In this study, municipal solid waste incineration bottom ash (IBA) was reused as fine aggregates to prepare ultra-high performance concrete (UHPC). The effects of IBA on the mechanical properties, workability, hydration, volume stability and microstructure of UHPC were investigated. The experimental results showed that the incorporation of an appropriate amount of IBA could improve the compressive strength of UHPC due to the internal curing effect. While the addition of excessive amount of IBA would reduce the strength significantly. From the microstructure analysis, the hydration of UHPC was promoted by adding IBA, leading to a higher hydration degree and denser microstructure of the paste compared to reference sample. The use of IBA in UHPC could effectively restrict the expansion due to the presence of metallic Al, glass, gypsum in the IBA as the UHPC matrix acted as a barrier in the vicinity of the IBA particles, which prevented the formation and propagation of cracks. Also, the highly impermeable UHPC cement paste, the use of supplementary cementitious materials and the high self-desiccation of UHPC further prevent the expansive chemical reactions from occurring. Thus, it was practicable to apply IBA in UHPC without considering the expansive risks and with easy pre-treatment, and it was demonstrated that the utilization of IBA in UHPC is a feasible solution for recycling IBA.

在这项研究中，将城市固体垃圾焚烧底灰（IBA）用作细骨料，以制备超高性能混凝土（UHPC）。研究了IBA对UHPC力学性能，可加工性，水合性，体积稳定性和微观结构的影响。实验结果表明，由于内部固化作用，加入适量的IBA可以提高UHPC的抗压强度。虽然添加过量的IBA会显着降低强度。从微观结构分析来看，通过添加IBA可以促进UHPC的水合作用，与参考样品相比，糊的水化程度更高，并且组织更致密。在UHPC中使用IBA可以有效地限制膨胀，原因是存在金属Al，玻璃，作为UHPC基质的IBA中的石膏在IBA颗粒附近充当屏障，从而阻止了裂纹的形成和传播。而且，高渗透性的UHPC水泥浆，使用辅助胶结材料和UHPC的高度自干性进一步防止了发生扩展的化学反应。因此，在不考虑膨胀风险且易于预处理的情况下，将IBA应用于UHPC是可行的，并且证明了在UHPC中利用IBA是回收IBA的可行解决方案。补充胶结材料的使用和UHPC的高度自干性进一步防止了发生广泛的化学反应。因此，在不考虑膨胀风险且易于预处理的情况下，将IBA应用于UHPC是可行的，并且证明了在UHPC中利用IBA是回收IBA的可行解决方案。补充胶结材料的使用和UHPC的高度自干性进一步防止了化学反应的发生。因此，在不考虑膨胀风险且易于预处理的情况下，将IBA应用于UHPC是可行的，并且证明了在UHPC中利用IBA是回收IBA的可行解决方案。