“Effect of polypropylene fibers inclusion on the mechanical behavior of clayey soil”

Abstract

A comprehensive laboratory testing program is conducted to evaluate the effect of PPF inclusion on strength under uniaxial loading, effects of PPF inclusion on desiccation cracking, and the behavior of PPF-reinforced specimens subject to multiple wetting-drying cycles. Modified proctor, unconfined compression, cracking tests were carried out in this study. The investigation is conducted on clay mixed with polypropylene fibers available in the Egyptian market. The CIF values of unreinforced and fiberreinforced clay specimens are evaluated by the means of cracking tests, while the UCS is investigated by conducting unconfined compression tests. The reinforced specimens are mixed with PPF fibers with fibers content of 0.5% or 1.0% dry weight of clay. The effects of each of the maximum dry density, the moisture content on the unreinforced and fiber-reinforced clay specimens' mechanical behavior are also studied. Three maximum dry densities of samples with 0.0%, 0.5% and 1.0% PPF are (1.95, 1.94, and 1.92) gm/c, respectively; and moisture contents are (10.5%, 11.7%, and 12.8%). The unreinforced and fiber-reinforced clay specimens are uniaxially loaded under a strain rate of 1 mm/min. The stress-strain curves are obtained for each specimen. The compressive strength parameters are obtained for every three identical specimens loaded under the same strain rate. The test results are analyzed to investigate the effects of the different parameters on the mechanical behavior of the unreinforced and the fiber-reinforced clay.