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Evaluating Mechanical Properties of Earth Material During Intelligent Compaction (2020)

Chapter: Appendix A - Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction

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Suggested Citation:"Appendix A - Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction." National Academies of Sciences, Engineering, and Medicine. 2020. Evaluating Mechanical Properties of Earth Material During Intelligent Compaction. Washington, DC: The National Academies Press. doi: 10.17226/25777.
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Suggested Citation:"Appendix A - Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction." National Academies of Sciences, Engineering, and Medicine. 2020. Evaluating Mechanical Properties of Earth Material During Intelligent Compaction. Washington, DC: The National Academies Press. doi: 10.17226/25777.
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Suggested Citation:"Appendix A - Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction." National Academies of Sciences, Engineering, and Medicine. 2020. Evaluating Mechanical Properties of Earth Material During Intelligent Compaction. Washington, DC: The National Academies Press. doi: 10.17226/25777.
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Suggested Citation:"Appendix A - Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction." National Academies of Sciences, Engineering, and Medicine. 2020. Evaluating Mechanical Properties of Earth Material During Intelligent Compaction. Washington, DC: The National Academies Press. doi: 10.17226/25777.
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Suggested Citation:"Appendix A - Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction." National Academies of Sciences, Engineering, and Medicine. 2020. Evaluating Mechanical Properties of Earth Material During Intelligent Compaction. Washington, DC: The National Academies Press. doi: 10.17226/25777.
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Suggested Citation:"Appendix A - Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction." National Academies of Sciences, Engineering, and Medicine. 2020. Evaluating Mechanical Properties of Earth Material During Intelligent Compaction. Washington, DC: The National Academies Press. doi: 10.17226/25777.
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Suggested Citation:"Appendix A - Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction." National Academies of Sciences, Engineering, and Medicine. 2020. Evaluating Mechanical Properties of Earth Material During Intelligent Compaction. Washington, DC: The National Academies Press. doi: 10.17226/25777.
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Suggested Citation:"Appendix A - Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction." National Academies of Sciences, Engineering, and Medicine. 2020. Evaluating Mechanical Properties of Earth Material During Intelligent Compaction. Washington, DC: The National Academies Press. doi: 10.17226/25777.
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Suggested Citation:"Appendix A - Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction." National Academies of Sciences, Engineering, and Medicine. 2020. Evaluating Mechanical Properties of Earth Material During Intelligent Compaction. Washington, DC: The National Academies Press. doi: 10.17226/25777.
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Suggested Citation:"Appendix A - Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction." National Academies of Sciences, Engineering, and Medicine. 2020. Evaluating Mechanical Properties of Earth Material During Intelligent Compaction. Washington, DC: The National Academies Press. doi: 10.17226/25777.
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Suggested Citation:"Appendix A - Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction." National Academies of Sciences, Engineering, and Medicine. 2020. Evaluating Mechanical Properties of Earth Material During Intelligent Compaction. Washington, DC: The National Academies Press. doi: 10.17226/25777.
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Suggested Citation:"Appendix A - Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction." National Academies of Sciences, Engineering, and Medicine. 2020. Evaluating Mechanical Properties of Earth Material During Intelligent Compaction. Washington, DC: The National Academies Press. doi: 10.17226/25777.
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Suggested Citation:"Appendix A - Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction." National Academies of Sciences, Engineering, and Medicine. 2020. Evaluating Mechanical Properties of Earth Material During Intelligent Compaction. Washington, DC: The National Academies Press. doi: 10.17226/25777.
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Suggested Citation:"Appendix A - Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction." National Academies of Sciences, Engineering, and Medicine. 2020. Evaluating Mechanical Properties of Earth Material During Intelligent Compaction. Washington, DC: The National Academies Press. doi: 10.17226/25777.
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Suggested Citation:"Appendix A - Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction." National Academies of Sciences, Engineering, and Medicine. 2020. Evaluating Mechanical Properties of Earth Material During Intelligent Compaction. Washington, DC: The National Academies Press. doi: 10.17226/25777.
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Suggested Citation:"Appendix A - Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction." National Academies of Sciences, Engineering, and Medicine. 2020. Evaluating Mechanical Properties of Earth Material During Intelligent Compaction. Washington, DC: The National Academies Press. doi: 10.17226/25777.
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Suggested Citation:"Appendix A - Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction." National Academies of Sciences, Engineering, and Medicine. 2020. Evaluating Mechanical Properties of Earth Material During Intelligent Compaction. Washington, DC: The National Academies Press. doi: 10.17226/25777.
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Suggested Citation:"Appendix A - Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction." National Academies of Sciences, Engineering, and Medicine. 2020. Evaluating Mechanical Properties of Earth Material During Intelligent Compaction. Washington, DC: The National Academies Press. doi: 10.17226/25777.
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Suggested Citation:"Appendix A - Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction." National Academies of Sciences, Engineering, and Medicine. 2020. Evaluating Mechanical Properties of Earth Material During Intelligent Compaction. Washington, DC: The National Academies Press. doi: 10.17226/25777.
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Suggested Citation:"Appendix A - Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction." National Academies of Sciences, Engineering, and Medicine. 2020. Evaluating Mechanical Properties of Earth Material During Intelligent Compaction. Washington, DC: The National Academies Press. doi: 10.17226/25777.
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Suggested Citation:"Appendix A - Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction." National Academies of Sciences, Engineering, and Medicine. 2020. Evaluating Mechanical Properties of Earth Material During Intelligent Compaction. Washington, DC: The National Academies Press. doi: 10.17226/25777.
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Suggested Citation:"Appendix A - Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction." National Academies of Sciences, Engineering, and Medicine. 2020. Evaluating Mechanical Properties of Earth Material During Intelligent Compaction. Washington, DC: The National Academies Press. doi: 10.17226/25777.
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Suggested Citation:"Appendix A - Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction." National Academies of Sciences, Engineering, and Medicine. 2020. Evaluating Mechanical Properties of Earth Material During Intelligent Compaction. Washington, DC: The National Academies Press. doi: 10.17226/25777.
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Suggested Citation:"Appendix A - Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction." National Academies of Sciences, Engineering, and Medicine. 2020. Evaluating Mechanical Properties of Earth Material During Intelligent Compaction. Washington, DC: The National Academies Press. doi: 10.17226/25777.
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Suggested Citation:"Appendix A - Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction." National Academies of Sciences, Engineering, and Medicine. 2020. Evaluating Mechanical Properties of Earth Material During Intelligent Compaction. Washington, DC: The National Academies Press. doi: 10.17226/25777.
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Suggested Citation:"Appendix A - Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction." National Academies of Sciences, Engineering, and Medicine. 2020. Evaluating Mechanical Properties of Earth Material During Intelligent Compaction. Washington, DC: The National Academies Press. doi: 10.17226/25777.
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Suggested Citation:"Appendix A - Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction." National Academies of Sciences, Engineering, and Medicine. 2020. Evaluating Mechanical Properties of Earth Material During Intelligent Compaction. Washington, DC: The National Academies Press. doi: 10.17226/25777.
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Suggested Citation:"Appendix A - Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction." National Academies of Sciences, Engineering, and Medicine. 2020. Evaluating Mechanical Properties of Earth Material During Intelligent Compaction. Washington, DC: The National Academies Press. doi: 10.17226/25777.
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A-1 Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction This appendix contains the proposed specifications developed during NCHRP Project 24-45, which was conducted to develop procedures to estimate mechanical properties of geomaterials using Intelligent Compaction (IC). These proposed specifications have been developed based on the findings obtained from the Phase 1 and Phase 3 activities. The framework for the IC specifications and the rationale for incorporating different items in the proposed specifications are discussed in Chapter 8 of the final report. Using AASHTO PP 81-14 as a baseline, two proposed specifications have been developed; one addresses backcalculation of layer modulus and the other addresses quality management and design verification using IC: • Proposed Standard Specification for Extracting Modulus of Compacted Geomaterials Using Intelligent Compaction (IC), and • Proposed Standard Specification for Quality Management and Design Verification of Earthwork and Unbound Aggregates Using Intelligent Compaction (IC). Two proposed test methods that supplement these specifications with device-specific protocols also are provided: • Proposed Standard Test Method for Determining Intelligent Compaction Measurement Value (ICMV) Using Intelligent Compaction (IC) Technology, and • Proposed Standard Test Method for Estimating Modulus of Embankment and Unbound Aggregate Layers with Portable Falling Weight Devices. Given the diversity of requirements and practices across differing state highway administrations (SHAs), the values and guidelines provided represent the research team’s best effort to provide a set of consensus values and procedures. The language of the proposed specifications has been maintained as general as possible so that individual SHAs can customize the documents to their requirements. Comments have been incorporated to explain the researchers’ thought process and to describe means of adapting the specification to local practices. Reflecting how the proposed specifications and test method documents will be used, the numbering of sections, tables, and figures is specific to each document rather than continuous throughout the appendix. A P P E N D I X A

