This paper focuses on the effect of chelating crystalline admixtures (CA) on mechanical, self-healing and transport properties of engineered cementitious composite (ECC). Four ECC with varying CA contents were prepared. The effect of CA on the mechanical properties of ECC was evaluated by compressive and tensile tests. The self-healing behavior was investigated by sorptivity test and crack closure behavior. Meanwhile, the water permeability test was adopted to characterize the transport properties of four ECC mixtures. The mercury intrusion porosimetry (MIP) was used to analyze the effect of CA on the pore structure of ECC. The test results show that chelating CA can significantly improve the compressive strength, ultimate tensile strength and transport properties of ECC. Moreover, the addition of chelating CA helps promote the recovery of transport performance and easily restore to the uncracked state. The closure rate and healed width of cracks are increased by CA. The enhancement effect provided by CA has a positive relation with CA content. The analysis of pore structure suggests that chelating CA can improve the pore structure and size distribution. ESEM and XEDS results show that chelating CA helps promote the formation of hydration products, which can enhance the mechanical properties of cementitious materials. The TG results indicate that even if the cementitious materials contain fly ash, chelating CA can accelerate the consumption of calcium hydroxide to form more calcium carbonate, which can improve the self-healing behavior of ECC.

本文重点研究螯合结晶外加剂 (CA) 对工程水泥基复合材料 (ECC) 的机械、自愈和运输性能的影响。制备了四种具有不同 CA 含量的 ECC。通过压缩和拉伸试验评估 CA 对 ECC 机械性能的影响。通过吸附试验和裂纹闭合行为研究了自修复行为。同时，采用透水性测试来表征四种ECC混合物的传输特性。采用压汞法（MIP）分析CA对ECC孔结构的影响。试验结果表明螯合CA可以显着提高ECC的抗压强度、极限抗拉强度和传输性能。而且，螯合CA的加入有助于促进传输性能的恢复，并容易恢复到未裂化状态。CA 增加了裂缝的闭合率和愈合宽度。CA提供的增强效果与CA含量呈正相关。孔结构分析表明螯合CA可以改善孔结构和尺寸分布。ESEM和XEDS结果表明螯合CA有助于促进水化产物的形成，从而提高胶凝材料的力学性能。TG结果表明，即使胶凝材料中含有粉煤灰，螯合CA也可以加速氢氧化钙的消耗，形成更多的碳酸钙，从而提高ECC的自愈性能。CA 增加了裂缝的闭合率和愈合宽度。CA提供的增强效果与CA含量呈正相关。孔结构分析表明螯合CA可以改善孔结构和尺寸分布。ESEM和XEDS结果表明螯合CA有助于促进水化产物的形成，从而提高胶凝材料的力学性能。TG结果表明，即使胶凝材料中含有粉煤灰，螯合CA也可以加速氢氧化钙的消耗，形成更多的碳酸钙，从而提高ECC的自愈性能。CA 增加了裂缝的闭合率和愈合宽度。CA提供的增强效果与CA含量呈正相关。孔结构分析表明螯合CA可以改善孔结构和尺寸分布。ESEM和XEDS结果表明螯合CA有助于促进水化产物的形成，从而提高胶凝材料的力学性能。TG结果表明，即使胶凝材料中含有粉煤灰，螯合CA也可以加速氢氧化钙的消耗，形成更多的碳酸钙，从而提高ECC的自愈性能。孔结构分析表明螯合CA可以改善孔结构和尺寸分布。ESEM和XEDS结果表明螯合CA有助于促进水化产物的形成，从而提高胶凝材料的力学性能。TG结果表明，即使胶凝材料中含有粉煤灰，螯合CA也可以加速氢氧化钙的消耗，形成更多的碳酸钙，从而提高ECC的自愈性能。孔结构分析表明螯合CA可以改善孔结构和尺寸分布。ESEM和XEDS结果表明螯合CA有助于促进水化产物的形成，从而提高胶凝材料的力学性能。TG结果表明，即使胶凝材料中含有粉煤灰，螯合CA也可以加速氢氧化钙的消耗，形成更多的碳酸钙，从而提高ECC的自愈性能。