FRP约束混凝土柱强度和延性性能试验研究

Experimental Study on Strength and Ductility of FRP Confined Concrete Columns

为研究碳纤维增强复合材料CFRP对约束混凝土柱延性性能的影响,玻璃纤维增强复合材料GFRP对约束混凝土柱的强度和延性的改善效果,以及高强度CFRP以外的其他材料的约束效应,并分析它们在约束混凝土柱中的作用机理,通过对纤维增强复合材料FRP约束柱布置纵向、环向位移传感器进行单轴压缩试验,由裂纹走向及破坏形态总结出了FRP约束柱的破坏过程,根据荷载-应变曲线、荷载-位移曲线研究了FRP约束混凝土圆柱的强度和延性性能。研究结果表明:(1)CFRP和GFRP作为约束材料,都可以产生强的约束效应,提高约束混凝土的强度,CFRP、GFRP约束混凝土强度分别增加了29.2%和58.6%;(2)强约束作用下,CFRP和GFRP约束混凝土柱的强度和延性性能得到显著改善;(3)由于单一FRP材料的线弹性性质,FRP约束混凝土柱破坏时脆性特征明显;(4)与CFRP相比,变形性能较好的GFRP能更好地改善混凝土柱的延性性能,设置1层GFRP相比1层CFRP延性可提高61.9%,设置2层GFRP相比2层CFRP延性可提高63.6%。

In order to study the effect of CFRP elastic brittle material on the ductility of confined con-crete columns, the improvement of strength and ductility of confined concrete columns effected by GFRP, the constraint effect of other materials besides the high-strength CFRP, and analyze the actionmechanism of the materials in confined concrete columns, through the uniaxial compression test of theFRP confined concrete columns with longitudinal and circumferential displacement sensor, the cracktrend and the failure process of FRP confined columns were summed up, and the strength and ductility ofFRP confined concrete columns were studied based on the load-strain curve and the load-displacementcurve. The results show that：（1） both CFRP and GFRP can be used as binding materials which can pro-duce strong constraint effect and increase the strength of confined concrete, the strength of CFRP andGFRP confined concrete increases by 29.2% and 58.6% respectively;（2） the strength and ductility per-formance of CFRP confined and GFRP confined concrete columns can be increased significantly by theaction of strong constraint;（3） the brittleness characteristic of FRP confined concrete columns is obviouswhile damagement due to the linear elastic properties of single type of FRP material;（4） the ductility ofconcrete columns is improved by GFRP which has better perpormance on deformability compared withCFRP, the ductility can be increased by 61.9% with one layer, while 63.6% incresement with two layers.