Freezing and Thawing Resistance of Hemp Fiber Reinforced Clays

Abstract

Clays are natural soils. In geotechnical engineering, clayey soils are problematic because of their volume-change properties when they interact with water. Additionally, they may lose strength when exposed to freezing and thawing. Various soil improvement methods are used to modify the clay soil’s properties. One of these methods is by adding natural fibers. The aim of the study was to investigate the strength and freezing-thawing properties of a high-plasticity clay (CH) with hemp fiber. For this purpose, fiber-reinforced clay samples were prepared by adding hemp fiber at different percentages (0.5%, 1%, and 1.5%) and different lengths (2 mm, and 5 mm) to a CH clay from Erzurum, Turkey, and the consistency, unconfined compressive strength (UCS), and freezing-thawing properties of the samples were investigated. According to the consistency limits test results, liquid limit values increased as the fiber length and the hemp fiber addition ratio increased, and the plastic limits of the specimens varied depending on the hemp fiber addition. The unconfined compressive strength of the samples increased with the increase in the hemp fiber percentage, and improvements occurred in their unconfined compressive strengths after four freezing-thawing cycles compared to unreinforced clay. According to the test results, it is thought that hemp fibers could be an alternative for improving the freezing and thawing resistance of clay soils.