data acquisition and control system shall provide the user the ability to select the sampling interval as a whole number of load cycles.

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-18 12.4.4 Zero deflection shall be defined as that at the start of the first load pulse. At the user specified sampling interval, the control system shall provide a record of peak deviator stress, standard error of the applied load (See Section 5.3), contact stress, confining pressure, permanent axial strain at the end of the load cycle, and temperature. The axial strains shall be based on the user provided specimen length and the difference in deflection the end of any load cycle and the zero deflection. 12.4.5 The control system shall terminate the test and return the deviator stress and confining pressure to zero when the axial strain exceeds 5 percent or the user specified test duration is reached. Note: in Project 9-19, flow number criteria will be developed for mixtures as a function of climate, and traffic level. These criteria will be used by the user to determine the maximum duration of the test. 12.4.6 Figure 5 presents a schematic of the specified loading and data acquisition. Figure 5. Schematic of Loading and Data Acquisition for Flow Time Test. 0.1 CONFINING PRESSURE +/- 2% CONTACT DEVIATOR STRESS +/- 2% TIME, SEC S T R E S S , k P a 0.9 REPEATED DEVIATOR STRESS +/- 2% δP(1) δP(2) CYCLE 1 CYCLE 2 D E F L E C T I O N , m m NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-19 12.4.7 The Flow Number Test Software shall include a screen to input test and file information including: 1. Project Name 2. Operating Technician 3. Specimen Identification 4. File Name 5. Specimen Diameter 6. Specimen Height 7. Target Test Temperature 8. Target Confining Stress 9. Target Contact Deviator Stress 10. Target Repeated Deviator Stress 11. Specimen Conditioning Time 12. Sampling Interval 13. Maximum Number of Load Cycles 14. Remarks 12.4.8 The Flow Number Test Software shall prompt the operator through the Flow Number Test. 1. Test and file information screen. 2. Insert specimen. 3. Apply confining pressure and contact stress. 4. Wait for temperature equilibrium, check for confining system leaks. 5. Test specimen, collect and store data. 6. Post test remarks. 7. Remove tested specimen. 12.4.9 During the test, the Flow Number Test Software shall provide the user the ability to select the following displays and the ability to change between displays: 1. Digital oscilloscope showing stress and strain as a function of time. 2. A display of the history of the peak deviator stress, permanent axial strain, and the rate of change of permanent axial strain as a function of the number of load cycles. The rate of change of permanent axial strain shall be computed in accordance with the algorithm presented in Section 13.

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-20 12.4.10 If at any time during the test, the peak deviator stress, standard error of the applied load, confining pressure, or temperature exceed the tolerances listed below, the Flow Number Test Software shall display a warning and indicate the parameter that exceeded the control tolerance. The test shall continue and the software shall include this warning in the data file and the hard copy output. Response Tolerance Peak deviator stress +/- 2 percent of target Load standard error 10 percent Confining pressure +/- 2 percent of target Temperature +/- 0.5 °C of target 12.4.11 Data files shall include the following information: 1. Test information supplied by the user in Section 12.4.7. 2. Date and time stamp. 3. Computed flow number. 4. Axial strain at the flow number. 5. Average temperature during the test. 6. Average confining stress during the test. 7. Average peak deviator stress. 8. Average contact stress. 9. Maximum standard error of the applied load. 10. Cycle and corresponding measured peak deviator stress, computed load standard error, measured contact stress, measured confining pressure, measured temperature, measured permanent axial strain, and computed rate of change of permanent strain. 11. Warnings 12. Post test remarks. 12.4.12 The Flow Number Test Software shall provide the capability of retrieving data files and exporting them to an ASCII comma delimited file for further analysis. NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-21 12.4.13 The Flow Number Test Software shall provide a one page hard copy output with the following: 1. Test information supplied by the user in Section 12.4.7. 2. Date and time stamp. 3. Computed flow number. 4. Axial strain at the flow number. 5. Average temperature during the test. 6. Average confining stress during the test. 7. Average peak deviator stress. 8. Average contact stress. 9. Maximum load standard error. 10. Warnings. 11. Post test remarks. 12. Plot of permanent axial strain versus load cycles. 13. Plot of rate of change of axial strain versus load cycles with the flow number indicated. 12.5 Dynamic Modulus Test Control and Data Acquisition 12.5.1 The control system shall control the axial stress and the confining pressure. The confining pressure shall be controlled within the tolerances specified in Section 10.2. 12.5.2 The control system shall be capable of applying confining stress, an initial contact deviator stress, then conditioning and testing the specimen with a haversine loading at a minimum of 5 user selected frequencies. 12.5.3 Conditioning and testing shall proceed from the highest to lowest loading frequency. Ten conditioning and ten testing cycles shall be applied for each frequency. 12.5.4 The control system shall have the capability to adjust the dynamic stress and contact stress during the test to keep the average dynamic strain within the range of 75 to 125 strain. Adjustment of the dynamic stress shall be performed during the ten conditioning cycles at each loading frequency. 12.5.5 A contact stress equal to 5 percent of the dynamic stress shall be maintained during conditioning and testing. 12.5.6 During the 10 testing cycles, record and store the load, specimen deformations from the individual transducers, confining pressure, and temperature as a function of time. The data acquisition rate shall be set to obtain 50 data points per loading cycle.

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-22 12.5.7 The Dynamic Modulus Test Software shall include a screen to input test and file information including: 1. Project Name 2. Operating Technician 3. Specimen Identification 4. File Name 5. Specimen Diameter 6. Specimen Height 7. Target Test Temperature 8. Target Confining Stress 9. Loading Rates 10. Specimen Conditioning Time 11. Remarks 12.5.8 The Dynamic Modulus Test Software shall prompt the operator through the Dynamic Modulus Test. 1. Test and file information screen. 2. Insert specimen and attach strain instrumentation. 3. Apply confining pressure and contact stress. 4. Wait for temperature equilibrium, check for confining system leaks. 5. Condition and test specimen. 6. Review dynamic modulus, phase angle, temperature, confining pressure, and data quality statistics (See Section 13) for each frequency tested. 7. Post test remarks. 8. Remove tested specimen. 12.5.9 During the conditioning and testing, the Dynamic Modulus Test Software shall provide a real-time display of the axial stress, and the axial strain measured individually by the transducers. 12.5.10 If at any time during the conditioning and loading portion of the test, confining pressure, temperature, or average accumulated permanent strain exceed the tolerances listed below, the Dynamic Modulus Test Software shall display a warning and indicate the parameter that exceeded the control tolerance. The test shall continue and the software shall include this warning in the data file and the hard copy output. Response Tolerance Confining pressure +/- 2 percent of target Temperature +/- 0.5 °C of target Permanent Axial Strain 0.0050 mm/mm NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-23 12.5.11 For each loading frequency, a separate data file shall be produced. This file shall include he test information supplied by the user in Section 12.5.7, a date and time stamp, and the following information for each frequency of loading included in the test. 1. Dynamic modulus. 2. Phase angle. 3. Average temperature during the test. 4. Average confining pressure. 5. Data quality measures (See Section 13) • The drift for the applied load, PY∆ , % • The standard error for the applied load, se(P), % • The average drift for the deformations, DY∆ , % • The average standard error for the deformations, se(Y), % • The uniformity coefficient for the deformations, UA % • The uniformity coefficient for the deformation phase angles, Uθ , degrees. 6. Time and corresponding measured axial stress, individual measured axial strains, measured confining pressure, and measured temperature, 7. Warnings 8. Post test remarks. 12.5.12 The Dynamic Modulus Test Software shall provide the capability of retrieving data files and exporting them to an ASCII comma delimited file for further analysis. 12.5.13 For each loading frequency, the Dynamic Modulus Test Software shall provide a one page hard copy output with the following. Figure 6 presents an example one page output. 1. Test information supplied by the user in Section 12.5.7. 2. Date and time stamp. 3. Dynamic modulus. 4. Phase angle. 5. Average temperature during the test. 6. Average confining pressure during the test. 7. Data quality measures (See Section 13) • The drift for the applied load, PY∆ , % • The standard error for the applied load, se(P), % • The average drift for the deformations, DY∆ , % • The average standard error for the deformations, se(Y), % • The uniformity coefficient for the deformations, UA % • The uniformity coefficient for the deformation phase angles, U θ, degrees. 9. Warnings

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-24 10. Post test remarks 11. Plot showing centered stress and centered strains as a function of time 12. Plot showing normalized stress and strains as a function of phase angle. This plot shall include both the measured and fit data. 13. Plot showing normalized stress as a function of normalized strain. This plot shall include both the measured and fit data. Figure 6. Example Dynamic Modulus Output. 13.0 Computations 13.1 Flow Time Test 13.1.1 The Flow Time is defined as the time corresponding to the minimum rate of change of axial strain during a creep test. To ensure that different laboratories DYNAMIC MODULUS STANDARD REPORT D ata generated on : 4-Apr-01 Dynamic Modulus, ksi: 45.7 Data exported on : 4-Apr-01 Phase Angle, Deg.: 30.1 Sample ID: FHWA D0 Project: WO 621 System Configuration : Data Quality Indicators: Test Frequency (Hz): 0.50 Number Of Movers 2 RMS Cmd. Error, %: 7.9 Specimen Gauge Length (in.): 4.00 Number Of Channels 11 Load Std. Error, %: 7.2 Specimen Dia. (in.): 4.00 Disp. Avg. Std. Error, %: 7.8 Specimen Cross-Sec. Area (in.^2): 12.57 Points Acquired : 500 Disp. Uniformity, %: 3.4 Test Temperature C: 40.0 Scan Time : 20 Phase Uniformity, Deg.: 4.5 Time Between Scans : 40 Avg. Total Drift, %: -4.2 NORMALIZED LOAD AND DISPLACEMENTS -200 -150 -100 -50 0 50 100 150 200 -180 -90 0 90 180 Angle, degrees N o r m a l i z e d L o a d o r D i s p . Load Disp1 Load Fit Disp1 Fit Disp2 Disp2 Fit DATA TRACES -30 -20 -10 0 10 20 30 L o a d , l b s -200 -100 0 100 200 300 D i s p . , m i c r o - i n Load Disp1 Disp2 LOAD VS. DISPLACEMENT -200 -150 -100 -50 0 50 100 150 200 -200 -150 -100 -50 0 50 100 150 200 Normalized Displacement N o r m a l i z e d L o a d Disp 1 Disp1 Fit Disp2 Disp2 Fit NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-25 produce comparable results for this test method, the procedure described in this section shall be followed in determining the flow time. The procedure consists of three steps: (1) numerical calculation of the creep rate ; (2) smoothing of the creep rate data; and (3) identification of the point at which the minimum creep rate occurs as the flow time. 13.1.2 The first step in determining the flow time is to estimate the rate of change (derivative) of the axial strain ε with respect to time t using a finite-difference formula. The rate of change of the strain with respect to time is estimated using the following equation: tdt d titii ∆ − ≅ ∆− ∆+ 2 εε ε (4) Where: dε i/dt = rate of change of strain with respect to time or creep rate at i sec, 1/s ε i-∆t = strain at i-∆t sec ε i+∆t = strain at i+∆t sec ∆t = sampling interval 13.1.3 The derivatives calculated in Section 13.1.2 shall then be smoothed by calculating the running average at each point, by adding to the derivative at that point the two values before and two values after that point, and dividing the sum by five:    ++++= ∆+∆+∆−∆ dt d dt d dt d dt id dt d dt d titititii 22 5 1' ε ε ε ε ε ε (5) Where: dε ’i/dt = smoothed creep rate at i sec, /s dε i-2∆t/dt = creep rate at i-2∆t sec, 1/s dε i-∆t/dt = creep rate at i-∆t sec, 1/s dε i /dt = creep rate at i sec, 1/s dε i+∆t/dt = creep rate at i+∆t sec, 1/s dε i+2∆t/dt = creep rate at i+2∆t sec, 1/s 13.1.4 The flow time is reported as the time at which the minimum value of the smoothed creep rate occurs, and shall be reported to nearest ∆t seconds. If there is no minimum, then the flow time is reported as being greater than or equal to the length of the test. If more than one point share the minimum creep rate, the first such minimum shall be reported as the flow time.    −

