SHEAR REINFORCEMENT EFFECT FOR RC BEAMS BY POST SHEAR REINFORCING METHODS WITH PLATE AND HEAD ANCHORED SHEAR REINFORCING BA RS

Abstract

 This study aims to clarify the shear reinforcement effect for RC beams by post shear reinforcing methods with plate and head anchored shear reinforcing bars (PHB). Three specific test series with total of seven RC slender beams were carried out under the four point bending test to investigate the influence of spacing, diameter and embedded length of PHB without the normal construction methods. All specimens had a rectangular cross section with a/d ratio of 3.2.
 The results showed that the shear capacity of RC beams was affected by the spacing of PHB, whether they are crossed by shear cracks or not. However the effect was smaller than that by using effective coefficient β_aw. This effect was reduced by enhancing the spacing of PHB, however the reduction ratio can be improved with a larger shear reinforcement ratio. Furthermore, the shear reinforcement effect can be promoted by shorter embedment length.
 Finally, this paper proposed the equations to predict the shear capacity of RC beams with PHB by considering the spacing and the number of PHB. The shear capacity calculated from the proposed equation showed a reasonable accuracy to estimate the experimental shear capacity.