Use of co-fired blended ash in the development of sustainable construction materials

Abstract

This experimental investigation studied the potential of co-fired blended ash (CFBA), obtained from co-firing sawdust and coal, for the development of bricks and mortar. The identified new raw material CFBA underwent chemical (X-ray fluorescence spectrometry), physical (specific gravity determination, sieve analysis), mineralogical (X-ray diffraction) and morphological (scanning electron microscopy) characterisation. CFBA was used as a partial fine aggregate substitute in the production of bricks and as a supplementary cementitious material in mortar. The developed bricks were tested for compressive strength, water absorption and efflorescence. Bricks developed with 15% sand substitution by CFBA were found to be in accordance with the Indian standard (IS 1077) and were suggested for non-load-bearing walls. In contrast, in the case of mortars (10–30% CFBA content), decreases in compressive strength (25–63%) and flexural strength (3–9%) were observed in comparison with standard mortars. Hence, the study concluded that the use of CFBA as an alternative raw material for the production of bricks was feasible.