Model tests on wicking geosynthetic composite reinforced bases over weak subgrade

Abstract

Road performance is significantly enhanced by incorporating geosynthetics through their reinforcement and drainage functions. This study introduces a novel geosynthetic that integrates these functions. It is made of biaxial polypropylene geogrids heat-bonded to wicking nonwoven geotextiles (WNWGs). WNWGs are chemically treated to be hydrophilic and thus possess rapid wetting and wicking properties while preserving the large lateral drainage functionality of conventional nonwoven geotextiles. To assess the combined reinforcement and drainage performance of this material, a series of model tests including rainfall simulation and plate loading tests were performed on the WNWG-geogrid composite reinforced bases over weak subgrade using a customized model test apparatus. The results confirmed that the inclusion of wicking geosynthetic composite significantly enhanced drainage, stiffness, and bearing capacity of road bases compared to the conventional nonwoven geotextile-geogrid reinforcement and the unreinforced condition. The modulus improvement factor (MIF) for this wicking composite was 2.74 as compared to 1.46 for the conventional nonwoven geotextile-geogrid reinforcement. The findings from this study demonstrate the promising performance of this new composite and provide a valuable reference for full-scale tests and applications on roads.