碳纤维布条状约束不同损伤程度的混凝土柱受压性能分析

Compression performance study of different damaged concrete column strengthened by CFRP sheets

本文基于已有碳纤维(CFRP)布条状约束损伤混凝土柱(即混凝土柱首先产生不同程度的损伤之后持载进行CFRP布条状加固)的轴压试验结果,研究不同损伤程度和CFRP布条带(3道和5道)横向缠绕约束(加固量)对受压柱及CFRP布受力性能的影响。分析结果表明:相同损伤程度下,加固柱的极限承载力和延性随着CFRP布条状加固量的增加而增大;加固量相同时,其极限承载力和延性随着损伤程度的增大而降低;3道CFRP布条带(净间距125mm)加固的试件,以裸露区域混凝土压碎而破坏;5道CFRP布条带(净间距50mm)加固的试件,以条状CFRP布拉断而破坏;当损伤程度较小时,CFRP布强度均可得到充分利用;当损伤程度达到0.4后,CFRP布条状加固效果均明显减弱。

In this paper, based on existing test results of carbon-fiber-reinforced polymer（ CFRP） strips strengthened damaged concrete columns under axial compression（ in detail,the concrete column was firstly damaged by different degree and then strengthened by CFRP strips while carrying loads）,the effects of different damage degrees and lateral wrapped constraints（ reinforcement amount） of CFRP strips（ the adopted number of strips were 3 and 5） on the mechanical properties of the compression columns and CFRP sheets are studied. The results show that,the ultimate strength and ductility of strengthened columns with the same damage degrees increase with the amount of CFRP strips,and the ultimate strength and ductility of strengthened columns with the same amount of CFRP strips decrease with the damage degree. Moreover,the specimens with the number of strips of 3 faile due to failure of the exposed concrete,while the specimens with the number of strips of 5 faile due to fracture of CFRP strips. In addition,the strength of CFRP sheets can be fully used when the damage degree is small,while the reinforcement effects of CFRP strips are significantly reduced when the damage degree is not less than 0. 4.