Quantifying the Influence of Geosynthetics on Pavement Performance (2017)

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A-1 APPENDIX A. REVIEW OF AVAILABLE TEST METHODS FOR DETERMINING PERFORMANCE-RELATED GEOSYNTHETIC PROPERTIES The geosynthetic properties that are related to pavement performance include the physical properties, mechanical properties, and interface properties between the geosynthetic layer and aggregates/soils. Many test methods have been conducted to evaluate the pavement performance-related geosynthetic properties. In general, these test standards and the corresponding geosynthetic properties are summarized below. Test standards for evaluating geogrid properties include: • Tex-621-J, to measure the aperture size, which must be at least 50 percent greater than the maximum aggregate size in the base course gradation (1, 2). • ASTM D1777, to measure the dimensions of the geogrid ribs (3). • ASTM D5818, to determine the resistance to installation damage (4). • ASTM D6637, to measure the rib tensile stiffness (5). • ASTM D7737, to measure the junction strength and junction efficiency (6). • ASTM D7748, to measure the flexural rigidity (7). • ASTM D6706, to determine the geogrid-aggregate/soil shear interfacial properties (8). Test standards for evaluating geotextile properties include: • ASTM D5199, to measure the sheet thickness (9). • ASTM D4751, to measure the apparent opening size, which should be smaller than the 15 percent passing particle size (10, 11). • ASTM D4491, to measure the permeability, which affects the drainage function (12). • ASTM D5493, to measure the permittivity, which influences the filtration function (13). • ASTM D4595, to measure the tensile stiffness (14). • ASTM D6241, to determine the California bearing ratio (CBR) puncture strength (15). • ASTM D6706, to determine the geotextile-aggregate/soil interfacial properties (8). A comprehensive review of available test methods for determining the performance- related geosynthetic properties is provided in Table A-1. The criteria of test method selection include the following: • The test method should have the characteristics of simple operation, less time consumption, and low cost • The test method should be repeatable and reliable • The test method should be applicable to different types of geosynthetic • The determined geosynthetic properties should be directly related to pavement performance • The determined geosynthetic properties should be capable of being input into the finite element program. Based on the selection criteria above, the best tests to measure the tensile sheet stiffness of geosynthetics and to determine the geosynthetic-aggregate/soil interfacial properties are direct tension test and pullout test, respectively. These two properties significantly affect the performance of geosynthetic-reinforced pavements.

Table A-1. Geosynthetic Properties Affecting Pavement Performance and Corresponding Standard Tests Material Type Property Test Standard Features Findings Reported in Literature TimeConsuming Expensive Repeatability Compatibility with Finite Element Model Geogrid Rib Thickness ASTM D1777 No No Yes Yes Thicker rib is preferred (16). Rib Stiffness ASTM D6637 No No Yes Yes Stiffer rib is highly recommended (17). Rib Shape N/A No No Yes No Square or rectangular ribs are better than round one (17). Aperture Shape N/A No No Yes No Triangular aperture can provide more tensile strength than square aperture (18). Aperture Size TEX-621-J No No Yes No Related to base aggregate size and the recommended value range is 25–50 mm (2, 17). Aperture Rigidity ASTM D6637 No No Yes No Higher stiffness is recommended (19). Percent Open Area TEX-621- J No No Yes No One important parameter for mechanical interlock capacity of geogrid (20). Flexural Rigidity ASTM D7748 No No Possible No Influence the load distribution in the geogrid structure (21). Junction Strength ASTM D7737 No No Possible No Require a minimum strength (17).

Junction Efficiency ASTM D7737 No No Possible No 70% is recommended as the minimum value (2). Tensile Strength ASTMD6637 No No Yes No A key property in current design methods (2). Pullout Resistance ASTM D6706 No Yes Yes Yes Related to interface coefficient (22). Wide-Width Strip Tensile Modulus ASTM D4595 No No Yes Yes Directly related to lateral confinement (23). Resistance to Installation Damage ASTM D5818 Yes No Possible No Influence the benefit ratio contributed to the pavement performance (2). Geotextile Thickness ASTM D5199 No No Yes Yes Related to the ability to resist damage and to distribute concentrated stresses (24). Apparent Opening Size ASTM D4751 No No Yes No Apparent opening size smaller than the 15% passing particle size (11). Permeability ASTM D4491 Yes No Yes No Related to drainage function; optimum value is not known (25). Permittivity ASTM D5493 Yes No Possible No Related to filtration function (2). Transmissivity ASTM D6574 Yes No Possible No Related to lateral drainage function (2). Flexural Rigidity ASTM D7748 No No Possible No Higher stiffness is preferred (26).

Pullout Resistance ASTM D6706 No Yes Yes Yes Related to interface coefficient (27). Wide-Width Strip Tensile Modulus ASTM D4595 No No Yes Yes Related to reinforcement function (27). CBR Puncture Strength ASTM D6241 No No Yes No Related to the ability to withstand damage (24). Resistance to Installation Damage ASTM D5818 Yes No Possible No Influence the benefit ratio contributed to the pavement performance (2). A-4