A-2 Evaluating Mechanical Properties of Earth Material During Intelligent Compaction PROPOSED STANDARD SPECIFICATION FOR EXTRACTING MODULUS OF COMPACTED GEOMATERIALS USING INTELLIGENT COMPACTION (IC) AASHTO Designation: PP YY-XX 1 1. SCOPE 1.1 The primary objective of this document is to develop a procedure to extract the modulus of compacted geomaterials employing Intelligent Compaction (IC) rollers in conjunction with modulus/deflection-based devices. 1.2 IC is defined as a process that uses rollers equipped with a measurement-documentation system that automatically records compaction parameters (e.g., spatial location, pass count, vibration amplitude, and frequency) in real time during the compaction process. IC rollers equipped with accelerometers use roller vibration measurements to estimate stiffness and uniformity through continuous monitoring of operations. 1.3 The Contractor shall supply sufficient numbers of rollers, and other associated equipment, necessary to complete the compaction requirements for the specific materials. 1.4 All tasks are the Contractor’s responsibility, unless designated otherwise within this provision. 2. REFERENCED DOCUMENTS 2.1 AASHTO Standards: M 57, Materials for Embankments and Subgrades M 147, Materials for Aggregate and Soil-Aggregate Subbase, Base, and Surface Courses T 2, Sampling of Aggregates T 307, Resilient Modulus of Soils and Aggregate Material T 310, In-Place Density and Moisture Content of Soil and Soil-Aggregate by Nuclear Methods 2.2 ASTM Standards: E 2835, Measuring Deflections using a Portable Impulse Plate Load Test Device E 2583, Measuring Deflections with a Light Weight Deflectometer (LWD) 3. DEFINITIONS 3.1 Intelligent Compaction (IC)—A system that provides continuous assessment of compaction through roller vibration monitoring and integrates a global positioning system. 3.2 Intelligent Compaction Measurement Value (ICMV)—A generic term that refers to a set of IC data used for measurements of resistance of deformation of underlying material and to assess uniformity based on the responses of the roller drum vibration measurements in units specific to the roller manufacturer. 3.3 Intelligent Compaction Retrofit Kit (a.k.a. Aftermarket Kit)—A set of stand-alone IC instrumentation that could be mounted on almost any dynamic vibratory roller to collect ICMV data. 1 AASHTO PP YY-XX is a generic designation for this proposed specification.

Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction A-3 3.4 Vibration Amplitude—The height of a roller drum’s lift from the pavement surface during vibratory compaction. 3.5 Mapping—Collecting IC data at a specific vibration setting and roller speed after completion of the compaction process. 3.6 Pre-Mapping—Collecting IC data at a specific vibration setting and roller speed before placement of a new geomaterial layer. 3.7 Proof Mapping—The process of using an IC roller to map the entire section upon completion of compaction for purposes of assessing the uniformity and consistency of compaction. 3.8 Light Weight Deflectometer (LWD)—A nondestructive deflection-based device to evaluate the stiffness of compacted layers by applying an impulse load through dropping a weight from a specified height on a loading plate on top of a compacted geomaterial layer. 4. MATERIALS 2 4.1 Unless waived or altered by the Engineer, materials shall conform to the requirements of the relevant specifications listed in Table 1. Table 1. Material specifications. Material Specification Embankment AASHTO M 57 Subgrade AASHTO M 57 Subbase AASHTO M 147 Base AASHTO M 147 4.2 The Contractor shall produce, deliver, and stockpile materials at the designated sites as directed by the Engineer that conforms to the requirements in Table 1. 4.3 The Contractor shall be responsible for maintaining a gradation process control program in accordance with random sampling procedures in AASHTO T 2. 4.4 A change in material source without permission of the engineer is prohibited. 4.5 The Contractor shall assume full responsibility for the production and placement of acceptable materials. 5. EQUIPMENT 5.1 Intelligent Compaction (IC) Roller Compactor—A vibratory roller equipped with a data acquisition (DAQ) system that processes compaction data in real time for the roller operator. The DAQ can be either a factory-installed/Original Equipment Manufacturer (OEM) system or a retrofit system. 5.1.1 IC Rollers—Rollers shall be equipped with accelerometers and mounted in or on the side of the drum to measure the interactions between the roller and compacted materials to evaluate the applied compaction effort. 2 SHAs can replace the AASHTO specifications and/or test methods with their own specifications and methods.

A-4 Evaluating Mechanical Properties of Earth Material During Intelligent Compaction 5.1.2 GPS Radio and Receiver Units—GPS units shall be mounted on each IC roller to monitor the drum locations and track the number of passes of the rollers. The mounted GPS units connect with hand-held survey-grade GPS rover(s) and with a local/virtual base station to transmit and record GPS data. The recorded GPS data, whether from the IC rollers or hand- held GPS rovers, shall include the date (in yyyymmdd format); time (in hh:mm:ss.xx format with a precision of 0.01 seconds required to differentiate sequence of IC data points during post-processing); latitude and longitude (in decimal degrees, dd.dddddddd, with longitudes recorded as negative values when measuring westward from the Prime Meridian); and elevation (in ft.). 5.1.3 On-Board Computer Display—The display unit will show the location of the roller, number of passes, and amplitude and frequency for vibratory rollers, and provides real- time, color-coded maps of the ICMV. The display unit shall be capable of transferring the data by means of a USB port or by automatic wireless uploading to a cloud-based computer storage system. The on-board computer should have the capability to measure, record, and export compaction parameters in Comma Delimited Separated Values (*.csv) format data files. 5.2 E 2583. 6. EXTRACTION OF MODULUS 6.1 The schematic of the implementation of the proposed IC process is illustrated in Figure 1. Figure 1. Field implementation process. 6.2 Select IC System and Material Type for All Layers—Specify the type of IC roller for use prior to the beginning of the compaction process to include the accuracy of the GPS unit. The specifications of the IC system must be approved by the Engineer. The installation of the retrofit kit on conventional rollers needs special configuration and installation processes that should be planned in advance of their use. Furnish the roller model and serial number prior to installation of the retrofit kit to accommodate any special equipment needed during the installation process. Furnish material conforming to the requirements of Section 4. Select IC System and Material Type for All Layers Perform Pre- Mapping Perform LWD and Field Moisture Content Tests Perform Construction of Layer and Compaction Perform Proof Mapping of Compacted Layer Perform LWD and Field Moisture Content Tests Post-Processing to Extract Layer Modulus Light Weight Deflectometer (LWD)—The LWD shall conform to ASTM E 2835 or

Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction A-5 6.3 Perform Pre-Mapping—Follow AASHTO T XXX 3 to pre-map the existing layer prior to placement and compaction of the layer of interest. Perform the pre-mapping process at low amplitude and low frequency vibration settings with forward passes of the IC roller over the section at a uniform speed of no more than 3 mph (5 km/h). Follow the AASHTO PP XX-XX 4 specification to ensure uniformity of the existing layer is achieved. 6.3.1 The mapping of the vibration amplitude (i.e., surface deformation of the existing layer under the drum) should be provided using a rectangular grid. An average value, d1, for the entire mapped section should be provided in the descriptive statistics or should be determined from the mapping of surface deformation. 6.3.2 The mapping of the forces imposed by the drum should be provided using a rectangular grid. An average value, Fd, for the entire mapped section should be provided in the descriptive statistics or should be determined from the mapping of drum forces. 6.4 Perform LWD and Field Moisture Content Tests—Perform tests for modulus and moisture at randomly selected locations, at the minimum frequency required (see Table 2). Follow the steps in AASHTO T YYY 5 to perform the LWD test to obtain modulus ELWD-1 of existing layer. The modulus should be adjusted for the moisture content at the time of spot testing (Eeff) as required by AASHTO T YYY in accordance with AASHTO T 310. Table 2. Minimum schedule of modulus-based tests. 6 Material Maximum Lot Size No. of Sublots No. of Tests per Sublot Embankment 4,000 yd2 (3,400 m2) 2 5 Subgrade 3,000 yd2 (2,500 m2) 2 5 Subbase 2,400 yd2 (2,000 m2) 2 5 Base 2,000 yd2 (1,700 m2) 2 5 6.5 Perform Construction of Layer and Compaction—Construct each layer uniformly, free of loose or segregated areas, in accordance with the plans and the applicable specification items listed in Section 4, “Materials.” Provide a smooth surface that conforms to the typical sections, lines, and grades shown on the plans or as directed. 3 AASHTO T XXX is a generic designation for the “Proposed Standard Test Method for Determining Intelligent Compaction Measurement Value (ICMV) Using Intelligent Compaction (IC) Technology.” The proposed test method was developed as part of NCHRP 24-45 and is included in this appendix. 4 AASHTO PP XX-XX is a generic designation for a proposed specification, “Proposed Standard Specification for Quality Management and Design Verification of Earthwork and Unbound Aggregates Using Intelligent Compaction (IC).” The proposed specification was developed as part of NCHRP 24-45 and is included in this appendix. 5 AASHTO T YYY is a generic designation for the “Proposed Standard Test Method for Estimating Modulus of Embankment and Unbound Aggregate Layers with Portable Falling Weight Devices.” The proposed test method was developed as part of NCHRP 24-45 and is included in this appendix. 6 SHAs can replace the values in Table 2 with their own values. The number of tests per sublot is listed as recommended by Nazarian et al. (2014), Modulus-Based Construction Specification for Compaction of Earthwork and Unbound Aggregate. NCHRP Project 10-84, El Paso, TX.

A-6 Evaluating Mechanical Properties of Earth Material During Intelligent Compaction 6.6 Perform Proof Mapping of Compacted Layer—Upon completion of the compaction process, map the section using the IC roller with the same vibration settings as in Section 6.3, “Pre-Mapping,” to generate color-coded maps of the vibration amplitude (surface deformation) using a rectangular grid. 6.6.1 Follow the AASHTO PP XX-XX specification to ensure uniformity and quality management of compacted geomaterials. 6.6.2 Review the variability (coefficient of variation, or COV) of the ICMV color-coded map of the compacted section and identify the more uniformly compacted areas. Identify the more uniform areas, shown as areas marked in green (COV of ICMV ≤ 25%). 6.7 Perform LWD and Field Moisture Content Spot Tests—Perform the spot tests as soon as possible and before the material loses 2% of its placement moisture content, at locations identified as more uniform areas in Section 6.6.2. Follow the steps in AASHTO T YYY to perform the LWD test to obtain the LWD modulus, ELWD-2. The modulus should be adjusted for the moisture content at the time of spot testing (Eeff) as required by AASHTO T YYY following AASHTO T 310. The density and moisture measurements shall be taken by the Engineer in the same locations where the spot tests were performed. Unless altered by the Engineer, compliance shall be documented in accordance with the minimum frequency of testing for modulus and moisture content reflected in Table 2. This frequency can be reduced as justified by the use of continuous compaction control during the Contractor’s process control. 6.8 Perform Post-Processing to Extract Layer Modulus—To extract the modulus of the proof-mapped compacted layer, use the inverse models of either of the two options below: 6.8.1 Option 1—Use inverse model by inputting: d2 and d1, blocked roller displacements (vibration amplitude) obtained after proof- mapping top (base) layer and underlying (subgrade) layer, respectively, k íb and k ís, regression parameters of top and underlying layers, respectively, as obtained from resilient modulus (see Section 7.1.1), ELWD-2, the averaged effective LWD modulus (Eeff) as obtained from the spot tests on the top (base) layer, ELWD-1, the averaged effective LWD modulus (Eeff) as obtained from the spot tests on top of the underlying layer (subgrade), h, top layer (base) thickness, D, diameter of drum, L, length of drum, and W, weight of drum in addition to centrifugal force as set during proof-mapping. For single-layer systems, use the corresponding model and the parameters corresponding to subgrade only. 6.8.2 Option 2—Use transfer function by means of the drum force by inputting: Fd2 and Fd1, blocked drum forces obtained after proof-mapping top (base) layer and underlying (subgrade) layer, respectively, ELWD-2, the averaged effective LWD modulus (Eeff) as obtained from the spot tests on the top (base) layer, and

Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction A-7 ELWD-1, the averaged effective LWD modulus (Eeff) as obtained from the spot tests on top of the underlying layer (subgrade). For single-layer systems, use the parameters corresponding to subgrade only. 7. DETERMINE NONLINEAR INPUT PARAMETERS FOR INVERSE MODEL 7.1 The following steps shall be used to determine the nonlinear k í input parameters for the inverse model. 7.1.1 Determine the resilient modulus (MR) parameters of the layer being tested and the underlying layer(s). In the order of preference, these values should be obtained from one of three options: 7.1.1.1 Option 1—Measure the resilient modulus of the geomaterial over the range of stress states in accordance with AASHTO T 307 on specimens prepared from the stockpile. Prepare specimens at their corresponding optimum moisture contents (OMC) and maximum dry densities (MDD). Obtain regression parameters k´1 through k´3 that best describe the following relationship for each material. (7.1) where θ= bulk stress, τoct = octahedral shear stress, Pa = atmospheric pressure (101.3 MPa, 14.7 psi) and k í = nonlinear regression parameters. 7.1.1.2 Option 2—Estimate k1 through k3 related to Equation 7.2 for the OMC and MDD from a catalog of materials tested locally (often in conjunction with the implementation of the mechanistic-empirical design algorithms) and convert them to k´1 through k´3 according to the process discussed in Section 7.1.2. (7.2) 7.1.1.3 Option 3—Estimate regression parameters k1 through k3 related to Equation 7.2 for the optimum moisture content and maximum dry density from relationships established in the literature. The relationships developed from the FHWA Long-Term Pavement Performance (LTPP) program are shown in Appendix I. 7.1.2 Convert the regression parameters k1 through k3 from Equation 7.2 (as determined in Section 7.1.1.2 or Section 7.1.1.3) to k´1 through k´3 for Equation 7.1 using the following relationships (7.3) (7.4) 2 3 1 1 1 k k oct opt a a a MR k P P P 2 3 1 1 k k oct opt a a a MR k P P P 21.32 1 1 kk k e 2 21.88k k 3 3k k (7.5) 8. MEASUREMENT AND PAYMENT 8.1 The work performed, materials furnished, equipment, labor, tools, and incidentals will not be measured or paid for directly but will be subsidiary to the pertinent items.

