Generally, engineered cementitious composites (ECC) have a high proportion of cement, resulting in substantial carbon dioxide emissions that detrimentally affect their environmental sustainability. In this paper, the industrial waste, extracted titanium tailing slag (ETTS), was employed as a partial replacement for cement in the preparation of high-strength ECC. The experimental results show that recycling ETTS to partially replace cement reduced the generation of portlandite (CH), hydrate calcium silicate (C-S-H) and ettringite (AFt) in the ECC matrix, moreover, the microstructures of ECC matrix was also coarsened, both of the above likely against the gaining of strength of ECC, such as the compressive and tensile strength of ECC were decreased from 88.9 MPa to 10.54 MPa in reference ECC (T0) to 75.6 MPa and 9.25 MPa as the replacement ratio up to 30 %, respectively. In addition, the X-ray diffraction analysis revealed that the ETTS-ECC mixture exhibits diffraction peaks of Friedel's salt, indicating that the hydration products in the matrix have a chemical adsorption effect on chloride ions. Moreover, the tensile strain capacity of ECC was significantly improved to 5.69–6.65 % from 2.81 % in T0 upon the ETTS incorporating, meanwhile, the average width of cracks in ECC was narrowed from 92.8 μm to 74.6 μm. The present findings are anticipated to increase the utilization of this industrial waste and mitigate the environmental impact associated with cement production.

中文翻译：

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回收提取钛尾矿渣 （ETTS） 的工程水泥基复合材料 （ECC） 的微观组织和力学性能


一般来说，工程水泥基复合材料 （ECC） 的水泥比例很高，导致大量二氧化碳排放，对其环境可持续性产生不利影响。在本文中，提取的工业废料钛尾矿渣 （ETTS） 被用作水泥的部分替代品，用于制备高强度 ECC。实验结果表明，回收 ETTS 以部分替代水泥减少了 ECC 基体中硅酸盐 （CH）、水合硅酸钙 （CSH） 和钙矾石 （AFt） 的生成，此外，ECC 基体的微观组织也变得粗糙，上述两种可能对 ECC 强度的增加不利，例如 ECC 的抗压和抗拉强度从参考 ECC （T0） 中的 88.9 MPa 降低到 10.54 MPa 到 75.6 MPa 和 9.25MPa 作为替代率分别高达 30 %。此外，X 射线衍射分析显示 ETTS-ECC 混合物表现出 Friedel 盐的衍射峰，表明基质中的水合产物对氯离子具有化学吸附作用。此外，在 ETTS 加入后，ECC 的拉伸应变能力从 T0 的 2.81 % 显著提高到 5.69–6.65 %，同时，ECC 中裂纹的平均宽度从 92.8 μm 缩小到 74.6 μm。目前的发现有望增加这种工业废料的利用率并减轻与水泥生产相关的环境影响。