An Experimental Investigation on Effect of Adding Natural and Synthetic Fibres on Mechanical and Behavioural Parameters of Soil–Cement Materials

Abstract

Soil–cement is a mixture of Portland cement, soil and water that sticks together due to the hydration of the cement and compression of its components to create a dense, durable compound, which has low permeability and is resistant to erosion. Unfortunately, these mixtures do not perform well under tensile load because soil–cement materials are brittle. In this study, three types of fibres were used to reinforce the materials to compensate for this flaw: jute (a natural fibre), polypropylene, and steel (a synthetic fibre) fibres. These fibres were randomly added to the soil–cement mixture in three percentages (1, 2, and 3%). Tests were then conducted on three different soil–cement gradations each with three fine contents of different mineral types (nine different gradations in total). First, sand equivalent and Atterberg limits were conducted on the soil samples. Then compaction, unconfined compression strength, indirect tensile strength and flexural tests were conducted on the soil–cement samples in two conditions: control (unreinforced) and reinforced soil–cement samples. Results showed an undeniable role of fibres in changing the behaviour of the soil–cement–fibre matrix from brittle to ductile producing post-peak behaviour. The results also show that compressive, tensile and flexural strengths of soil–cement materials improved dramatically by adding steel fibres to the matrix.