CONVERSION OF ALUMINO-SILICEOUS REJECTS FROM POWER AND STEEL INDUSTRIES INTO BINARY GEOPOLYMER BRICK: EXPLOITING-GBFS MATERIAL SYNERGY UNDER AMBIENT CONDITIONS FOR SUPPORTING CIRCULAR ECONOMY

Abstract

In recent year, advances in construction material have enabled the utilization of abundant reject material for value added purposes. The mining and metallurgical industries, particularly those with mineral rich rejects, have emerged as alternative sources of material for the construction application. The combination of granulated blast furnace slag (GBFS) from the steel industry and fly ash (FA) has been identified as one of the most suitable materials combinations for producing geopolymer blocks without the need for reinforcement or with the additives. Binary blended FA and GBFS based geopolymer bricks were cast with variable raw precursors and activator ratio using mini brick plant setup and cured at ambient temperature. The decisive parameters based on Indian standards for
which the testing was done are compressive strength, water absorption, efflorescence and density. The compressive strength achieved for the test cubes casted for prism test was in the range of 20 - 30 MPa at ambient temperature. The bricks were found to meet the requirements established by Indian Standard 1077:1992 for producing energy-efficient masonry products. The cost and embodied energy (EE) of the developed geopolymer bricks were estimated. As being a binary blend of FA and GBFS cured at room temperature, the developed bricks could reduce the EE and carbon dioxide emission (CO2) and energy required for heat curing. The comparative analysis for the conventionally available bricks with the geo-brick showed promising results. Utilization of steel and power industry waste is a way to achieve circular economy in the waste.