A-8 Evaluating Mechanical Properties of Earth Material During Intelligent Compaction Appendix I – Estimating Resilient Modulus Constitutive Model Coefficients (as per FHWA-LTPP) Crushed Stone Base Materials: k1 = 0.7632 + 0.008(P3/8) + 0.0088(LL) – 0.00371(wopt) -0.0001(γopt) (I.1) k2 = 2.2159 – 0.0016 (P3/8) + 0.0008 (LL) – 0.038(wopt) – 0.006(γopt) + 0.00000024(γ2opt / P#40) (I.2) k3 = –1.1720 – 0.0082(LL) – 0.0014(wopt) + 0.0005 (γopt) (III.3) Embankments, Soil – Aggregate Mixture, Coarse-Grained: k1 = – 0.5856 + 0.0130(P3/8) – 0.0174(P#4) + 0.0027(P#200) + 0.0149(PI) + 0.0000016(γopt) – 0.0426(ws) + 1.6456[γs / γopt] + 0.3932[ws / wopt] – 0.00000082[γ2opt / P#40] (I.4) k2 = 0.7833 – 0.0060 (P#200) – 0.0081(PI) + 0.0001(γopt) – 0.1483[ws / wopt] + 0.000000027[γ2opt/ P#40] (I.5) k3 = – 0.1906 – 0.0026(P#200) + 0.00000081[γ2opt / P#40] (I.6) Embankments, Soil – Aggregate, Fine-Grained: k1 = – 0.7668 + 0.0051(P#4) + 0.0128 (P#200) + 0.0030(LL) – 0.051(wopt) + 1.179[γs / γopt] (I.7) k2 = 0.4951 – 0.0141(P#4) – 0.0061(P#200) + 1.3941[γs / γopt] (I.8) k3 = 0.9303 + 0.293(P3/8) + 0.0036(LL) – 3.8903[ γs / γopt] (I.9) Fine-Grained Clay Soil: k1 = 1.3577 + 0.0106(Clay) – 0.0437(ws) (I.10) k2 = 0.5193 – 0.0073(P#4) + 0.0095(P#40) – 0.0027(P#200) – 0.0030(LL) – 0.0049(wopt) (I.11) k3 = 1.4258 – 0.0288(P#4) + 0.0303(P#40) – 0.0521(P#200) + 0.025(Silt) + 0.0535(LL) – 0.0672(wopt) – 0.0026(γopt) + 0.0025(γs) – 0.6055 [ws / wopt] (I.12) where: LL = Liquid limit PI = Plasticity index of soil ws = Water content of the test specimen (%) γs = Dry density of the test specimen wopt = Optimum water content (%) γopt = Maximum dry unit weight of soil P3/8 = Percentage passing sieve #3/8 sieve P#4= Percentage passing #4 sieve P#40= Percentage passing #40 sieve P#200 = Percent passing #200 sieve Clay = Percentage of clay (%) Silt = Percentage of silt (%)

Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction A-9 PROPOSED STANDARD SPECIFICATION FOR QUALITY MANAGEMENT AND DESIGN VERIFICATION OF EARTHWORK AND UNBOUND AGGREGATES USING INTELLIGENT COMPACTION (IC) AASHTO Designation: PP XX-XX 1 1. SCOPE 1.1 The primary objective of this document is to develop specifications and procedures that can be used for quality management and design verification of compacted geomaterials employing Intelligent Compaction (IC) rollers. 1.2 This work shall consist of compaction of roadway embankment, subgrade or other unbound geomaterials without stabilizing agents such as lime or cement using Intelligent Compaction (IC) rollers within the limits of the work described in the plans or provisions. 1.3 IC is defined as a process that uses rollers equipped with a measurement-documentation system that automatically records compaction parameters (e.g., spatial location, pass count, vibration amplitude and frequency) in real time during the compaction process. IC rollers equipped with accelerometers use roller vibration measurements to estimate stiffness and uniformity through continuous monitoring of operations. 1.4 The contractor shall supply sufficient numbers of rollers, and other associated equipment, necessary to complete the compaction requirements for the specific materials. 1.5 This specification is to be applied during the contractor’s quality control. 1.6 All tasks are the contractor’s responsibility, unless designated otherwise within this provision. 2. REFERENCED DOCUMENTS 2.1 AASHTO Standards: M 57, Materials for Embankments and Subgrades M 147, Materials for Aggregate and Soil-Aggregate Subbase, Base, and Surface Courses T 307, Resilient Modulus of Soils and Aggregate Material T 2, Sampling of Aggregates 3. DEFINITIONS 3.1 Intelligent Compaction (IC)—A system that provides continuous assessment of compaction through roller vibration monitoring and integrates a global positioning system. 3.2 Intelligent Compaction Measurement Value (ICMV)—A generic term that refers to a set of IC data for measurements of resistance of deformation of underlying material and to assess uniformity based on the responses of the roller drum vibration measurements in units specific to the roller manufacturer. 3.3 Intelligent Compaction Retrofit Kit (a.k.a. Aftermarket Kit)—A set of stand-alone IC instrumentation that could be mounted on almost any dynamic vibratory roller to collect ICMV data. 1 AASHTO PP XX-XX is a generic designation for this proposed specification.

A-10 Evaluating Mechanical Properties of Earth Material During Intelligent Compaction 3.4 Vibration Amplitude—The height of a roller drum’s lift from the pavement surface during vibratory compaction. 3.5 Mapping—Collecting IC data at a specific vibration setting and roller speed after completion of the compaction process. 3.6 Pre-Mapping—Collecting IC data at a specific vibration setting and roller speed before placement of a new geomaterial layer. 3.7 Proof Mapping—The process of using an IC roller to map the entire section upon completion of compaction for assessing the uniformity and consistency of compaction. 3.8 Stiffness—A measurement value defined as the resistance to deformation of a material under an applied load, in this case the load imposed by the drum centrifugal force and its weight. 4. MATERIALS 2 4.1 Unless waived or altered by the Engineer, materials shall conform to the requirements of the relevant specifications listed in Table 1. Table 1. Material specifications. Material Specification Embankment AASHTO M 57 Subgrade AASHTO M 57 Subbase AASHTO M 147 Base AASHTO M 147 4.2 The Contractor shall produce, deliver, and stockpile materials that conform to the requirements in Table 1 at the designated sites as directed by the Engineer. 4.3 The Contractor shall be responsible for maintaining a gradation process control program in accordance with random sampling procedures in AASHTO T 2. 4.4 A change in material source without permission of the engineer is prohibited. 4.5 The Contractor shall assume full responsibility for the production and placement of acceptable materials. 5. EQUIPMENT 5.1 Intelligent Compaction (IC) Roller Compactor—A vibratory roller equipped with a data acquisition (DAQ) system that processes compaction data in real time for the roller operator. The DAQ can be either a factory-installed/Original Equipment Manufacturer (OEM) system or a retrofit system. 5.1.1 IC Rollers—Rollers shall be equipped with accelerometers mounted in or on the side of the drum to measure the interactions between the roller and compacted materials to evaluate the applied compaction effort. 5.1.2 GPS Radio and Receiver Units—GPS units shall be mounted on each IC roller to monitor the drum locations and track the number of passes of the rollers. The mounted GPS units connect with hand-held survey-grade GPS rover(s) and with a local/virtual base station to 2 SHAs can replace the AASHTO specifications and/or test methods with their own specifications and methods.

Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction A-11 transmit and record GPS data. The recorded GPS data, whether from the IC rollers or hand- held GPS rovers, shall include the date (in yyyymmdd format); time (in hh:mm:ss.xx format with a precision of 0.01 seconds required to differentiate sequence of IC data points during post-processing); latitude and longitude (in decimal degrees, dd.dddddddd, with longitudes recorded as negative values when measuring westward from the Prime Meridian); and elevation (in ft.). 5.1.3 On-Board Computer Display—The display unit will show the location of the roller, number of passes, and amplitude and frequency for vibratory rollers, and provides real- time, color-coded maps of the ICMV. The display unit shall be capable of transferring the data by means of a USB port or by automatic wireless uploading to a cloud computer storage system. The on-board computer should have the capability to measure, record, and export compaction parameters in the Comma Delimited Separated Values (*.csv) format data files. 6. FIELD IMPLEMENTATION 6.1 The schematic of the implementation of the proposed IC process is illustrated in Figure 1. Figure 1. Field implementation process. 6.2 Select IC System and Material Type for All Layers—Specify the type of IC roller for use prior to the beginning of the compaction process to include the accuracy of the GPS unit. The specifications of the IC system must be approved by the Engineer. The installation of the retrofit kit on conventional rollers needs special configuration and installation processes that should be planned in advance of their use. Furnish the roller model and serial number prior to installation of the retrofit kit to accommodate the need for any special equipment and installation process. Furnish materials conforming to the requirements of Section 4. 6.3 Simulate Roller Measurements—Using the design pavement structure and properties and drum dimensions and weight, predict target stiffness, ks-target, of single-layer or two-layer system using forward prediction model following the steps provided in Section 7. Select IC System and Material Type for All Layers Simulate Roller Measurements Perform Pre-Mapping Perform Construction and Compaction Perform Proof Mapping Assess Compaction Uniformity and Identify Less-Stiff Areas

A-12 Evaluating Mechanical Properties of Earth Material During Intelligent Compaction 6.4 Perform Pre-Mapping—Follow AASHTO T XXX 3 to pre-map the existing layer to generate color-coded maps of the ICMV and COV of ICMV and to assess the uniformity of the existing layer prior to placement and compaction of the layer of interest. Perform the pre-mapping process at low amplitude and low frequency vibration settings with forward passes of the IC roller over the section at a uniform speed of no more than 3 mph (5 km/h). Mapping of the coefficient of variation (COV) of the ICMV should be provided using a rectangular grid based on areas practical for rework. Areas in the map with a high COV of ICMV (COV > 50%) indicate that uniformity was not achieved. 6.5 Perform Construction and Compaction—Construct each layer uniformly, free of loose or segregated areas, in accordance with the plans and the applicable specification items listed in Section 4, “Materials.” Provide a smooth surface that conforms to the typical sections, lines, and grades shown on the plans or as directed. 6.6 Perform Proof Mapping of Compacted Layer—Upon completion of the compaction process, map the section using the IC roller with the same vibration settings as in Section 6.4, “Perform Pre-Mapping,” to generate color-coded maps of stiffness, ks, in addition to ICMV and COV of ICMV. The mapping of stiffness and/or ICMVs and their respective COVs should be provided using a rectangular grid based on areas practical for rework. 6.7 Assess Compaction Uniformity and Identify Less-Stiff Areas—The following steps should be performed to insure uniformity and to identify the less-stiff areas. 6.7.1 Maps with cells with a high COV of the ICMV (COV > 50%) indicate that uniformity was not achieved and the compacted layer must be subject to rework. 6.7.2 Evaluate the stiffness color-coded map of the compacted section provided after proof mapping to identify the relatively less-stiff areas (marked in red) and compare to target stiffness, ks-target, obtained in Section 7.2 Rework areas that do not meet the established target values. 7. ESTABLISHING TARGET STIFFNESS 7.1 The following steps shall be used to set the target stiffness values: 7.1.1 Determine the resilient modulus parameters of the layer under test and the underlying layer(s). In the order of preference, these values should be obtained from one of the options below: 7.1.1.1 Option 1—Measure the resilient modulus of the geomaterial over the range of stress states in accordance with AASHTO T 307 on specimens prepared from the stockpile. Prepare specimens at their corresponding optimum moisture contents (OMC) and maximum dry densities (MDD). Obtain regression parameters k´1 through k´3 that best describe the following relationship for each material. 2 3 1 1 1 k k oct opt a a a MR k P P P (7.1) where θ= bulk stress, τoct = octahedral shear stress, Pa = atmospheric pressure (101.3 MPa, 14.7 psi) and k í = nonlinear regression parameters. 3 AASHTO T XXX is a generic designation for a proposed specification, “Determining Intelligent Compaction Measurement Value (ICMV) Using Intelligent Compaction (IC) Technology,” which was developed as part of NCHRP Project 24-45 and is included in this appendix.

Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction A-13 7.1.1.2 Option 2—Estimate k1 through k3 related to Equation 7.2 for the OMC and MDD from a catalog of materials tested locally, often in conjunction with the implementation of the mechanistic-empirical design algorithms and convert them to k´1 through k´3 according to the process discussed in Section 7.1.2. 7.1.1.3 Option 3—Estimate regression parameters k1 through k3 related to Equation 7.2 for the optimum moisture content and maximum dry density from relationships established in the literature. The relationships developed from the FHWA Long-Term Pavement Performance (LTPP) program are shown in Appendix I. 7.1.2 Convert the regression parameters k1 through k3 from Equation 7.2 determined in Section 7.1.1.2 or 7.1.1.3 to k´1 through k´3 for Equation 7.1, using the following relationships 2 3 1 1 k k oct opt a a a MR k P P P (7.2) 21.32 1 1 kk k e (7.3) 2 21.88k k (7.4) 3 3k k (7.5) 7.2 Estimate target stiffness, ks-target, of two-layer systems using a forward prediction model by inputting regression parameters k í of top and underlying layers, drum dimensions, and weight, including centrifugal force of selected vibratory setting and top layer thickness. For single-layer systems, use the regression parameters corresponding to subgrade only. 8. MEASUREMENT AND PAYMENT 8.1 The work performed, materials furnished, equipment, labor, tools, and incidentals will not be measured or paid for directly but will be subsidiary to the pertinent items.

A-14 Evaluating Mechanical Properties of Earth Material During Intelligent Compaction Appendix I – Estimating Resilient Modulus Constitutive Model Coefficients (as per FHWA-LTPP) Crushed Stone Base Materials: k1 = 0.7632 + 0.008(P3/8) + 0.0088(LL) – 0.00371(wopt) -0.0001(γopt) (I.1) k2 = 2.2159 – 0.0016 (P3/8) + 0.0008 (LL) – 0.038(wopt) – 0.006(γopt) + 0.00000024(γ2opt / P#40) (I.2) k3 = –1.1720 – 0.0082(LL) – 0.0014(wopt) + 0.0005 (γopt) (III.3) Embankments, Soil – Aggregate Mixture, Coarse-Grained: k1 = – 0.5856 + 0.0130(P3/8) – 0.0174(P#4) + 0.0027(P#200) + 0.0149(PI) + 0.0000016(γopt) – 0.0426(ws) + 1.6456[γs / γopt] + 0.3932[ws / wopt] – 0.00000082[γ2opt / P#40] (I.4) k2 = 0.7833 – 0.0060 (P#200) – 0.0081(PI) + 0.0001(γopt) – 0.1483[ws / wopt] + 0.000000027[γ2opt/ P#40] (I.5) k3 = – 0.1906 – 0.0026(P#200) + 0.00000081[γ2opt / P#40] (I.6) Embankments, Soil – Aggregate, Fine-Grained: k1 = – 0.7668 + 0.0051(P#4) + 0.0128 (P#200) + 0.0030(LL) – 0.051(wopt) + 1.179[γs / γopt] (I.7) k2 = 0.4951 – 0.0141(P#4) – 0.0061(P#200) + 1.3941[γs / γopt] (I.8) k3 = 0.9303 + 0.293(P3/8) + 0.0036(LL) – 3.8903[ γs / γopt] (I.9) Fine-Grained Clay Soil: k1 = 1.3577 + 0.0106(Clay) – 0.0437(ws) (I.10) k2 = 0.5193 – 0.0073(P#4) + 0.0095(P#40) – 0.0027(P#200) – 0.0030(LL) – 0.0049(wopt) (I.11) k3 = 1.4258 – 0.0288(P#4) + 0.0303(P#40) – 0.0521(P#200) + 0.025(Silt) + 0.0535(LL) – 0.0672(wopt) – 0.0026(γopt) + 0.0025(γs) – 0.6055 [ws / wopt] (I.12) where: LL = Liquid limit PI = Plasticity index of soil ws = Water content of the test specimen (%) γs = Dry density of the test specimen wopt = Optimum water content (%) γopt = Maximum dry unit weight of soil P3/8 = Percentage passing sieve #3/8 sieve P#4= Percentage passing #4 sieve P#40= Percentage passing #40 sieve P#200 = Percent passing #200 sieve Clay = Percentage of clay (%) Silt = Percentage of silt (%)

Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction A-15 PROPOSED STANDARD TEST METHOD FOR DETERMINING INTELLIGENT COMPACTION MEASUREMENT VALUE (ICMV) USING INTELLIGENT COMPACTION (IC) TECHNOLOGY AASHTO Designation: T XXX 1 1. SCOPE 1.1 This test method describes the procedure for determining the Intelligent Compaction Measurement Value (ICMV) using Intelligent Compaction technology on compacted geomaterials used in embankments, subgrade and base layers. The test method is used for quality control testing of compacted geomaterials during construction. 1.2 The values given in Customary Units are to be regarded as the standard; however, some units are provided in SI. The values given in parentheses are not standard and may not be exact mathematical conversions. Use each system of units separately. Combining values from the two systems may result in nonconformance with the standard. 2. DEFINITIONS 2.1 Intelligent Compaction (IC)—A system that provides continuous assessment of compaction through roller vibration monitoring and integrates a global positioning system. 2.2 Intelligent Compaction Measurement Value (ICMV)—A generic term that refers to a set of IC data for measurements of resistance of deformation of underlying material and to assess uniformity based on the responses of the roller drum vibration measurements in units specific to the roller manufacturer. 2.3 Vibration Frequency—The rotational speed of the roller drum’s lifting off and compaction on pavement surface. 2.4 Vibration Amplitude—The height of a roller drum’s lift from the pavement surface during vibratory compaction. 2.5 Roller Pass—The area covered by the width of the roller in a single direction. Roller pass number is the count of roller machine passes within a given mesh for a construction lift. 2.6 Proof Mapping—The process of using an IC roller to map the entire section upon completion of compaction for assessing the uniformity and consistency of compaction. 3. EQUIPMENT 3.1 Intelligent Compaction (IC) Roller Compactor—A vibratory roller equipped with a data acquisition (DAQ) system that processes compaction data in real time for the roller operator. The DAQ can be either a factory-installed/Original Equipment Manufacturer (OEM) system or a retrofit system. The IC roller shall be in accordance with the rollers shown on the Department’s Approved Product List, “Intelligent Compaction Rollers,” and shall comply with the following requirements: 3.1.1 IC rollers shall be equipped with accelerometers mounted in or on the side of the drum to measure the interactions between the roller and compacted materials to evaluate the applied compaction effort. 1 AASHTO T XXX is a generic designation for this proposed test method.

A-16 Evaluating Mechanical Properties of Earth Material During Intelligent Compaction 3.1.2 IC rollers shall be equipped with GPS radio and receiver units mounted on each roller to monitor the drum locations and track the number of passes of the roller. The mounted GPS units connect with hand-held survey-grade GPS rover(s) and with a local/virtual base station to transmit and record GPS data. Whether from the IC rollers or hand-held GPS rovers, the recorded GPS data shall be in the following formats: Date: The date stamp shall be in yyyymmdd format. required to differentiate sequence of IC data points during post-processing. Latitude and longitude: shall be in decimal degrees, dd.dddddddd. Longitudes are negative values when measuring westward from the Prime Meridian. Elevation: shall be in ft. Essential GPS data elements for each data point are shown in Table 1. Table 1. GPS data elements for each data point. Item No. Data Field Name Example of Data 1 Date Stamp (yyyymmdd) 20150205 2 Time Stamp (hh:mm:ss.xx) 16:49:31.18 3 Longitude (decimal degrees) -101.87905175 4 Latitude (decimal degrees) 35.11711655 5 Elevation (ft.) 737.092 3.1.3 On-Board Computer Display—The display unit will show the location of the roller, number of passes, amplitude, and frequency for vibratory rollers, and provide real-time, color-coded maps of the ICMVs. The display unit shall be capable of transferring the data by means of a USB port or by automatic wireless uploading to a cloud computer storage system. The on-board computer should have the capability to measure, record, and export compaction parameters in Comma Delimited Separated Values (*.csv) format data files. 4. PROCEDURE 4.1 Close off the entire testing area from any vehicular or construction equipment for the entire testing period. Clear out any other safety concerns that would impact the testing procedure and safety of the testers prior to testing. 4.2 Calibrate the GPS System on the IC roller. Perform the GPS calibration process prior to any IC data collection. Verify that the hand-held survey-grade GPS rover(s) and IC roller are connected with the local/virtual base station. 4.3 Move the IC roller slowly to a designated position to allow the GPS header computation to be stabilized to obtain accurate GPS location. Once the roller stops, record the last reading, which is associated with the center of the drum. Record the coordinates of both sides of the drum (Figure 1) using the hand-held survey-grade GPS rover that was previously synchronized with the base station. The coordinates of the drum center shall be interpolated from the coordinates of the two sides of the drum. Compare the coordinates reported by the IC roller with the interpolated coordinates from the GPS rover. Adjust the IC roller coordinates to match the interpolated numbers. The tolerance of the differences is 12 in. (300 mm) in the northing and easting directions. 4.4 Identify the layer IDs using project-typical sections. The operator must input (or select) the header information using the on-board display prior to compacting the given material and enter a file name to store the IC data. Time: The time stamp shall be in hh:mm:ss.xx format, with a precision of 0.01 seconds

Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction A-17 Figure 1. GPS calibration process. 4.4.1 IC Data File Name—The operator should name the data file using the following convention: data (yyymmdd); material (see Table 2); traffic direction (NB, SB, WB, EB); lane type (ML, FR, RAMP); Stations (to nearest foot, xxxx+xx to xxxx+xx); PM (proof mapping); and smooth drum (SD) or padfoot roller (PF). Example: 20160517-SG-NBML-194015TO196045-PM-SD 4.4.2 Required Fields in Header—Each file should contain information about site, material and roller type (see Table 3 for sample header information): Design Name, Project ID or Section Title that identifies site. Additional information such as Location Description, Starting Station, Operator, may be added. Material Type (see Table 2). Roller Model—If provided, additional roller characteristics (roller type and weight and drum dimensions) may be excluded. Roller Type—May be excluded if Roller Model provided. Roller Drum Width (in.)—May be excluded if Roller Model provided. Roller Drum Diameter (in.)—May be excluded if Roller Model provided. Roller Weight (lbs.)—May be excluded if Roller Model provided. GPS Mode. GPS Tolerance. Name Index of ICMV Type. ICMV Type Unit Index (1: CCV; 2: CMV; 3: Evib; 4: HMV; 5: Kb; 6: MDP; 7: Other), when ICMV Type name not included. 4.5 Collect the IC data when the compaction of the entire layer is completed. Start each pass at least 25 ft. (7.5 m) to 50 ft. (15 m) from test section to allow the IC roller to reach the desired frequency and speed. For this purpose, make each pass continuously, regardless of length, by operating the IC roller according to manufacturer’s recommendations to provide reliable and repeatable measurements during proof mapping, on each lift, using consistent operating settings for the following: Low Amplitude and Low Frequency (when in vibration mode) Speed = 3 mph (5 km/h) Roller GPS Drum Center Line Independent Rover

