Use of carbonation sludge in clay based building materials processing for eco-friendly, lightweight and thermal insulation

Abstract

The present study is concerned with the preparation and characterization of highly porous bricks using the carbonation sludge (CS). The characteristics of raw materials were determined by SEM, TGA, XRF and XRD analyses. The clay bricks with CS (0%, 5%, 10%, 20%, 30% and 40% by weight) were pressed, dried and then fired at 1000 degrees C and 1100 degrees C for 2 h. The features of the fired bricks like loss on ignition, dilatometric behavior, water absorption, apparent porosity, bulk density, compressive strength, thermal conductivity and leach analysis were determined. The addition of CS in brick structure is reduced the bulk density of the fired samples. The use of CS up to 40% has resulted in an increase in porosity values for the samples. It was found that the compressive strengths of the bricks up to 30 wt% CS addition were in accordance with standards for the fired bricks. A decrease from 0.79 W/mK to 0.26 W/mK was observed in terms of thermal conductivity. The mechanical and physical features of the bricks were affected by the increasing of firing temperature. Based on these findings, the CS may be valorisation as pore-forming additive in the brick production. Therefore, the utilization CS waste in industrial scale reduces the solid waste load of sugar factories and enables sustainable, eco-friendly and cleaner clay brick production. (C) 2019 Elsevier Ltd. All rights reserved.