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-26 13.2 Flow Number Test 13.2.1 The Flow Number is defined as the number of load cycles corresponding to the minimum rate of change of permanent axial strain during a repeated load test. To ensure that different laboratories produce comparable results for this test method, the procedure described in this section shall be followed in determining the Flow Number. The procedure consists of three steps: (1) numerical calculation of the creep rate; (2) smoothing of the creep rate data; and (3) identification of the point at which the minimum creep rate occurs as the Flow Number. 13.2.2 The first step in determining the Flow Number is to estimate the rate of change (derivative) of the permanent axial strain, ε p, with respect to the number of load cycles, N, using a finite-difference formula. The rate of change of the permanent strain with respect to the number of cycles is estimated using the following equation: ( ) ( ) ( ) NdN d NipNipip ∆ ∆ −∆+ 2 εε ε (6) Where: d(ε p)i/dN = rate of change of permanent axial strain with respect to cycles or creep rate at cycle i, 1/cycle (ε p)i-∆N = permanent strain at i-∆N cycles (εp)i+∆N = permanent strain at i+∆N cycles ∆N = sampling interval 13.2.3 The derivatives calculated in Section 12.2.3 shall then be smoothed by calculating the running average at each point, by adding to the derivative at that point the two values before and two values after that point, and dividing the sum by five:     ++++= ∆+∆+∆− ∆− dN d dN d dN d dN d dN d dN d NipNipipNipNipip 22 )()()()()( 5 1')( ε ε ε ε ε ε (7) Where: d(ε p)’i/dN = smoothed creep rate at i sec, 1/cycle d(ε p)i-2∆N/dN = creep rate at i-2∆N cycles, 1/cycle d(ε p)i-∆N/dN = creep rate at i-∆N cycles, 1/cycle d(ε p)i/dN = creep rate at i cycles, 1/cycle d(ε p)i+∆N/dN = creep rate at i+∆N cycles, 1/cycle d(ε p)i+2∆N/dN = creep rate at i+2∆N cycles, 1/cycle     NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-27 13.2.4 The Flow Number is reported as the cycle at which the minimum value of the smoothed creep rate occurs. If there is no minimum, then the Flow Number is reported as being greater than or equal to the length of the test. If more than one point share the minimum creep rate, the first such minimum shall be reported as the Flow Number. 13.3 Dynamic Modulus Test 13.3.1 The data produced from the dynamic modulus test at frequency ω 0 will be in the form of several arrays, one for time [ti], one for each of the j = 1, 2, 3,…m transducers used [yj]. In the typical arrangement, there will be m = 3 transducers: the first transducer will be a load cell, and transducers 2 and 3 will be specimen deformation transducers. However, this approach is general and can be adapted to any number of specimen deformation transducers. The number of i = 1, 2, 3…n points in each array will be equal to 500 based on the number of cycles and acquisition rate specified in Section 12.5.6. It has been assumed in this procedure that the load will be given in Newtons (N), and the deformations in millimeters (mm). The analysis has been devised to provide complex modulus in units of Pascals (1 Pa = 1 N/m2) and phase angle in units of degrees. The general approach used here is based upon the least squares fit of a sinusoid, as described by Chapra and Canale in Numerical Methods for Engineers (McGraw-Hill, 1985, pp. 404-407). However, the approach used here is more rigorous, and also includes provisions for estimating drift of the sinusoid over time by including another variable in the regression function. Regression is used, rather than the Fast Fourier transform (FFT), because it is a simpler and more direct approach, which should be easier for most engineers and technicians in the paving industry to understand and apply effectively. The regression approach also lends itself to calculating standard errors and other indicators of data quality. This approach should however produce results essentially identical to those produced using FFT analysis. 13.3.2 The calculation proceeds as follows. First, the data for each transducer are centered by subtracting from the measured data the average for that transducer: jjiji YYY − =' (8) Where: Yji’ = Centered data for transducer j at point i in data array Yji = Raw data for transducer j at point i in data array jY = Average for transducer j

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-28 13.3.3 In the second step in the procedure, the [X’X] matrix is constructed as follows: [ ] ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( )            = ΣΣΣΣ ΣΣΣΣ ΣΣΣΣ ΣΣΣ ==== ==== ==== === n i i n i ii n i ii n i i n i ii n i i n i ii n i i n i ii n i ii n i i n i i n i i n i i n i i tttttt tttttt tttttt tttN XX 1 0 2 1 00 1 0 1 0 1 00 1 0 2 1 0 1 0 1 0 1 0 1 2 1 1 0 1 0 1 sinsincossinsin sincoscoscoscos sincos sincos ' ωωωωω ωωωωω ωω ωω (9) Where N is the total number of data points, ω0 is the frequency of the data, t is the time from the start of the data array, and the summation is carried out over all points in the data array. 13.3.4 The inverse of this matrix, [X’X]-1, is then calculated. Then, for each transducer, the [X’Yj] array is constructed: [ ] ( ) ( ) = Σ Σ Σ Σ = = = = n i ji n i ji n i ji n i ji j tY tY tY Y YX 1 0 1 0 1 1 sin' cos' ' ' ' ω ω (10) Where Yj represents the output from one of the three transducers (j=1 for the load cell, j=2 and 3 for the two deformation transducers). Again, the summation is carried out for all points in the data arrays. 13.3.5 The array representing the regression coefficients for each transducer is then calculated by multiplying the [X’X]-1 matrix by the [X’Yj] matrix: [ ] [ ]j j j j j YXXX B A A A '' 1 2 2 1 0 − =       (11)                                        NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-29 Where the regression coefficients can be used to calculate predicted values for each of the j transducers using the regression function: ( ) ( ) jiijijijjji tBtAtAAY εω ω ++++= 020210 sincosˆ (12) Where jiYˆ is the predicted value for the i th point of data for the jth transducer, and ε ji represents the error term in the regression function. 13.3.6 From the regression coefficients, several other functions are then calculated as follows:     −= 2 2 arctan j j j A B θ (13) 2 2 2 2* jjj BAY += (14) %100 * 1 =∆ j Nj j Y tA Y (15) − = Σ = * %100 4 ''– )( 2 1 ^ j n i jiji j Yn YY Yse (16) Where: θ j = Phase angle for transducer j, degrees |Yj*| = Amplitude for transducer j, N for load or mm for displacement jY∆ = Drift for transducer j, as percent of amplitude. tN = Total time covered by data ' ^ jiY ’ = Predicted centered response for transducer j at point i, N or mm se(Yj) = Standard error for transducer j, % n = number of data points = 500 The calculations represented by Equations 13 through 16 are carried out for each transducer—typically the load cell, and two deformation transducers. This produces values for the phase angle, and standard errors for each transducer output. The phase angles given by Equation 13 represent absolute phase angles, that is, θ j is an arbitrary value indicating the angle at which data collection started.                

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-30 13.3.7 The phase angle of the deformation (response) relative to the load (excitation) is the important mechanical property. To calculate this phase angle, the average phase angle for the deformations must first be calculated: 1 2 − = Σ = m m j j D θ θ (17) Where D θ is the average absolute phase angle for the deformation transducers, and θj is the phase angle for each of the j = 2, 3, …, m deformation transducers. For the typical case, there are one load cell and two deformation transducers, so m = 3, and Equation 17 simply involves summing the phase angle for the two deformation transducers and dividing by two. 13.3.8 The relative phase angle at frequency ω between the deformation and the load, θ (ω), is then calculated as follows: ( ) PD θθ ω θ −= (18) Where θ P is the absolute phase angle calculated for the load. 13.3.9 A similar set of calculations is needed to calculate the overall modulus for the material. First, the average amplitude for the deformations must be calculated: 1 * * 2 = Σ = m Y Y m j j D (19) Where *DY represents the average amplitude of the deformations (mm). 13.3.10 Then, the dynamic modulus |E*| at frequency ω is calculated using the following equation: ( ) AY LY E D gP * * * =ω (20) Where |E*(ω )| is in Pa, Lg is the average gage length for the deformation transducers (mm), and A is the loaded cross-sectional area for the specimen, m 2 . NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-31 13.3.11 The final part of the analysis involves calculation of several factors indicative of data quality, including the average drift for the deformations, the average standard error for the deformations, and uniformity coefficients for deformation amplitude and phase: %100 * 2 2 1 × =∆ ∑ ∑ = = m j j m j Nj D Y tA Y (21) ( ) ( ) 1 2 – = ∑ = m Yse Yse m j j D (22) ( ) – – = ∑ = * %100 1 ** 2 2 D m j Dj A Ym YY U (23) ( ) 1 2 2 – – = ∑ = m U m j Dj θ θ θ (24) Where: DY∆ = Average deformation drift, as percent of average deformation amplitude se(YD) = Average standard error for all deformation transducers, % UA = Uniformity coefficient for deformation amplitude, % Uθ = Uniformity coefficient for deformation phase, degrees 14.0 Calibration and Verification of Dynamic Performance 14.1 Prior to shipment, the complete Simple Performance Test System shall be assembled at the manufacturer’s facility and calibrated. This calibration shall include calibration of the computer control and data acquisition electronics/software, static calibration of the load, deflection, specimen deformation, confining pressure and temperature measuring systems; and verification of the dynamic performance of the load and specimen deformation measuring systems. 14.2 The results of these calibrations shall be documented, certified by the manufacturer, and provided with the system documentation.

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-32 14.3 Static calibration of the load, deflection, specimen deformation, and confining pressure systems shall be performed in accordance with the following standards: System ASTM Standard Load ASTM E4 Deflection ASTM D 6027 Specimen Deformation ASTM D 6027 Confining Pressure ASTM D 5720 14.4 The calibration of the temperature measuring system shall be verified over the range that the testing system will be used. A NIST traceable reference thermal detector with resolution equal to or better than the temperature sensor shall be used. 14.5 Verification of the dynamic performance of the force and specimen deformation measuring systems shall be performed by loading a proving ring or similar verification device with the specimen deformation measuring system attached. The manufacturer shall be responsible for fabricating the verification device and shall supply it with the Simple Performance Test System. The verification shall include loads of 0.6, 1.2, 3.0, and 4.8 kN (0.13, 0.27, 0.67, and 1.08 kips) at frequencies of 0.1, 1, and 25 Hz. The verification shall include measurement of load, and displacement of the verification device using the specimen deformation measuring system. All of the resulting load versus deformation data shall be within 2 percent of that determined by static loading of the verification device. The phase difference between load and displacement measurements shall be less than 1 degree. 14.6 The Simple Performance System shall include a calibration mode for subsequent annual calibration in accordance with the standards listed in Section 14.3 and the method described in 14.4. It shall also include a dynamic verification mode to perform the verification test described in Section 14.5. Access points for calibration work shall be clearly shown in the system reference manual. 15.0 Verification of Normal Operation 15.1 The manufacturer shall develop and document procedures for verification of normal operation for each of the systems listed in Section 14.3, and the dynamic performance verification discussed in Section 14.5. It is anticipated that these verification procedures will be performed by the operating technician on a frequent basis. Equipment used in the verification process shall be provided as part of the Simple Performance Test System. NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-33 16.0 Documentation 16.1 The Simple Performance Test System shall include an on-line help and documentation. 16.2 A reference manual completely documenting the Simple Performance Test System shall be provided. This manual shall include the following Chapters: 1. System Introduction. 2. Installation. 3. Loading System. 4. Confining Pressure System. 5. Environmental Chamber. 6. Control and Data Acquisition System. 7. Flow Time Test. 8. Flow Number Test. 9. Dynamic Modulus Test. 10. Calibration. 11. Verification of Dynamic Performance. 12. Verification of Normal Operation. 13. Preventative Maintenance. 14. Spare Parts List 15. Drawings. 17.0 Warranty 17.1 The Simple Performance Test System shall carry a one year on-site warranty.

