Influence of reinforcement couplers on the cracking of reinforced concrete members

Abstract

The influence of threaded reinforcement couplers on the appearance of normal cracks in reinforced concrete beams is analyzed in the article. The method for calculation of cracking moment when tensile reinforcement is spliced by couplers is presented. The analysis of experimental and numerical results obtained by calculation method mentioned above has shown that the first normal cracks usually appear at the end of the coupler. The initial cracking moment of the beams with reinforcement couplers is smaller than of the beams without the couplers. It is also observed that cracking moment is directly proportional to the area of concrete shearing surface at the end of the coupler. The area of such surface depends on the size of reinforcement ribs, distance between them and the diameter of the coupler. In the later cracking stage of the beams parameters of the crack development at the end of the coupler and these for the other cracks become almost the same.