Enhancement of Expansive Soils with the Treatment of Lignosulfonate

Expansive soils possess swelling behavior on the absorption of water, causing heaving on the ground surface. Two artificial highly-plastic soils are tested for the enhancement in engineering properties after treatment with a hydrophobic chemical. The water-proofing nature of the chemical resulted in the reduction of swelling and shrinking behavior. This study involves the evaluation of swell pressure, compressibility, strength on the dry and wet side of optimum moisture content. Shrinkage behavior is evaluated based on linear shrinkage test done at 2% higher than the liquid limit of the soil. The optimum dosage of lignosulfonate is decided based on the swell-shrinkage characteristics with different variation of the chemical. Crack intensity factor obtained from linear shrinkage tests is decreased by 50% after the addition of optimum chemical content. For soil A with a liquid limit of 140.94%, the optimum chemical mix is at 3% of the mass of soil while for soil B with a liquid limit of 105%, it is at 2% chemical.