水泥类型和砂对高性能混凝土的性能影响及开裂风险分析

发布时间：2018-02-19 19:11

本文关键词： 混凝土矿物掺合料力学性能相对湿度收缩抗裂性能　出处：《浙江大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着混凝土越来越广泛的应用于工程领域,但是随之而来的结构早期开裂问题也越来越严重。混凝土早期开裂问题已经成为导致混凝土结构性能劣化、影响其耐久性的重要原因。特别是当今大规模发展的高速公路隧道混凝土工程中存在着大量的早期开裂现象,已严重影响到了国民经济的快速发展。因此,配制具有良好和易性和抗裂性能的复掺矿物掺合料混凝土,从试验和理论综合研究与混凝土开裂相关问题,对于提高混凝土工程耐久性,保证混凝土工程的质量与安全具有重要意义。本文以此为主线,主要的研究工作如下： 1.混凝土实际工程中,由于原材料来源不稳定,给混凝土的质量控制带来了严重的影响。从混凝土生命周期的源头出发,研究了水泥类型、砂的细度模数对混凝土工作性能和基本力学性能的影响,对复掺矿物掺合料混凝土的基本力学性能也进行了长达360d的测试,研究混凝土基本力学性能随龄期的发展规律及其相互之间的关系,在抗压强度预测公式中考虑了混凝土抗压强度随龄期的发展速率的影响,在研究抗压强度与劈裂抗拉强度关系考虑混凝土龄期对两者的影响。 2.通过试验研究了水泥类型、砂的细度模数对混凝土抗渗性能、自由收缩性能、开裂性能的影响,并据此综合评价了不同配合比混凝土耐久性能和收缩抗裂性能的差异。 3.通过对比复掺矿物掺合料混凝土与基准配合比混凝土性能,得到在混凝土中复掺适量的矿物掺合料,可以改善混凝土的后期力学性能,抗渗性能以及收缩开裂性能。 4.从影响混凝土的开裂因素的研究入手,综合分析混凝土的力学性能、温度变形、收缩等因素对混凝土开裂的影响,建立了非荷载作用下混凝土的开裂风险预测模型,系统地分析了混凝土温湿度场和应力的变化规律,利用大型有限元分析软件ANSYS对混凝土约束平板的应力场进行仿真分析。
[Abstract]:With the more and more extensive application of concrete in the engineering field, the problem of early cracking of concrete structures is becoming more and more serious. The problem of early cracking of concrete has become the cause of deterioration of the performance of concrete structures. Especially, there exists a large number of early cracking phenomena in the large-scale development of highway tunnel concrete engineering, which has seriously affected the rapid development of the national economy. In order to improve the durability of concrete engineering, the mixed mineral admixture concrete with good and easy properties and crack resistance is prepared. The problems related to the cracking of concrete are studied comprehensively from the test and theory, so as to improve the durability of concrete engineering. It is of great significance to ensure the quality and safety of concrete engineering. This paper takes this as the main line, the main research work is as follows:. 1. In actual concrete engineering, because of the instability of raw material source, the quality control of concrete has been seriously affected. Starting from the source of concrete life cycle, the type of cement is studied. The influence of the fineness modulus of sand on the working and basic mechanical properties of concrete was also studied. The basic mechanical properties of concrete with mineral admixtures were also tested for 360 days. The development law of basic mechanical properties of concrete with age and the relationship between them are studied. The influence of the development rate of compressive strength of concrete with age is considered in the prediction formula of compressive strength. The relationship between compressive strength and splitting tensile strength is studied, and the influence of concrete age on them is considered. 2. The effects of cement type and the fineness modulus of sand on the impermeability, free shrinkage and cracking performance of concrete are studied, and the difference of durability and shrinkage and crack resistance of concrete with different mix ratio is evaluated synthetically. 3. By comparing the properties of concrete mixed with mineral admixture and reference concrete, it is found that the addition of mineral admixture in concrete can improve the mechanical properties, impermeability and shrinkage cracking of concrete. 4. Starting with the study of the factors affecting the cracking of concrete, the influence of mechanical properties, temperature deformation, shrinkage and other factors on the cracking of concrete is analyzed synthetically, and the prediction model of crack risk of concrete under non-load is established. The variation law of temperature and humidity field and stress of concrete is analyzed systematically, and the stress field of concrete confined plate is simulated by using the finite element analysis software ANSYS.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU528

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