Experimental study on RC beams shear‐strengthened with composite polymer mortar and steel strands wire mesh

Abstract

AbstractThis paper presents an experimental investigation of the use of composite polymer mortar (CPM) and steel strands wire mesh (SSWM) to strengthen reinforced concrete (RC) beams in shear. In order to maximize the shear resistance of the steel strands, a new type of anchor device called wedge‐shaped steel plate hoops (WSSPHs) was developed. And the study aimed to examine the effect of shear‐to‐span ratio and prestressing level on the mechanical properties of the beams. A total of nine beams were constructed and tested under four‐point bending monotonic load, comprising three control beams and six strengthened beams. The study analyzed the damage modes, load‐deflection curves, strength, stiffness, and ductility of the beams. The test results indicated that (1) the mechanical properties of the strengthened beams were improved, with the shear capacity improving by 38.47%–71.37% after strengthening. (2) It was observed that SSWM could be utilized more effectively in high shear‐to‐span ratio beams among the strengthened beams with the same prestressing level. (3) Additionally, the larger prestressing level was found to change the design damage mode of the test beams, with RB‐2.5‐0.5 failing in bending. Finally, a model was proposed to predict the shear capacity of the test beams based on the specification GB 50011‐2010. The model considered the effect of the initial prestressing of the steel strands.