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D-1 Proposed AASHTO Standard Method of Test for Evaluating the Raveling Resistance of Asphalt-Treated Recycled Pavement Applications Using a Short-Pin Fixture A P P E N D I X D Standard Method of Test for Evaluating Raveling in Asphalt-Treated Recycled Pavement Applications Using a Short- Pin Fixture AASHTO Designation: TP XXX-XX ASTM Designation: E XXXX-XX 1. SCOPE 1.1. This standard covers the determination of raveling resistance of asphalt-treated cold recycled pavements through the number of blows and raveling torque values with a short-pin raveling test. In this test method, the short-pin shear fixture is driven into a pavement using a dynamic cone penetrometer (DCP) upper assembly (an 8-kg [17.6-lb] hammer) per ASTM D 6951 - 18, and the number of blows required to drive the fixture into the pavement is recorded. The DCP upper assembly is removed and the peak torque observed while rotating a handheld torque wrench connected to the short-pin raveling fixture while the number of blows is recorded. These measurements can be used to make time-critical decisions regarding opening to traffic and surfacing of the recycled pavements. 1.2. This test method is applicable for number of blows and torque measurements conducted on asphalt-treated cold pavement recycling techniques, including cold in-place recycling (CIR), cold central-plant recycling (CCPR), and full-depth reclamation (FDR). The recycled pavements may include emulsified or foamed asphalt with or without active fillers such as cement, lime, and fly ash. 1.3. The values stated in SI units are to be regarded as the standard. The values in parentheses are provided for information purposes only. 1.4. This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety concerns associated with its use. It is the responsibility of the user of this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory regulations prior to use.
D-2 2. REFERENCED DOCUMENTS 2.1. ASTM Standards: - D 6951/D 6951M - 18, Standard Test Method for Use of the Dynamic Cone Penetrometer in Shallow Pavement Applications - C1067 - 12, Standard Practice for Conducting a Ruggedness Evaluation or Screening Program for Test Methods for Construction Materials - C670 - 15, Standard Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials - C802 - 14, Standard Practice for Conducting an Interlaboratory Test Program to Determine the Precision of Test Methods for Construction Materials 3. TERMINOLOGY 3.1. Definitions: - Raveling resistance â resistance of a recycled pavement to raveling stress induced by rotation of a short-pin fixture driven into the pavement and rotated with a torque wrench 4. SUMMARY OF METHOD 4.1. The short-pin field shear fixture is driven into compacted asphalt-treated cold recycled pavement by lifting the sliding hammer of the upper assembly of a DCP to the handle and then dropping it. The total number of blows to drive the fixture into the compacted recycled pavement is counted and recorded. The short-pin fixture, embedded in the compacted recycled pavement, is then twisted using a digital handheld wrench. The peak torque in a clockwise rotation is recorded in ft-lb, or any other unit of measure as appropriate. Three replicate tests are conducted on different locations of the same pavement of interest. 5. SIGNIFICANCE AND USE 5.1. Number of blows counted from dropping the hammer and torque measured using handheld wrench provide information that can be used to assess mixture raveling resistance and make time-critical decisions regarding opening to traffic and surfacing of the recycled pavements. 6. APPARATUS 6.1. Handheld digital torque wrench: a torque wrench at least 305-mm [12-in.] in length with a digital display that can measure torque over a range of 15â300 ft-lbs with accuracy of Â±1.0% to which a 19 -mm [0.75-in.] socket may be attached. 6.2. The short-pin raveling fixture is shown schematically in Fig. 1. It consists of a steel base plate with circular geometry: 127-mm [5.0-in.] diameter), four 10.3-mm [0.406-in.] diameter and 25.4-mm [1.0-in.] long pins, one 12.7-mm [0.50-in.] diameter and 75-mm [2.95-in.] pin in the center of the steel base plate, one 25.4-mm [1.00- in.] diameter upper center shaft with a hexagonal milled end. 6.3. 10-lb plate: a 4.5-kg [10-lb] barbell plate with an external diameter not exceeding 254 mm [10.00 in.] â made of a solid cast iron with machined hole (diameter > 19 mm [0.75 in.]) and a durable finishing. 6.4. Test template for measurement shown in Fig. 2 and illustrated with the other equipment. 6.5. The hammer used in this test method shall conform to the general requirements described in ASTM D 6951/D 6951M - 18. An 8-kg [17.6-lb] DCP hammer (upper assembly) is shown schematically in Fig. 2. This device is typically constructed of stainless steel conforming to ASTM D 6951/D6951M - 18. - Hammer weight measurement of 8.0 kg [17.6 lb]; tolerance is 0.01 kg [0.02 lb]. - Drop of hammer measurement of 575 mm [22.6 in.]; tolerance is 1.0 mm [0.04 in.].
