Improving The Engineering Behaviour Of Residual Soil With Fly Ash And Treated Natural Fibres In Alkaline Condition

This study explores the possibility of using sustainable materials in the form of fly ash as a precursor in alkali activation (AA) reactions, as well as coir fibres as discrete reinforcement. For enhancing the longevity of fibres in an alkaline environment and improving the mechanical performance of the soil-fibre composite, an effort was made in this study to physically coat the natural fibre surface with linseed oil and turpentine oil. The effect of surface treatment on coir fibres was initially analysed by field emission scanning electron microscopy and energy dispersive x-ray tests. To evaluate the effects, unconfined compressive strength, indirect tensile strength, and flexural strength tests were performed at 7 and 28 days of curing on AA-treated soil reinforced with treated and untreated coir fibres. The test results demonstrated that treated fibres significantly enhanced the mechanical properties of the AA-treated soil in terms of peak stress and post-peak behaviour.