Abstract:
This research investigated the utilization of rock wool, water treatment sludge and non-metallic printed circuit boards as a partial replacement for conventional fine aggregates in mortar. The sand-cement ratio was 2 and the water-cement ratio was 0.45. Each of the industrial wastes was used as a partial replacement of the fine aggregate at 1, 5, 10 and 20% by weight. The cement mortar samples were cured at 7, 14 and 28 days. The chemical compositions and particle sizes of the wastes were analyzed. The results indicated that the density, compressive and transverse strengths of the mortars decreased with increasing the wastes in the mixtures. The water absorption increased with the addition of the waste content. However, the increasing waste replacements improved thermal conductivity of the cement mortars. The cement mortar with rock wool and water treatment sludge contents could resist fire exposure over 400 ºC. Thus, the suitable utilization of the industrial wastes as a partial replacement for fine aggregate in cement mortar was 10% at 28 days curing. As the mechanical properties of 10% waste substitution were in the standards of concrete roofing tile (TIS 535-2556) and hollow concrete block (TIS 58-2533). Moreover, the heat transfer and energy consumption of building reduced with the waste replacements. Therefore, these supplementary materials could be used in construction materials as environmentally-friendly and economically-feasible alternatives.