Song Bochen, Li Yefan, Zhang Wengang
School of Civil Engineering and Geomatics, Shandong University of Technology, Zibo 255000, China.
The Fourth Construction Co., Ltd. of China Construction Eighth Engineering Division, Qingdao 266000, China.
Materials (Basel). 2025 Apr 18;18(8):1866. doi: 10.3390/ma18081866.
With the increasing rate of urbanization and the annual rise in municipal domestic waste, the use of harmless municipal solid waste incineration fly ash (HMSWIFA) as a construction material has been gradually adopted and promoted. However, significant differences exist in how various characteristics of HMSWIFA affect the performance of recycled aggregate concrete (RCA). To analyze the effects of HMSWIFA content and particle size on the macroscopic properties and microstructure of RCA, this paper conducts compressive, flexural, frost resistance, and Scanning Electron Microscope (SEM) characterization on RCA with varying dosages and particle sizes of HMSWIFA as a cement replacement. The results indicate that HMSWIFA enhances the compressive strength (CS) and frost resistance of RCA. Experimental data reveal that HMSWIFA with a particle size of 600-900 μm exhibits the best modification effect at an admixture level of 10-15%: the 28-day CS increased by 1.90-3.60%, the mass loss after freezing and thawing decreased by 0.37-0.45%, and the increase in dynamic elastic modulus reached 16.09-16.44%. Notably, the flexural strength (FS) experienced a reduction of 1.81% at a high dosage of the optimal particle size. This study elucidates the coupling relationship of "particle size-admixture-performance" in HMSWIFA-modified recycled concrete, demonstrating that reasonable control of the particle size distribution of HMSWIFA can achieve a synergistic effect of mechanical enhancement and durability improvement. The research findings provide a valuable reference for the application of municipal waste incineration HMSWIFA in RCA, facilitating the recycling of waste resources to mitigate pollution and enhance energy efficiency.
随着城市化进程的加快以及城市生活垃圾逐年增加，无害化城市固体垃圾焚烧飞灰（HMSWIFA）作为一种建筑材料的应用已逐渐得到采用和推广。然而，HMSWIFA的各种特性对再生骨料混凝土（RCA）性能的影响存在显著差异。为分析HMSWIFA含量和粒径对RCA宏观性能和微观结构的影响，本文对以不同剂量和粒径的HMSWIFA作为水泥替代品的RCA进行了抗压、抗折、抗冻性和扫描电子显微镜（SEM）表征。结果表明，HMSWIFA提高了RCA的抗压强度（CS）和抗冻性。实验数据显示，粒径为600 - 900μm的HMSWIFA在掺量为10 - 15%时表现出最佳改性效果：28天CS提高了1.90 - 3.60%，冻融后质量损失降低了0.37 - 0.45%，动态弹性模量提高了16.09 - 16.44%。值得注意的是，在最佳粒径的高掺量下，抗折强度（FS）降低了1.81%。本研究阐明了HMSWIFA改性再生混凝土中“粒径 - 掺量 - 性能”的耦合关系，表明合理控制HMSWIFA的粒径分布可实现力学增强和耐久性改善的协同效应。研究结果为城市垃圾焚烧HMSWIFA在RCA中的应用提供了有价值的参考，有助于废弃物资源的回收利用，减轻污染并提高能源效率。