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-34 Annex A NCHRP Project 9-19 Draft Test Protocol W1: Simple Performance Test for Permanent Deformation Based Upon Static Creep / Flow Time Strength of Asphalt Concrete Mixtures Arizona State University, September, 2000 NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-35 1. Scope 1.1 This test method covers procedures for the preparation, testing and measurement of the resistance to tertiary flow of cylindrical asphalt concrete specimens in a triaxial state of compressive loading. 1.2 In this test, a cylindrical sample of bituminous paving mixture is subjected to a static axial load. Permanent axial and/or radial strains are recorded through out the test. 1.3 The test is conducted at a single effective temperature Teff and design stress levels. 1.4 This standard is applicable to laboratory prepared specimens 100 mm in diameter and 150 mm in height for mixtures with nominal maximum size aggregate less than or equal to 37.5 mm (1.5 in). 1.4 This standard may involve hazardous material, operations, and equipment. This standard does not purport to address all safety problems associated with its use. It is the responsibility of the user of this procedure to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to use. 2. Referenced Documents 2.1 AASHTO Standards TP4 Method for Preparing and Determining the Density of Hot Mix Asphalt (HMA) Specimens by Means of the SHRP Gyratory Compactor PP2 Practice for Mixture Conditioning of Hot Mix Asphalt (HMA) T67 Standard Practices for Load Verification of Testing Machines (cross-listed with ASTM E4) T269 Percent Air Voids in Compacted Dense and Open Bituminous Paving Mixtures 3. Definitions 3.1 Flow Time – is defined as the postulated time when shear deformation, under constant volume, starts. 3.2 Compliance – is the reciprocal of the modulus and represents the ratio of strain to stress for a viscoela

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-36 3.3 Effective Temperature Teff – is a single test temperature at which an amount of permanent deformation would occur equivalent to that measured by considering each season separately throughout the year 4. Summary of Method 4.1 A cylindrical sample of bituminous paving mixture is subjected to a static axial load. The test can be performed either without confinement, or a confining pressure is applied to better simulate in situ stress conditions. The flow time is defined as the postulated time when shear deformation, under constant volume, starts. The applied stress and the resulting permanent and/or axial strain response of the specimen is measured and used to calculate the flow time. 5. Significance and Use 5.1 Current Superpave volumetric mix design procedure lacks a fundamental design criterion to evaluate fundamental engineering properties of the asphalt mixture that directly affect performance. In this test, the selection of the design binder content and aggregate structure is fundamentally enhanced by the evaluation of the mix resistance to shear flow (Flow Time). 5.2 This fundamental engineering property can be used as a performance criteria indicator for permanent deformation resistance of the asphalt concrete mixture, or can be simply used to compare the shear resistance properties of various bituminous paving mixtures. 6. Apparatus 6.1 Load Test System – A load test system consisting of a testing machine, environmental chamber, measuring system, and specimen end fixtures. 6.1.1 Testing Machine – The testing machine should be capable of applying static loads up to 25 kN (5,600 1bs). An electro-hydraulic machine is recommended but not necessarily required. The loading device should be calibrated as outlined in the “Equipment Calibration” Section of the testing manual. 6.1.2 Confining Pressure Device: a system capable of maintaining a constant confining pressure, up to 207 kPa (30 psi), such as an air pressure intensifier or a hydraulic pump. The device shall be equipped with a pressure relief valve, and a system to pressurize and depressurize the cell with gas or fluid. The device should also have a high temperature control subsystem for testing up to 60 °C (140 °F) within an accuracy of ± 0.5 °C (1 °F) at constant pressure. NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-37 Note 1 – It has been found that feedback control of a servovalve to control the pressure is the preferred method of control. However, manual valves or proportional valves may be adequate for some applications. The axisymmetric triaxial cells of AASHTO T292 or T294 may be used for this purpose. Other types of triaxial cells may be permitted. In all cases, see-through cells are not recommended for use with gas confining media. Sight glass ports or reduced area windows are recommended with gas media for safety reasons. It is not required that the specimen be visible through the cell wall if specimen centering and proper instrumentation operation can be verified without a see-through pressure vessel. Certain simulations of pavement loads and extended material characterization desired for local conditions may suggest using confining pressures greater than 207 kPa. For pressures higher than 690 kPa (100 psi), fluid cells are recommended. 6.1.3 Environmental Chamber – A chamber for controlling the test specimen at the desired temperature is required. The environmental chamber shall be capable of controlling the temperature of the specimen over a temperature range from 25 to 60 °C (77 to 140 °F ) to an accuracy of ± 0.5 °C (1 °F). The chamber shall be large enough to accommodate the test specimen and a dummy specimen with temperature sensor mounted at the center for temperature verification. Note 2 – If the chamber does not have sufficient room for a dummy specimen, it is permissible to have a second chamber controlling the temperature of the dummy. The separate dummy chamber must be operated similar to the operation of the main test specimen chamber so that the dummy will accurately register the time required to obtain temperature equilibrium on the test specimen. 6.1.4 Measurement System - The system shall include a data acquisition system comprising analog to digital conversion and/or digital input for storage and analysis on a computer. The system shall be capable of measuring and recording the time history of the applied load, axial and radial deformations for the time duration required by this test method. The system shall be capable of measuring the load and resulting deformations with a resolution of 0.5 percent. 6.1.4.1 Load - The load shall be measured with an electronic load cell having adequate capacity for the anticipated load requirements. The load cell shall be calibrated in accordance with AASHTO T67. The load measuring transducer shall have accuracy equal to or better than 0.25 percent of full scale.

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-38 Note 3 – A 25 kN (5600 lbf) load cell has been found to be the approximate maximum capacity limit for this test method because of range versus resolution factors. It is recommended that if the selected load cell capacity is 25 kN or greater, the system should be equipped with either manual or automatic amplification selection capability so that it can be used to enhance control of the system at lower anticipated loads. 6.1.4.2 Axial and Radial Deformations – Axial and/or radial deformations shall be measured with displacement transducers referenced to gauge points contacting the specimen as shown in Figure 1. The axial deformations shall be measured at a minimum of two locations 180° apart (in plan view); radial deformations shall be measured at a minimum of four locations aligned, in planform, on diametral, perpendicular lines which intersect at the center of the specimen. Note 4 – Analog transducers such as linear variable differential transformers (LVDTs) having a range of ± 0.5 mm (0.02 in) and inherent nonlinearity equal to or better than ±0.025 percent of full scale have been found adequate for this purpose. Software or firmware linearization techniques may be used to improve the inherent nonlinearity. Amplification and signal conditioning techniques may be used with the ± 0.5 mm range LVDTs to obtain resolutions down to 0.001mm (0.00004 in) or better for small strain tests conditions. These techniques may be manual or automatic. In general, increasing the resolution by manual signal amplification will result in reduction of the overall range of the instrument by the same factor. 6.1.5 Loading Platens – Platens, with a diameter equal to or greater than that of the test specimen are required above and below the specimen to transfer the load from the testing machine to the specimen. Generally, these platens should be made of hardened or plated steel, or anodized high strength aluminum. Softer materials will require more frequent replacement. Materials that have linear elastic modulus properties and hardness properties lower than that of 6061-T6 aluminum shall not be used. 6.1.6 Flexible Membrane: for the confined tests, the specimen should be enclosed in an impermeable flexible membrane. The membrane should be sufficiently long to extend well onto the platens and when slightly stretched be of the same diameter as the specimen. Typical membrane wall thickness range between 0.012 and 0.0625 inches (0.305 – 1.588 mm). 6.1.7 End Treatment – Friction reducing end treatments shall be placed between the specimen ends and the loading platens. NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-39 Note 5 - End treatments consisting of two 0.5 mm (0.02 in) thick latex sheets separated with silicone grease have been found to be suitable friction reducing end treatments. 6.2 Gyratory Compactor – A gyrator compactor and associated equipment for preparing laboratory specimens in accordance with AASHTO TP4 shall be used. Field cores shall meet the requirements of paragraphs 7.4 through 7.6 of this test method and any reports on cores so tested will contain a detailed description of the location of any lift boundaries within the height of the specimen (e.g. lift order, thickness and material homogeneity). 6.3 Saw – A machine for sawing test specimens ends to the appropriate length is required. The saw machine shall be capable of cutting specimens to the prescribed dimensions without excessive heating or shock. Note 6 – A diamond masonry saw greatly facilitates the preparation of test specimens with smooth, parallel ends. Both single or double-bladed diamond saws should have feed mechanisms and speed controls of sufficient precision to ensure compliance with paragraphs 7.5 and 7.6 of this method. Adequate blade stiffness is also important to control flexing of the blade during thin cuts. 6.4 Core Drill - A coring machine with cooling system and a diamond bit for cutting nominal 100 mm (4 in) diameter test specimens. Note 7 – A coring machine with adjustable vertical feed and rotational speed is recommended. The variable feeds and speeds may be controlled by various methods. A vertical feed rate of approximately 0.05 mm/rev (0.002 in/rev) and a rotational speed of approximately 455 RPM has been found to be satisfactory for several of the Superpave mixtures. 7. Test Specimens 7.1 Size – Testing shall be performed on 100 mm (4 in) diameter by 150 mm (6 in) high test specimens cored from gyratory compacted mixtures. 7.2 Aging – Mixtures shall be aged in accordance with the short-term oven aging procedure in AASHTO PP2. 7.3 Gyratory Specimens – Prepare 165 mm (6.5 in) high specimens to the required air void content in accordance with AASHTO TP-4.

