Evaluation of geogrid base reinforcement in flexible pavement using cyclic plate load testing

Abstract

In this paper, the performance of geogrid base reinforcement in flexible pavements was evaluated using cyclic plate load testing. A 40-kN cyclic load was applied through a 305-mm diameter steel plate. The investigated parameters included geometry, location and tensile modulus of geogrids. The stress distribution, permanent vertical strain and developed porewater pressure in the subgrade, as well as, the strain distribution along geogrids were studied. The test results showed that the inclusion of geogrid can significantly improve the performance of a flexible pavement and that the traffic benefit ratio can be increased up to 15.3 at a rut depth of 19.1 mm. Better performance was observed when geogrid layer was placed at the upper one-third of the base aggregate layer. The results also demonstrated that the geogrid helps in redistributing the applied load to a wider area on top of the subgrade layer, thus resulting in less accumulated permanent deformation in the subgrade.

Keywords:

• geogrid
• flexible pavement
• cyclic plate load tests
• traffic benefit ratio
• interlocking

Acknowledgements

This research was funded by the Louisiana Transportation Research Center (LTRC), the Louisiana Department of Transportation and Development, and Tensar International Corporation. The authors would like to express their thanks to Mark Morvant, Zhongjie Zhang, Gavin Gautreau, Benjamin Comeaux and Amar Raghavendra at LTRC for providing valuable help and support in this study.

Notes

1. Email: [email protected]

Additional information

Notes on contributors

Qiming Chen

1