Fly ash utilization in lightweight aggregates for sustainable construction

Abstract

This study describes the development of new lightweight angular fly ash aggregate (FAA) and consequent comparison of properties of FAA with traditional aggregate (gravel) and commercially available low-density round shaped aggregates LDA (Pellets). The manufacturing process of these FAA involves blending of fly ash with water at various ratios of water to fly ash and placing the mix in the mould. This is followed by sintering the cubes at high temperature and crushing them to obtain the aggregate of different sizes. The properties of both round and angular lightweight aggregates like crushing value, impact value, bulk density, porosity, specific gravity and water absorption are compared with the properties of the conventional aggregates (gravel). The compressive strength of concrete cubes of mix M20 with different percentage of coarse aggregates replaced by LDA (Pellets) and FAA are also determined. This study concludes that FAA is lightweight and also can be used as a substitute for conventional aggregates for sustainable construction.