Damping Characteristics of Silty Sand Reinforced With Carpet Waste Strips

A fiber reinforced soil behaves as a composite material in which fibers of relatively high tensile strength are embedded in a matrix of soil. Shear stresses in the soil mobilize tensile resistance in the fibers, which in turn imparts greater strength to the soil. In this paper a study on the influence of synthetic fibrous materials in improving the dynamic strength characteristics of a fine sandy soil is reported. The study is aimed at converting fibrous carpet waste into a value-added product for soil reinforcement. A series of stress controlled cyclic triaxial tests were carried out on fine sand specimens reinforced with randomly distributed carpet strips. The dynamic deformation properties of the reinforced sand are defined in terms of shear modulus and damping ratio. The effects of parameters such as fiber content and aspect ratio, number of cyclic loading and the level of confining pressure on the aforesaid parameters were investigated. The results clearly indicate the increase of damping ratio of reinforced samples in different confining pressure. The increase is more pronounced in higher fiber contents and aspect ratios.