Size effect on axial stress-strain behavior of CFRP-confined square concrete columns
Size effect on axial stress-strain behavior of CFRP-confined square concrete columns
复制标题
CFRP约束方混凝土柱轴向应力应变性能的尺寸效应
DOI：
10.1016/j.conbuildmat.2016.04.158
复制
发表时间：
2016
影响因子：
7.4
通讯作者：
Yu T.
中科院分区：
文献类型：
--
作者：
Wang D. Y.;Wang Z. Y.;Smith S. T.;Yu T.
纤维增强聚合物（FRP）约束混凝土柱的轴压性能的研究已发表的一般是基于小尺寸的标本。已经发表了有限的研究大尺寸的列，也有有限的研究从小尺寸的标本获得的放大结果的有效性。本文介绍了23根不同尺寸的碳纤维布约束混凝土方柱的单调轴压试验结果。根据（i）试样尺寸，（ii）理论横向FRP围压，（iii）FRP包裹层的层数，以及（iv）内部钢筋的包含和排除，将试样分为10组。在每组中，试样由不同的横截面尺寸，但相同的理论侧围压力。试验结果表明，试件尺寸对FRP约束中小尺寸柱（即宽度小于等于300 mm的截面）的轴向应力-应变行为没有显著影响。轴向应力-应变响应表现出不同的试样尺寸的增加。对于FRP约束的大尺寸柱（即本文定义的宽度等于或大于350 mm的截面），情况尤其如此。在角部区域的FRP包裹的断裂应变被建议定义为FRP的有效侧向断裂应变，并且该应变被示出为随着试样尺寸的增加而减小。基于试验结果，提出了考虑尺寸效应影响的FRP有效应变系数修正模型。
Research published on the axial compressive behavior of fibre-reinforced polymer (FRP)-confined concrete columns has been generally based on small-sized specimens. There have been limited studies published on large-sized columns and there have also been limited studies on the validity of upscaling results obtained from small-sized specimens. On account of such knowledge gap, this paper presents the test results of 23 carbon FRP-confined square concrete columns of varying sizes subjected to monotonic axial compression. The specimens were sorted into 10 groups based on (i) specimen size, (ii) theoretical lateral FRP confining pressure, (iii) number of layers of FRP wrap, and (iv) inclusion and exclusion of internal steel reinforcement. In each group, the specimens consisted of different cross-sectional sizes but the same theoretical lateral confining pressure. The experimental results showed that specimen size had no significant effect on the axial stress-strain behavior of FRP-confined medium- and small-sized columns (i.e. sections defined herein equal to and less than 300 mm in width). The axial stress-strain responses exhibited differences as the specimen size increased. This was especially the case for FRP-confined large-sized columns (i.e. sections defined herein equal to and larger than 350 mm in width). The rupture strain of the FRP wrap at the corner regions is proposed to be defined as the effective lateral rupture strain of FRP, and this strain was shown to decrease with an increase of specimen size. Based on the test results, a modified FRP effective strain factor model considering the influence of size effect is proposed.