ABSTRACT Clay soil posses a great threat causes problem on civil engineering structures due to its tendency to swell when it is in contact with water and shrinks when they dry out. Stabilization using chemical admixtures is the oldest and popular method of soil improvement. In this study, an investigation was conducted to explore the possibility of using processed termite mound as a stabilizing admixture to improve clay soils. This investigation involves the determination of the swelling potential of expansive soil in its natural state as well as when mixed with varying proportion of termite dust from (0 to 30%). The processed termite mound in this experimental work is obtained from termite mound (anthill), dried and ground followed by sieving through sieve no.36. Consistency limits, specific gravity, swelling properties were determined for the samples. Addition of processed termite mound decreases liquid limit, plasticity index, plastic limit, shrinkage limit, shrinkage index, specific gravity and activity. Experimental results also showed that the swelling percentage decreased while rate of swell increased with increasing percentage of processed termite mound content. The rates of swelling and swelling percentage of the stabilized specimens were also affected by curing in a positive direction such that the effectiveness of the stabilizer increased with termite mound content. The CBR and UCS values obtained also increases with stabilizer content. Based on results obtained from the study, the use of 25%- 30% termite mound is recommended for the improvement of clay as sub-grade material.
