柱端局部采用纤维增强混凝土柱抗震性能研究

发布时间：2018-01-15 08:01

本文关键词：柱端局部采用纤维增强混凝土柱抗震性能研究　出处：《西安建筑科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：钢筋混凝土(RC)框架柱是高层建筑结构的主要承重构件,应防止其发生脆性剪切破坏。纤维增强混凝土(FRC)具有很高的受拉韧性,在直接拉伸荷载作用下,表现出多裂缝开裂与应变硬化特性,具有良好的抗损伤能力,可用于以受剪为主的构件和高剪应力作用下的受弯构件。但FRC材料的造价比普通混凝土高,整个柱全部采用FRC尚不现实,故将FRC用于柱端塑性铰区,不仅可以提高柱的抗震性能,而且可以控制其造价。另外,配制FRC约有50%以上的水泥可用工业废料粉煤灰替代。因此,研究局部采用FRC柱的抗震性能,对于提高RC结构的抗震性能和减灾防灾、减少环境污染、保护生态环境等有重要意义。本文对9根下端局部采用FRC材料柱以及1根RC柱对比试件进行了拟静力试验,研究剪跨比、轴压比及FRC强度等对其滞回特性、变形能力、耗能能力及刚度退化规律的影响,评估其抗震性能。采用OpenSees非线性分析软件对试验柱的裂缝开展和破坏过程进行了数值模拟；在此基础上,对这种柱进行了参数分析,研究剪跨比、轴压比、FRC强度及箍筋体积配箍率对其抗震性能的影响。结果表明：用OpenSees数值模拟的滞回曲线与试验滞回曲线趋势走向相似；与普通RC柱相比,柱端局部采用FRC材料柱,剪跨比为2时仍为压弯破坏,强度和刚度退化缓慢,具有较好的变形能力、耗能能力和损伤容限；轴压比及剪跨比对FRC柱的承载力、变形能力和耗能能力有明显影响；局部使用FRC材料柱仅需配置抗剪箍筋,不必另外配置约束箍筋,即可满足变形和耗能要求。考虑FRC材料的受拉性能建立了压弯承载力计算公式,推导了受剪承载力计算公式,公式的计算值与试验值吻合较好。
[Abstract]:Reinforced concrete RC frame column is the main load-bearing member of high-rise building structure, which should be prevented from brittle shear failure. Fiber reinforced concrete frame column has high tensile toughness. Under the direct tensile load, it shows the characteristics of multi-crack cracking and strain hardening, and has a good ability to resist damage. It can be used for shear-oriented members and flexural members under high shear stress, but the cost of FRC material is higher than that of ordinary concrete, so it is not realistic for the whole column to adopt FRC. Therefore, the application of FRC in the plastic hinge region at the end of column can not only improve the seismic performance of column, but also control its cost. In addition, more than 50% FRC can be replaced by industrial waste fly ash. It is very important to study the seismic behavior of local FRC columns in order to improve the seismic performance of RC structures, reduce environmental pollution and protect the ecological environment. In this paper, pseudostatic tests were carried out on 9 specimens with FRC material column and 1 RC column at the lower end. The hysteretic properties and deformability of the specimens were studied, such as shear span ratio, axial compression ratio and FRC strength. The influence of energy dissipation capacity and stiffness degradation law is evaluated to evaluate its seismic performance. The crack development and failure process of test columns are numerically simulated by OpenSees nonlinear analysis software. On this basis, the parameters of the column are analyzed, and the shear span ratio and axial compression ratio are studied. The effect of FRC strength and stirrups volume hoop ratio on its seismic performance. The results show that the trend of hysteresis curve simulated by OpenSees is similar to that of experimental hysteretic curve. Compared with the common RC column, the FRC material column is used locally at the end of the column, and the shear span ratio of 2:00 is still compressive and bending failure, the strength and stiffness degenerate slowly, and it has better deformation ability, energy dissipation capacity and damage tolerance. The bearing capacity, deformation capacity and energy dissipation capacity of FRC columns are obviously affected by axial compression ratio and shear span ratio. In order to meet the requirements of deformation and energy dissipation, only shear stirrups and constrained stirrups are required for local use of FRC columns. Considering the tensile properties of FRC materials, a formula for calculating the compressive and bending capacity is established. The formula of shear bearing capacity is deduced, and the calculated value is in good agreement with the experimental value.
【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】：TU37;TU352.11

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