盐冻作用下混凝土性能试验及考虑其影响的连续梁动力参数分析

发布时间：2018-03-22 17:31

本文选题：混凝土　切入点：盐冻　出处：《吉林大学》2016年硕士论文　论文类型：学位论文

【摘要】：混凝土盐冻其实是冻融和盐类化合物侵蚀的耦合作用,由于盐类化合物的侵蚀和冻融有一定的促进作用,这便导致混凝土盐冻损伤要比冻融或盐类化合物侵蚀单独作用时的损伤要严重得多。在寒冷地区,常采用撒除冰盐的方法来清除桥面积雪,这导致混凝土桥梁的盐冻破坏屡屡发生。影响混凝土盐冻性能的因素很多,并且其盐冻损伤机理十分复杂。目前,关于混凝土盐冻损伤机理的研究刚刚起步,还未形成理论系统。桥梁动力参数常常被应用到桥梁结构损伤识别和状态评估中。桥梁结构混凝土在经受盐冻后,其动力参数如何计算意义重大。本文主要开展了混凝土抗盐冻性能试验及考虑盐冻损伤的混凝土连续梁动力参数分析方法研究,主要研究工作如下:1、对吉林省境内的523座高速公路桥梁和170座普通公路桥梁的盐冻病害进行了调研,依据调研结果对混凝土桥梁的盐冻损伤机理进行了探讨。2、由于影响混凝土抗盐冻性能的因素很多,这些因素对混凝土抗盐冻性能的影响之间有存在相互耦合,这不利于考察单因素对混凝土抗盐冻性能的影响。作者提出采用水泥胶砂盐冻试验来探讨部分参数对混凝土抗盐冻性能的影响。依据水泥胶砂盐冻试验,主要探讨了氯盐溶度和矿物掺合料对混凝土抗盐冻性能的影响。3、测试了掺入15%粉煤灰情况下混凝土试件的质量损失以及相对动弹性模量等参数,对测试数据进行拟合分析得到了盐冻对混凝土桥梁动力参数计算所需基本参数的影响规律。基于影响规律和梁式结构振动的基本原理,形成了盐冻损伤后混凝土连续梁的动力参数计算方法。最后把形成的动力参数计算方法应用到了一座两跨连续梁的动力参数数值模拟计算中,讨论了盐冻损伤对连续梁动力参数的影响规律。
[Abstract]:Concrete salt freezing is actually a coupling action between freezing and thawing and salt compound erosion. This results in far more severe damage to concrete salt freezing than when freeze-thaw or salt compounds erode alone. In cold regions, snow on the bridge deck is often cleared by the use of desiccated salt. As a result, the salt freezing damage of concrete bridges occurs frequently. There are many factors affecting the salt freezing properties of concrete, and the mechanism of salt freezing damage is very complex. At present, the research on the salt freezing damage mechanism of concrete has just started. The dynamic parameters of the bridge are often applied to the damage identification and state assessment of the bridge structure. The concrete of the bridge structure is subjected to salt freezing. It is of great significance to calculate the dynamic parameters of concrete. In this paper, the test of concrete anti-salt freezing performance and the analysis method of dynamic parameters of concrete continuous beams considering salt freezing damage are mainly carried out. The main research work is as follows: 1. The salt frozen diseases of 523 highway bridges and 170 ordinary highway bridges in Jilin Province were investigated. Based on the investigation results, the mechanism of salt freezing damage of concrete bridges is discussed. 2. Because there are many factors affecting the salt freezing resistance of concrete, the influence of these factors on the salt freezing resistance of concrete has mutual coupling. This is not conducive to the investigation of the effect of single factor on the salt freezing resistance of concrete. The author puts forward the use of cement sand salt freezing test to study the effect of some parameters on the salt freezing resistance of concrete. The influence of chlorine salinity and mineral admixture on the salt freezing resistance of concrete was discussed. The mass loss and relative dynamic elastic modulus of concrete samples with 15% fly ash were measured. The influence of salt freezing on the basic parameters of concrete bridge is obtained by fitting the test data, which is based on the influence law and the basic principle of beam structure vibration. The calculation method of dynamic parameters of concrete continuous beam after salt freezing damage is formed. Finally, the dynamic parameter calculation method is applied to the numerical simulation of dynamic parameters of a two-span continuous beam. The influence of salt freezing damage on dynamic parameters of continuous beam is discussed.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U441

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