With the increasing generation of construction waste, the rational utilization of recycled micro powder has become crucial for the efficient development of construction waste resource recycling. This study investigates the chloride ion penetration performance of Recycled Composite Micro Powder Concrete (RCMPC) under freeze-thaw conditions. By incorporating Recycled Concrete Powder (RCP) and Recycled Brick Powder (RBP) in a ratio of 2:8 to replace various proportions of cement, specimens with different water-to-binder ratios (0.35, 0.45, 0.55) were designed and subjected to freeze-thaw cycles (FTC), pore structure analysis, rapid chloride ion migration, and diffusion tests. The results indicate that the frost resistance of the concrete decreases with the addition of Recycled Composite Micro Powder (RCMP). As the RCMP content increases, the mass loss rate and relative dynamic modulus decline, while the thickness of the damage layer increases. Moreover, the chloride ion migration coefficient and diffusion coefficient exhibit a linear increase with the number of FTC, with specimens containing higher RCMP content showing poorer chloride ion penetration performance. Based on the experimental results, this paper establishes a chloride ion diffusion model for RCMPC considering freeze-thaw damage, which demonstrates good predictive capability for the chloride ion diffusion behavior of RCMPC in freeze-thaw environments, providing a theoretical basis for its application in cold and marine regions.

中文翻译：

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冻融环境下再生复合微粉混凝土的氯离子渗透性能研究


随着建筑垃圾产生的增加，合理利用回收的微粉已成为建筑垃圾资源化循环利用的高效发展的关键。本研究研究了再生复合微粉混凝土 （RCMPC） 在冻融条件下的氯离子渗透性能。通过以 2：8 的比例加入再生混凝土粉 （RCP） 和再生砖粉 （RBP） 以替代不同比例的水泥，设计了具有不同水料比 （0.35、0.45、0.55） 的试件，并进行了冻融循环 （FTC）、孔隙结构分析、氯离子快速迁移和扩散测试。结果表明，随着再生复合微粉 （RCMP） 的加入，混凝土的抗冻性降低。随着 RCMP 含量的增加，质量损失率和相对动态模量下降，而损伤层的厚度增加。此外，氯离子迁移系数和扩散系数随 FTC 数量的增加呈线性增加，RCMP 含量较高的样品表现出较差的氯离子渗透性能。基于实验结果，本文建立了考虑冻融损伤的 RCMPC 氯离子扩散模型，对 RCMPC 在冻融环境下的氯离子扩散行为具有良好的预测能力，为其在寒冷和海洋地区的应用提供了理论依据。