Utilization of incinerator residue in concrete

Abstract

Physical and chemical properties of the incinerator residue fractions passing 5 mm sieve were examined, including tests on their use as fine aggregate in a typical concrete mix. In the raw ('unwashed') incinerator residue, a lot of fine materials and fibres were attached to the particle which caused a poor setting of concrete and inconsistent concrete strength for various residue samples. Washing was then employed to remove these light and fine materials. The specific gravity of 'washed' incinerator residue is similar to natural sand, but the absorption value was two and a half times higher than that of natural sand. The chemical composition of the various residue samples was fairly constant with respect to the compounds SiO2, Fe2O3, Al2O3, Na2O, CaO, MgO, ZnO and PbO. Concrete mixes made with 'washed' samples as fine aggregate compared favourably with that made with natural sand in terms of compressive strength at ages greater than 7 days.