Experimental and numerical analysis of deep beams with openings strengthened with galvanized corrugated and flat steel sheets

This study investigates the behavior of deep reinforced concrete beams with openings strengthened using galvanized corrugated steel sheets (GCSS) and galvanized flat steel sheets (GFSS). An experimental program was conducted on ten deep beam specimens with different opening configurations, strengthened by externally bonded GCSS and GFSS around the openings. The key test parameters are different types of galvanized steel sheets (corrugated and flat) and different opening configurations (circular and square) with different opening sizes. It is found that the application of galvanized steel alters the mode of failure of the strengthened beams compared to the unstrengthened beam which failed due to premature shear failure. The deep beams strengthened with galvanized steel sheets exhibited higher initial stiffness, energy absorption capacity, and ultimate loads compared to the control beam. Finite element modeling (FEM) using ABAQUS software was performed to simulate their experimental behavior and the prediction accuracy is examined against the test results. A parametric study using the validated FEM is carried out to examine the influence of the thickness of the galvanized plates and opening size ratio on the shear strength of the deep beams. The findings reveal that shear strength increases with the increase of the plate thickness and an opening ratio of 0.33 is recommended for practical applications of deep beams strengthened with galvanized steel sheets.