Environmental-friendly mortar produced with treated and untreated coal wastes as cement replacement materials

This study aims to examine the influence of untreated coal waste (UCW) and treated (TCW) as supplementary cementitious materials (SCMs) on environmental, mechanical, durability, microstructural characteristics mortar mixes. UCW preparation procedure consists sequential steps crushing grinding. Afterward, is thermally activated through incinerating at 750 °C be promoted TCW. Experimental work includes mixing mixtures by partially replacing cement with binders (UCW TCW) different incorporation levels 4, 8, 12, 16% weight. Toxicity characteristic leaching (TCLP) test was applied investigate environmental impacts wastes. TCLP results pointed out that heavy metals including manganese, cadmium, lead, chromium could successfully entrap in matrix. The compressive flexural strengths mechanical were determined 3, 7, 28, 90, 180 curing days. Moreover, specimens immersed 3% sulfuric acid (H2SO4) for 60 150 Durability showed H2SO4 attack resistance binary mortars containing 4% performed better than plain mortar. Based scanning electron microscopy (SEM) images, ettringite found main hydration product after 28 days; however, existence calcium silicate hydrate (CSH) hydroxide (Ca(OH)2) matrix 90 days explains more compact microstructure attained using replacement compared control mixtures.Graphic abstract