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-40 7.4 Coring - Core the nominal 100 mm (4 in) diameter test specimens from the center of the gyratory specimens. Both the core drill and the gyratory specimen should be adequately supported to ensure that the resulting test specimen is cylindrical with sides that are smooth, parallel, and free from steps, ridges, and grooves. 7.5 Diameter – Measure the diameter of the test specimen at the mid height and third points along axes that are 90 degrees apart. Record each of the six measurements to the nearest 1 mm (0.05 in). Calculate the average and the standard deviation of the six measurements. If the standard deviation is greater than 2.5 mm (0.01 in) discard the specimen. For acceptable specimens, the average diameter, reported to the nearest 1 mm, shall be used in the stress calculations. 7.6 End Preparation- The ends of all test specimens shall be smooth and perpendicular to the axis of the specimen. Prepare the ends of the specimen by sawing with a single or double bladed saw. To ensure that the sawed samples have parallel ends, the prepared specimen ends shall meet the tolerances described below. Reject test specimens not meeting these tolerances. 7.6.1 The specimen ends shall have a cut surface waviness height within a tolerance of ± 0.05 mm across any diameter. This requirement shall be checked in a minimum of three positions at approximately 120° intervals using a straight edge and feeler gauges approximately 8-12.5 mm (0.315- 0.5 in) wide or an optical comparator. 7.6.2 The specimen end shall not depart from perpendicular to the axis of the specimen by more than 0.5 degrees (i.e. 0.87 mm or 0.03 in across the diameter of a 100 mm diameter specimen). This requirement shall be checked on each specimen using a machinists square and feeler gauges. 7.7 Air Void Content – Determine the air void content of the final test specimen in accordance with AASHTO T269. Reject specimens with air voids that differ by more than 0.5 percent from the target air voids. 7.8 Replicates – The number of test specimens required depends on the number of axial and/or radial strain measurements made per specimen and the desired accuracy of the average flow time values. Table 1 summarizes the LVDTs and replicate number of specimens needed to obtain a desired accuracy limit. NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-41 Table 1. Recommended Number of Specimens. Estimated Standard Error of the Mean, % Per Mixture’s Nominal Aggregate Size LVDTs per Specimen (Total for either vertical or horizontal, not combined total) Number of Specimens 12.5mm 19mm 37.5mm 2 2 7.6 9.5 18.8 2 3 6.2 7.7 15.3 3 2 6.7 8.9 17.4 3 3 5.5 7.3 14.2 4 2 6.2 8.6 16.6 4 3 5.0 7.0 13.6 7.9 Sample Storage – Wrap completed specimens in polyethylene and store in an environmentally protected storage area at temperatures between 5 and 25 °C (40 and 75°F). Note 8 – To eliminate effects of aging on test results, it is recommended that specimens be stored no more than two weeks prior to testing. 8. Test Specimen Instrumentation 8.1 Attach mounting studs for the axial LVDTs to the sides of the specimen with epoxy cement. Figure 2 presents details of the mounting studs and LVDT mounting hardware. Note 9 – Quick setting epoxy such as Duro Master Mend Extra Strength Quick Set QM-50 has been found satisfactory for attaching studs. Under certain conditions when using the triaxial cell with confining pressure, the mounting studs may not require gluing to the specimen. While the surface contact area of the mounting studs is normally minimized consistent with transducer support requirements, it is generally recommended that the area of the studs be sufficiently large to bridge any open void structure features evident on the cut face of the specimen. The minimum diameter mounting stud consistent with support requirements is normally set at 8 mm (0.315 in), maximum diameters have not been established. A circular stud contact surface shape is not required, rectangular or other shapes are acceptable.

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-42 8.2 The gauge length for measuring axial deformations shall be 100 mm ±1 mm. Suitable alignment and spacing fixture shall be used to facilitate mounting of the axial deformation measuring hardware. The gauge length is normally measured between the stud centers. 9. Procedure 9.1 The recommended test protocol for the Simple Performance Test for use in the Superpave volumetric mix design consists of testing the asphalt mix at one effective pavement temperature Teff and one design stress level selected by the design engineer. The effective pavement temperature Teff covers approximately the temperature range of 25 to 60 °C (77 to 140 °F). The design stress levels covers the range between 69 and 207 kPa (10 –30 psi) for the unconfined tests, and 483 to 966 kPa for the confined tests. Typical confinement levels range between 35 and 207 kPa (5 – 30 psi). 9.2 Place the test specimen in the environmental chamber and allow it to equilibrate to the specified testing temperature. For the confined tests, in a standard geotechnical cell, glue the gauge points to the specimen surface as necessary, fit the flexible membrane over the specimen and mount the axial hardware fixtures to the gauge points through the membranes. Place the test specimen with the flexible membrane on in the environmental chamber. A dummy specimen with a temperature sensor mounted at the center can be monitored to determine when the specimen reaches the specified test temperature. In the absence of the dummy specimen, Table 2 provides a summary of the minimum required temperature equilibrium times for samples starting from room temperature (i.e. 25 °C). Table 2. Recommended Equilibrium Times. Specimen Test Temperature, °C (°F) Time, hrs 25 (77) 0.5 30 (86) 1.0 37.8 (100) 1.5 >54.4 (130) 2.0 Unconfined Tests 9.3 After temperature equilibrium is reached, place one of the friction reducing end treatments on top of the platen at the bottom of the loading frame. Place the specimen on top of the lower end treatment, and mount the axial LVDTs to the hardware previously attached to the specimen. Adjust the LVDT to near the end of its linear range to allow the full range to be available for the accumulation of compressive permanent deformation. NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-43 9.4 Place the upper friction reducing end treatment and platen on top of the specimen. Center the specimen with the load actuator visually in order to avoid eccentric loading. 9.5 Apply a contact load equal to 5 percent of the static load that will be applied to the specimen, while ensuring the proper response of the LVDTs (i.e., check for proper direction sensing for all LVDTs). 9.6 Place the radial LVDTs in contact with the specimen, adjust the LVDTs to near the end of their linear range to allow the full range to be available for the accumulation of radial permanent deformation. Adjust and balance the electronic measuring system as necessary. 9.7 Close the environmental chamber and allow sufficient time (normally 10 to 15 minutes) for the temperature to stabilize within the specimen and the chamber. 9.8 After the time required for the sample to reach the testing temperature, apply a rapid (50 µsec) axial static load at 50 mm/sec which yields the desired stress on the specimen. 9.9 Hold the load constant until tertiary flow occurs or the total axial strain reaches approximately 2%. The test time will depend on the temperature and the stress levels applied. 9.10 During the load application, record the load applied, the axial and radial deflection measured from all LVDTs through the data acquisition system. Confined Tests 9.11 After temperature equilibrium is reached, place one of the friction reducing end treatments on top of the platen at the bottom of the loading frame. Place the specimen on top of the lower end treatment, place the top platen and extend the flexible membrane over the top and bottom platens. Attach the O-rings to seal the specimen on top and bottom platens from the confining air/fluid. Center the specimen with the load actuator visually in order to avoid eccentric loading. 9.12 Mount the axial LVDTs to the hardware previously attached to the specimen. Adjust the LVDT to near the end of its linear range to allow the full range to be available for the accumulation of compressive permanent deformation. 9.13 Connect the appropriate hose through the upper or lower platen (or take other appropriate steps) to keep the specimen’s internal void structure under atmospheric pressure while pressure greater than atmospheric is applied to the outside of the membrane during testing.

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-44 9.14 Assemble the triaxial cell over the specimen, ensure proper seal with the base and connect the fluid (or gas) pressure lines. 9.15 Apply a contact load equal to 5 percent of the static load that will be applied to the specimen, while ensuring the proper response of the LVDTs (i.e., both decrease accordingly). Place the radial LVDTs in contact with the specimen, adjust the LVDTs to near the end of their linear range to allow the full range to be available for the accumulation of radial permanent deformation. 9.16 Record the initial LVDT readings and slowly increase the lateral pressure to the desired test level (e.g. 2 psi /sec). Adjust and balance the electronic measuring system as necessary. Close the environmental chamber and allow sufficient time (normally 10 to 15 minutes) for the temperature to stabilize within the specimen and the chamber 9.17 After the time required for the sample to reach the testing temperature, apply a rapid (50 µsec) axial static load, which yields the desired deviatoric stress on the specimen. Hold the load constant until the tertiary flow occurs or the total axial strain reaches 4 - 5%. The test time will depend on the temperature and the stress levels applied. 9.18 During the load application, record the load, confining pressure, the axial and radial deflection measured from all LVDTs through the data acquisition system. 10. Calculations 10.1 Calculate the average axial deformation for each specimen by averaging the readings from the two axial LVDTs. Convert the average deformation values to total axial strain (ε Ta), in/in, by dividing by the gauge length, L (100mm (4-inches). Typical total axial strain versus time is shown in Figure 3. 10.2 Compute the total axial compliance D(t) = ε T/σ d , where σ d is the deviator stress applied during testing in psi. ( σ d = applied constant load (1b) divided by the cross sectional area of the specimen (in2 ). 10.3 Plot the total axial compliance versus time in log space. 10.4 Using the data generated between the total axial compliance and time, determine the axial creep compliance parameters (Do, D1, M1) from the linear portion of the creep compliance data between a time of ten seconds until the end of the linear curve (see Figure 4). The creep compliance parameters are estimated as follows: Do : is the instantaneous compliance, and can be assumed to be the value of the total compliance at a time equal to 100µsec (if the load is applied rapidly at 50µsec). D1 : is the intercept of the creep compliance – time relationship, which is the estimated value of the total compliance at a time of one second. NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-45 M1 : is the slope of the creep compliance-time relationship. 10.5 The flow point is viewed as the lowest point in the curve of rate of change in axial compliance vs. loading time (see Figure 5). The rate of change of creep compliance D’(t) versus loading time should be plotted and the flow time (Ft) is estimated using the following mathematical procedure: Ten data points are taken from every log scale unit of time at approximately equal intervals. Then, at a specific time t1, a polynomial equation is fitted by five points (two points forward and two points backward above the time t1). The form of this equation is: D(t)I = a + bt + ct2 Where D(t)1 = compliance at time t for t1 point evaluated t = time of loading a,b,c = regression coefficients By taking the derivative of the above equation, one obtains the following: d(D(t ) ) dt = b + 2ct i Therefore, the rate of change in compliance at time ti is equal to b+2cti. For each data point selected one can obtain the rate of change in compliance by repeating the above procedure. Once all the rates of change in compliance are calculated, one can find the zero value of rate of change in compliance, i.e., the flow point. This is accomplished by another polynomial curve fitting, using equal data points on both sides of the minimum value. Theoretically the "flow point" is the time corresponding to a rate of compliance change equal to zero. 11. Report 11.1 Report all specimen information including mix identification, storage conditions, dates of manufacturing and testing, specimen diameter and length, volumetric properties, stress levels used, confining pressure, creep compliance parameters (Do, D1, M1) and flow time.

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-46 Figure 1. Schematic of Static Creep / Flow Time Test. Load Cell Axial LVDT Specimen Greased Double Membrane Hardened Steel Disks Radial LVDTs NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-47 On-Sample Assembly Lateral View Longitudinal Cross-Section Figure 2. Axial LVDTs Instrumentation. Frictionless Bushing Guiding Rod LVDT Mounting Stud Holding Brackets

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-48 Figure 3. Total Axial Strain Vs. Time From a Static Creep / Flow Time Test. NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-49 Figure 4. Regression Constants “D1” and “M1” from Log Compliance – Log Time Plot.

