Effects of coir fibers on tensile and compressive strength of lime treated soft soil

•Tensile strength was more sensitive than compressive strength to lime and coir fiber reinforced soft soil.•The desired tension failure was caused by the tensile stress acting perpendicular to the loaded diameter.•The combination of discrete coir fiber and lime resulted in a good earthen reinforcement material.

The purpose of this study is mainly to investigate the tensile and compression strengths of natural and treated soft soil. The tensile strengths and compression strengths of compacted specimens of natural soil, lime and coir fiber treated soil were obtained using the indirect tensile test and unconfined compressive test. The results revealed that both tensile and compressive strengths increased with the addition of lime, coir fiber and the increasing of the curing time. From the test results, the relationship of the unconfined compressive strength of the soft soil was predicted by the correlation agreed with the indirect tensile strength. It was indicated that lime and fiber reinforced soils took on the strain-hardening ductile failure characteristic. The load causing this failure was the highest obtained during the test, and the outer fractures occurred subsequent to the central fracture.