Quarry waste in the production of aerated concrete

Abstract

The focus of this study is to produce load-bearing aerated concrete using quarry waste as filler material. The quarry waste used is in the form of limestone dust. The study consists of three phases, where all these phases have three different goals. In the first phase, several mixes where tested to find the type and the percentage range of aluminium powder sufficient for aeration. The aim set for the second phase was to obtain the optimum mix design by finding the percentage of aluminium powder that resulted in low density and sufficient strength. In this phase, two sands were tested, obtained from Quarry Gott in Birguma and Quarry Vella in Naxxar to check whether the properties vary on changing the filler material. In the third phase, having determined the optimum percentage of aluminium powder, another variable is introduced, partial cement replacement. Three different types of curing methods were employed being air, high temperature combined with humidity (chamber) and oven curing methods. After sufficient curing the cubes were tested to obtain the compressive strength of concrete produced. The aim of this experimentation is to achieve a low density between the range of 1OOO-l200kg/m3 and a sufficient strength higher than 7N/mm2 so that this material could be used in lightweight blockwork. This might be a possible solution to lighten local heavy, non-insulated blocks. Aerated concrete blocks also decrease construction time; increase fire rating, thermal insulation and noise insulation.