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APPENDIX E
Final Version of the SPT
Equipment Specifications

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E2
NCHRP
Project 9-29
Simple Performance Tester for Superpave
Mix Design
Equipment Specification
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.
October 16, 2007

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E3
Table of Contents
1.0 Summary .......................................................................................................................2
2.0 Definitions ......................................................................................................................5
3.0 Test Specimens ...............................................................................................................5
4.0 Simple Performance Test System ...................................................................................6
5.0 Compression Loading Machine ......................................................................................7
6.0 Loading Platens...............................................................................................................8
7.0 Load Measuring System .................................................................................................8
8.0 Deflection Measuring System.........................................................................................9
9.0 Specimen Deformation Measuring System ....................................................................9
10.0 Confining Pressure System ...........................................................................................11
11.0 Environmental Chamber ...............................................................................................12
12.0 Computer Control and Data Acquisition ......................................................................13
13.0 Computations ................................................................................................................23
14.0 Calibration and Verification of Dynamic Performance ................................................30
15.0 Verification of Normal Operation.................................................................................31
16.0 Documentation..............................................................................................................31
17.0 Warranty .......................................................................................................................31
Appen. A. Specification Compliance Test Methods for the
Simple Performance Test System .............................................................................32
Appen. B. Minimum Testing Program For Comparison of a Non-Standard Specimen
Deformation Measuring System to the Standard Specimen Deformation
Measuring System .....................................................................................................38
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E4
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:
Test Method For Static Creep/Flow Time of Asphalt Concrete Mixtures in
Compression
Test Method for Repeated Load Testing of Asphalt Concrete Mixtures in Uniaxial
Compression
Test Method for Dynamic Modulus of Asphalt Concrete Mixtures for Permanent
Deformation
Test Method for Dynamic Modulus of Asphalt Concrete Mixtures for Fatigue
Cracking
Note: This equipment specification represents a revision of the equipment
requirements contained in NCHRP Report 465 and AASHTO TP62. The
requirements of this specification supersede those contained in NCHRP Report 465
and AASHTO TP62.
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.
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5.0 Permanent Strain Permanent Strain Rate 0.0050
4.5 0.0045
4.0 0.0040
3.5 0.0035
Strain Rate, % per Sec
3.0 0.0030
Strain, %
2.5 0.0025
2.0 0.0020
Flow Number = Minimum
1.5 Strain Rate 0.0015
1.0 0.0010
0.5 0.0005
0.0 0.0000
0 1000 2000 3000 4000 5000 6000
Time, Sec
Figure 1. Schematic of Flow Time Test Data.
5.0 Permanent Strain Permanent Strain Rate 0.0050
4.5 0.0045
Permanent Strain Rate, % per Cycle
4.0 0.0040
3.5 0.0035
Permanent Strain, %
3.0 0.0030
2.5 0.0025
2.0 0.0020
Flow Number = Minimum
1.5 Permanent Strain Rate 0.0015
1.0 0.0010
0.5 0.0005
0.0 0.0000
0 1000 2000 3000 4000 5000 6000
Load Cycle
Figure 2. Schematic of Flow Number Test Data.
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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
E* = (1)
o
Ti
= (360) (2)
Tp
Where:
|E*| = dynamic modulus
= phase angle, degree
o = stress amplitude
o = strain amplitude
Ti = time lag between stress and strain
Tp = period of applied stress
PERIOD, TP
TIME LAG, TI
AXIAL STRAIN
LOAD
2OO 2 O
O
0.00 0.05 0.10 0.15
TIME, SEC
Figure 3. Schematic of Dynamic Modulus Test Data.
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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 Note
Average Diameter 100 mm to 104 mm 1
Specimen Dimensions Standard Deviation of Diameter 0.5 mm 1
Height 147.5 mm to 152.5 mm 2
End Flatness 0.5 mm 3
End Perpendicularity 1.0 mm 4
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Notes: 1. Using calipers, measure the diameter at the center and third points of the test specimen along axes
that are 90 ° apart. Record each of the six measurements to the nearest 0.1 mm. Calculate the
average and the standard deviation of the six measurements.
2. Measure the height of the test specimen in accordance with Section 6.1.2 of ASTM D 3549.
3. Using a straightedge and feeler gauges, measure the flatness of each end. Place a straight edge
across the diameter at three locations approximately 120 ° apart and measure the maximum
departure of the specimen end from the straight edge using tapered end feeler gauges. For each end
record the maximum departure along the three locations as the end flatness.
4. Using a combination square and feeler gauges, measure the perpendicularity of each end. At two
locations approximately 90 ° apart, place the blade of the combination square in contact with the
specimen along the axis of the cylinder, and the head in contact with the highest point on the end of
the cylinder. Measure the distance between the head of the square and the lowest point on the end of
the cylinder using tapered end feeler gauges. For each end, record the maximum measurement from
the two locations as the end perpendicularity.
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 tests.
