碳纤维布约束型钢混凝土矩形柱轴压承载力

为了研究碳纤维布(CFRP)约束型钢混凝土矩形柱的轴压性能，对29个构件进行静力加载试验，考虑配筋率、预载水平、截面圆角半径和高宽比、纤维布加固率和加固方式共6个参数. 结果表明：所有约束柱均以核心区混凝土压碎和纤维布断裂为破坏标志；随着预载水平提高，布的有效拉应变不断减小，柱承载力降低；随着圆角半径增大和高宽比减小，纤维布环向应变更高且分布趋于均匀；随着加固率增加，柱破坏模式由弱约束转成强约束，纤维布加固效率降低；在同等用量布的加固下，当条带宽度和间距减小时，构件承载力增幅增加. 基于各因素对约束应力的影响，确定了区分大尺寸柱强弱约束模式的界限值；采用叠加法建立了多参数的约束型钢柱轴压承载力计算式.

Axial compression bearing capacity of steel reinforced concrete rectangular columns confined by carbon fiber reinforced polymer

Twenty-nine specimens were conducted to the axial compression experiment, in order to study the axial compression performance of steel reinforced concrete rectangular columns confined by carbon fiber reinforced polymer (CFRP). Six parameters were considered, which included reinforcement ratio, preload level, corner radius and aspect ratio of cross sections, as well as amount and scheme of CFRP. Results indicated that the confined columns all failed in the fracture of CFRP when the core concrete crushed. With the increasing preload level, both the effective tensile strain of CFRP and the bearing capacity of confined columns decreased gradually. With the increasing corner radius and decreasing aspect ratio, the circumferential strain of CFRP got higher value and more uniform distribution. As increasing amount of CFRP, the constraint mode of the column changed from weak constraint to strong constraint, and the utilization of CFRP decreased. When the width and spacing of the strips decreased, the increment of bearing capacity increased with the same amount of CFRP. Finally, considering various parameters, the boundary value for determining the strong and weak modes was proposed. The formulation of the axial bearing capacity of confined steel reinforced rectangular columns was set up by superposition method.