Application of Triangular Polypropylene Fibres on Soil Subjected to Freeze–Thaw Cycles

Abstract

Freeze–thaw cycle is a weathering process which occurs in regions with cold climate, with temperature range falling below 0 °C in winters and above 25 °C in summers. As a result of frost heaving and thaw weakening, the engineering properties of soil consequently get altered and henceforth the strength of soil reduces. The effects of the changing thermal regimes of the ground are the major contributors to the deterioration of structures including road pavements in the cold regions. Reduction in strength of soil leads to damaged engineering structures and reduced life span. The present study deals with application of polypropylene fibres of triangular cross section to soil subjected to freeze–thaw cycles. To the best knowledge of authors, no literature has been found on reinforcement of soil with triangular fiber. Soil from cold region of India, Jammu and Kashmir, was reinforced with polypropylene fibres of 6 and 12 mm length of triangular cross section (0, 0.5 and 1 %, by weight). A scanning electron microscope analysis was done to study the bond behaviour of triangular fibers with soil. The samples for unconfined compressive strength test were prepared and subjected to 0, 1, 3, 5 and 10 number of 48-h controlled freeze–thaw cycles. The results show a significant increase of UCS of fiber reinforced soil by 8–100 %. It was observed that inclusion of fibers helps in prevention of strength reduction of soil subjected to freeze–thaw cycle.