Effect of rubber tire on behaviour of subgrade expansive Iraqi soils

Abstract

In this study focuses on improving an expansive soils geotechnical properties treated by tire crumble and decreasing the natural contamination by this waste material. The waste rubber of tire in the form of crumble with size ranging between 0.08 to 2 mm with proportion from 0 to 10% was used in this examination. Routine tests such as compaction, unconfined compressive strength, consolidation and swelling pressure test have been done on untreated and treated soils with crumble tire rubber. According to the test results it was found that, the maximum dry density of treated samples decrease with increased tire crumble content, while a slight reduction in the optimum moisture content was found simultaneously. Also, the results of unconfined compression tests showed that, the crumble tire rubber could not improve the properties despite the fact that that the soil still in the hardened consistency. In like manner results demonstrate that using crumble rubber might be successful procedure in upgrading the soil characteristics against swelling potential of soils by approximately 29.8, 43.4, 49.39, 14.77 times than untreated soil for (1, 3, 5, 10%) tire crumble rubber content. In addition the results show increasing crumble tire rubber content from 1 to 5% gave low displacement values by about (26.01 - 43.9)% than its value in untreated samples. Finally, it has additionally seen that using of crumble tire rubber aides in decreasing the compression index, consolidation coefficient, permeability coefficient and volume change coefficient.