D-3 Fig. 1 Schematics of short-pin raveling fixture. 2. 80 0 0.750 0. 80 0 2. 00 0 0. 75 0 1. 00 0 0.750 0. 80 0 2. 00 0 1. 25 0 3. 25 0 1. 00 0 37.5Â° 0.750 Ã1.000 0.406 0.500 3. 00 0 0.500 0.500Ã5.000 Ã.250 THRU Ã.531 .250 Ã.625 THRU Ã1.125 .050 Ã4.000 37.5Â° 0. 50 0 5. 00 0 1.000 0.406 1.000 Fig 2. Template used for torque measurement. 4 inches Shear or raveling fixture
D-4 Fig. 3 Schematic of upper hammer assembly. 7. HAZARDS 7.1. Injury can occur while operating DCP upper assembly (hammer) due to lifting and dropping the falling weight. Thus, care must be taken to avoid injury. 8. PROCEDURE 8.1. Place the short-pin fixture on the recycled pavement surface. To ensure uniform contact and load distribution of the steel base plate, the test surface should be smooth to the extent possible and free of any loose material. 8.2. The DCP hammer (upper assembly) is then placed on top of the test fixture. The hammer-fixture system should be leveled using a bubble level resting on the base plate prior to testing. 8.3. The DCP hammer is lifted to the standard drop height and then released to deliver the force that drives the fixture into the recycled pavement. During the operation, the hammer weight guide shaft should be held firmly without applying any downward pressure. 8.4. Repeat lifting and releasing the weight until the long pins of the fixture are fully embedded into the recycled pavement and the base plate is resting on the pavement surface. The fixture handle should be plumb with respect to the pavement surface; change the test location if it is not plumb. 8.5. Record the number of blows required to drive the test fixture until the bottom of the steel plate is uniformly in contact with the recycled pavement surface. 8.6. Remove the DCP upper assembly and place two 4.53-kg (10-lb) plates on top of the short-pin fixture and over the 19-mm (0.75-in.) upper shaft to avoid any possible uplift of the fixture. 8.7. Attach a digital handheld torque wrench device to the upper shaft of the fixture using a 19-mm (0.75-in.) socket. 8.8. On the pavement surface, draw a 12-in. line extending from the center of the base plate. Next, draw a 4-in. line perpendicular to the 12-in. line at the end furthest from the base plate. 8.9. Rotate the torque wrench clockwise through the 4-in. [304.8-mm] line at a constant rate over a 4-second period. 8.10. Record the maximum torque observed as expressed in ft-lbs. 8.11. Repeat steps 8.1â8.10 at three replicate locations with a center-to-center spacing of approximately 1 ft and far enough apart from prior measurements that each measurement is not influenced by the disturbed recycled pavement surface. An example of test locations for shear and raveling resistance is shown in Fig. 4. 3 ft 2 ft Raveling 1 Shear 1 Raveling 2 Shear 2 Raveling 3 Shear 3 Fig. 4 Illustration of rapid test locations.
