碳化腐蚀作用下预应力空心板疲劳特性试验研究

发布时间：2018-04-20 05:16

本文选题：碳化腐蚀 + 预应力空心板　；参考：《郑州大学》2015年硕士论文

【摘要】：近年来我国交通运输事业发展迅速,在2014年底我国公路通车总里程已突破435万公里,通车里程达到世界第一。在如此庞大交通网建设中,桥梁作为一种重要的建筑形式,是保证交通运输系统正常运转的关键环节。但随当今环境问题日益恶化,不利环境因素如碳化、氯离子侵蚀等加剧了桥梁结构耐久性的衰退,进而影响到其疲劳特性及服务寿命。其中,碳化腐蚀对桥梁结构耐久性的影响已逐渐引起广大学者的关注,相关研究也相续开展,但目前针对该问题的研究还主要是针对碳化腐蚀对混凝土材料耐久性影响开展的,且未充分考虑构件耐久性损伤程度与其疲劳特性间的关系。本论文通过制作预应力空心板梁构件,开展碳化耐久性试验、疲劳特性试验,同时结合数值模拟方法,分析了碳化腐蚀对预应力空心板梁耐久性及其疲劳特性的影响,本文主要研究内容如下:1、预应力空心板构件制作及碳化腐蚀试验研究通过运用相似性原理实现了预应力空心板梁模型的设计与制作,并对碳化实验设备进行相关改造开展了预应力空心板梁的快速碳化试验。通过混凝土的弹性模量、抗压强度以及抗折强度试验结果,分析了碳化腐蚀深度对混凝土力学性能的影响。2、预应力空心板构件静载破坏试验研究通过运用三分点加载方法进行试验板静载破坏试验,得到了预应力空心板梁的极限承载能力,为疲劳试验应力比设计提供了基础数据。并总结了加载破坏过程中构件应变、挠度以及裂缝扩展变化规律。3、不同碳化腐蚀程度预应力空心板构件梁疲劳特性试验研究对受到不同程度碳化腐蚀的试验空心板进行疲劳试验,测得了不同碳化腐蚀程度下的预应力空心板构件在疲劳荷载下的应变、挠度、裂缝扩展情况以及动态应变、位移、频率、模阻系数等数据,总结分析了碳化腐蚀对预应力空心板梁的疲劳特性的影响,且在此基础上建立了挠度增加系数与疲劳次数之间的数学模型。4、不同碳化腐蚀程度预应力空心板梁疲劳特性数值模拟研究运用Ansys软件,结合不同碳化程度混凝土材料的弹性模量、抗压强度、泊松比,分析了不同碳化腐蚀程度下预应力空心板梁的具体疲劳特性,通过与试验结果的对比,分析了疲劳本构模型对不同碳化腐蚀混凝土桥梁疲劳特性分析的适应性。
[Abstract]:In recent years, China's transportation industry has developed rapidly. At the end of 2014, the total mileage of highway opened to traffic in China has exceeded 4.35 million kilometers, and the mileage of traffic has reached the first in the world. In the construction of such a large traffic network, bridge, as an important building form, is the key link to ensure the normal operation of transportation system. However, with the worsening of environmental problems nowadays, adverse environmental factors such as carbonation and chloride ion erosion have aggravated the deterioration of the durability of bridge structures, thus affecting their fatigue characteristics and service life. Among them, the influence of carbonization corrosion on the durability of bridge structure has gradually attracted the attention of many scholars, and related studies have been carried out, but the current research on this problem is mainly aimed at the impact of carbonization corrosion on the durability of concrete materials. The relationship between durability damage degree and fatigue characteristics is not fully considered. In this paper, by making prestressed hollow slab beam members, carbonation durability test and fatigue characteristic test are carried out. At the same time, combined with numerical simulation method, the influence of carbonization corrosion on the durability and fatigue characteristics of prestressed hollow slab beam is analyzed. The main contents of this paper are as follows: the fabrication of prestressed hollow slab members and the experimental study of carbonization corrosion. The design and manufacture of prestressed hollow slab beam model are realized by using the similarity principle. The experiment of rapid carbonization of prestressed hollow slab beam was carried out. Through the test results of elastic modulus, compressive strength and flexural strength of concrete, This paper analyzes the influence of carbonization corrosion depth on the mechanical properties of concrete. The static load failure test of prestressed hollow slab members is carried out by means of three-point loading method. The ultimate bearing capacity of prestressed hollow slab beam is obtained, which provides the basic data for the design of fatigue test stress ratio. The strain of component during loading failure is summarized. Experimental study on fatigue characteristics of Prestressed Hollow Slab members with different degree of Carbonization corrosion the fatigue tests of hollow slabs with different degree of carbonization corrosion are carried out. The strain, deflection, crack propagation, dynamic strain, displacement, frequency and coefficient of die resistance of prestressed hollow slab members with different carbonization corrosion degree under fatigue load were measured. The influence of carbonization corrosion on fatigue characteristics of prestressed hollow slab beam is summarized and analyzed. On the basis of this, a mathematical model. 4. The numerical simulation of fatigue characteristics of prestressed hollow slab beams with different carbonization corrosion degree is established. The Ansys software is used to simulate the fatigue characteristics of prestressed hollow slab beams. Combined with the elastic modulus, compressive strength and Poisson's ratio of concrete materials with different carbonization degree, the concrete fatigue characteristics of prestressed hollow slab beams with different carbonization corrosion degree are analyzed, and the results are compared with the test results. The adaptability of fatigue constitutive model to fatigue characteristic analysis of different carbonized corroded concrete bridges is analyzed.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441.4;U446

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