Cashew nut shell ash as a supplementary additive in lime stabilized expansive soil composites

Abstract

In recent times, agro-industrial wastes have been valorized as supplementary additives in soil treatment and improvement of soft and poor soils. One such agro-industrial waste viz. Cashew Nut Shell Ash (CNSA) was evaluated to comprehend its performance as a supplementary additive to lime in treating expansive soils. The experimental programme investigated the performance of stabilized soil composites (SSC), stabilized using combinations of 3%, 5.5% and 7% lime modified with 0.25%, 0.5%, 1% and 2 % CNSA. The SSC were cast in to cylinders of dimensions 38 mm × 76 mm, air cured in sealed covers for seven days and tested for their uniaxial compressive strength. Comparison of the outcomes with the strengths developed by some other wastes like bagasse ash (BA), egg shell ash (ESA) and press mud (PM) available from literature was also done. It was revealed that CNSA as a supplementary additive to lime was able to boost the early strength of the lime SSC after seven days of curing but only when the lime dosage was 5.5%.