Li Fei, Jin Shenghao, Cheng Peifeng, Wang Zehui, Yang Zehao
Changda Construction Technology Co., Ltd., Weifang 261205, China.
School of Civil Engineering and Transportation, Northeast Forestry University, Harbin 150040, China.
Polymers (Basel). 2024 Dec 19;16(24):3535. doi: 10.3390/polym16243535.
Given the current construction waste accumulation problem, to utilize the resource of red brick solid waste, construction waste red brick was used as a concrete coarse aggregate combined with polypropylene fiber to prepare PPF (polypropylene fiber)-reinforced recycled brick aggregate concrete. Through a cube compression test, axial compression test, and four-point bending test of 15 groups of specimens, the influences of the aggregate replacement rate of recycled brick and the PPF volume on the mechanical properties of recycled brick aggregate concrete reinforced by PPF were studied, and a strength parameter calculation formula was constructed and modified based on the above. Finally, combined with a life cycle assessment (LCA), the carbon emissions of raw materials were analyzed and evaluated. It was found that the mechanical properties of recycled concrete enhanced by PPF are critical at an addition rate of 50% and then decrease slowly with an increase in the aggregate content. PPF effectively alleviates the problem of strength reductions caused by regenerated aggregate substitution through the fiber-bridging effect. Based on the experimental data, a mechanical transformation model considering fiber reinforcement and BA weakening was constructed, and the regression accuracy R2 was around 0.90. The environmental benefit obtained when only replacing the natural aggregate is low. Although the incorporation of fiber improves the carbon emissions of the material to a certain extent, the benefits are more noticeable compared with the increase in strength. The results show that garbage recovery and strength demand benefits are achieved when the amount of recycled brick aggregate is 50% of the total. The strength conversion model established in this paper has of high accuracy and was created with careful consideration of fiber reinforcement and the regenerated aggregate weakening correction, providing it with more robust adaptability and extensibility. The mechanical properties of the recycled brick aggregate concrete enhanced by PPF are excellent and sustainable when the replacement rate of BA is 50% and the PPF volume is 0.1%.
针对当前建筑垃圾堆积问题，为利用红砖固体废弃物资源，将建筑垃圾红砖作为混凝土粗骨料并结合聚丙烯纤维制备了PPF（聚丙烯纤维）增强再生砖骨料混凝土。通过对15组试件进行立方体抗压试验、轴心抗压试验和四点弯曲试验，研究了再生砖骨料替代率和PPF掺量对PPF增强再生砖骨料混凝土力学性能的影响，并在此基础上构建和修正了强度参数计算公式。最后，结合生命周期评估（LCA），对原材料的碳排放进行了分析和评估。结果发现，PPF增强再生混凝土的力学性能在掺量为50%时临界，之后随骨料含量增加而缓慢下降。PPF通过纤维桥接效应有效缓解了再生骨料替代导致的强度降低问题。基于试验数据，构建了考虑纤维增强和BA弱化的力学转换模型，回归精度R2约为0.90。仅替代天然骨料时获得的环境效益较低。虽然纤维的掺入在一定程度上提高了材料的碳排放，但与强度增加相比，效益更为显著。结果表明，当再生砖骨料用量占总量的50%时，实现了垃圾回收和强度需求效益。本文建立的强度转换模型精度高，充分考虑了纤维增强和再生骨料弱化修正，具有更强的适应性和扩展性。当BA替代率为50%且PPF掺量为0.1%时，PPF增强再生砖骨料混凝土的力学性能优异且具有可持续性。