D-5 9. Reporting 9.1. Report the following information: 9.1.1. Test date, test location, lane, weather, recycling process, recycling agent, recycling agent content, active filler, active filler content, lane, offset, test number, number of blows, torque, nuclear density gauge reading. 9.2. Report the individual number of blows as whole numbers and torque measurements to 0.1 ft-lbs. Report the average of three number of blows measurements and three torque measurements to the nearest 0.1 blows or 0.1 ft-lbs, respectively. 10. PRECISION AND BIAS 10.1. A ruggedness evaluation was performed for this test method in accordance with ASTM C1067 - 12, Standard Practice for Conducting a Ruggedness Evaluation or Screening Program for Test Methods for Construction Materials. The tolerances on the long-pin shear fixture in Section 6. Apparatus was determined by the ruggedness study. A partial interlaboratory study was conducted in accordance with ASTM C802, Standard Practice for Conducting an Interlaboratory Test Program to Determine the Precision of Test Methods for Construction Materials. However, only three laboratories participated. This was because the test is new, and commercially available equipment was not available. The ILS was conducted in the field, rather than in a laboratory, as prescribed in ASTM C802 - 14. Thus, preliminary single-operator and multi-laboratory precision that can be found in NCHRP Research Report 960 are reported, which should be replaced with an ILS when commercially available equipment is available. 10.2. Number of Blows Single-Operator PrecisionâThe single-operator coefficient of variation was found to be 8 percent. Therefore, results of two properly conducted tests by the same operator on the same material are not expected to differ from each other by more than 22.5 percentA of their average. Multi-Laboratory PrecisionâThe multi-laboratory coefficient of variation was found to be 14.2 percent. Therefore, results of two properly conducted tests by two different laboratories on specimens of the same material are not expected to differ from each other by more than 39.6 percentA of their average. AThese numbers represent the difference limits in percent (d2s%) as described in Practice C670. Note 1âThese precision statements are based on an interlaboratory study that involved three laboratories, six materials, and three replicate tests per operator, with number of blows ranging from four to 19. 10.3. Torque Value Single-Operator Precisionâ The single-operator coefficient of variation was found to be 11.1 percent. Therefore, results of two properly conducted tests by the same operator on the same material are not expected to differ from each other by more than 31.1 percentA of their average. Multi-Laboratory Precisionâ The multi-laboratory coefficient of variation was found to be 13.8 percent. Therefore, results of two properly conducted tests by two different laboratories on specimens of the same material are not expected to differ from each other by more than 38.7 percentA of their average. AThese numbers represent the difference limits in percent (d2s%) as described in ASTM C670. Note 2â These precision statements are based on an interlaboratory study that involved three laboratories, six materials, and three replicate tests per operator, with torque values ranging from 15.2 ft-lbf to 50.8 ft-lbf. 10.4. BiasâBecause there is no accepted reference material suitable for determining the bias in this test method, no statement on bias is made. 11. KEYWORDS 11.1. Raveling resistance; asphalt-treated recycled pavement, short-pin raveling fixture, number of blows; torque; dynamic cone penetrometer (DCP); cold in-place recycling (CIR); cold central-plant recycling (CCPR); full-depth reclamation (FDR); sliding hammer; driving force; destructive testing; recycled pavement testing; recycled pavement layer raveling resistance.
Abbreviations and acronyms used without definitions in TRB publications: A4A Airlines for America AAAE American Association of Airport Executives AASHO American Association of State Highway Officials AASHTO American Association of State Highway and Transportation Officials ACIâNA Airports Council InternationalâNorth America ACRP Airport Cooperative Research Program ADA Americans with Disabilities Act APTA American Public Transportation Association ASCE American Society of Civil Engineers ASME American Society of Mechanical Engineers ASTM American Society for Testing and Materials ATA American Trucking Associations CTAA Community Transportation Association of America CTBSSP Commercial Truck and Bus Safety Synthesis Program DHS Department of Homeland Security DOE Department of Energy EPA Environmental Protection Agency FAA Federal Aviation Administration FAST Fixing Americaâs Surface Transportation Act (2015) FHWA Federal Highway Administration FMCSA Federal Motor Carrier Safety Administration FRA Federal Railroad Administration FTA Federal Transit Administration HMCRP Hazardous Materials Cooperative Research Program IEEE Institute of Electrical and Electronics Engineers ISTEA Intermodal Surface Transportation Efficiency Act of 1991 ITE Institute of Transportation Engineers MAP-21 Moving Ahead for Progress in the 21st Century Act (2012) NASA National Aeronautics and Space Administration NASAO National Association of State Aviation Officials NCFRP National Cooperative Freight Research Program NCHRP National Cooperative Highway Research Program NHTSA National Highway Traffic Safety Administration NTSB National Transportation Safety Board PHMSA Pipeline and Hazardous Materials Safety Administration RITA Research and Innovative Technology Administration SAE Society of Automotive Engineers SAFETEA-LU Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (2005) TCRP Transit Cooperative Research Program TDC Transit Development Corporation TEA-21 Transportation Equity Act for the 21st Century (1998) TRB Transportation Research Board TSA Transportation Security Administration U.S. DOT United States Department of Transportation
N O N -P R O F IT O R G . U .S . P O S TA G E P A ID C O LU M B IA , M D P E R M IT N O . 88 Transportation Research Board 500 Fifth Street, N W W ashington, D C 20001 AD D RESS SERVIC E REQ U ESTED ISBN 978-0-309-67367-9 9 7 8 0 3 0 9 6 7 3 6 7 9 9 0 0 0 0