摘要
混凝土的收缩是指混凝土凝结初期或硬化过程中出现的体积缩小现象,徐变则是指混凝土在荷载的长期作用下所产生的变形现象,正确地估计和预测收缩徐变对预制混凝土构件的影响,对指导工程设计、监控及施工进程具有重要的现实意义。本文论述了预制混凝土构件收缩徐变的机理及其影响因素,介绍了预制构件中常用的早强混凝土、自密实混凝土和预制预应力构件,从原材料、生产工艺和养护制度的角度对比分析了预制构件和普通混凝土构件收缩徐变特性的不同,阐述了预制构件收缩徐变控制不当可能产生的危害,并提出了控制预制构件收缩徐变的方法,以期为预制混凝土构件的实际工程应用提供建议。
Shrinkage of concrete refers to the phenomenon of volume reduction that occurs during the early stage of concrete setting or hardening process,and creep refers to the deformation phenomenon that occurs when concrete is under the long-term action of loading,correctly estimating and predicting the impact of shrinkage and creep on precast concrete components is of great practical significance in guiding the engineering design,monitoring and construction process.This paper describes the mechanism of shrinkage and creep of precast concrete members and its influencing factors,introduces the early-strength concrete,self-compacting concrete and precast prestressed members commonly used in precast members,and analyzes the difference in shrinkage and creep characteristics of precast members and ordinary concrete members from the perspectives of raw materials,production process and curing system,describes the hazards that may be produced by improper control of shrinkage and creep in precast members,and proposes the method of controlling shrinkage and creep in precast members,with a view to provide suggestions for the practical application of precast concrete members in the engineering field.
出处
《混凝土世界》
2023年第11期83-87,共5页
China Concrete
基金
国家重点研发计划项目(2022YFC3801800)
国家自然基金面上项目(52178184)。
关键词
预制混凝土构件
收缩
徐变
控制措施
Precast concrete elements
shrinkage
creep
control measures