A-18 Evaluating Mechanical Properties of Earth Material During Intelligent Compaction Table 2. Material type designation acronyms. Item No. Material Type Acronym 1 Untreated Subgrade Soil SG 2 Lime Treated Subgrade LTS 3 Cement Treated Subgrade CTS 4 Untreated Flexible Base FB 5 Lime Treated Flexible Base LTB 6 Cement Treated Flexible Base CTB 7 Asphalt Treated Base ATB 8 Embankment EMB 9 Other material not listed above Specify Table 3. IC data information. Item No. Data Field Name Example of Data 1 Design Name 20150205-LTS-NBML-1715+15 to 1745+45-PM 2 Material Type LTS 3 Roller Model HAMM3412 4 GPS Mode RTK Fixed 5 GPS Tolerance (in.) Medium (2.0 in.) 6 ICMV type CMV 7 ICMV index 3 The output from the roller is designated as the Intelligent Compaction Measurement Value (ICMV), which represents the stiffness of the materials based on the rolling resistance or vibration of the roller drums and the resulting response from the underlying materials. IC data files must include at least the following information: Roller Pass Number Roller Travel Direction (forward or reverse) Roller Travel Speed Vibration Setting (on or off) Vibration Frequency (Hz) Vibration Amplitude (mm) Intelligent Compaction Measurement Values (ICMVs) Sample information is available in Table 4. Table 4. IC data elements for each data point. Item No. Data Field Name Example of Data 1 Roller Pass Number 1 2 Direction Forward, Reverse or index 3 Roller Speed (mph) 3 4 Vibration On Yes, No, On, Off or index 5 Vibration Frequency (Hz) 28.4 6 Vibration Amplitude (mm) 1.95 7 Intelligent Compaction Measurement Value (ICMV) 30.5

Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction A-19 4.6 Deliver the electronic IC data files and a hard copy of the color-coded map to the Engineer. The IC data will be color-coded using green, yellow, and red colors as shown in Table 5 and Figure 2. Table 5. Color-coded map requirements. Color Criteria * Red Area less than 75% of Average ICMV Data Yellow Area in the range of Average to 75% of Average ICMV Data Green Area greater than 75% of Average ICMV Data * The criteria listed in this table are for producing color-coded maps using Veta software only. The color sequence is listed from lowest to highest stiffness. Submit compaction information and data elements using Veta. Operator may combine roller data for multiple rollers operating in echelon into a section file. Figure 2. Criteria for color-coded map of ICMV data. 4.7 Provide displayed results to the Engineer for review upon request. 5. PROCEDURE 5.1 Close off the entire testing area from any vehicular or construction equipment for the entire testing period. Clear out any other safety concerns that would impact the testing completion of daily IC operations (see Figures 3 and 4). The descriptive statistics of the collected ICMVs, as well as the vibration amplitude and frequency, shall be controlled for any discontinuity or irregular trend in the data. Plots must be scaled to be legible. ICMV75%0 Average GreenYellowRed Value for 75% is for % of calculated average IC Data Quality Control Report. Report the collected IC data in the desired format upon

A-20 Evaluating Mechanical Properties of Earth Material During Intelligent Compaction Inspector Name: Date: Project Location: Coordinate System: County: Roller Type: Material Type: Roller Model: Layer Type: Intelligent Compaction Data Report Worksheet Figure 3. IC data report worksheet (page 1). Color-Coded Map of ICMV Color-Coded Map of COV of ICMV Color-Coded Map of Vibration Frequency Color-Coded Map of Vibration Amplitude Color-Coded Map of Drum Forces, Fd Color-Coded Map of Stiffness, ks

Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction A-21 Inspector Name: Date: Project Location: Coordinate System: County: Roller Type: Material Type: Roller Model: Layer Type: Intelligent Compaction Data Report Worksheet Figure 4. IC data report worksheet (page 2). Descriptive Statistics of ICMV

A-22 Evaluating Mechanical Properties of Earth Material During Intelligent Compaction PROPOSED STANDARD TEST METHOD FOR ESTIMATING MODULUS OF EMBANKMENT AND UNBOUND AGGREGATE LAYERS WITH PORTABLE FALLING WEIGHT DEVICES AASHTO Designation: T YYY 1 1. SCOPE 1.1 This test method describes the procedure for measuring the deflection with a Light Weight Deflectometer (LWD) and for determining the in-place modulus of compacted geomaterials used in embankments, subgrades, and base layers (without stabilizing agents), and establishing the target modulus for comparison with the measured values. 1.2 The LWD test relates surface deflection with the modulus and is defined as the maximum axial stress of a material divided by the maximum axial strain during that loading. 1.3 The measurements are made with a device that conforms to ASTM E 2835 or E 2583. 1.4 The values given in Customary Units are to be regarded as the standard; however, some units are provided in the International System of Units (SI). The values given in parentheses are not standard and may not be exact mathematical conversions. Use each system of units separately. Combining values from the two systems may result in nonconformance with the standard. 2. REFERENCED DOCUMENTS 2.1 ASTM Standards: E 2835, Standard Test Method for Measuring Deflections using a Portable Impulse Plate Load Test Device E 2583, Standard Test Method for Measuring Deflections with Light Weight Deflectometer (LWD) 3. DEFINITIONS 3.1 Deflection—The amount of downward vertical movement due to the application of an external load to the material surface. 3.2 LWD Effective Modulus—A composite surface modulus obtained based on a Boussinesq elastic solution obtained from the peak surface deflection response of a layered system of geomaterials to an impact loading. 3.3 LWD Adjusted Modulus—The adjusted composite surface modulus after accounting for difference in the lab and field moduli at the same moisture conditions and density. 4. EQUIPMENT 4.1 LWD—The LWD shall conform to either ASTM E 2835 or ASTM E 2583 (see Figure 1). The LWD apparatus include the following features: 4.1.1 A loading device that consists of a falling weight with a guide system, lock pin, and spring assembly. The fixed drop height shall be in accordance with the manufacturer’s recommendation. The load is a force pulse, typically 1,000 lb. to 2,000 lb. (4.5 kN to 9 kN), generated by a falling mass dropped onto a spring or buffer assembly that transmits the load pulse to a plate resting on the material under test. 1 AASHTO T YYY is a generic designation for this proposed test method.

Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction A-23 Figure 1. Components of light weight deflectometer (LWD) that comply with (a) ASTM E 2835 and (b) ASTM E 2583. 4.1.2 A handle grip, located at the top of the device, that is used to hold the LWD guide rod plumb and to limit the upward movement of the falling weight. 4.1.3 A top fix and release mechanism that holds the falling weight at a constant height. 4.1.4 A guide rod that allows the falling mass to drop freely. 4.1.5 A lock pin that has two positions—locked and unlocked—to release the falling weight for use. 4.1.6 A buffer system (damping system) that provides a controlled transient pulse length to the impact force, typically in the range of 16 ms to 30 ms, and which can be composed of a spring or a set of steel bearing plates that transmits the load pulse to the plate resting on the material to be tested. The spring element is typically a series of rubber cones/buffers or a cylindrical pad system. 4.1.7 A loading plate, consisting of a bearing plate whose diameter typically varies from 8 in. to 12 in. (200 mm to 300 mm) and which provides an approximate uniform distribution of the impulse load to the surface. 4.1.8 A load cell that measures the applied load of each impact (available only on devices that conform to ASTM E 2583). 4.1.9 A deflection sensor that measures maximum vertical movement with an accelerometer or geophone. The location of the deflection sensor may vary depending on the manufacturer’s design. 4.2 Miscellaneous Equipment—A spade, broom, trowel, and cotton gloves for operation of the LWD. 1. Handle Grip 2. Top fix and release mechanism 3. Guide rod 4. Round grip 5. Falling mass 6. Lock pin 7. Set of steel springs 8. Buffers 9. Anti-tipping fixture 10. Geophone seating lever 11. Load cell 12. Load canter ball 13. Carry grip 14. Loading plate 15. Socket for connection to readout unit 16. Adapter plate 17. Geophone (spring loaded) 18. Communication port (1) (2) (3) (4) (5) (8) (10) (15) (14) (17) (18) (11) (a) (b) (1) (2) (3) (4) (5) (6) (7) (9)(12) (13) (13) (14) (16) (15)

