再生骨料混凝土结构构件研究进展(Ⅱ)——长期服役性能

Research Progress on Recycled Aggregate Concrete Structural Components (II): Long-Term Service Performance

除了关注再生骨料混凝土结构的短期力学性能外,其长期服役性能的稳定性和可靠性同样值得重点关注,这直接关系到结构体系的长期安全稳定。系统地梳理了再生骨料混凝土内钢筋锈蚀、混凝土锈胀开裂、锈蚀钢筋与混凝土之间的黏结性能,以及再生骨料混凝土梁、柱构件长期服役性能等方面的研究进展,并指出了当前科学研究及标准制定过程中的不足之处。分析表明:尽管通过配合比及施工工艺优化等措施促使再生骨料混凝土结构构件的短期力学性能已经与普通混凝土结构构件相差无几,但前者的长期服役性能会出现显著削弱,尤其是在氯盐侵蚀和荷载损伤共同作用的服役环境下。再生骨料取代率对混凝土结构构件长期服役性能的影响不可忽略,因此在进行再生骨料混凝土结构耐久性设计时,必须给予特别考虑。鉴于此,开展再生骨料混凝土结构构件长期服役性能的追踪研究显得尤为必要。通过深入探究其长期服役性能的劣化机理,为再生骨料混凝土结构的标准修订及应用推广提供更为丰富的数据支撑和理论参考,从而实现建筑行业的低碳可持续发展。

In addition to the short-term mechanical performance of recycled aggregate concrete ( RAC) structures, the stability and reliability of long-term service performance are also worthy of special attention, which is directly associated with the long-term safety and stability of such structures. This paper systemati-cally reviewed the research progress in the steel corrosion within RAC, corrosion-induced cracking of RAC, the bonding strength between corroded steel bars and RAC, as well as the long-term service performance of RAC beam and column components. It also pointed out the shortcomings in current scientific research and standard-setting processes. The analysis results indicated that although the short-term mechanical perform-ance of RAC structural components were comparable to those of natural aggregate concrete (NAC) structur-al components through optimized mix proportion design and construction methods, the long-term service performance of the former was significantly weakened, especially under service conditions of combined chlo-ride attack and loading damage. Furthermore, the influence of recycled aggregate (RA) replacement ratio on the long-term service performance of RAC structural components cannot be ignored, and special consid-erations are needed in the durability design of such structures. Therefore, it is necessary to carry out follow-up research on the long-term service performance of RAC structural components. Through delving into the deterioration mechanisms underlying their long-term service performance, more abundant data support and theoretical references are provided for the standard revision and application promotion of RAC structures to achieve low-carbon and sustainable development in the construction industry.