Valorization of Fired Clay Bricks Debris (grog) Using Egg Shell and Coconut Shell in the Synthesis of an Ecological Compressed Earth Blocks: Microstructure and Engineering Properties

The aim of this work is to valorize fired clay brick debris (grog, CH) by using egg and coconut shells in the production of eco-friendly compressed earth bricks for sustainable building materials. Samples were cured at ambient temperature (23 ± 3 °C) and obtained by altering different percentages of (CO) and (CN) at 13%, 26% and 40%, respectively; while another mix design of calcined eggshell and coconut shell were incorporated together into the grog powder. Some comprehensive physico-mechanical properties such as water absorption (WA), bulk density (BD), apparent porosity (AP), moisture content (MC), compressive strength (σ) and elastic modulus (EM) were carried out. Chemical composition, X-ray diffraction (XRD) analysis, Fourier Transformed Infra-red (FT-IR), Energy Dispersive X-ray (EDX) analysis and Scanning Electron Microscopy (SEM) were studied. Results show an increase in compressive strength with increasing percentages of calcined eggshell, from 87CH 13CO, 74CH 26CO, 60CH 40CO as 1.38, 2.70, 3.88 MPa, respectively. For 87CH 13CN, 74CH 26CN, 60CH 40CN coconut shell addition show an increase in the percentages of compressive strength. The bulk density decreases with the increase in percentages of calcined eggshell and coconut shell and the percentage of grog decrease. Linear correlation equtions between mechanical properties and mix proportion were determined. SEM micrograph shows a dense microstructure with an agglomeration on the structure. Results obtained indicates an improvement in the engineering properties due to the addition of eggshell waste and these improved properties are suitable to enhance sustainable eco-friendly building materials.