A-24 Evaluating Mechanical Properties of Earth Material During Intelligent Compaction 5. PROCEDURE 5.1 Close off the entire testing area from any vehicular or construction equipment for the entire testing period. Clear out any other safety concerns that would impact the testing procedure and safety of the testers prior to testing. 5.2 For surface preparation, the test area shall be leveled so that the entire undersurface of the load plate is in contact with the material being tested. Loose particles on the surface and protruding material shall be removed. If required, any unevenness shall be filled with fine sand. The test shall not be conducted if the temperature is below freezing. The test area shall be at least 1.5 times larger than the loading plate. 5.3 Select the 8 in. (200 mm) or 12 in. (300 mm) diameter loading plate. Position the loading plate on a properly prepared test site. Set the loading plate parallel to the testing surface on a thin (not to exceed ¼-in. thickness) layer of uniform fine sand using the least quantity for uniform loading. Twisting or working the loading plate back and forth is permitted to help provide uniform seating of the plate. 5.4 After surface preparation and after the loading plate is positioned on the surface, center the loading device on the top of the loading plate and connect the data processing and storage system to the deflection sensor using the cable provided. (The specific components of the loading device will vary depending on the LWD manufacturer and model.) Turn on the readout unit system to be ready for testing. 5.5 Use the following procedure for each drop: 5.5.1 Raise the falling mass to the preset drop height and snap into the release mechanism. 5.5.2 Adjust the guide rod to vertical by either observing the level or visually estimate by others in two perpendicular directions to the rod and itself. 5.5.3 Drop the falling mass by releasing the lock pin. 5.5.4 Catch the falling mass after rebound from striking the plate as recommended by the manufacturer. A test is considered invalid if the operator does not catch the falling weight after the weight rebounds from the load plate or the load plate moves laterally. When the test is invalid, a new test area is required to be performed at least 2 ft. away from the original area of testing. 5.5.5 Raise and snap the load mass into the release mechanism after each rebound. 5.6 Conduct three seating drops by repeating steps 5.5.1 to 5.5.5. 5.7 Following the three seating drops, conduct three drops of the falling mass by repeating steps 5.5.1 to 5.5.5 for analysis and record the deflection and applied load (if applicable) for each drop. 5.8 Record supporting information such as location, material type, and other identification information as needed. 5.9 Measure the in situ moisture content of the material as per AASHTO T 310, “Standard Method of Test for In-Place Density and Moisture Content of Soil and Soil-Aggregate by Nuclear Methods,” or using another method specified by the Engineer right after the modulus/deflection-based measurements are made. 5.10 Follow the process described in steps 6.1 to 6.4 to calculate the LWD effective modulus if desired.

Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction A-25 6. ADJUSTMENT OF MEASUREMENTS 2 6.1 Alternatively, the measured LWD deflection, deff, can be converted to adjusted deflection, dadj, from: dadj = deff / Kadj (6.1) where Kadj is calculated as discussed in Section 6.2. 6.2 To establish the LWD adjustment factor, Kadj, obtain Kadj from: Kadj = Klab-field Kmoist (6.2) where Klab-field is an adjustment factor that accounts for differences in lab and field moduli at the same moisture content and density, and Kmoist is an adjustment factor for differences in the compaction and testing moisture contents. 6.3 Estimate Klab-field from the following relationship: Klab-field = (Fenv)λ (6.3) where λ = -0.36 and Fenv is calculated from: where Sopt = degree of saturation at optimum moisture content and S = degree of saturation at compaction moisture content.3 6.4 Estimate Kmoist in the following manner: where η = 0.18 for fine-grained soils and 1.19 for unbound aggregates, ωT = moisture content at time of testing (in percent), and ωC = moisture content at time of compaction (in percent). 7. CALCULATION OF LWD EFFECTIVE MODULUS 7.1 Calculate the average of the three deflection measurements obtained in step 5.7. Report the average deflection in inches (or mm). 7.2 Estimate the peak load, F, as per ASTM E 2835 or ASTM E 2583, based on the LWD model used, following the below equation: 0.68184 1.33194 100 1.20693log 0.40535 1 opt env S S F e (6.4) C T moistK e (6.5) mghCF 2 (7.1) where h = drop height, m = falling mass, g = gravitational force, and C = buffer constant provided by the manufacturer. 2 Please see NCHRP Research Results Digest 391: Modulus-Based Construction Specification for Compaction of Earthwork and Unbound Aggregate for the rationale of this approach. 3 The relationship λ= -0.36 is essentially the relationship proposed by Cary and Zapata (2010) simplified by replacing wPI with zero. See NCHRP Research Results Digest 391 for further discussion.

A-26 Evaluating Mechanical Properties of Earth Material During Intelligent Compaction 7.3 Estimate the Poisson’s ratio, ν, of the geomaterial using recommended values shown in Table 1. Table 1. Typical Poisson’s Ratio values for unbound granular and subgrade materials. Material Description Poisson’s RatioRange Typical Clay (Saturated) 0.4 – 0.5 0.45 Clay (Unsaturated) 0.1 – 0.3 0.20 Sandy Clay 0.2 – 0.3 0.25 Silt 0.3 – 0.35 0.32 Dense Sand 0.2 – 0.4 0.30 Coarse-grained Sand 0.15 0.15 Fine-grained Sand 0.25 0.25 Bedrock 0.1 – 0.4 0.25 7.4 Estimate the shape factor, f, based on the soil type and plate rigidity. See Table 2 for recommended values. Table 2. Recommended shape factors (f) for LWD effective modulus estimation. Soil Type Plate Type Shape Factor, f Clay (elastic material) Rigid π/2 Cohesionless Sand Rigid 8/3 Material with Intermediate Characteristics Rigid π/2 to 2 Clay (elastic material) Flexible 2 Cohesionless Sand Flexible 8/3 7.5 Calculate the effective modulus of the geomaterials, Eeff, from: 1 eff eff F E f a d (7.2) where F = LWD peak load, a = radius of load plate, deff = peak deflection on top of the compacted layer, ν = Poisson’s ratio of the geomaterials, and f = plate rigidity factor. 7.6 Follow the process described in steps 5.1 to 5.5 to adjust the LWD effective deflection to account for the differences between laboratory and field conditions as well as the differences in the moisture content of geomaterials at the time of compaction and time of quality management testing. 8. REPORT 8.1 Prepare a one-page report that consists of the following information. Date and time of test Any unusual observations made during the test 2ν

Proposed Standard Specifications and Test Methods to Estimate Mechanical Properties of Geomaterials Using Intelligent Compaction A-27 Layer(s) tested and base layer thickness (if applicable) Lift type and thickness (if applicable) Nearest station Load applied Deflection readings for each drop Average measured deflection Adjusted deflection Moisture content of soil at the time of testing Estimated effective LWD modulus Adjusted effective LWD modulus

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Satisfactory pavement performance can only be assured with appropriate process controls to ensure compacted materials meet proper density and stiffness requirements.

The TRB National Cooperative Highway Research Program's NCHRP Research Report 933: Evaluating Mechanical Properties of Earth Material During Intelligent Compaction details the development of procedures to estimate the mechanical properties of geomaterials using intelligent compaction (IC) technology in a robust manner so that departments of transportation can incorporate it in their specifications.

Appendix A, containing the proposed specifications and test methods, is included in the report. Appendices B through H appear in a supplementary file.

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