4.2 Appendix A 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.
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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, 13.5 kN (3.0 kips) 0.01 to 25 Hz
sinusoidal
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.
n
(x i
^i )
-x
2
100%
se( P) = i =1
x
n-4 ^o
(3)
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Where:
se(P) = Standard error of the applied load
xi = Measured load at point i
^i
x = Predicted load at point i from the best fit sinusoid, See Equation 16
^o
x = 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 0.12 kN (25 lb) to 13.5 kN (3.0 kips) when verified in accordance
with ASTM E4.
7.3 The resolution of the load measuring system shall comply with the requirements of
ASTM E4.
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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 a glued gauge point system for
measuring deformations on the specimen over a gauge length of 70 mm (2.76 in) ± 1
mm (0.04 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 Figure 4 shows a schematic of the standard specimen deformation measuring system
with critical dimensions. Other properties of the deformation measuring system are
listed below.
Property Value
Gauge point contact area 80 mm ± 10 mm2
2
Dimension of the gauge point in the 10mm ± 2mm
direction of the guage length
Mass of mounting system and transducer 80 g max
Transducer spring force 1 N max
9

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Table A1. Summary of Specification Compliance Tests.
Item Section Method
Assembled Size 4.4 and Measure
4.6
Specimen and Display Height 4.4 Measure
Component Size 4.7 Measure
Electrical Requirements 4.5 and Documentation and trial
4.6
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 Trial tests on asphalt specimens and manufacturer
through provided dynamic verification device.
5.4
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 8.1 Visual
Measuring System
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 8.5 Measure on steel specimens with various degrees
and Bending of lack of parallelism
Configuration of Specimen 9.1 Visual
Deformation Measuring
System
Gauge Length of Specimen 9.1 Measure
Deformation Measuring
System
Transducer Range 9.2 Independent deflection verification (See
verification procedures below)
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Table A1. 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 9.5 Trial
System Complexity
Confining Pressure Range 10.1 and Independent pressure verification (See verification
10.5 procedures below)
Confining Pressure Control 10.2 Trial tests on asphalt specimens
Confining Pressure System 10.3 and Visual
Configuration 10.4
Confining Pressure Resolution 10.5 Independent pressure verification (See verification
and Accuracy procedures below)
Temperature Sensor 10.6 and Independent temperature verification (See
11.4 verification procedures below)
Specimen Installation and 9.5, 10.7 Trial
Equilibration Time and 11.3
Environmental Chamber 11.1 Independent temperature verification (See
Range and Control verification procedures below)
Control System and Software 12 Trial
Data Analysis 13 Independent computations on trial test
Initial Calibration and 14 Certification and independent verification
Dynamic Performance
Verification
Calibration Mode 14.6 Trial
Verification of Normal 15 Review
Operation Procedures and
Equipment
On-line Documentation 16.1 Trial
Reference Manual 16.2 Review
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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.
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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 oC.
5.2 A rubber band or O-ring will be used to fasten the reference thermal detector to the
system temperature sensor.
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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
0.5, 4.5, 8.5, and 12.5 kN (0.1, 1.0, 1.9, and 2.8 kips) at frequencies of 0.1, 1, and 10 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.
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Appendix B
Minimum Testing Program For Comparison of a Non-Standard Specimen Deformation
Measuring System to the Standard Specimen Deformation Measuring System
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1.0 Summary
1.1 This Annex describes the minimum testing, analysis, and reporting required to
demonstrate that a nonstandard specimen deformation measuring system produces
the same dynamic modulus and phase angle results as the standard glued gauge point
system specified in Section 9.0 of the these specifications.
1.2 The basic approach is to collect dynamic modulus and phase angle data on a single
mixture using the simple performance test system with the standard glued gauge
point system and the proposed alternative. Standard statistical hypothesis tests are
then performed on the resulting data to verify that there is no difference in the mean
and variance of the dynamic modulus and phase angles measured with the two
systems.
1.3 To provide data over a wide range of modulus and phase angles, the testing will be
performed for the conditions listed in Table B-1.
Table B-1. Testing Conditions.
Temperature, °C (°F) Confinement, kPa (psi) Frequencies, Hz
25 (77) Unconfined 10, 1, and 0.1
45 (113) Unconfined 10, 1, and 0.1
45 (113) 140 (20 psi) 10, 1, and 0.1
1.4 Tests on twelve independent specimens will be performed with each specimen
deformation measuring system. Thus a total of 24 specimens will be fabricated and
tested.
2.0 Test Specimens
2.1 The testing shall be performed on simple performance test specimens meeting the
dimensional tolerances of Section 3.0 of these specifications.
2.2 Use a coarse-graded 19.0 mm nominal maximum aggregate size mixture with a PG
64-22 binder. The mixture shall meet the requirements of AASHTO MP2 for a
surface course with a design traffic level of 10 to 30 million ESALs. The percent
passing the 2.36 mm sieve shall be less than 35 percent. Prepare test specimens at
the optimum asphalt content determined in accordance with AASHTO PP28 for a
traffic level of 3 to <30 million ESALs. Mixtures shall be short term oven aged for
2 hours at the compaction temperature in accordance with AASHTO R30.
