Development of Eco-Efficient Self Compacting Cementitious System via Successful Integration of Waste Burnt Brick Powder Modified through Hydrated Lime

Abstract

Burnt Brick is a very abundant resource in Pakistan, with Pakistan being the third largest producer in South Asia. Of all the solid waste generated in country, 18% is burnt bricks. The recycling of waste and industrial byproducts from different industrial sectors leads to environmental and economic benefits. This study is aimed at development of eco-efficient self-compacting cementitious system via successful integration of waste burnt bricks (powder) modified through hydrated lime. Six formulations were prepared and the parameters studied include water demand, super plasticizer demand, initial and final setting time, flow of self-compacting paste system, shrinkage test, water absorption and resistance to acid attack. The Scanning Electron Microscopy analysis show that the particles of burnt bricks powder are irregular with rough porous surface which tend to increase the water demand and leading to more adsorption capacity compared to cement and thus has higher SP demand. The greater T25 cm time and T30 time of BBP sample indicate higher viscosity and thus will offer better segregation resistance. Results has shown lesser shrinkage in formulations than control sample and this is because of the lesser cement content in the paste phase which results in lesser consumption of water during hydration process. The shrinkage has been studied for first 24 hours. Decreased water absorption is due to better packing efficiency caused by smaller average particle size of Burnt Brick powder which reduce undesirable voids and discontinuous porosity. Strength improvement has also been noticed for up to 10% cement replacement.