Strength Behaviour of Clayey Soil Mixed with Pond Ash, Cement and Randomly Distributed Fibres

Abstract

An experimental program was undertaken to study the effect of inclusion of pond ash and randomly distributed polypropylene fibres on the strength behaviour of cement-stabilized clayey soil. In the present investigation, 19 combinations of fibre-reinforced cement-stabilized clayey soil-pond ash mixes at three different percentages of pond ash (i.e. 10, 20 and 30%) and two different percentages of polypropylene fibres (i.e. 0.5 and 1%) of length 6 and 12 mm with 5% cement content were prepared. The combinations of clayey soil-cement-pond ash-fibres were subjected to a series of standard proctor test, unconfined compressive strength and split tensile strength tests. Based on favourable test results obtained, it can be concluded that partial replacement of cement-stabilized clayey soil by pond ash with the inclusion of polypropylene fibres causes a significant increase in strength, decrease in the stiffness, and rate of loss of post-peak strength. The fibre inclusion changed the brittle behaviour of the composite to ductile. The inclusion of 1% fibres of 6 mm length or 0.5% fibre of 12 mm length has the same impact on the unconfined compressive strength and split tensile strength of the mixtures. The study demonstrates that pond ash can be used successfully as partial replacement of the clayey soil by using reinforcement and cement.