Interface strength behavior of expanded polystyrene EPS geofoam

Abstract

In the present investigation, the interface strength behavior of expanded polystyrene EPS geofoam with EPS geofoam and with various other construction materials such as jute geotextile, geogrid, and fly ash are presented. A series of large direct shear tests were conducted with shear box of dimensions 305mm length, 305mm width, and 175mm height. The experimental investigations were carried out by using four different densities of EPS geofoam blocks, 015, 020, 022, and 030kNm3 under four different normal stresses 25, 50, 75, and 100kPa. The effects of density of EPS geofoam and the applied normal stresses on the interface strength parameters were investigated. The results of the interface strength are expressed in the form of shear stress versus normal stress and the direct shear failure envelopes were found to be linear. The experimental results indicate that the density of EPS geofoam does not have significant effect on its interface strength behavior. For all densities of EPS geofoam, it was observed that there was no significant variation in interface friction angle values. However, a slight increase in adhesion Ca was observed with the increase in the density of EPS geofoam.