Mitigating Pumping in Pavement Shoulder Using Wicking Geotextile: An Experimental Study

Pumping is one of the major factors contributing toward concrete pavement failures, one which reduces the pavement life, affects road safety, and increases maintenance costs. Existing methods such as nonwoven geotextiles used as drainage systems can drain gravitational (free) water under saturated conditions but not the capillary water under an unsaturated conditions. The objective of this study is to explore and identify the feasibility of using a new wicking geotextile for pumping mitigation in pavement shoulder via laboratory tests and field test section monitoring. Laboratory results showed that soil installed with wicking geotextile was noticeably drier than that with a French drain as a drainage system because the wicking geotextile can drain capillary water. Nearly 3 years of field monitoring verified the effectiveness of using wicking geotextile to reduce water content, especially where the pavement was prone to pumping damage. In addition, exposing the edge of the wicking geotextile to the air further noticeably increased its drainage ability.