全再生混凝土概念的衍化与研究进展

全面梳理和分析了再生混凝土的发展历程与演变特点,提出了全再生混凝土的基本概念,基于文献分析,针对不同组分、不同取代率下再生混凝土的工作性能、力学性能和耐久性能开展了对比分析。整理了当再生粗骨料、再生细骨料分别单取代且取代率达到100%及再生粗、细骨料双取代的取代率都达到100%后混凝土各性能变化的量值,最后总结了再生粉体对混凝土的影响,在文献脉络梳理的基础上,明确了全再生混凝土的内涵和外延,并尝试总结了全再生混凝土的力学性能理论预测模型,给出了今后全再生混凝土的研究方向和建议。研究结果表明:在众多的配合比设计方法中,基于自由水灰比的配合比设计方法最为成熟,应用最为广泛; 再生骨料单取代混凝土的工作性能、力学性能和耐久性能均随着取代率的增加而降低,对于再生粗、细骨料双取代的混凝土,再生粗骨料对抗压强度的影响要大于再生细骨料,再生细骨料对工作性能的影响要大于再生粗骨料。

Evolvement and Research Progress of Concept for Full Recycled Concrete

The development process and evolution characteristics of recycled concrete were comprehensively reviewed and analyzed, then a novel concept of full recycled concrete was put forward. Based on literature analysis, the work performance, mechanical property and durability of recycled concrete under different replacement rates of different recycled component were compared. The changes in concrete properties when the single replacement rate of recycled coarse aggregate and recycled fine aggregate reached 100% and the double replacement rate of recycled coarse and fine aggregates reached 100% were sorted out. Finally, the impact of recycled powder on concrete was also summarized. On the basis of literature, the connotation and extension of recycled concrete were defined, as well as the prediction model of mechanical properties was summarized. The suggestions for the future research direction of the full recycled concrete were provided. The results show that among all the mix design methods, the mix design method based on free water-cement ratio is the most mature and widely used. The workability, mechanical property and durability of recycled concrete containing recycled coarse aggregate or recycled fine aggregate decrease with the increase of the replacement rate. When both recycled coarse aggregates and recycled fine aggregates are replaced, the effect of recycled fine aggregate on compressive strength is greater than that of recycled coarse aggregates, whereas for workability, the conclusion is opposite.