Estudo das formulações de tijolo solo – cimento por substituição parcial da cal hidratada ou resíduo do processamento da cal

Abstract

Currently, there is a growing demand for environmentally friendly building materials, and soil-cement bricks are emerging as an alternative for increasingly sustainable buildings, as they can be used to reuse materials and do not require burning in their production, which contributes to the reduction of gases released into the atmosphere. However, it is important to note that the production of cement used as a binder releases CO₂, so the sustainability of soil-cement bricks is associated with the balance between the emissions savings from the absence of burning and the environmental impact of cement manufacturing. This study investigated the technological properties of soil-cement specimens obtained from the partial replacement of lime or lime residues in their formulations (1%, 3%, 5%, 7%, and 10%). The raw material (soil), sourced from the Serra do Gavião quarry in Teresina, Piauí, was analyzed using particle size analysis, Atterberg limit, X-ray fluorescence (XRF), X-ray diffraction (XRD), thermogravimetric analysis (TGA), compaction test, residual analysis, and consistency test. The results suggest that the soil used is suitable for the manufacture of soil-cement bricks and that lime and lime residue act as an effective binder in soil stabilization, contributing to improving the mechanical properties of the final material. Technological, physical, and mechanical tests were performed on the specimens, including pozzolanic activity index, water absorption, simple compressive strength, and durability, to ensure the quality of the material and its suitability for use in civil construction. The results, based on ANOVA statistical analysis, indicated that the partial replacement of 3% lime and 3% lime residue contributed to increased mechanical strength and decreased water absorption. It presented good durability at the 3% percentage of the specimens, both in terms of volume variation and mass loss, making the partial replacement of cement with lime and lime residue at the 3% percentage feasible for the production of soil-cement bricks. Furthermore, they demonstrated environmental advantages such as the reuse of lime residue and the reduced use of cement, which can contribute to the reduction of clinker production.