Structural and Mechanical Properties of Termite Soil as a Partial Replacement to Cement

Abstract

Materials selection is done regarding to the availability, cost and performance of the candidates. In buildings, cement is the material that is widely used, even though it is releases co2 (estimated about 7% of the worldwide production of co2). There is therefore a need to look for new materials that are more environmental friendly. Prior research on earth-based materials has shown that termite soil may serve as an alternative to cements in the stabilization of building materials. This study presents the results and an experimental study of the mechanical properties of termite soil addition as a partial replacement to cement. We examine the effects of termite soil and Portland cement on the structure and mechanical properties (compressive strength, flexural strength and fracture toughness) of sustainable building materials. The evolution of structure is characterized using X-ray Diffraction (XRD) and Energy Dispersive Spectroscopy (EDX). The mechanical properties are also elucidated after 7 days, 14 days and 28 days. The study shows that the 28 day Compressive strength decreases with increasing of volume percentage of termite soil for volume percentages up to 60%. The 28 day strength was also greater than 3 the requirement of (NIS 87: 2000) for non-bearing load walls (δmin=2.8N/mm²› 2.5 N/mm²). Furthermore, the flexural strength for 20% replacement (at all curing days) was greater than 7 N/mm². The fracture toughness was also observed to decrease with increasing volume percentage of termite soil addition up to 20 volume percent. This resulted in a maximum fracture toughness of 4.24 MPa√m for the materials with 20vol.% of termite soil stabilization. The implications of the results are discussed for the development of sustainable termite-stabilized building materials.