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作者简介:李富民(1972),男,甘肃静宁人,教授,博士研究生导师,工学博士,Email:lfmfm@163.com。
摘要:针对预应力混凝土结构耐久性的现实问题和未来矛盾日益突出的趋势,对预应力混凝土结构耐久性的研究进展进行了系统梳理和总结。提出了预应力混凝土结构耐久性的研究体系,包括研究背景、对象、思路、目标、科学问题、技术问题、内容、技术路线等;对预应力混凝土结构耐久性问题的研究现状分5个方面进行了综述,包括混凝土损伤有关耐久性问题、预应力钢筋腐蚀有关耐久性问题、锚固连接体系腐蚀有关耐久性问题、耐久性测试和提升及试验技术、耐久性数值模拟技术;提出了7个有关预应力混凝土结构耐久性研究尚需进一步解决的问题,即环境作用定量模型、腐蚀介质传输行为、腐蚀疲劳损伤演化模型、锚固连接体系腐蚀行为、岩土预应力结构的腐蚀行为、耐久性提升技术、耐久性数值模拟技术。所做研究可为进一步拓展和完善预应力混凝土结构耐久性研究提供参考。
关键词:预应力混凝土结构;耐久性;综述;研究体系;腐蚀;损伤演化
中图分类号:TU378文献标志码:A
Review of Research on Durability of Prestressed Concrete StructuresLI Fumin, DENG Tianci, WANG Jianghao, LUO Xiaoya
(Jiangsu Key Laboratory of Environmental Impact and Structural Safety in Engineering,
China University of Mining and Technology, Xuzhou 221116, Jiangsu, China)Abstract: Aimed at the existing problems and future requirements on the durability of prestressed concrete (PC) structures, the research proceeding on durability of PC structures was summarized systematically and analyzed. The research system of the durability of PC structures was put forward, where the research background, objects, clue, aim, scientific issues, technological issues, contents and technical lines were concerned in. The stateoftheart of the research was reviewed as five parts: the issues of durability about the damage of concrete, the issues of durability about the corrosion of steel bars, the issues of durability about the corrosion of anchorage and joint system, the technology of testing, raising and experiment of durability, and the technology of numerical simulation of durability. Seven issues about the durability of PC structures, which needed more research work, were suggested. The issues included the quantitative models of environmental action, the transporting behavior of corrosive mediums, the evolving models of corrosion fatigue damage, the corrosion behavior of anchorage and joint system, the corrosion behavior of geotechnical PC structures, the technology of raising durability and the technology of numerical simulation of durability. The study can provide references for further expanding and improving the research work on durability of PC structures.
Key words: prestressed concrete structure; durability; review; research system; corrosion; damage evolution
0引言
由于预应力混凝土结构采用较高强度等级的混凝土以及力筋拥有多道保护层体系,因此曾被认为具有优良的耐久性能,然而现实情况并非如此乐观。在侵蚀环境(尤其氯盐环境)下,对于先张法体系、抽芯成孔或金属波纹管成孔的后张法体系中,良好的保护层体系对力筋的腐蚀只能起到延缓作用而并不能起到阻止作用,腐蚀介质穿过保护层体系(包括腐蚀透金属波纹管)到达力筋表面只是一个时间问题[1],而这种延缓作用其实远不能完成许多预应力工程所承载的“百年大计”之使命;更为甚者,后张预应力混凝土结构还存在着灌浆质量无法保证(包括先进的真空辅助灌浆工艺[23])这一关键问题,这使得即使在塑料波纹管体系中也有可能会发生力筋的腐蚀问题[4]。另一方面,预应力混凝土结构中混凝土的应力水平往往较高,因而对碱骨料反应以及冻融循环作用的破坏更为敏感。
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