碳纤维复材布加固拉挤型玻璃纤维复材方管混凝土短柱试验研究

EXPERIMENTAL STUDY OF CONCRETE-FILLED PULTRUDED GFRP SHORT COLUMNS STRENGTHENED WITH CFRP SHEETS

为研究碳纤维复材(CFRP)布加固对拉挤型玻璃纤维复材GFRP管混凝土短柱力学性能的影响,开展以CFRP布加固层数和混凝土强度等级为设计参数的试验,得到了试件的破坏模式、极限承载力、荷载-位移曲线以及荷载-应变曲线。通过对CFRP加固层数、混凝土强度等级对拉挤型GFRP管混凝土短柱的极限承载力、延性以及刚度影响的分析,结果表明:CFRP布加固后拉挤型GFRP管混凝土短柱的承载力明显提升,当CFRP加固层数为3时的试件极限承载力平均提升116.93%,试件破坏模式也随着CFRP布的加固层数由脆性破坏向塑性破坏转变,试件破坏现象随CFRP布加固层数的增加由侧壁开裂破坏逐渐转向端部破坏,延性得到了一定的提高。保持拉挤型GFRP管壁厚t为5 mm,当拉挤型GFRP管的高宽比H/B为2.25,且宽厚比B/t为20时,管内混凝土强度等级为C30的试件整体变形能力最好,其极限承载力明显高于混凝土强度等级为C20和C40的试件的极限承载力。

In order to study the influence of carbon fiber reinforced ploymer(CFRP)sheets on the mechanical properties of concrete-filled glass fiber reinforced ploymer(GFRP)short columns strengthened with CFRP sheets,the experimental research on the design parameters of CFRP sheets layers and concrete strength grades was carried out.The failure modes,ultimate bearing capacity,load-displacement curves and load-strain curves of the specimens were obtained.The ultimate bearing capacity,ductility and stiffness of the pultruded GFRP tubes concrete short columns were analyzed.The results showed that the ultimate bearing capacity of the pultruded GFRP tubes concrete short column was obviously improved after CFRP sheets reinforcement.When the layers of the reinforced CFRP sheet were 3,the average ultimate bearing capacity of the specimens increased by 116.93%,and the failure modes of the specimens were changed from brittle failure to ductile failure with the increase of CFRP layer.When the specimen failed,the side wall cracking damage gradually turned to the end damage,and the ductility was improved.Keeping the wall-thickness(t)of the pultruded GFRP tube at 5 mm,when the aspect ratio(H/B)of the pultruded GFRP tube was 2.25 and the aspect ratio(B/t)was 20,the overall deformation capacity of the specimens with the concrete strength grade C30 had better deformation capacity and the ultimate bearing capacity which was significantly higher than the concrete strength grades C20 and C40.