Role of heat-treated laterite on the strengthening of geopolymer designed with laterite as solid precursor

Abstract

This paper aims to develop a low-cost, green construction material for low-income house builders. A series of geopolymer samples were prepared by partially substituting the Cameroonian lateritic soil (LS) with different quantities of heat-treated laterite (20~50 wt. %). The chemical composition of the LS was determined through inductively coupled plasma spectroscopy (ICP). The specimens were subjected to thermogravimetric and differential thermal analyses (TGA/DTA), X-ray diffractometry (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). In addition, the compressive strength of dry and wet specimens was measured with a hydroelectric device. The results show that the geo-polymerization and properties like setting time and mechanical strength of the samples were improved through the combined action of the raw LS and the laterite treated at 500-600°C; the crystallized particles from non-clayed minerals and from aggregates of kaolinite also contribute to strength of the samples; crystalline phases formed a tridimensional skeleton in the microstructure of the geopolymer. The research provides a promising composite that can serve as a low-cost construction material with reduced environmental impact.