Axial-flexural interaction in square RC columns confined by intermittent CFRP wraps
Axial-flexural interaction in square RC columns confined by intermittent CFRP wraps
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DOI：
10.1016/j.compositesb.2015.10.047
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发表时间：
2016-03
影响因子：
13.1
通讯作者：
Alireza Saljoughian;D. Mostofinejad
中科院分区：
文献类型：
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作者：
Alireza Saljoughian;D. Mostofinejad
碳纤维布加固混凝土构件是一种广泛应用于包括钢筋混凝土柱在内的所有结构受力构件加固的方法。以往的研究主要集中在加固纯轴压钢筋混凝土柱，而大多数钢筋混凝土柱实际上起着梁柱的作用;也就是说，本文的目的是对采用间断式碳纤维布加固的柱在同时承受轴向荷载和弯矩的情况下的承载力和延性进行试验评估载荷和弯矩。评估是通过比较间歇包裹柱与无侧限柱的强度和延性来完成的。为此，10个方形RC柱，133 × 133 mm宽和500 mm高，受到零，30，60，90和120 mm的加载偏心。研究结果表明，与无侧限钢筋混凝土柱相比，CFRP间断包裹钢筋混凝土方柱可提高其承载力和偏心受压延性，从而改善其性能。实验结果与ACI 440.2R和FIB Bulletin 14等不同规范中建议的表达式的比较表明，这些规范与实验测量值相比具有保守性。
External reinforcing of concrete elements by CFRP composites is a well-accepted method adopted for strengthening all structural load-bearing members including reinforced concrete (RC) columns. Previous studies have been mostly focused on strengthening RC columns for pure axial-loads, while most RC columns practically function as beam-columns; that is, they are subjected to both axial loads and bending moments simultaneously.It is the objective of the current study to carry out an experimental assessment of the load bearing capacity and ductility of columns externally strengthened with intermittent CFRP wraps when subjected to simultaneous axial loading and bending moment. The assessment is accomplished by comparing intermittently wrapped columns with unconfined ones in terms of their strength and ductility. For this purpose, 10 square RC columns, 133 × 133 mm across and 500 mm in height, were subjected to zero, 30, 60, 90, and 120 mm loading eccentricities. The results of the study showed that, compared to unconfined RC columns, intermittent wrapping of square RC columns with CFRP improved their performance through enhanced load carrying capacity and ductility under eccentric loading.Finally, the P–M (axial loading-bending moment) interaction diagrams were drawn for the strengthened columns. Comparison of the experimental results with those obtained from the expressions suggested in different codes such as ACI 440.2R and fib bulletin 14 showed the conservative estimates of these codes in comparison to experimental measurements.