Effects of agricultural by-product on mechanical properties of cemented waste soil

Abstract

Waste soil produced from construction sites currently emerges as a big problem to environment. These soils cannot be reused directly cause of its weakness in strength properties. Hence, this study focuses on improving mechanical properties of waste soil by using cement and corn husk fiber . The environment has also benefited from using corn husk fiber since corn husk is agricultural by-product. In order to evaluate the impact of corn husk fiber and cement on mechanical characteristics of waste soil, a series of laboratory experiments containing tension and compression test is carried out. In addition, scanning electron microscopy (SEM) test is conducted to investigate interaction between fibers and soil-cement matrix. Fiber content from 0 to 1% by dry soil mass and corn husk lengths of 10 and 30 mm are used in this research. The results present that strength properties of cemented soil are enhanced when fiber is added. The most improvements corresponding to compressive strength , splitting tensile strength , and direct tensile strength are 30.6%, 206.1%, and 27.9%, respectively. A strong interaction between fibers and soil-cement matrix observed from SEM results in the improvement of strength properties of cemented soil. Fiber inclusion contributes to the more ductile and durable behavior under loading. Fiber length and fiber content have a remarkable effect on the cemented soil behavior. The increase in fiber length and content leads to the increase in residual stress and the decrease in loss of post-peak stress. • Corn husk is utilized in waste soil reinforcement. • Effect of corn husk fiber on cemented soil is investigated. • The addition of fiber delays failure process of cemented soil. • Fiber inclusion improves failure strength up to 206%. • Presence of fibers at crack contributes to the appearance of residual direct tensile stress.