Investigating the effect of compressive strength of concrete on the flexural behavior of reinforced concrete beam reinforced with CFRP

Nowadays, it is very common to use CFRP polymer materials to strengthen reinforced concretemembers. One of the main methods in strengthening the bending of reinforced concretemembers is the use of CFRP coating. Although the beam strengthening method using CFRPcoating has been widely used, still more numerical and laboratory researches are needed toinvestigate the effect of different parameters that improve the flexural performance ofreinforced concrete members. In this research, after the introduction, the basic concepts inreinforcing reinforced concrete beams are reviewed. Then, according to the necessity ofresearch in the field of identifying the behavior of beams reinforced with CFRP, the main goalof this research is to investigate the effect of compressive strength of concrete on the bendingbehavior of ordinary reinforced concrete beams reinforced with CFRP. For this purpose, a ۲.۲-meter beam under bending loading in three different modes was analyzed in Abaqus software.In the first case, the compressive strength of concrete is assumed to be ۲۰, in the second case,۳۵, and in the third case, ۵۰ MPa. Finally, the force-displacement diagram, stress contour, anddamage contour for CFRP are examined. The results of this research show that, as the strengthof concrete increases, the amount of hardness increases, but the amount of ductility decreases.In other words, as the strength of concrete increases, the reinforced concrete beam becomesmore brittle. Also, increasing the compressive strength of the samples from ۲۰ to ۵۰ MPacauses a ۷۳% increase in the flexural strength of the reinforced concrete beam reinforced withCFRP.

Keywords:

CFRP , reinforced concrete beam , strengthening , bending behavior , ultimate bending strength , compressive strength of concrete