反复荷载作用下冻融混凝土与变形钢筋粘结性能试验研究

发布时间：2018-06-14 08:37

本文选题：冻融混凝土 + 变形钢筋　；参考：《西安建筑科技大学》2014年硕士论文

【摘要】：我国部分地区处于寒冷地带，这些地区的混凝土建筑经常遭受冻融破坏，，对混凝土的各项性能产生了很大影响。目前，对冻融后混凝土构件的抗震性能，国内外学者开展的研究工作相对较少。首先，本文对C30、C40、C50三种强度的钢筋混凝土试件分别进行0次、100次、200次、300次的冻融试验，对试验结果进行分析总结，并在此基础上得到了混凝土强度等级和冻融次数与混凝土抗压强度、质量损失率和相对动弹模量之间的关系。又进一步进行加载试验，得到了不同强度不同冻融循环次数下钢筋与混凝土试件在单调与反复荷载作用下的粘结-滑移曲线。其次，对单调试验数据分析后，总结出曲线特征，得到了不同强度下极限粘结强度、峰值滑移、残余强度与冻融循环次数之间的关系。对反复试验数据分析后，对比单调试验数据，引入粘结退化率、摩阻力退化率和残余粘结应力退化率，得到了它们与冻融循环次数和混凝土强度等级的关系。最后，根据试验数据，建立单调加载下冻融混凝土与变形钢筋粘结滑移本构关系和反复加载条件下冻融混凝土与变形钢筋粘结滑移循环加载曲线的本构关系，通过引入残余粘结应力退化率、粘结退化损失率和关键参数的方法最终得到反复加载条件下冻融混凝土与变形钢筋粘结滑移本构关系。
[Abstract]:Some parts of our country are in the cold zone, the concrete buildings in these areas are often damaged by freezing and thawing, which has a great influence on the performance of concrete. At present, there are few researches on seismic behavior of freeze-thawed concrete members at home and abroad. First of all, in this paper, three kinds of reinforced concrete specimens with C _ (30) C _ (40) C _ (50) and C _ (30) C _ (40) C _ (50) have been subjected to the freezing and thawing tests of 100 times, 200 times and 300 times respectively, and the test results are analyzed and summarized. On this basis, the relationship between concrete strength grade, freeze-thaw times and compressive strength, mass loss rate and relative dynamic modulus of concrete is obtained. Furthermore, the bond slip curves of steel bars and concrete specimens under monotonic and repeated loads are obtained under different strength and different freeze-thaw cycles. Secondly, after analyzing the monotonic test data, the curve characteristics are summarized, and the relationship between ultimate bond strength, peak slip, residual strength and freeze-thaw cycle times under different strength is obtained. After analyzing the repeated test data, compared with the monotonic test data, the bond degradation rate, friction degradation rate and residual bond stress degradation rate are introduced, and the relationship between them and the number of freeze-thaw cycles and the strength grade of concrete is obtained. Finally, based on the experimental data, the bond-slip constitutive relation between freeze-thawed concrete and deformed steel bar under monotone loading and the constitutive relation between freeze-thawed concrete and deformed steel bar under repeated loading are established. By introducing residual bond stress degradation rate, bond degradation loss rate and key parameters, the bond-slip constitutive relationship between freeze-thawed concrete and deformed steel bar under repeated loading is obtained.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU528

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