Effect of waste rubber fibres on the geotechnical properties of clay stabilized with cement

Abstract The voluminous generation of discarded waste rubber tires of about 1.5 million per year has created an aggravating situation across the globe because it exerts the deleterious effect on the human health and ecological systems. This paper focuses on the influence of inclusion of waste rubber tire fibres on some of the geotechnical properties of uncemented/cemented clay. For this investigation, three percentages of cement (0%, 3%, and 6%) and five percentages of rubber fibre (0%, 2.5%, 5%, 7.5%, and 10%) were considered. The tests namely, compaction, unconfined compressive strength, split tensile strength, California bearing ratio, swelling pressure, wet/dry cycles durability along with the scanning electron microscopy were conducted on the clay-cement-rubber fibre mixtures to ascertain the suitability of rubber fibres with cement stabilized clay. The test results revealed that the incorporation of rubber fibre reduces the unconfined compressive strength and split tensile strength of cement-stabilized clay but prosperously improves the rate of loss of post-peak strength and change the brittle failure behavior of cemented clay to ductile. The results of California bearing ratio test showed that the resistance against the penetration of the cement stabilized clay decreases as the content of rubber fibre increases. The swelling pressure of the clay was found to decrease with the increase in cement and rubber fibre content. The encouraging results of wet/dry cycles durability test proves the propriety of other tests on clay-cement-rubber fibre mixtures. Based on the test results, the maximum percentage of rubber fibre content mixed with cement-stabilized clay was found to be 7.5%. The study has shown that clay-cement-rubber fibre mixtures containing 6% cement and upto to 7.5% rubber fibre can be use as fill material, backfill material for retaining wall, sub-base of low volume traffic roads, and side slope of the canal.