The Effect of Bottom Ash Ball-Milling Time on Properties of Controlled Low-Strength Material Using Multi-Component Coal-Based Solid Wastes

As the conventional disposal method for industrial by-products and wastes, landfills can cause environmental pollution huge economic costs. However, some secondary materials be effectively used to develop novel underground filling materials. Controlled low-strength material (CLSM) is a highly flowable, controllable, material. The rational use of coal industry prepare CLSM significant in reducing value-added solid waste. In this work, five different (bottom ash (BA), fly ash, desulfurized gypsum, gasification slag, gangue) cement were as mixtures multi-component waste-based CLSM. microstructure phase composition obtained samples analyzed by scanning electron microscopy X-ray diffraction. addition, particle size/fineness was also measured. changes fresh hardened properties studied using BA after ball milling 20 min (BAI group) 45 (BAII that replaced with four mass ratios (10 wt%, 30 50 70 wt%). results showed satisfied limits requirements American Concrete Institute Committee 229 Improving ratio ball-milling time significantly reduced flowability bleeding CLSM; still high category, lowest BAI70 (i.e., content BAI group wt%) BAII70 BAII decreased 48% 64%, respectively. Furthermore, 3 d compressive strengths increased 93%, respectively, compared without BA, which favorable, whereas 28 strength did not change significantly. Moreover, removability modulus calculated, greater than 1, indicating suitable structural backfilling requires certain strength. This study provides basis large-scale utilization waste construction mine filling.