Engineering properties of kaolinite clay reinforced with polypropylene fibers

Abstract

Fiber reinforcement of soils is generally used to improve the properties of sandy soils. The number of investigations on potential use of fibers in clay soil is limited. The results of previous investigations show that addition of fibers to soil is an effective and reliable technique for improving strength and stability of soils. The objective of this research is to investigate the effect of fiber reinforcement to the shear strength properties of kaolinite clay. Reinforced kaolinite clay samples were prepared at fiber inclusion ratios of 0.25%, 0.50% and 1.00% by weight. Impact compaction with standard and modified energies was used for direct shear tests. Both impact and kneading compaction technique was used for unconfined compression and splitting tensile tests. Also linear shrinkage tests were conducted. Addition of polypropylene fibers improved internal friction angle, cohesion unconfined compressive strength, CBR value and splitting tensile strength and decreased linear shrinkage. The low weight percentages needed for stabilization makes it an economical alternative improvement technique for clays where immediate soil improvement is targeted.