摘要
随着城市高质量快速发展,建筑废弃物的总量持续攀升。同时大规模的资源开采需求进一步加剧了对自然资源的消耗,生态环境面临严峻挑战。为了解决这些问题,实现资源可持续利用,建筑废弃物的高效再利用成为关键突破口。本工作通过多尺度(宏-细-微观)试验研究,系统探讨了添加硅灰和钢纤维协同作用对100%再生粗骨料混凝土性能提升的作用机理。研究结果表明,添加5%硅灰能够促进水泥水化反应,生成更多的水化产物,从而提高再生混凝土的微观结构致密性并细化微孔隙。CT扫描与三维孔隙重构显示,2%钢纤维穿过的孔隙占总孔隙的91.3%,这一结果表明,钢纤维有效抑制了加载过程中混凝土裂缝扩展。因此,在5%硅灰和2%钢纤维协同作用下,再生混凝土90 d抗压和抗拉强度相较于未添加硅灰和钢纤维的再生混凝土分别提高26.41%和42.21%。本研究可为建筑废弃物资源化再利用提供理论依据和技术支撑。
The total amount of construction waste continues to climb with the high-quality development of cities.At the same time,the large-scale demand for resource extraction further intensifies the consumption of natural resources,and the ecological environment faces serious challenges.To address these problems and achieve sustainable resource utilization,the efficient reuse of construction waste has become a key breakthrough.In this work,multi-scale(macro-meso-micro)experimental research is carried out to systematically investigate the action mechanism of the addition of silica fume and steel fiber on the performance enhancement in 100%recycled coarse aggregate concrete.The research results show that the addition of 5%silica fume promotes the cement hydration reaction,generating more hydration products,thereby improving the microstructure compactness and refining the micro-pores of recycled concrete.The CT scanning and three-dimensional pore reconstruction reveal that the pores traversed by 2%steel fibers accounted for 91.3%of the total pores.This result indicates that steel fibers effectively inhibit the crack expansion of concrete during the loading process.Therefore,under the combined effect of 5%silica fume and 2%steel fibers,the 90 d compressive and tensile strengths increase by 26.41%and 42.21%,respectively,compared to recycled concrete without adding silica fume and steel fibers.This study provides a theoretical basis and technical support for the resource utilization of construction waste.
作者
李红涛
雷振东
张青川
张宏东
赫金贵
LI Hongtao;LEI Zhendong;ZHANG Qingchuan;ZHANG Hongdong;HE Jingui(Western Huan Yu Construction Group Co.,Ltd.,Qingyang 745000,Gansu,China)
出处
《材料导报》
北大核心
2025年第S2期467-472,共6页
Materials Reports
关键词
建筑废弃物
水化反应
再生混凝土
CT扫描
三维孔隙重构
construction waste
hydration reaction
recycled concrete
CT scanning
three-dimensional pore reconstruction
