Strength development and post freeze-thaw behavior of kaolin reinforced with fibers

Abstract

In this study, unconfined compression tests have been performed to investigate the effect of freeze–thaw cycles on strength properties of kaolin reinforced with fibers. Kaolin was mixed with bentonite in percentages of 10, 30, and 50 in terms of the dry mass of soil. Bentonite admixed kaolin specimens were prepared at optimum moisture contents and reinforced with varying fiber contents. The specimens were subjected to 0, 1 and 5 freeze–thaw cycles. It was found that, fiber inclusion to soil improved the mechanical properties of the soil; the peak strength increased by the existence of fibers and the strength loss after the peak strength decreased. It was also seen that the increment of the plasticity index required more fiber content to achieve a similar amount of compressive strength with the specimens that had a lower plasticity index. The unconfined compressive strength of unreinforced specimens decreased with increasing the number of freeze–thaw cycles, whereas reinforced specimens showed better performance and the strength reduction decreased with the optimum amount of reinforcing content. The lowest values of compressive strength are obtained after the 5th cycles of freezing-thawing of the specimens.