Numerical Study on the Behavior of Rc Beams With Openings Strengthened With Ultra High Performance – Fiber Reinforced Concrete (Uhp-Frc)

Abstract

Ultra high performance-Fiber reinforced concrete (UHP-FRC) is a newly developed building material that has major advantages in terms of high strain ability and high compressive and tensile strength, which is useful for strengthening or repairing concrete members. Web openings are usually constructed in simple reinforced concrete (RC) beams in the shear zones that occasionally demand the crossing of water or sewage pipes and utility cables to accommodate the utility. The presence of opening has a remarkable effect on the ultimate strength of (RC) beams and the beams failed due to shear . This research analyzes numerically simple RC beams with opening strengthening using a UHP-FRC plate. Through the computer program ABAQUS, a numerical study focusing on the nonlinear analysis of finite elements was carried out. The FEM was verified using the experimental studies simple RC beam with/without openings were cast and tested. The UHP-FRC plates were used on both sides of the RC beam around the opening. The numerical study was carried out to investigate the impacts of using UHP-FRC plates with five different thicknesses (10, 20, 30, 40 and 50) mm with constant width 100mm and three different plates with width (50,70 and100) mm with constant thickness 20mm. The result showed that the use of plates thickness from 10 to 20 mm increased the ultimate loads about 52.99% to 62.81%, the use of plates thickness from 30up to 50 mm could not provide any enhancement in the ultimate loads, and the use of plates with different width from 50 up to 100 mm increased the ultimate loads about 23.91% to 62.81%. Overall, the strengthening technique using UHP-FRC plate of RC beam with the opening significantly enhance the ultimate load, ductility and shear strength.