Incorporating incineration bottom ash in environmentally friendly ultra-high performance concrete: Impact on mechanical properties, durability, and environmental benefits

To reduce carbon emissions during concrete production and enhance resource utilisation of incineration bottom ash (IBA), the incorporation of IBA as fine aggregate substitute for quartz sand in the preparation of environmentally friendly ultra-high performance concrete (EFUHPC) was evaluated. This study systematically examined the effects of varying IBA replacement ratios (0 %, 5 %, 10 %, 15 %, and 20 %) on the workability, mechanical properties, durability, microstructure, and toxicity of EFUHPC. It was observed that 1) the flexural strength, compressive strength, elastic modulus, and ultrasonic pulse velocity of EFUHPC were reduced by 3.11–17.47 % 3.72–12.89 % 3.75–12.96 % and 2.59–9.07 %, due to IBA incorporation, respectively. 2) the drying shrinkage and chloride migration coefficient of EFUHPC increased by 4.93–13.01 % and 10.65–24.36 %, due to IBA incorporation. 3) the porosity, cumulative pore volume and the threshold pore diameter of EFUHPC increased, due to IBA doping. 4) the EFUHPC can effectively solidify heavy metal ions in IBA. 5) using IBA to prepare EFUHPC can reduce its energy consumption, carbon emission and cost. The results of this research provide an effective direction to elucidate the potential of IBA in promoting sustainable development and environmental conservation.