A-5 References 1. TxDOT. (1999). Testing Geogrids. Tex-621-J, Texas Department of Transportation, Austin, Texas. 2. Zornberg, J.G., Prozzi, J.A., Gupta, R., Luo, R., McCartney, J.S., Ferreira, J.Z., and Nogueira, C. (2008). Validating Mechanisms in Geosynthetic Reinforced Pavements. Report No. FHWA/TX-08/0-4829-1, Center for Transportation Research, The University of Texas at Austin, Austin, Texas. 3. ASTM. (2002). Standard Test Method for Thickness of Textile Materials. ASTM D1777- 96, American Society for Testing and Materials (ASTM), West Conshohocken, Pennsylvania. 4. ASTM. (2000). Standard Practice for Obtaining Samples of Geosynthetics from a Test Section for Assessment of Installation Damage. ASTM D5818-95, American Society for Testing and Materials (ASTM), West Conshohocken, Pennsylvania. 5. ASTM. (2010). Standard Test Method for Determining Tensile Properties of Geogrids by the Single or Multi-Rib Tensile Method. ASTM D6637-10, American Society for Testing and Materials (ASTM), West Conshohocken, Pennsylvania. 6. ASTM. (2011). Standard Test Method for Individual Geogrid Junction Strength. ASTM D7737-11, American Society for Testing and Materials (ASTM), West Conshohocken, Pennsylvania. 7. ASTM. (2014). Standard Test Method for Flexural Rigidity of Geogrids, Geotextile and Related Products. ASTM D7748-14, American Society for Testing and Materials (ASTM), West Conshohocken, Pennsylvania. 8. ASTM. (2001). Standard Test Method for Measuring Geosynthetic Pullout Resistance in Soil. ASTM D6706-01, American Society for Testing and Materials (ASTM), West Conshohocken, Pennsylvania. 9. ASTM. (2012). Standard Test Method for Measuring the Nominal Thickness of Geosynthetics. ASTM D5199-12, American Society for Testing and Materials (ASTM), West Conshohocken, Pennsylvania. 10. ASTM. (1999). Standard Test Method for Determining Apparent Opening Size of a Geotextile. ASTM D4751-99, American Society for Testing and Materials (ASTM), West Conshohocken, Pennsylvania. 11. Narejo, D.B. (2003). Opening Size Recommendations for Separation Geotextiles Used in Pavements. Geotextiles and Geomembranes, Vol. 21, No. 4, pp. 257–264. 12. ASTM. (2014). Standard Test Method for Water Permeability of Geotextiles by Permittivity. ASTM D4491-99, American Society for Testing and Materials (ASTM), West Conshohocken, Pennsylvania. 13. ASTM. (2006). Standard Test Method for Permittivity of Geotextiles under Load. ASTM D5493-06, American Society for Testing and Materials (ASTM), West Conshohocken, Pennsylvania. 14. ASTM. (2011). Standard Test Method for Tensile Properties of Geotextiles by the Wide- Width Strip Method. ASTM D4595-11, American Society for Testing and Materials (ASTM), West Conshohocken, Pennsylvania.

A-6 15. ASTM. (2014). Standard Test Method for Static Puncture Strength of Geotextile and Geotextile-Related Products Using a 50-mm Probe. ASTM D6241-14, American Society for Testing and Materials (ASTM), West Conshohocken, Pennsylvania. 16. Webster, S.L. (1991). Geogrid Reinforced Base Course for Flexible Pavements for Light Aircraft: Literature Review and Test Section Design. Interim Report, No. DOT/FAA/RD- 90/28, 40p. 17. Han, J., Zhang, Y., and Parsons, R.L. (2011). Qualifying the Influence of Geosynthetics on Performance of Reinforced Granular Base in Laboratory. Geotechnical Engineering Journal of the SEAGS & AGSSEA, Vol. 42, No. 1, pp. 74–83. 18. Dong, Y.L., Han, J., and Bai, X.H. (2011). Numerical Analysis of Tensile Behavior of Geogrids with Rectangular and Triangular Apertures. Geotextiles and Geomembranes, Vol. 29, pp. 83–91. 19. Ling, H.I., and Liu, Z. (2001). Performance of Geosynthetic-Reinforced Asphalt Pavement. Journal of Geotechnical and Geoenvironmental Engineering, American Society of Civil Engineers, Vol. 127, No. 2, pp. 178–184. 20. Simac, R.M. (1990). Connections for Geogrid Systems. Geotextiles and Geomembranes, Vol. 9, pp. 537–546. 21. Moghaddas-Nejad, F., and Small, J.C. (1996). Effect of Geogrid Reinforcement in Model Track Tests on Pavement. J. Transp. Eng., ASCE, Vol. 122, No. 6, pp. 468–474. 22. Cuelho, E.V., and Perkins, S.W. (2005). Resilient Interface Shear Modulus from Short- Strip, Cyclic, Pullout Tests. Proceedings of the Sessions of the Geo-Frontier Conference, American Society of Civil Engineers, Vol. 166, pp. 2863–2873. 23. Al-Qadi, I.L., Dessouki, S., Tutumluer, E., and Kwon, J. (2011). Geogrid Mechanism in Low-Volume Flexible Pavements: Accelerated Testing of Full Scale Heavily Instrumented Pavement Sections. International Journal of Pavement Engineering, Vol. 12, No. 2, pp. 121–135. 24. Giroud, J.P. (1984). Geotextiles and Geomembranes. Geotextiles and Geomembranes, Vol. 1, pp. 5–40. 25. Loulizi, A., Al-Qadi, I.L., Bhutta, S.A., Flintsch, G.W. (1999). Evaluation of Geosynthetics Used as Separators. Transportation Research Record: Journal of the Transportation Research Board, No. 1687, pp. 104–111. 26. Bhosale, S., and Kambale, B.R. (2008). Laboratory Study for Evaluation of Membrane Effect of Geotextile in Unpaved Road. Proceedings of the 12th International Conference of International Association for Computer Methods and Advances in Geomechanics (IACMAG), Goa, India, pp. 4385–4391. 27. Paulson, J.N. (1987). Geosynthetic Material and Physical Properties Relevant to Soil Reinforcement Applications. Geotextiles and Geomembranes, Vol. 6, pp. 211–223.