Effect Of Rubber Crumbs Volumetric Content On The Shear Strength Of Gravelly Soil In Direct Shear Apparatus

Effective recycling and reuse of waste tires can play an important role in addressing environmental and health issues with scrap tire landfills. In New Zealand, gravel-rubber mixtures have been considered as seismic-isolation foundation systems for medium-density low-rise buildings. In this context, this paper, unlike previous studies where sand-rubber mixtures were investigated, gravelly soil is mixed with rubber crumbs with various volumetric proportions of 10%, 25%, and 40%. These gravel-rubber mixtures were tested using a medium-size direct shear apparatus under three vertical stress levels: 30 and 60 kPa, and 100 kPa. The effect of rubber crumbs content on the peak shear strength, friction angle, and dilatancy behaviour of gravelly soil is studied. The results indicate a decrease in shear strength and increase in vertical strain corresponding to peak shear stress with increasing rubber content. A significant reduction in dilatancy was also observed with increasing proportion of rubber crumbs in the mixtures.