Mechanical Behaviour of Bentonite-Cement Mixtures Subjected to Change in Moisture Content

Abstract

The expansive soils are subjected to change in volume due to variation in water content which results in problems such as high compressibility, reduced bearing capacity, differential settlement etc. Motivated by the issue, this experimental study aims to evaluate the mechanical behavior of bentonite- cement mixtures subjected to change in moisture content. Compaction, Atterberg limits and unconfined compressive strength tests were conducted to assess the influence of cement content (2, 4, 6, 8 and 10% by dry weight of soil), water content (ωopt−3%, ωopt and ωopt +3%) and curing period on the mechanical behaviour of the bentonite soil. The results revealed that with addition of cement, the maximum dry unit weight of the bentonite increased and optimum water content decreased. A continuous reduction the liquid limit was observed with the inclusion of cement. Whereas, up to 6% incorporation of cement had led to increment in plastic limit of bentonite. The upsurge in the strength of bentonite was observed with addition of cement and prolongation curing period. The rise in strength of bentonite-cement specimens prepared at ωopt +3% were higher than that of specimens prepared at ωopt and ωopt −3% water content.