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-50 Figure 5. Typical Plot of the Rate of Change in Compliance Vs. Loading Time on a Log-Log Scale. NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-51 Annex B NCHRP Project 9-19 Draft Test Protocol W2: Simple Performance Test for Permanent Deformation Based Upon Repeated Load Test of Asphalt Concrete Mixtures Arizona State University, September, 2000

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-52 1. Scope 1.5 This test method covers procedures for the preparation, testing and measurement of permanent deformation of cylindrical asphalt concrete specimens in a triaxial state of compressive loading. 1.6 The procedure uses a loading cycle of 1.0 second in duration, and consisting of applying 0.1-second haversine load followed by 0.9-second rest period. Permanent axial and/or radial strains are recorded through out the test. 1.7 The test is conducted at a single effective temperature Teff and design stress levels. 1.8 This standard is applicable to laboratory prepared specimens 100 mm in diameter and 150 mm in height for mixtures with nominal maximum size aggregate less than or equal to 37.5 mm (1.5 in). 1.9 This standard may involve hazardous material, operations, and equipment. This standard does not purport to address all safety problems associated with its use. It is the responsibility of the user of this procedure to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to use. 2. Referenced Documents 2.1 AASHTO Standards TP4 Method for Preparing and Determining the Density of Hot Mix Asphalt (HMA) Specimens by Means of the SHRP Gyratory Compactor PP2 Practice for Mixture Conditioning of Hot Mix Asphalt (HMA) T67 Standard Practices for Load Verification of Testing Machines (cross-listed with ASTM E4) T269 Percent Air Voids in Compacted Dense and Open Bituminous Paving Mixtures 3. Definitions 3.1 Permanent Deformation – is a manifestation of two different mechanisms and is a combination of densification (volume change) and repetitive shear deformation (plastic flow with no volume change). NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-53 3.2 Flow Number - is defined as the number of load repetitions at which shear deformation, under constant volume, starts. 3.3 Effective Temperature Teff – Is a single test temperature at which an amount of permanent deformation would occur equivalent to that measured by considering each season separately throughout the year 4. Summary of Method 4.1 A cylindrical sample of bituminous paving mixture is subjected to a haversine axial load. The load is applied for duration of 0.1-second with a rest period of 0.9-second. The rest period has a load equivalent to the seating load. The test can be performed either without confinement, or a confining pressure is applied to better simulate in situ stress conditions. Cumulative permanent axial and radial strains are recorded through out the test. In addition, the number of repetitions at which shear deformation, under constant volume, starts is defined as the Flow Number. 5. Significance and Use 5.1 Current Superpave volumetric mix design procedure lacks a fundamental design criterion to evaluate fundamental engineering properties of the asphalt mixture that directly affect performance. In this test, the selection of the design binder content and aggregate structure is fundamentally enhanced by the evaluation of the mix resistance to shear flow (Flow Number of Repetitions). 5.2 This fundamental engineering property can be used as a performance criteria indicator for permanent deformation resistance of the asphalt concrete mixture, or can be simply used to compare the shear resistance properties of various bituminous paving mixtures. 6. Apparatus 6.1 Load Test System – A load test system consisting of a testing machine, environmental chamber, measuring system, and specimen end fixtures. 6.1.1 Testing Machine – The testing machine should be capable of applying haversine loads up to 25 kN (5,600 1bs). An electro-hydraulic machine is recommended but not necessarily required. The loading device should be calibrated as outlined in the “Equipment Calibration” Section of the testing manual. 6.1.2 Confining Pressure Device: a system capable of maintaining a constant confining pressure, up to 207 kPa (30 psi), such as an air pressure intensifier or a hydraulic pump. The device shall be equipped with a pressure relief valve and a system to

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-54 pressurize and depressurize the cell with gas or fluid. The device should also have a high temperature control subsystem for testing up to 60 °C (140 °F) within an accuracy of ± 0.5 °C (1 °F) at constant pressure. Note 1 – It has been found that feedback control of a servovalve to control the pressure is the preferred method of control. However, manual valves or proportional valves may be adequate for some applications. The axisymmetric triaxial cells of AASHTO T292 or T294 may be used for this purpose. Other types of triaxial cells may be permitted. In all cases, see-through cells are not recommended for use with gas confining media. Sight glass ports or reduced area windows are recommended with gas media for safety reasons. It is not required that the specimen be visible through the cell wall if specimen centering and proper instrumentation operation can be verified without a see-through pressure vessel. Certain simulations of pavement loads and extended material characterization desired for local conditions may suggest using confining pressures greater than 207 kPa. For pressures higher than 690 kPa (100 psi), fluid cells are recommended. 6.1.3 Environmental Chamber – A chamber for controlling the test specimen at the desired temperature is required. The environmental chamber shall be capable of controlling the temperature of the specimen over a temperature range from 25 to 60 °C (77 to 140 °F ) to an accuracy of ± 0.5 °C (1 °F). The chamber shall be large enough to accommodate the test specimen and a dummy specimen with temperature sensor mounted at the center for temperature verification. Note 2 – If the chamber does not have sufficient room for a dummy specimen, it is permissible to have a second chamber controlling the temperature of the dummy. The separate dummy chamber must be operated similar to the operation of the main test specimen chamber so that the dummy will accurately register the time required to obtain temperature equilibrium on the test specimen. 6.1.4 Measurement System - The system shall include a data acquisition system comprising analog to digital conversion and/or digital input for storage and analysis on a computer. The system shall be capable of measuring and recording the time history of the applied load, axial and radial deformations for the time duration required by this test method. The system shall be capable of measuring the load and resulting deformations with a resolution of 0.5 percent. 6.1.4.1 Load - The load shall be measured with an electronic load cell having adequate capacity for the anticipated load requirements. The load cell shall be calibrated in accordance with AASHTO T67. The load measuring transducer shall have accuracy equal to or better than 0.25 percent of full scale. NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-55 Note 3 – A 25 kN (5600 lbf) load cell has been found to be the approximate maximum capacity limit for this test method because of range versus resolution factors. It is recommended that if the selected load cell capacity is 25 kN or greater, the system should be equipped with either manual or automatic amplification selection capability so that it can be used to enhance control of the system at lower anticipated loads. 6.1.4.2 Axial and Radial Deformations – Axial and/or radial deformations shall be measured with displacement transducers referenced to gauge points contacting the specimen as shown in Figure 1. The axial deformations shall be measured at a minimum of two locations 180° apart (in plan view); radial deformations shall be measured at a minimum of four locations aligned, in planform, on diametral, perpendicular lines which intersect at the center of the specimen. Note 4 – Analog transducers such as linear variable differential transformers (LVDTs) having a range of ± 0.5 mm (0.02 in) and inherent nonlinearity equal to or better than ±0.025 percent of full scale have been found adequate for this purpose. Software or firmware linearization techniques may be used to improve the inherent nonlinearity. Amplification and signal conditioning techniques may be used with the ± 0.5 mm range LVDTs to obtain resolutions down to 0.001mm (0.00004 in) or better for small strain tests conditions. These techniques may be manual or automatic. In general, increasing the resolution by manual signal amplification will result in reduction of the overall range of the instrument by the same factor. 6.1.5 Loading Platens – Platens, with a diameter equal to or greater than that of the test specimen are required above and below the specimen to transfer the load from the testing machine to the specimen. Generally, these platens should be made of hardened or plated steel, or anodized high strength aluminum. Softer materials will require more frequent replacement. Materials that have linear elastic modulus properties and hardness properties lower than that of 6061-T6 aluminum shall not be used. 6.1.6 Flexible Membrane: for the confined tests, the specimen should be enclosed in an impermeable flexible membrane. The membrane should be sufficiently long to extend well onto the platens and when slightly stretched be of the same diameter as the specimen. Typical membrane wall thickness range between 0.012 and 0.0625 inches (0.305 – 1.588 mm). 6.1.7 End Treatment – Friction reducing end treatments shall be placed between the specimen ends and the loading platens.

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-56 Note 5 - End treatments consisting of two 0.5 mm (0.02 in) thick latex sheets separated with silicone grease have been found to be suitable friction reducing end treatments. 6.2 Gyratory Compactor – A gyrator compactor and associated equipment for preparing laboratory specimens in accordance with AASHTO TP4 shall be used. Field cores shall meet the requirements of paragraphs 7.4 through 7.6 of this test method and any reports on cores so tested will contain a detailed description of the location of any lift boundaries within the height of the specimen (e.g. lift order, thickness and material homogeneity). 6.3 Saw – A machine for sawing test specimens ends to the appropriate length is required. The saw machine shall be capable of cutting specimens to the prescribed dimensions without excessive heating or shock. Note 6 – A diamond masonry saw greatly facilitates the preparation of test specimens with smooth, parallel ends. Both single or double-bladed diamond saws should have feed mechanisms and speed controls of sufficient precision to ensure compliance with paragraphs 7.5 and 7.6 of this method. Adequate blade stiffness is also important to control flexing of the blade during thin cuts. 6.4 Core Drill - A coring machine with cooling system and a diamond bit for cutting nominal 100 mm (4 in) diameter test specimens. Note 7 – A coring machine with adjustable vertical feed and rotational speed is recommended. The variable feeds and speeds may be controlled by various methods. A vertical feed rate of approximately 0.05 mm/rev (0.002 in/rev) and a rotational speed of approximately 455 RPM has been found to be satisfactory for several of the Superpave mixtures. 7. Test Specimens 7.1 Size – Testing shall be performed on 100 mm (4 in) diameter by 150 mm (6 in) high test specimens cored from gyratory compacted mixtures. 7.2 Aging – Mixtures shall be aged in accordance with the short-term oven aging procedure in AASHTO PP2. 7.3 Gyratory Specimens – Prepare 165 mm (6.5 in) high specimens to the required air void content in accordance with AASHTO TP-4. NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-57 7.4 Coring - Core the nominal 100 mm (4 in) diameter test specimens from the center of the gyratory specimens. Both the core drill and the gyratory specimen should be adequately supported to ensure that the resulting test specimen is cylindrical with sides that are smooth, parallel, and free from steps, ridges, and grooves. 7.5 Diameter – Measure the diameter of the test specimen at the mid height and third points along axes that are 90 degrees apart. Record each of the six measurements to the nearest 1 mm (0.05 in). Calculate the average and the standard deviation of the six measurements. If the standard deviation is greater than 2.5 mm (0.01 in) discard the specimen. For acceptable specimens, the average diameter, reported to the nearest 1 mm, shall be used in the stress calculations. 7.6 End Preparation- The ends of all test specimens shall be smooth and perpendicular to the axis of the specimen. Prepare the ends of the specimen by sawing with a single or double bladed saw. To ensure that the sawed samples have parallel ends, the prepared specimen ends shall meet the tolerances described below. Reject test specimens not meeting these tolerances. 7.6.1 The specimen ends shall have a cut surface waviness height within a tolerance of ± 0.05 mm across any diameter. This requirement shall be checked in a minimum of three positions at approximately 120° intervals using a straight edge and feeler gauges approximately 8-12.5 mm (0.315- 0.5 in) wide or an optical comparator. 7.6.2 The specimen end shall not depart from perpendicular to the axis of the specimen by more than 0.5 degrees (i.e. 0.87 mm or 0.03 in across the diameter of a 100 mm diameter specimen). This requirement shall be checked on each specimen using a machinists square and feeler gauges. 7.7 Air Void Content – Determine the air void content of the final test specimen in accordance with AASHTO T269. Reject specimens with air voids that differ by more than 0.5 percent from the target air voids. 7.8 Replicates – The number of test specimens required depends on the number of axial and/or radial strain measurements made per specimen and the desired accuracy of the average flow time values. Table 1 summarizes the LVDTs and replicate number of specimens needed to obtain a desired accuracy limit.

