Geotechnical characteristics of polypropylene macro fibre reinforced black cotton soil treated with potassium hydroxide

Abstract

Synthetic fibres are increasingly being used as reinforcement to help stabilise expanding soils. This work is an attempt to stabilise the black cotton soil with the reinforcement of polypropylene macro fibre in which potassium hydroxide (KOH) is utilised as an alkali activator as a contribution to this field. The KOH concentrations of 3%, 4%, and 5% with 10M were assumed, and the tests were carried out. It is also reinforced with varying percentages of polypropylene macro fibre (PP macro fibre), such as 0.3, 0.6, 0.9, 1.2, 1.5, and 1.8. California Bearing Ratio (CBR), Unconfined Compression Strength (UCS), and swell pressure experiments are carried out in the laboratory. Overall, it concluded that the addition of KOH to the soil decreased the swelling percentage of the soil by changing its mineral structure because of the presence of K ions. There was also a decrease in the shrinkage of the soil. The optimum moisture content is decreased, and the maximum dry density is increased. By reinforcing the soil with the PP macro fibre, it increased the strength of the soil.