抗氯盐侵蚀高性能混凝土配合比设计与耐久性调控

发布时间：2018-02-13 01:27

本文关键词： 氯离子扩散系数多因素模型高性能混凝土配合比设计有限元可靠度耐久性调控　出处：《广西大学》2014年硕士论文　论文类型：学位论文

【摘要】：氯离子侵蚀引起钢筋锈蚀是造成混凝土结构,特别是氯盐环境下混凝土结构过早破坏的主要原因,如何提高混凝土的耐久性以使其满足设计的服役寿命是耐久性研究的关键问题。本文围绕此问题,建立了混凝土氯离子扩散系数的多因素模型,提出了能同时满足强度和氯离子扩散系数限值要求的混凝土配合比设计方法,建立了氯盐侵蚀环境下混凝土结构耐久性调控的有限元法。本论文的主要研究工作如下： 1、通过对混凝土氯离子扩散系数的单因素分析,研究确定了混凝土氯离子扩散系数的主要影响因素,并基于收集的RCM试验数据,考虑水胶比与矿物掺合料的共同影响,利用最小二乘法研究建立了混凝土氯离子扩散系数的多因素模型,并通过拟合优度和显著性检验证明了该模型具有较好的普适性。 2、提出了能同时满足强度和氯离子扩散系数限值要求的抗氯盐侵蚀高性能混凝土配合比设计方法,该方法在传统的混凝土配合比设计方法的基础上,引入氯离子扩散系数多因素模型和龄期衰减系数模型,可以有效设计出能同时保证强度和抗氯盐侵蚀性能的高性能混凝土配合比,试验结果表明,基于该混凝土配合比制备得到的混凝土能够同时满足强度等级和氯离子扩散系数的限值要求。 3、建立了氯盐侵蚀环境下混凝土结构耐久性调控的有限元法,该方法利用氯离子扩散的有限元法和可靠度计算的蒙特卡洛法,确定设计服役寿命下满足耐久性目标的氯离子扩散系数限值,进而结合抗氯盐侵蚀高性能混凝土配合比设计方法,通过调整混凝土配合比以满足氯离子扩散系数的限值要求,在此基础上提出了混凝土的耐久性调控技术。
[Abstract]:Corrosion of steel bars caused by chloride ion erosion is the main cause of premature destruction of concrete structures, especially in chloride environment. How to improve the durability of concrete to meet the design service life is a key problem in the durability research. In this paper, a multi-factor model of chloride diffusion coefficient of concrete is established. The design method of concrete mix ratio which can meet both the strength and the limit of chloride ion diffusion coefficient is proposed, and the finite element method for the durability control of concrete structures under chloride erosion environment is established. The main research work of this paper is as follows:. 1. Through the single factor analysis of chloride diffusion coefficient of concrete, the main influencing factors of chloride ion diffusion coefficient of concrete are studied and determined. Based on the collected RCM test data, the influence of water binder ratio and mineral admixture is considered. The multi-factor model of chloride diffusion coefficient of concrete was established by using the least square method, and it was proved that the model had better universality by the test of fit degree and significance. 2. The design method of mixture ratio of high performance concrete with resistance to chloride salt erosion can meet the requirements of strength and chloride ion diffusion coefficient at the same time. This method is based on the traditional design method of concrete mix ratio. By introducing the multi-factor model of chloride diffusion coefficient and the age attenuation coefficient model, the mixture ratio of high performance concrete which can guarantee both strength and resistance to chloride salt erosion can be effectively designed. The experimental results show that, The concrete based on the mixture ratio of the concrete can satisfy both the strength grade and the limit of chloride diffusion coefficient. 3. The finite element method for the durability control of concrete structures under chloride erosion environment is established. The finite element method for chloride ion diffusion and the Monte Carlo method for reliability calculation are used in this method. The limit value of chloride ion diffusion coefficient to meet the durability target is determined under the design service life. Furthermore, combined with the design method of chloride salt resistant high performance concrete mixture ratio, the concrete mix ratio is adjusted to meet the limit requirement of chloride ion diffusion coefficient. On this basis, the durability control technology of concrete is put forward.
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU528

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