大体积混凝土温度应力场与温控措施研究

发布时间：2018-10-11 07:31

【摘要】：目前大体积混凝土已应用于土木工程的各个领域中。但是,大体积混凝土在浇筑施工过程中,水泥会产生大量的水化热,这样混凝土内部积聚热量温度高,产生压应力；外部由于空气流通、散发,温度低,产生拉应力；这样很容易引起混凝土的张拉开裂。所以,对于大体积混凝土的施工,控制大体积混凝土的裂缝尤为关键。我国规范对大体积混凝土的求解只给出了方便求解的经验公式,但是给出的经验公式忽略了温度场连续变化以及外界温度不断变化的影响等其他影响因素。因此按照规范给出的方法计算出来的温度以及应力跟现场实际的情况相差很大。很多专家学者纷纷致力于大体积混凝土求解的研究中。本文,从目前两种最为广泛的求解温度场方法(即有限差分法和有限单元法)出发,首先从建筑工程大体积混凝土出发,结合具体某高层建筑的大体积混凝土筏板基础,对其进行基于有限差分法的计算,并将计算结果与现场实测的结果进行对比分析,结果表明有限差分法对温度场计算方法可行。然后,又从一个水利工程出发,结合一个桥墩的大体积混凝土,采用ANSYS软件对整个浇筑过程进行有限单元法分析计算,为现场大体积施工提供了一定的指导作用。最后,本文提出了大体积混凝土温度控制的几个具体技术措施,并对这些措施进行了研究,旨在更加有效的降低大体积混凝土产生裂缝的可能性。因此,在大体积混凝土浇筑过程中,本文对大体积混凝土的水化热分析计算及裂缝控制的研究具有重要意义。
[Abstract]:At present, mass concrete has been used in various fields of civil engineering. However, during the construction of mass concrete, the cement will produce a large amount of hydration heat, thus the internal heat accumulation temperature of the concrete will be high, and the compressive stress will be produced, while the external air circulation, the emission, the low temperature and the tensile stress will be produced. This will easily lead to tensile cracking of concrete. Therefore, for the construction of mass concrete, the crack control of mass concrete is particularly critical. The code of our country only gives the empirical formula for solving mass concrete conveniently, but the empirical formula neglects the continuous variation of temperature field and the influence of changing external temperature, etc. Therefore, the temperature and stress calculated according to the method given in the code are quite different from the actual situation in the field. Many experts and scholars have devoted themselves to the research of mass concrete solution. In this paper, starting from the two most widely used methods to solve the temperature field at present, namely, the finite difference method and the finite element method, the mass concrete raft foundation of a concrete high-rise building is combined with the mass concrete in building engineering. The finite difference method is used to calculate the temperature field, and the results are compared with the measured results. The results show that the finite difference method is feasible for the temperature field calculation. Then, starting from a water conservancy project and combining with the mass concrete of a bridge pier, the finite element method is used to analyze and calculate the whole pouring process by using ANSYS software, which provides some guidance for the field mass construction. Finally, several concrete technical measures for temperature control of mass concrete are put forward, and these measures are studied in order to reduce the possibility of cracks in mass concrete more effectively. Therefore, in the process of mass concrete pouring, this paper is of great significance to the study of hydration heat analysis and crack control of mass concrete.
【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU755

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