Tyre rubber and expansive soils: two hazards, one solution Available to Purchase

This paper presents the results of an experimental programme using shredded waste tyre rubber to reinforce expansive soils. Soil samples were reinforced with fine and coarse rubber particles at four different contents by weight. The rubber-reinforced soils were then subjected to unconfined compression, split tensile, direct shear and desiccation-induced crack tests. Improvements in cracking intensity and shear strength were found with higher rubber contents. However, rubber contents greater than 10% raised failure concerns during compression and/or tension, attributed to clustering of rubber particles under non-confinement test conditions. Although the coarser rubber slightly outperformed the finer rubber, the effect of larger rubber size was mainly translated to higher ductility, lower stiffness and higher energy adsorption capacity rather than peak strength improvements. The swelling properties previously investigated by the authors were revisited and cross-checked with the strength-related features to arrive at the optimum rubber content. In this case, 10% rubber was found to result in a notable decrease in the swell−shrink (and hence cracking) capacity as well as improving the strength-related properties and thus was deemed as the optimum choice.