2.3 Prepare 24 test specimens within the air void content range of 3.5 to 4.5 percent.
Rank the test specimens based on air void content. Group the test specimens into
two subsets such that the average and standard deviation of the air void contents are
approximately equal.
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3.0 Dynamic Modulus Testing
3.1 Perform the dynamic modulus testing with the Simple Performance Test System in
accordance with the Standard Test Method for Determining the Dynamic Modulus
and Flow Number for Hot Mix Asphalt (HMA) Using the Simple Performance Test.
Repeat tests as needed to ensure that the data quality indicators are within their
allowable ranges.
3.2 Perform the testing in blocks of three specimens in the order listed in Table B-2.
Plan the testing such that all testing in a block will be completed on the same day.
Table B-2. Block Order Testing.
Block Temperature, Confinement, Specimen
°C (°F) kPa (psi) Deformation System
1 25 (77) 0 Standard
Proposed
2 25 (77) 0 Standard
Proposed
3 25 (77) 0 Standard
Proposed
4 25 (77) 0 Standard
Proposed
5 45 (113) 140 (20) Standard
Proposed
6 45 (113) 140 (20) Standard
Proposed
7 45 (113) 140 (20) Standard
Proposed
8 45 (113) 140 (20) Standard
Proposed
9 45 (113) 0 Standard
Proposed
10 45 (113) 0 Standard
Proposed
11 45 (113) 0 Standard
Proposed
12 45 (113) 0 Standard
Proposed
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4.0 Data Analysis
4.1 For each combination of device, temperature, confining pressure, and frequency,
prepare summary tables listing the measured dynamic modulus and phase angles, and
the data quality indicators. A total of 18 summary tables, 9 for each measuring
system will be prepared. Each of these summary tables will represent a specific
combination of temperature, confining pressure, and frequency of loading.
4.2 For each summary table, compute the mean and variance of the dynamic modulus
and phase angle measurements using Equations B-1 and B-2.
12
y
i =1
i
y= (B1)
12
12
(y
i =1
i - y)2
s2 = (B2)
11
where:
y = sample mean
s2 = sample variance
yi = measured values
5.0 Statistical Hypothesis Testing
5.1 For each combination of temperature, confining pressure, and frequency of loading
test the equality of variances between the standard specimen deformation system and
the proposed specimen deformation measuring system using the F-test described
below. In the description below, the subscript s refers to the standard system and the
subscript p refers to the proposed system.
Null Hypothesis:
Variance of proposed system equals that of standard system, p = s
2 2
Alternative Hypothesis:
Variance of proposed system is greater than that of standard system, p > s
2 2
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Test Statistic:
2
sp
F= 2
ss
where
sp2 = computed sample variance for the proposed system
ss2 = computed sample variance for the standard system
Region of Rejection:
For the sample sizes specified, the test statistic must be less than 2.82 to conclude
that the variances are equal.
5.2 Summarize the resulting test statistics for dynamic modulus and phase angle.
5.3 If the results conclude the variance is greater for the proposed measuring for any of
the combinations of temperature, confinement, and loading frequency tested, then the
proposed measuring system is unacceptable.
5.4 For combinations of temperature, confinement, and loading frequency where equality
of variances is confirmed by the hypothesis test in Item 5.1, test the equality of
means between the standard specimen deformation system and the proposed
specimen deformation measuring system using the t-test described below. In the
description below, the subscript s refers to the standard system and the subscript p
refers to the proposed system.
Null Hypothesis:
Mean from the proposed system equals that from the standard system, p = s
2 2
Alternative Hypothesis:
Mean from the proposed system is not equal to that from the standard system,
p 2 s 2
Test Statistic:
(y - ys )
t=
p
n
6
where:
s p + ss
2 2
s=
2
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y p = computed sample mean from the proposed system
y s = computed sample mean from the standard system
sp2 = computed sample variance for the proposed system
ss2 = computed sample variance for the standard system
Region of Rejection:
For the sample sizes specified, the absolute value of the test statistic must be less
than 2.07 to conclude that the means are equal.
5.5 Summarize the resulting test statistics for dynamic modulus and phase angle.
5.6 If the results conclude the means are not equal for any of the combinations of
temperature, confinement, and loading frequency tested, then the proposed
measuring system is unacceptable.
6.0 Report
6.1 Design data for the mixture used in the evaluation.
6.2 Air void contents for individual specimens and the average and standard deviations
of the air void contents for the two subsets.
6.3 Tabular chronological summary of the block testing showing starting date and time
and completion date and time for each block.
6.4 Summary tables of dynamic modulus, phase angle, and data quality indicators for
each combination of temperature, confining pressure, and loading frequency for the
two measuring systems.
6.5 Summary tables of the mean and variance of the dynamic modulus and phase angle
for each combination of temperature, confining pressure, and loading frequency for
the two measuring systems.
6.6 Summary tables of the hypothesis tests for the variance and mean of the dynamic
modulus and phase angle for each combination of temperature, confining pressure,
and loading frequency.
6.7 Conclusions concerning the acceptability of the proposed measuring system.
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