Development of Sustainable and Eco-Friendly Materials from Termite Hill Soil Stabilized with Cement for Low-Cost Housing in Chad

Abstract

This paper explores the effects of cement stabilization (5, 10, 15 and 20 wt%) on the structural and mechanical properties (compressive/flexural strengths and fracture toughness) of abandoned termite mound soil. The crystal structures and crystallinity of the constituents were determined using X-ray diffraction (XRD), while the microstructure was characterized via scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The functional groups were also identified using Fourier transform infra-red spectroscopy (FTIR). The compressive/flexural strengths of the stabilized and un-stabilized termite mound soil were also studied after curing for 7, 14 and 28 days. The fracture toughness mechanism was analyzed with the aid of the R-curve method. Additionally, the underlying deformation and cracking mechanisms are elucidated via in-situ/ex-situ optical and scanning electron microscopy. The stabilized termite mound soil displayed the highest mechanical properties of 13.91 MPa, 10.25 MPa and 3.52 kPa·m1/2 for compressive strength, flexural strength and fracture toughness, respectively. Besides displaying good mechanical properties and being locally available at no cost, renewable and an eco-friendly material, the termite mound soil will contribute to lowering the cost of housing in Sub-Saharan Africa, particularly in Chad.