Experimental investigation of rehabilitated RC haunched beams via CFRP with 3D-FE modeling analysis

Abstract

This paper investigates the behavior of damaged Reinforced Concrete Haunched Beams (RCHBs) rehabilitated by Carbon Fiber Reinforced Polymer (CFRP) strips. The study consists of two parts. In the first part, a comprehensive experimental study was carried out on ten RCHBs and two control beams (prismatic) which were designed to fail in shear. The second part concerns with the finite element (FE) modeling of rehabilitated RCHBs. A novel finite element based approach is proposed to form a limit zone that exhibits all possible load capacities of rehabilitated RCHBs. Lower and upper intervals of this zone are determined by the maximum and minimum limits of load capacities of rehabilitated RCHBs. FE modeling of undamaged and strengthened haunched beams by CFRP represents the maximum limit, while FE modeling of the damaged beams rehabilitated by CFRP only without crack repair by epoxy represents the minimum limit. Experimental results show that shear load capacity of RCHBs rehabilitated with CFRP strips increases as compared to the capacity of them before rehabilitation. The amount of increase varies with respect to the type of RCHBs and the rehabilitation strategy. The nonlinear FE models show a good agreement with test results (R2 = 0.8349) where load-deflection curves of all experimentally rehabilitated RCHBs lie between maximum and minimum limits of FE analysis. Furthermore, there is a very good correlation between load capacity of rehabilitated RCHBs and the capacity of undamaged and strengthened RCHBs which is obtained from maximum limit of FE analysis results (R2 = 0.859).