Development of novel un-fired masonry unit manufactured using silica-rich sandstone mining and cutting waste

Abstract

This paper aims to give a complete characterization of the novel un-fired bricks manufactured from base material comprising dimensional silica-rich sandstone cutting waste in combination with waste from coal-fired thermal plants with a minimum amount of cement and lime as binder. The study has given promising results with bricks able to achieve a compressive strength in the range of 16–20 MPa besides other enhanced parameters such as water absorption, the initial rate of absorption (IRA), and durability with favorable socio-economic impacts and climate benefits. 250 numbers of these industry-sized novel bricks were cast and subjected to an array of tests such as density, dimensional test, drop test, water absorption, IRA, efflorescence, compressive strength, flexural tensile strength, stress-strain characteristics and durability. The test results were substantiated with the micro-structural characterization through Scanning Electron Microscopy (SEM), X-Ray diffraction (XRD) and Fourier transform infrared (FTIR). The novel bricks manufactured in this study are of exceptional quality satisfying all the requirements of Indian Standards. These bricks can mitigate the problems of landfills formed by wastes generated from the dimensional stone cutting industry and are eco-friendly as they require no burning in kilns, reduce carbon emissions and utilize waste materials thereby ensuing the benefit of reducing carbon footprint. The study of the sand free un-fired bricks in this paper is totally original and gives the most effective alternative to energy-intensive conventional masonry units such as burnt clay bricks and fly ash bricks. This work has also been granted a patent of 20 years by the patent office, the government of India on July 26, 2021 with patent no: 372690.