Evaluation of Interface Shear Strength of Natural Kenaf Geogrid and Recycled Concrete Aggregate for Sustainable Pavement Applications

Abstract

In this research, a natural kenaf geogrid was used to reinforce recycled concrete aggregate (RCA) as a base/subbase material. The interface shear behavior of kenaf geogrid-reinforced RCA was investigated using a large-scale direct shear test (LSDT). The influence of aperture sizes of geogrid, gradations of RCA, and normal stress on the interface friction angle (δ) and adhesion (ca) of kenaf geogrid-reinforced RCA was evaluated. The interface shear strength of kenaf geogrid-reinforced RCA were found to be dependent upon the gradation of RCA and the aperture size of kenaf geogrids (D). The higher D resulted in the higher δ, while exhibited less effect on ca of the large-sized RCA samples. Furthermore, it was found that the higher D resulted in the higher ca of the small-sized RCA samples and indicated less influence on the δ. A practical correlation between the interface shear strength coefficient (α) and D/FD ratio, where FD is RCA particles finer than D, is proposed for the rapid estimation of the interface shear strength between the kenaf geogrid and RCA. The outcome of this research will lead to the promotion of using kenaf geogrids as a natural reinforcement in waste RCA for sustainable pavement base/subbase applications.

Keywords

• ground improvement
• earth reinforcement
• pavement
• kenaf geogrid
• recycled material
• interface shear strength