Investigation of geosynthetic-soil confinement using asphalt pavement analyzer

Abstract

Interaction between geosynthetics (geogrid or geotextile) and aggregates under traffic wheel loading has been considered one of high-priority problems by the Transportation Research Board. The practical use of geosynthetics above the subgrade or in base course has demonstrated their effects on the reduction of rut depths and the prolonging of pavement life. However, no standard test method is available to appropriately evaluate the geosynthetic-soil confinement effect and distinguish the benefits among different types of geosynthetics and soils. This proposed test method is to modify the asphalt pavement analyzer to evaluate geosynthetic-soil confinement. In this test, a geosynthetic sheet is placed within a base course to form a reinforced base course, which is subjected to wheel loading. The measured rut depth with the number of cycles of wheel loading can be used to evaluate the geosynthetic-soil confinement. In this study, two different base course materials and four different geosynthetics were used. The experimental results clearly show that this proposed new test method can distinguish the benefits of rut reduction among different types of geosynthetics and base course materials.