再生混凝土结构长期工作性能研究进展

再生混凝土结构的应用是建筑垃圾资源化利用和建筑材料可持续发展的重大需求,受到国内外学术界和工程界的共同关注和高度重视.再生混凝土结构长期工作性能研究是再生混凝土研究的一个重要方向,其中再生混凝土的抗冻融性能、抗碳化性能、抗氯离子渗透性能、徐变性能、再生混凝土内钢筋锈蚀及锈裂、锈蚀钢筋与再生混凝土黏结性能和再生混凝土构件的长期工作性能是决定再生混凝土结构长期工作性能的重要组成部分.本文就以上7个方面的相关研究进行了总结和分析,归纳了亟待深化研究的问题.结果表明:1)以上再生混凝土长期工作性能研究均有不同程度进展,并取得了很多较有价值的结论,但也有部分研究结论并不完全一致,甚至相互冲突,究其原因,主要因再生骨料来源、配合比设计和试验方法不同所致,仍需进一步深入研究;2)多数研究围绕中、低强再生混凝土展开,高强再生混凝土方面涉及较少,可多开展高强再生混凝土长期工作性能研究,与目前大力推广使用的高强钢筋同步进行,使二者充分发挥其性能,避免浪费;3)宏观规律性结论较多,细微观结构机理研究较少,可多进行细微观机理研究;4)相较再生混凝土材料长期工作性能研究成果而言,再生混凝土构件和结构部分的研究相对薄弱,后续可多开展构件或结构方面的研究;5)再生混凝土长期工作性能研究多为单因素作用研究,而实际工程多为多因素耦合作用,后续可进一步深入多因素耦合作用效果研究,以最大程度实现理论与实际吻合.期望本文能为后续再生混凝土长期工作性能的研究提供思路和方向,为再生混凝土的推广应用提供数据和理论支持.

A review of recent advances in the long-term working characteristic of recycled concrete structure

The application of recycled concrete structure is in line with the utilization of construction waste resources and the sustainable development of building materials. It has received attention from academic and engineering circles at home and abroad. The long-term working characteristic of recycled concrete structures is an important aspect in the research of recycled concrete, among which the freezing and thawing resistance, carbonation resistance, chloride-permeation resistance, creep of recycled concrete, steel corrosion and rust cracking in recycled concrete, corroded steel and recycled concrete bonding properties, and long-term performance of recycled concrete components are essential components to determine the long-term working performance of recycled concrete structures. The above-mentioned qualities of recycled concrete structures are studied in this paper, which is summarized as follows: 1) Progress has been made on the long-term working characteristic of recycled concrete structures, and some valuable conclusions have been drawn. However, some of the research conclusions are not completely consistent or even mutually exclusive, which might be attributed to the difference in recycled aggregate, mix design, and test methods. Therefore, further research is still needed. 2) Most of the research is mainly based on medium and low-strength recycled concrete, involving less on high-strength recycled concrete. More research on the long-term working characteristic of high-strength recycled concrete should be conducted along with the promotion of high-strength steel bars, so that recycled concrete and steel bars can fully draw on their respective advantages and waste can be avoided. 3) There are many macro researches yet few micro studies, so research on micro study should be enhanced. 4) Compared with the research results of long-term working characteristic of recycled concrete materials, the research on recycled concrete component and structural parts is relatively scarce, and subsequent research on components or structures should be carried out. 5) Long-term working characteristic of recycled concrete studies are mostly single factor studies, while engineering is mostly multi-factor coupling. Multi-factor coupling research can be carried out in the future in order to combine theory with practice. It is expected that this paper is able to provide ideas and directions for the study of the long-term working characteristic of recycled concrete, and provide statistical and theoretical support for the promotion and application of recycled concrete.