福州琅岐闽江大桥承台大体积混凝土水化热分析与温控研究

发布时间：2018-02-23 07:16

本文关键词： 水泥水化热大体积混凝土仿真计算温度控制　出处：《重庆交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着我国桥梁事业的高速发展,桥梁建设规模的不断增大,大体积混凝土结构在桥梁工程中的应用越来越普遍。随之而产生的大体积混凝土水化热温度控制问题已变得越来越重要,大体积混凝土由于体积庞大、散热困难,在浇筑完成后的几天内其内部温度上升非常迅速,混凝土本身内表形成较大的温差。由于混凝土抗拉能力低,内表温差形成的温度梯度导致温度应力,容易使混凝土开裂,从而影响结构的安全性。因此,施工过程中的温度控制对于大体积混凝土结构来说非常关键。本文介绍了水泥水化热的形成机理及对工程的影响,大体积混凝土水化热研究的意义及国内外研究现状,混凝土的热学性能及水泥水化热的计算,热传导方程,边界条件等,以及瞬态温度场有限元计算原理。同时,本文通过福州琅岐闽江大桥主桥3#主塔墩承台大体积混凝土温度控制的实际实施过程,揭示了大体积混凝土内部温度场和温度应力的变化规律、以及施工工程中采用的温控手段和措施达到的效果。通过对承台的仿真计算和施工监测数据分析,从混凝土的配合比选择、双掺技术、控制浇筑温度、布置冷水管、分层分块浇筑、振捣及养护等几方面研究大体积混凝土的温度场及温控效果,整理出大体积混凝土的温度场变化的一般规律,总结了施工中大体积混凝土温度控制手段和措施的实际效果,提出了大体积混凝土结构水化热温升的控制措施和建议。
[Abstract]:With the rapid development of bridge industry in China, the scale of bridge construction is increasing. The application of mass concrete structure in bridge engineering is becoming more and more common. The problem of mass concrete hydration temperature control has become more and more important. Mass concrete is difficult to dissipate because of its large volume. The internal temperature rises very rapidly within a few days after pouring, and the inner surface of the concrete forms a large temperature difference. Because of the low tensile capacity of concrete, the temperature gradient formed by the inner surface temperature difference leads to the temperature stress, which easily causes the concrete to crack. Therefore, the temperature control during construction is very important for mass concrete structure. The formation mechanism of hydration heat of cement and its influence on engineering are introduced in this paper. The significance of research on hydration heat of mass concrete and its present situation at home and abroad, the thermal properties of concrete and the calculation of hydration heat of cement, heat conduction equation, boundary conditions, and the finite element calculation principle of transient temperature field, etc. Through the actual process of temperature control of mass concrete in the cap of the main tower pier of the main bridge of Luangqi Minjiang River Bridge in Fuzhou, this paper reveals the variation law of temperature field and temperature stress in mass concrete. Through the simulation calculation of the cap and the analysis of the construction monitoring data, from the concrete mix ratio selection, the double mixing technology, the control of the pouring temperature, the arrangement of the cold water pipe, In this paper, the temperature field and temperature control effect of mass concrete are studied in several aspects, such as stratified pouring, vibrating and curing, and the general rules of temperature field change of mass concrete are sorted out. This paper summarizes the practical effect of the temperature control measures of mass concrete in construction, and puts forward the control measures and suggestions for the hydration heat temperature rise of mass concrete structures.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U445.57

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