Behavior of hybrid FRP-concrete-steel tubular columns : experimental and theoretical studies

Abstract

FRP管-混凝土-钢管组合柱(DSTC)是一种新型组合构件,由FRP外管、钢内管以及两者之间填充的混凝土三部分组成,三种材料的协同互补和共同工作使该组合柱具有许多优于现有组合构件的力学性能。本文阐述了该新型组合构件的截面形式,介绍了构件轴心受压和四点弯曲试验的结果,并分析和探讨了其力学性能。试验结果表明,尽管DSTC内部空心,但FRP外管仍然可以对混凝土提供有效的约束,使构件具有良好的延性。基于轴心受压试验所得到的应力-应变曲线,对受弯构件进行了截面分析,分析结果与试验结果基本吻合。 Hybrid FRP-concrete-steel double-skin tubular colums are a new form of hybrid members recently proposed by the first author. The new column consists of an outer tube made of fiber-reinforced polymer (FRP) and an inner tube made of steel, with the space between filled with concrete. In this new hybrid column, the three constituent materials are optimally combined to achieve several advantages not available with existing columns. In this paper, the section forms of the new column are first introduced. Results from axial compression tests and four-point bending tests are next presented to demonstrate some of the expected advantages. These test results confirm that the concrete in the new column is very effectively confined by the two tubes, leading to a very ductile response. Based on the stress-strain curves from the axial compression tests, a section analysis for the bending tests is descibed and is shown to predict the test results reasonably closely.