Effect of Shredded Rubber on Undrained Shear Strength of Fine-Grained Sands

Abstract

In many urban cities due to the enormous growth in the number of vehicles, scrap rubber disposal has been a critical environmental problem. In recent years, important research efforts have been dedicated to investigating the use of scrap rubbers in civil engineering applications, like recycling or reuse of scrap rubbers is the preferred possibility from a waste management perspective. This study furthers the knowledge of the undrained shear strength in clean and mixed well-sorted sands (different shape properties) with waste sand-sized rubber. For this purpose, shredded rubber content varies from 0 to 25% and initial effective consolidation stress of 100 to 300 kPa. Thirty-six undrained shear tests (CU) were conducted using a triaxial apparatus. On randomly mixing sands with shredded rubber, a dilative and strain-hardening and softening behavior governed, and undrained strength generally decreased. The results indicated that undrained shear strength is augmented with the growth of the effective mean stress. Peak index and Young’s modulus decreased, and flow potential increased with shredded rubber content increment in composite specimens. The undrained shear strength parameters (qpeak and qf) across 200 and 300 kPa effective mean stress were higher in the sand with a large angularity (low rr and rs). Further, a decrease in particle shape scale (rs and rr) ratios caused an increase in peak index and elasticity modulus and reduced occurrence in flow potential.