反复荷载作用下碳化混凝土与变形钢筋粘结性能试验研究

发布时间：2018-06-26 19:06

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

【摘要】：混凝土碳化会引起钢筋混凝土结构的耐久性劣化，从而对结构的承载能力及正常使用性能产生重要的影响。钢筋和混凝土的可靠粘结才能保证钢筋混凝土结构的正常工作，然而碳化会改变混凝土材料的自身性能，必然会影响钢筋与混凝土之间的粘结性能。目前，虽然有许多关于钢筋与混凝土粘结性能的研究，但是考虑混凝土碳化对粘结性能影响的研究几乎没有。此外，钢筋混凝土结构在地震等反复荷载作用下的动力反应与钢筋和混凝土的粘结性能紧密相关，因此，开展反复荷载作用下碳化混凝土与钢筋粘结性能的研究具有重要的理论和现实意义。首先，本文对C20、C30、C40三种强度等级的钢筋混凝土试件进行快速完全碳化，测出未碳化和完全碳化的标准立方体试块的抗压强度，然后对所有粘结试件进行单调与反复荷载作用下的钢筋拉拔试验，得到相应的粘结—滑移曲线。其次，本文通过对比未碳化试件与完全碳化试件的粘结—滑移曲线，分析碳化对混凝土与变形钢筋粘结性能的影响。研究发现碳化提高了混凝土自身的抗压强度，从而也增强了试件的粘结强度、初期加载的粘结刚度以及耗能能力，并对反复加载下的粘结性能退化有一定的改善作用。最后，在试验数据的基础上，根据已有的经验模型建立单调与反复荷载作用下碳化混凝土与变形钢筋的粘结—滑移本构关系。本文从混凝土自身材料的性能变化出发，不考虑混凝土碳化后钢筋锈蚀的影响，通过试验研究了反复荷载作用下碳化混凝土与变形钢筋之间的粘结性能，对将来钢筋混凝土结构的耐久性评估及抗震性能研究具有重要的理论参考意义。
[Abstract]:Concrete carbonation will cause durability deterioration of reinforced concrete structure, which will have an important impact on the bearing capacity and normal service performance of the structure. The reliable bond between steel bar and concrete can ensure the normal work of reinforced concrete structure. However, carbonization will change the performance of concrete material and will inevitably affect the bond performance between steel bar and concrete. At present, although there are a lot of researches on the bond behavior of steel bar and concrete, there is almost no research on the effect of concrete carbonization on bond performance. In addition, the dynamic response of reinforced concrete structures under seismic and other repeated loads is closely related to the bond properties of steel bars and concrete. It is of great theoretical and practical significance to study the bond behavior of carbonized concrete and reinforcement under repeated loads. First of all, in this paper, the reinforced concrete specimens with three different strength grades, C20C30C40, are carbonized rapidly, and the compressive strength of uncarbonated and fully carbonized standard cube specimens is measured. Then all the bonded specimens are tested under monotone and repeated loads and the corresponding bond-slip curves are obtained. Secondly, by comparing the bond-slip curves between uncarbonated specimens and fully carbonized specimens, the effects of carbonation on the bond properties of concrete and deformed steel bars are analyzed. It is found that carbonation improves the compressive strength of concrete itself, and thus enhances the bond strength of the specimen, the initial loading bond stiffness and the energy dissipation ability, and it also improves the degradation of the bond performance under repeated loading. Finally, based on the experimental data, the bond-slip constitutive relationship between carbonized concrete and deformed steel bar under monotone and repeated loads is established according to the existing empirical model. In this paper, based on the performance change of concrete material, the bond behavior between carbonized concrete and deformed steel bar under repeated loading is studied by experiments without considering the effect of corrosion of steel bar after carbonization. It has important theoretical reference significance for durability evaluation and seismic performance research of reinforced concrete structures in the future.
【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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