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-58 Table 1. Recommended Number of Specimens Estimated Standard Error of the Mean, % Per Mixture’s Nominal Aggregate Size LVDTs per Specimen (Total for either vertical or horizontal, not combined total) Number of Specimens 12.5mm 19mm 37.5mm 2 2 7.6 9.5 18.8 2 3 6.2 7.7 15.3 3 2 6.7 8.9 17.4 3 3 5.5 7.3 14.2 4 2 6.2 8.6 16.6 4 3 5.0 7.0 13.6 7.9 Sample Storage – Wrap completed specimens in polyethylene and store in an environmentally protected storage area at temperatures between 5 and 25 °C (40 and 75 °F). Note 8 – To eliminate effects of aging on test results, it is recommended that specimens be stored no more than two weeks prior to testing. 8. Test Specimen Instrumentation 8.1 Attach mounting studs for the axial LVDTs to the sides of the specimen with epoxy cement. Figure 2 presents details of the mounting studs and LVDT mounting hardware. Note 9 – Quick setting epoxy such as Duro Master Mend Extra Strength Quick Set QM-50 has been found satisfactory for attaching studs. Under certain conditions when using the triaxial cell with confining pressure, the mounting studs may not require gluing to the specimen. While the surface contact area of the mounting studs is normally minimized consistent with transducer support requirements, it is generally recommended that the area of the studs be sufficiently large to bridge any open void structure features evident on the cut face of the specimen. The minimum diameter mounting stud consistent with support requirements is normally set at 8 mm (0.315 in), maximum diameters have not been established. A circular stud contact surface shape is not required, rectangular or other shapes are acceptable. NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-59 8.2 The gauge length for measuring axial deformations shall be 100 mm ±1 mm. Suitable alignment and spacing fixture shall be used to facilitate mounting of the axial deformation measuring hardware. The gauge length is normally measured between the stud centers. 9. Procedure 9.1 The recommended test protocol for the Simple Performance Test for use in the Superpave volumetric mix design consists of testing the asphalt mix at one effective pavement temperature Teff and one design stress level selected by the design engineer. The effective pavement temperature Teff covers approximately the temperature range of 25 to 60 °C (77 to 140°F). The design stress levels covers the range between 69 and 207 kPa (10 –30 psi) for the unconfined tests, and 483 to 966 kPa for the confined tests. Typical confinement levels range between 35 and 207 kPa (5 – 30 psi). 9.2 Place the test specimen in the environmental chamber and allow it to equilibrate to the specified testing temperature. For the confined tests in a standard geotechnical cell, glue the gauge points to the specimen surface as necessary, fit the flexible membrane over the specimen and mount the axial hardware fixtures to the gauge points through the membrane. Place the test specimen with the flexible membrane on in the environmental chamber. A dummy specimen with a temperature sensor mounted at the center can be monitored to determine when the specimen reaches the specified test temperature. In the absence of the dummy specimen, Table 2 provides a summary of the minimum required temperature equilibrium times for samples starting from room temperature (i.e. 25 °C). Table 2. Recommended Equilibrium Times. Specimen Test Temperature, °C (°F) Time, hrs 25 (77) 0.5 30 (86) 1.0 37.8 (100) 1.5 >54.4 (130) 2.0 Unconfined Tests 9.3 After temperature equilibrium is reached, place one of the friction reducing end treatments on top of the platen at the bottom of the loading frame. Place the specimen on top of the lower end treatment, and mount the axial LVDTs to the hardware previously attached to the specimen. Adjust the LVDT to near the end of its linear range to allow the full range to be available for the accumulation of compressive permanent deformation.

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-60 9.4 Place the upper friction reducing end treatment and platen on top of the specimen. Center the specimen with the load actuator visually in order to avoid eccentric loading. 9.5 Apply a contact load equal to 5 percent of the total load that will be applied to the specimen, while ensuring the proper response of the LVDTs (i.e., check for proper direction sensing for all LVDTs). 9.6 Place the radial LVDTs in contact with the specimen, adjust the LVDTs to near the end of their linear range to allow the full range to be available for the accumulation of radial permanent deformation. Adjust and balance the electronic measuring system as necessary. 9.7 Close the environmental chamber and allow sufficient time (normally 10 to 15 minutes) for the temperature to stabilize within the specimen and the chamber. 9.8 After the time required for the sample to reach the testing temperature, apply the haversine load which yields the desired stress on the specimen. The maximum applied load (Pmax) is the maximum total load applied to the sample, including the contact and cyclic load: Pmax = Pcontact + Pcyclic 9.9 The contact load (Pcontact) is the vertical load placed on the specimen to maintain a positive contact between loading strip and the specimen: Pcontact = 0.05 x Pmax 9.10 The cyclic load (Pcyclic) is the load applied to the test specimen which is used to calculate the permanent deformation parameters: Pcyclic = Pmax - Pcontact 9.11 Apply the haversine loading (Pcyclic) and continue until 10,000 cycles (2.8 hours) or until the specimen fails and results in excessive tertiary deformation to the specimen, whichever comes first. The total number of cycles or the testing time will depend on the temperature and the stress levels applied. 9.12 During the load applications, record the load applied, the axial and radial deflection measured from all LVDTs through the data acquisition system. Signal-to-noise ratio should be at least 10. All data should be collected in real time and collected/processed so as to minimize phase errors due to sequential channel sampling. In order to save storage space during data acquisition for 10,000 cycles, it is recommended to use the data acquisition of the cycles shown in Table 3. NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-61 Table 3. Suggested Data Collection for the Repeated Load Permanent Deformation Test Data collected During Cycles Data collected During Cycles Data collected During Cycles 1 through 100 700 4,500 130 750 5,000 170 800 5,500 200 850 6,000 230 900 6,500 270 950 7,000 300 1,000 7,500 350 1,300 8,000 400 1,700 8,500 450 2,000 9,000 500 2,300 9,500 550 2,700 10,000 600 3,000 650 4,000 Confined Tests 9.13 After temperature equilibrium is reached, place one of the friction reducing end treatments on top of the platen at the bottom of the loading frame. Place the specimen on top of the lower end treatment, place the top platen and extend the flexible membrane over the top and bottom platens. Attach the O-rings to seal the specimen on top and bottom platens from the confining air/fluid. Center the specimen with the load actuator visually in order to avoid eccentric loading. 9.14 Mount the axial LVDTs to the hardware previously attached to the specimen. Adjust the LVDT to near the end of its linear range to allow the full range to be available for the accumulation of compressive permanent deformation. 9.15 Connect the appropriate hose through the upper or lower platen (or take other appropriate steps) to keep the specimen’s internal void structure under atmospheric pressure while pressure greater than atmospheric is applied to the outside of the membrane during testing. 9.16 Assemble the triaxial cell over the specimen, ensure proper seal with the base and connect the fluid (or gas) pressure lines.

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-62 9.17 Apply a contact load equal to 5 percent of the load that will be applied to the specimen, while ensuring the proper response of the LVDTs (i.e., both decrease accordingly). Place the radial LVDTs in contact with the specimen, adjust the LVDTs to near the end of their linear range to allow the full range to be available for the accumulation of radial permanent deformation. 9.18 Record the initial LVDT readings and slowly increase the lateral pressure to the desired test level (e.g. 2 psi /sec). Adjust and balance the electronic measuring system as necessary. Close the environmental chamber and allow sufficient time (normally 10 to 15 minutes) for the temperature to stabilize within the specimen and the chamber 9.19 After the time required for the sample to reach the testing temperature, apply the haversine load which yields the desired stress on the specimen. Continue until 10,000 cycles (2.8 hours) or until the specimen fails and results in excessive tertiary deformation to the specimen, whichever comes first. The total number of cycles or the testing time will depend on the temperature and the stress levels applied. 9.20 During the load applications, record the load applied, confining pressure, the axial and radial deflection measured from all LVDTs through the data acquisition system. Signal- to-noise ratio should be at least 10. All data should be collected in real time and collected/processed so as to minimize phase errors due to sequential channel sampling. In order to save storage space during data acquisition for 10,000 cycles, it is recommended to use the data acquisition of the cycles shown in Table 3. 10. Calculations 10.1 Calculate the average axial deformation for each specimen by averaging the readings from the two axial LVDTs. Convert the average deformation values to total axial strain (ε Ta), in/in, by dividing by the gauge length, L (100mm (4-inches). Typical total axial strain versus time is shown in Figure 3. 10.2 Compute the cumulative axial permanent strain. 10.3 Plot the cumulative axial permanent strain versus number of loading cycles in log space. Determine the permanent deformation parameters, intercept (a) and slope (b), from the linear portion of the permanent strain curve (see Figure 4). 10.4 The flow number of repetitions is viewed as the lowest point in the curve of rate of change in axial strain vs. number of loading cycles (see Figure 5). The rate of change of axial strain versus number of loading cycles should be plotted and the flow number (FN) is estimated where a minimum or zero slope is observed. NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-63 11. Report 11.1 Report all specimen information including mix identification, storage conditions, dates of manufacturing and testing, specimen diameter and length, volumetric properties, stress levels used, confining pressure, axial permanent deformation parameters: a, b and flow number of repetitions. Figure 1. Schematic of Repeated Load Permanent Deformation Test. Load Cell Axial LVDT Specimen Greased Double Membrane Hardened Steel Disks Radial LVDTs

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-64 On-Sample Assembly Lateral View Longitudinal Cross-Section Figure 2. Axial LVDTs Instrumentation. Frictionless Bushing Guiding Rod LVDT Mounting Stud Holding Brackets NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-65 Figure 3. Cumulative Permanent Strain Vs. Loading Cycles From a Repeated Load Permanent Deformation Test.

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-66 Figure 4. Regression Constants “a” and “b” from Log Permanent Strain – Log Number of Loading Cycles Plot. Figure 5. Typical Plot of the Rate of Change in Permanent Strain Vs. Loading Cycles. NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-67 Annex C NCHRP Project 9-19 Draft Test Protocol X1: Simple Performance Test for Permanent Deformation Based Upon Dynamic Modulus of Asphalt Concrete Mixtures Arizona State University, September, 2000

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-68 1. Scope 1.1 This test method covers procedures for preparing and testing asphalt concrete mixtures to determine the dynamic modulus and phase angle at a single effective temperature Teff and design loading frequency. 1.2 This test method is a part of test protocols that include determination of the dynamic modulus of the asphalt mix for paving purposes. The other test methods are Standard Test Method for Simple Performance Test for Fatigue Cracking based Upon Dynamic Modulus of Asphalt Concrete Mixture and Standard Test Method for Dynamic Modulus of Asphalt Concrete Mixtures, which is for constructing a master curve for characterizing asphalt concrete for pavement thickness design and performance analysis 1.3 This standard is applicable to laboratory prepared specimens of mixtures with nominal maximum size aggregate less than or equal to 37.5 mm (1.5 in). 1.4 This standard may involve hazardous material, operations, and equipment. This standard does not purport to address all safety problems associated with its use. It is the responsibility of the user of this procedure to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to use. 2. Referenced Documents 2.1 AASHTO Standards TP4 Method for Preparing and Determining the Density of Hot Mix Asphalt (HMA) Specimens by Means of the SHRP Gyratory Compactor PP2 Practice for Mixture Conditioning of Hot Mix Asphalt (HMA) T67 Standard Practices for Load Verification of Testing Machines (cross-listed with ASTM E4) T269 Percent Air Voids in Compacted Dense and Open Bituminous Paving Mixtures 3. Definitions 3.1 Dynamic Modulus – |E*|, the norm value of the complex modulus calculated by dividing the peak-to-peak stress by the peak-to-peak strain for a material subjected to a sinusoidal loading. NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-69 3.2 Complex Modulus – E*, a complex number that defines the relationship between stress and strain for a linear viscoelastic material. 3.3 Phase angle – δ , the angle in degrees between a sinusoidally applied stress and the resulting strain in a controlled-stress test. 3.4 Linear viscoelastic – within the context of this test, refers to behavior in which the dynamic modulus is independent of stress or strain amplitude. 3.5 Effective Temperature Teff – Is a single test temperature at which an amount of permanent deformation would occur equivalent to that measured by considering each season separately throughout the year 4. Summary of Method 4.1 A sinusoidal (haversine) axial compressive stress is applied to a specimen of asphalt concrete at a given temperature and loading frequency. The applied stress and the resulting recoverable axial strain response of the specimen is measured and used to calculate the dynamic modulus and phase angle. 4.2 Figure 1 presents a schematic of the dynamic modulus test device. 5. Significance and Use 5.1 Dynamic modulus values, measured at one effective temperature Teff and one design frequency selected by the design engineer, are used as performance criteria for permanent deformation resistance of the asphalt concrete mixture to be used in conjunction of the Superpave Volumetric Mix Design Method. Note 1 – The effective temperature Teff covers approximately the temperature range of 25 to 60 °C (77 to 140 °F). Note 2 – 10 Hz frequency can be used for highway speed and 0.1 Hz for creep – intersection traffic. 5.2 Dynamic modulus values measured over a range of temperatures and frequencies of loading can be shifted into a master curve for characterizing asphalt concrete for pavement thickness design and performance analysis. 5.3 This test method covers the determination of the dynamic modulus values measured unconfined within the linear viscoelastic range of the asphalt mixture.

