Comparison of seismic performances of reinforced concrete frames strengthened by different techniques

Abstract The aim of this study is to compare the seismic performances of strengthening techniques applied to reinforced concrete (RC) non-ductile frames tested under the effects of seismic loads. In the experimental part of the study, one-third scale, one-bay, two-storey non-ductile hollow brick infilled RC frames were strengthened with five different techniques and tested under reversed cyclic lateral loads. One being reference, five of the frames were infilled with hollow bricks and plastered on both sides, one was strengthened with plain mortar, one was strengthened with steel fiber reinforced mortar, two were strengthened with precast RC plates. The last frame was strengthened with RC infill wall. Strengthening techniques increased strength and stiffnesses of the frames in the ranges from 57% to 189% and from 186% to 486% respectively. In the numerical analysis part, an existing RC non-ductile building located in Istanbul, strengthened with the techniques, were analyzed using a computer program. Numerical results were evaluated in terms of interstorey drift ratio together with the overall seismic performance of the building.

摘要 本研究旨在对比地震荷载作用下，应用于钢筋混凝土（RC，Reinforced Concrete）非延性框架的各类加固技术的抗震性能。在实验环节中，研究人员制作了1榀1/3缩尺比例、单跨两层的非延性空心砖填充钢筋混凝土框架，采用5种不同加固技术对其进行加固，并开展低周反复侧向荷载（reversed cyclic lateral loads）试验。本次试验共设置6榀框架：1榀作为参照组，仅填充空心砖并双侧抹灰；其余5榀分别采用对应加固技术处理，其中1榀采用素砂浆加固，1榀采用钢纤维增强砂浆加固，2榀采用预制钢筋混凝土板加固，最后1榀采用钢筋混凝土填充墙加固。实验结果显示，各类加固技术可使框架的承载强度与初始刚度分别提升57%至189%、186%至486%。在数值分析部分，研究人员以位于伊斯坦布尔的一栋既有非延性钢筋混凝土建筑为对象，采用上述加固技术完成加固后，借助计算机程序开展数值模拟分析，并结合建筑整体抗震性能，以层间位移角（interstorey drift ratio）为评价指标对数值结果进行评估。