混凝土桥梁结构环境模拟试验方案及加载装置研究

发布时间：2019-05-14 03:08

【摘要】：混凝土性能劣化导致的耐久性问题给全球各个国家都带来了前所未有的挑战。近年来,国内外诸多学者从混凝土的宏观和微观角度做了大量的研究工作,以期预测混凝土的使用寿命、提高混凝土的耐久性能。试验是研究混凝土耐久性问题的基础方法和重要手段。但迄今为止,关于混凝土桥梁结构的耐久性试验方法尚未形成统一的试验标准,而且在有关混凝土的耐久性试验中,多是针对材料的耐久性能试验,鲜有根据桥梁结构的真实服役环境和其受力特点来考虑的多因素耦合情况。本文基于交通运输部应用基础研究项目(2013 319 812 100),对混凝土桥梁结构的环境模拟试验方案进行研究。论文首先根据桥梁结构的实际服役环境,在系统调查各地区病害特点并研究其破坏机理的基础上,把我国混凝土桥梁结构的耐久性病害大致分为北方冻融破坏、南方锈腐破坏(即“北冻南腐”)两大类,并以典型的城市为例,建立了南方、北方两种病害的环境模型。其次借助于相似基本理论,提出了模拟试验与真实环境间应具有四个方面的相似性,同时给出了环境模拟试验方案的制定依据。再从试验室功能设计、布局设计和指标参数设计三个方面,对结构气候环境模拟试验室的建设概况进行了介绍,对试验室盐雾、淋雨、碳化等主要功能的实现进行了示意。然后根据试验方案的制定依据,设计了试验用标准试件,同时依照桥梁结构典型受力构件梁和柱的受力特点,分别设计出柱式试件加载装置和梁式试件的加载装置。最后,根据南方、北方两种病害环境模型中考虑的耐久性影响因素,同时参照国内外加速试验中的环境参数设置,分别设计出南方和北方桥梁结构多因素耦合环境模拟的试验方案,并对试验步骤进行详细阐述,以期使桥梁耐久性试验方案实现统一,对推进混凝土桥梁结构的耐久性研究具有实用价值。
[Abstract]:The durability problem caused by the deterioration of concrete performance has brought unprecedented challenges to all countries in the world. In recent years, many scholars at home and abroad have done a lot of research work from the macro and micro point of view of concrete, in order to predict the service life of concrete and improve the durability of concrete. Test is the basic method and important means to study the durability of concrete. However, up to now, the durability test methods of concrete bridge structures have not yet formed a unified test standard, and in the durability tests of concrete, most of them are aimed at the durability tests of materials. There are few multi-factor coupling cases according to the real service environment of the bridge structure and its stress characteristics. Based on the applied basic research project of the Ministry of Transport (2013 319812100), the environmental simulation test scheme of concrete bridge structure is studied in this paper. Firstly, according to the actual service environment of the bridge structure, on the basis of systematically investigating the disease characteristics of each area and studying its failure mechanism, the durability disease of the concrete bridge structure in our country is roughly divided into freeze-thaw failure in the north. There are two kinds of rust corruption in the south (that is, "north frozen south corruption"). Taking the typical cities as an example, the environmental models of the two diseases in the south and the north are established. Secondly, with the help of the basic theory of similarity, it is proposed that there should be four similarities between the simulation test and the real environment, and the basis for the formulation of the environmental simulation test scheme is given at the same time. Then, from three aspects of laboratory function design, layout design and index parameter design, the general situation of the construction of structural climate environment simulation laboratory is introduced, and the realization of the main functions such as salt fog, rain shower and carbonation in the laboratory is indicated. Then, according to the basis of the test scheme, the standard specimens for the test are designed. At the same time, according to the stress characteristics of the beams and columns of the typical stress members of the bridge structure, the loading devices of the column specimens and the beam specimens are designed respectively. Finally, according to the factors affecting the durability of the environmental models of the two diseases in the south and the north, and referring to the setting of environmental parameters in the accelerated test at home and abroad, The test scheme of multi-factor coupling environment simulation of bridge structure in the south and north is designed respectively, and the test steps are described in detail in order to unify the durability test scheme of the bridge. It is of practical value to study the durability of propulsion concrete bridge structure.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U446.1

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