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-70 Note 3 - Future research may indicate the need for confined stress states and nonlinear material characterization. Confinement may be applied with various types of axisymmetric triaxial cells to address these needs. 6. Apparatus 6.1 Dynamic Modulus Test System – A dynamic modulus test system consisting of a testing machine, environmental chamber, measuring system, and specimen end fixtures. 6.1.1 Testing Machine – A materials testing machine capable of producing a controlled haversine compressive loading of paragraphs 9.7 and 9.8 is required. Note 4 - The testing machine shall have a capability of applying load over a range of frequencies from 0.1 to 30 Hz. Stress levels up to 2800 kPa (400 psi) may be required at certain temperatures and frequencies. However, for virtually all effective temperatures in the US, stress levels between 10 kPa and 690 kPa (1.5-100 psi) have been found to be sufficient. This latter range of stress levels converts to an approximate range of 0.08-5.5 kN 18-1218 lbf) on a 100 mm diameter specimen. If the machine is to be dedicated only to this test procedure with no requirement for additional strength testing or low temperature testing, it is recommended that the lowest capacity machine capable of applying the required waveforms be used. Alternatively, larger capacity machines may be used with low capacity load cells or signal amplifiers. It has been found that feedback controlled testing machines equipped with appropriate servovalves can be used for this test. As a general rule of thumb, the dynamic load capacity of a testing machine between 10 and 30 Hz will be approximately 65-75 percent of the monotonic (“static”) capacity, but this rule varies by manufacturer. A 25-50 kN capacity servohydraulic testing machine has been found to be adequate for virtually all of the tests in the suite of simple performance tests. 6.1.2 Environmental Chamber – A chamber for controlling the test specimen at the desired temperature is required. The environmental chamber shall be capable of controlling the temperature of the specimen over a temperature range from 25 to 60 °C (77 to 140 °F ) to an accuracy of ± 0.5 °C (1 °F). The chamber shall be large enough to accommodate the test specimen and a dummy specimen with temperature sensor mounted at the center for temperature verification. Note 5 – A chamber that will control temperatures down to –10 °C (14 °F) may be required for other tests mentioned in paragraph 1.2 of this method. Note 6 – If the chamber does not have sufficient room for a dummy specimen, it is permissible to have a second chamber controlling the NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-71 temperature of the dummy. The separate dummy chamber must be operated similar to the operation of the main test specimen chamber so that the dummy will accurately register the time required to obtain temperature equilibrium on the test specimen. 6.1.3 Measurement System - The system shall include a data acquisition system comprising analog to digital conversion and/or digital input for storage and analysis on a computer. The system shall be capable of measuring and recording the time history of the applied load and the axial deformations for the cycles required by this test method. The system shall be capable of measuring the period of the applied sinusoidal load and resulting deformations with a resolution of 0.5 percent. 6.1.3.1 Load - The load shall be measured with an electronic load cell having adequate capacity for the anticipated load requirements. The load cell shall be calibrated in accordance with AASHTO T67. The load measuring transducer shall have an accuracy equal to or better than 0.25 percent of full scale. Note 7 – A 25 kN (5600 lbf) load cell has been found to be the approximate maximum capacity limit for this test method because of range versus resolution factors. It is recommended that if the selected load cell capacity is 25 kN or greater, the system should be equipped with either manual or automatic amplification selection capability so that it can be used to enhance control of the system at the minimum anticipated loads given in paragraph 9.7. 6.1.3.2 Axial Deformations – Axial deformations shall be measured with displacement transducers referenced to gauge points contacting the specimen as shown in Figure 2. The deformations shall be measured at a minimum of two locations 180° apart (in planview); however, three locations located 120° apart is recommended to minimize the number of replicate specimens required for testing. Note 8 – Analog transducers such as linear variable differential transformers (LVDTs) having a range of ± 0.5 mm (0.02 in) and inherent nonlinearity equal to or better than ±0.025 percent of full scale have been found adequate for this purpose. Software or firmware linearization techniques may be used to improve the inherent nonlinearity. Amplification and signal conditioning techniques may be used with the ± 0.5 mm range LVDTs to obtain resolutions down to 0.001mm (0.00004 in) or better for small strain tests conditions. These techniques may be manual or automatic. In general, increasing the resolution by manual signal amplification will result in reduction of the overall range of the instrument by the same factor.

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-72 6.1.4 Loading Platens – Platens, with a diameter equal to or greater than that of the test specimen are required above and below the specimen to transfer the load from the testing machine to the specimen. Generally, these platens should be made anodized high strength aluminum. Softer materials will require more frequent replacement. Materials that have linear elastic modulus properties and hardness properties lower than that of 6061-T6 aluminum shall not be used. Steel platens may cause too much seating load to the specimen at high temperature and are not recommended. 6.1.5 End Treatment – Friction reducing end treatments shall be placed between the specimen ends and the loading platens. Note 9 - End treatments consisting of two 0.5 mm (0.02 in) thick latex sheets separated with silicone grease have been found to be suitable friction reducing end treatments. 6.2 Gyratory Compactor – A gyrator compactor and associated equipment for preparing laboratory specimens in accordance with AASHTO TP4 shall be used. Field cores shall meet the requirements of paragraphs 7.4 through 7.6 of this test method and any reports on cores so tested will contain a detailed description of the location of any lift boundaries within the height of the specimen (e.g. lift order, thickness and material homogeneity). 6.3 Saw – A machine for cutting test specimens to the appropriate length is required. The saw or grinding machine shall be capable of cutting specimens to the prescribed dimensions without excessive heating or shock. Note 10 – A double bladed diamond masonry saw greatly facilitates the preparation of test specimens with smooth, parallel ends. Both single- and double-bladed diamond saws should have feed mechanisms and speed controls of sufficient precision to ensure compliance with paragraphs 7.5 and 7.6 of this method. Adequate blade stiffness is also important to control flexing of the blade during thin cuts. 6.4 Core Drill - A coring machine with cooling system and a diamond bit for cutting nominal 100 mm (4 in) diameter test specimens. Note 11 – A coring machine with adjustable vertical feed and rotational speed is recommended. The variable feeds and speeds may be controlled by various methods. A vertical feed rate of approximately 0.05 mm/rev (0.002 in/rev) and a rotational speed of approximately 455 RPM has been found to be satisfactory for several of the Superpave mixtures. NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-73 7. Test Specimens 7.1 Size – Dynamic modulus testing shall be performed on 100 mm (4 in) diameter by 150 mm (6 in) high test specimens cored from gyratory compacted mixtures. 7.2 Aging – Mixtures shall be aged in accordance with the short-term oven aging procedure in AASHTO PP2. 7.3 Gyratory Specimens – Prepare 165 mm (6.5 in) high specimens to the required air void content in accordance with AASHTO TP-4. Note 12 – Testing should be performed on test specimens meeting specific air void tolerances. The gyratory specimen air void content required to obtain a specified test specimen air void content must be determined by trial and error. Generally, the test specimen air void content is 1.5 to 2.5 percent lower than the air void content of the gyratory specimen when the test specimen is removed from the middle as specified in this test method. 7.4 Coring - Core the nominal 100 mm (4 in) diameter test specimens from the center of the gyratory specimens. Both the core drill and the gyratory specimen should be adequately supported to ensure that the resulting test specimen is cylindrical with sides that are smooth, parallel, and free from steps, ridges, and grooves. 7.5 Diameter – Measure the diameter of the test specimen at the mid height and third points along axes that are 90 degrees apart. Record each of the six measurements to the nearest 1 mm (0.05 in). Calculate the average and the standard deviation of the six measurements. If the standard deviation is greater than 2.5 mm (0.01 in) discard the specimen. For acceptable specimens, the average diameter, reported to the nearest 1 mm, shall be used in the stress calculations. 7.6 End Preparation- The ends of all test specimens shall be smooth and perpendicular to the axis of the specimen. Prepare the ends of the specimen by sawing with a single or double bladed saw. The prepared specimen ends shall meet the tolerances described below. Reject test specimens not meeting these tolerances. 7.6.1 The specimen ends shall have a cut surface waviness height within a tolerance of ± 0.05 mm across any diameter. This requirement shall be checked in a minimum of three positions at approximately 120° intervals using a straight edge and feeler gauges approximately 8-12.5 mm (0.315- 0.5 in) wide or an optical comparator. 7.6.2 The specimen end shall not depart from perpendicular to the axis of the specimen by more than 0.5 degrees (i.e. 0.87 mm or 0.03 in across the

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-74 diameter of a 100 mm diameter specimen). This requirement shall be checked on each specimen using a machinists square and feeler gauges. 7.7 Air Void Content – Determine the air void content of the final test specimen in accordance with AASHTO T269. Reject specimens with air voids that differ by more than 0.5 percent from the target air voids. 7.8 Number – The number of test specimens required depends on the number of axial strain measurements made per specimen and the desired accuracy of the average dynamic modulus. Table 1 summarizes the replicate number of specimens that should be tested to obtain an accuracy limit of less than ±15 percent. Table 1. Recommended Number of Specimens LVDTs per Specimen Number of Specimens Estimated Limit of Accuracy 2 4 13.4 3 2 13.1 7.9 Sample Storage – Wrap completed specimens in polyethylene and store in an environmentally protected storage area at temperatures between 5 and 25°C (40 and 75 °F). Note 13 – To eliminate effects of aging on test results, it is recommended that specimens be stored no more than two weeks prior to testing. 8. Test Specimen Instrumentation 8.1 Attach mounting studs for the axial LVDTs to the sides of the specimen with epoxy cement. Figure 3 presents details of the mounting studs and LVDT mounting hardware. Note 14 – Quick setting epoxy such as Duro Master Mend Extra Strength Quick Set QM-50 has been found satisfactory for attaching studs. Under certain conditions when using the triaxial cell mentioned in Note 3, the mounting studs may not require gluing to the specimen. While the surface contact area of the mounting studs is normally minimized consistent with transducer support requirements, it is generally recommended that the area of the studs be sufficiently large to bridge any open void structure features evident on the cut face of the specimen. The minimum diameter mounting stud consistent with support requirements is normally set at 8 mm (0.315 in), maximum diameters NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-75 have not been established. A circular stud contact surface shape is not required, rectangular or other shapes are acceptable. 8.2 The gauge length for measuring axial deformations shall be 100 mm ±1 mm. An alignment and spacing fixture similar to that shown in Figure 3 can be used to facilitate mounting of the axial deformation measuring hardware. The gauge length is normally measured between the stud centers. 9. Procedure 9.1 The recommended test protocol for the Simple Performance Test for use in the Superpave volumetric mix design consists of testing the asphalt mix at one effective pavement temperature Teff and one design frequency selected by the design engineer. The effective pavement temperature Teff covers approximately the temperature range of 25 to 60 °C (77 to 140°F). The design frequency covers the range between 0.1 to 10 Hz 9.2 Place the test specimen in the environmental chamber and allow it to equilibrate to the specified testing temperature. A dummy specimen with a temperature sensor mounted at the center can be monitored to determine when the specimen reaches the specified test temperature. In the absence of the dummy specimen, Table 2 summarizes minimum recommended temperature equilibrium times from room temperature (i.e. 25 °C). Table 2. Recommended Equilibrium Times. Specimen Test Temperature, °C (°F) Time, hrs 30 (86) TBD* 40 (104) 50 (122) 60 (140) * To be determined 9.3 Place one of the friction reducing end treatments on top of the platen at the bottom of the loading frame. Place the specimen on top of the lower end treatment, and mount the axial LVDTs to the hardware previously attached to the specimen. Adjust the LVDT to near the end of its linear range to allow the full range to be available for the accumulation of compressive permanent deformation. 9.4 Place the upper friction reducing end treatment and platen on top of the specimen. Center the specimen with the load actuator visually in order to avoid eccentric loading. 9.5 Apply a contact load (Pmin) equal to 5 percent of the dynamic load that will be applied to the specimen. 9.6 Adjust and balance the electronic measuring system as necessary.

