Effects of Black Cotton Soil and Red Clay SoilLightweight Expanded Clay Aggregates (LECA) on Water Absorption, Sorptivity and Mass Loss of Concrete

This study aims to evaluate the effects of black cotton and red clay lightweight expanded clay aggregates (LECA) on water absorption, sorptivity and mass loss of the concrete when used as self-curing agent in concrete. Concrete cubes of 150x150x150mm dimensions with varying percentages of LECA content by weight of fine aggregates were cast. The cast concrete cubes were used in determining the mass loss, sorptivity and water absorption of concrete. The results showed that the mass loss increases with increase in the percentage LECA content up to 15 % LECA content then it starts decreasing nwith increase in the percentage of LECA content at 15 % LECA content, the mass loss was around 8 % more than that of 0 % LECA content. Water absorption decreases with increase of percentage LECA up to 10 % and then thereafter increases with increase in percentage LECA content at 10 % LECA content, the water absorption of red clay LECA and black cotton LECA were approximately 7 % and 14 % less than that of 0 % LECA content respectively. At concrete age of 28 days, considering the least water absorption of 10 %LECA content, the water absorption of red clay LECA was higher than that of Black cotton clay LECA by approximately 8 %. Results also showed that Sorptivity increases with increase in percentage LECA content where sorptivity of concrete with Red Clay LECA was higher than Black cotton LECA. Concrete with black cotton soil and red clay soil LECA can be used in areas with limited exposure to water due to its high sorptivity. LECA content with respect to fine aggregate should be limited to 15 % in order to achieve maximum mass loss.