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-76 9.7 Apply haversine loading (Pdynamic) to the specimen without impact in a cyclic manner. The dynamic load should be adjusted to obtain axial strains between 50 and 150 microstrain. Note 15 – The dynamic load depends upon the specimen stiffness and generally ranges between 10 and 690 kPa (1.5 and 100 psi). Higher load is needed at colder temperatures. Table 3 presents target dynamic load levels based on temperature. Table 3. Target Dynamic Loads Temperature, °C (°F) Range, kPa Range, psi 25 (77) 70 – 690 10 –100 38 (100) 40-200 6 –29 54 (130) 10 - 70 1.5 – 10 9.8 Test the specimens at selected temperature by first precondition the specimen with 200 cycles at 25 Hz using the target dynamic loads in Table 3 (interpolate if necessary). Then load the specimen using the selected frequency and number of cycles as specified in Table 4. Table 4. Cycles for Test Sequence. Frequency Number of Cycles 10 100 5 50 1 25 0.5 6 0.1 6 9.9 If excessive permanent deformation (greater than 1000 micro units of strain) occurs, reduce the maximum loading stress level to half. Discard the specimen and use a new specimen for testing under reduced load conditions. 10. Calculations 10.1 Capture and store the last 6 loading cycles of full waveform data for each transducer. Determine the average amplitude of the sinusoidal load and deformation from each axial displacement transducer over the first 5 cycles of the last 6 loading cycle group NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-77 (since the displacement will lag behind the load, the computations may use data from the 6th cycle, but might not have enough of the waveform to fully determine the properties in the 6th cycle). 10.2 Average the signals from the displacement transducers. Determine the average time lag between the peak load and the peak deformation over the 5 loading cycles. Note 16 – Different approaches are available to determine these. The approach is highly dependent upon the number of data points collected per cycle. Approaches that have been used include peak search algorithms, various curve fitting techniques, and Fourier Transform. Curve fitting techniques and other numerical techniques have also been used to determine the phase angle from the more stable center portion of the waveform instead of the peaks. If any displacement transducer is out of range or otherwise obviously reading incorrectly during a cycle, discard the data for that cycle. Note 17 – For testing that will be used for statistical within-specimen variability and for establishing local precision and bias statements, paragraphs 10.3 through 10.7 must include computations from each individual displacement transducer in addition to the results from the averaged displacements. Therefore, it is a strict requirement that the data storage requirements of paragraph 10.1 be met. 10.3 Calculate the loading stress, σ o, as follows (see Figure 4): σ o P A = Where: P = average load amplitude A = area of specimen σ o = stress. 10.4 Calculate the recoverable axial strain for each frequency, ε o, as follows: εo GL = ∆ Where: ∆ = average deformation amplitude. GL = gage length σ o = strain

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-78 10.5 Calculate dynamic modulus, |E*| for each frequency as follows: o oEModulusDynamic ε σ =|*|, 10.6 Calculate the phase angle for each frequency: Where ti = average time lag between a cycle of stress and strain (sec) tp = average time for a stress cycle (sec.) 10.7 Calculate the dynamic modulus divided by sine of phase angle for each frequency: φ sin *E 11. Report 11.1 Report the average stress and strain for each temperature-frequency combination tested. 11.2 Report the dynamic modulus and phase angle for each temperature-frequency combination tested. 11.3 Report the average dynamic modulus divided by sin of phase angle for the test specimen for each temperature-frequency tested. )360(x t t p i =φ NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-79 Figure 1. Schematic of Dynamic Modulus Test Device. Load Cell Axial LVDT Specimen Greased Double Membrane Hardened Steel Disks

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-80 On-Sample Assembly Figure 2. Schematic of Gauge Points. NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-81 Lateral View Longitudinal Cross-Section Figure 3. Mounting Hardware Details. LVDT Mounting Stud

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-82 Phase lag Phase lag Amplitude Load Displacement Figure 4. Ideal Waveform Schematic. NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-83 Annex D Specification Compliance Test Methods for the Simple Performance Test System

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-84 Table D1. Summary of Specification Compliance Tests. Item Section Method Assembled Size 4.4 and 4.6 Measure Specimen and Display Height 4.4 Measure Component Size 4.7 Measure Electrical Requirements 4.5 and 4.6 Documentation and trial Air Supply Requirements 4.8 Documentation and trial Limit Protection 4.9 Documentation and trial Emergency Stop 4.10 Documentation, visual inspection, trial Loading Machine Capacity 5.1 Independent force verification (See verification procedures below) Load Control Capability 5.2 through 5.4 Trial tests on asphalt specimens and manufacturer provided dynamic verification device. Platen Configuration 5.5 Visual Platen Hardness 6.1 Test ASTM E10 Platen Dimensions 6.2 Measure Platen Smoothness 6.3 Measure Load Cell Range 7.1 Load cell data plate Load Accuracy 7.2 Independent force verification (See verification procedures below) Load Resolution 7.3 Independent force verification (See verification procedures below) Configuration of Deflection Measuring System 8.1 Visual Transducer Range 8.2 Independent deflection verification (See verification procedures below) Transducer Resolution 8.3 Independent deflection verification (See verification procedures below) Transducer Accuracy 8.4 Independent deflection verification (See verification procedures below) Load Mechanism Compliance and Bending 8.5 Measure on steel specimens with various degrees of lack of parallelism Configuration of Specimen Deformation Measuring System 9.1 Visual Gauge Length of Specimen Deformation Measuring System 9.1 Measure Transducer Range 9.2 Independent deflection verification (See verification procedures below) NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-85 Table D1. Summary of Specification Compliance Tests (Continued). Item Section Method Transducer Resolution 9.3 Independent deflection verification (See verification procedures below) Transducer Accuracy 9.4 Independent deflection verification (See verification procedures below) Specimen Deformation System Complexity 9.5 Trial Confining Pressure Range 10.1 and 10.5 Independent pressure verification (See verification procedures below) Confining Pressure Control 10.2 Trial tests on asphalt specimens Confining Pressure System Configuration 10.3 and 10.4 Visual Confining Pressure Resolution and Accuracy 10.5 Independent pressure verification (See verification procedures below) Temperature Sensor 10.6 and 11.4 Independent temperature verification (See verification procedures below) Specimen Installation and Equilibration Time 9.5, 10.7 and 11.3 Trial Environmental Chamber Range and Control 11.1 Independent temperature verification (See verification procedures below) Control System and Software 12 Trial Data Analysis 13 Independent computations on trial test Initial Calibration and Dynamic Performance Verification 14 Certification and independent verification Calibration Mode 14.6 Trial Verification of Normal Operation Procedures and Equipment 15 Review On-line Documentation 16.1 Trial Reference Manual 16.2 Review

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-86 INDEPENDENT VERIFICATION PROCEDURES FOR SIMPLE PERFORMANCE TESTING MACHINE 1.0 General 1.1 The testing machine shall be verified as a system with the load, deflection, specimen deformation, confining pressure, and temperature measuring systems in place and operating as in actual use. 1.2 System verification is invalid if the devices are removed and checked independently of the testing machine. 2.0 Load Measuring System Static Verification 2.1 Perform load measuring system verification in accordance with ASTM E-4. 2.2 All calibration load cells used for the load calibration shall be certified to ASTM E-74 and shall not be used below their Class A loading limits. 2.3 When performing the load verification, apply at least two verification runs of at least 5 loads throughout the range selected. 2.4 If the initial verification loads are within +/- 1% of reading, these can be applied as the “As found” values and the second set of verification forces can be used as the final values. Record return to zero values for each set of verification loads. 2.5 If the initial verification loads are found out of tolerance, calibration adjustments shall be made according to manufacturers specifications until the values are established within the ASTM E-4 recommendations. Two applications of verification loads shall then be applied to determine the acceptance criteria for repeatability according to ASTM E-4. 2.6 At no time will correction factors be utilized to corrected values that do not meet the accuracy requirements of ASTM E-4. 3.0 Deflection and Specimen Deformation Measuring System Static Verification 3.1 Perform verification of the deflection and specimen deformation measuring systems in accordance with ASTM D 6027 Test Method B. 3.2 The micrometer used shall conform to the requirements of ASTM E-83. NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-87 3.3 When performing verification of the deflection and strain measuring system, each transducer and associated electronics must be verified individually throughout it’s intended range of use. 3.4 Mount the appropriate transducer in the micrometer stand and align it to prevent errors caused by angular application of measurements. 3.5 Apply at least 5 verification measurements to the transducer throughout it’s range. Re-zero and repeat the verification measurements to determine repeatability. 3.6 If the readings of the first verification do not meet the specified error tolerance, perform calibration adjustments according to manufacturers specifications and repeat the applications of measurement to satisfy the error tolerances. 4.0 Confining Pressure Measuring System Verification 4.1 Perform verification of the confining pressure measuring system in accordance with ASTM D-5720. 4.2 All calibrated pressure standards shall meet the requirements of ASTM D-5720. 4.3 Attach the pressure transducer to the pressure standardizing device. 4.4 Apply at least 5 verification pressures to the device throughout it’s range recording each value. Determine if the verification readings fall within +/- 1 % of the value applied. 4.5 If the readings are within tolerance, apply a second set of readings to determine repeatability. Record the return to zero values for each set of verification pressures. 4.6 If readings are beyond tolerance, adjust the device according to manufacturers specifications and repeat the dual applications of pressure as described above to complete verification. 5.0 Temperature Measuring System Verification 5.1 Verification of the temperature measuring system will be performed using a using a NIST traceable reference thermal detector that is readable and accurate to 0.1 °C. 5.2 A rubber band or O-ring will be used to fasten the reference thermal detector to the system temperature sensor.

NCHRP 9-29 First-Article Equipment Specifications for Simple Performance Test System Version 1.1 November 19, 2001 Includes Amendment 1 A-88 5.3 Comparisons of the temperature from the reference thermal detector and the system temperature will be made at 6 temperatures over the operating range of the environmental chamber. 5.4 Once equilibrium is obtained at each temperature setting, record the temperature of the reference thermal detector and the system temperature sensor. 5.5 Also check stability of the environmental chamber by noting the maximum and minimum temperatures during cycling at the set temperature. 6.0 Dynamic Performance Verification 6.1 The verification of the dynamic performance of the equipment will be performed after static verification of the system. 6.2 The dynamic performance verification will be performed using the verification device provided with the system by the manufacturer. 6.3 First, the verification device will be loaded statically to obtain the static relationship between force and displacement. This relationship will be compared to that provided by the manufacturer in the system documentation. 6.4 The verification device will then be used to simulate dynamic modulus test conditions. Load and displacement data will be collected on the verification device using loads of 0.6, 1.2, 3.0, and 4.8 kN at frequencies of 0.1, 1, and 25 Hz. The peak load and displacements will be determined and plotted along with the static data. The data shall plot within +/- 2 percent of the static force displacement relationship. 6.5 The verification device will also be used to check the phase difference between the load and specimen deformation measuring system. The phase difference shall be less than 1 degree.