Parametric study of anti-explosion performance of reinforced concrete T-shaped beam strengthened with steel plates

Parametric studies are performed to investigate the influence of the weight and position of explosive charges, reinforcement lengths of steel plates, and reinforcement methods, such as pasting steel plate on the bottom of reinforced concrete T-shaped (RCTS) beam, pasting steel plate on both sides of web plate, pasting U-shaped steel plate on the web of RCTS beam, fully packaged the beam with steel plate and pasting steel plate on the top and bottom of RCTS beam, on the dynamic behavior of the RCTS beam under blasting load by numerical simulation method. Numerical results show that the failure modes of the RCTS beam are closely related to the weight and position of explosive charges. With the increase of explosive charges, the deformation modes of the beam are changed from elastic deformation to tension bending deformation, and finally the flexural shear failure is occurred. With the height increase of vertical direction of explosion, the failure patterns of the beam are changed from bending shear to tensile bending. Changing the explosion positions from the mid-span to the end of the beam, the damage positions are also changed with the moving of explosive. The damage modes of the beam and the positions, where the cracks are formed, have a strong dependence on the position and the weight of explosive charges due to the local effect of blasting load. Compared with the ordinary RCTS beam, the initiation time of cracks of the RCTS beam strengthened with steel plates is delayed and the growth speed of the cracks is also significantly reduced. The crack distributions of the beam strengthened with steel plates are mainly concentrated on the reinforced area. Moreover, the number of the formed cracks is also reduced and the compressive stresses of concrete in the compression zone of the beam strengthened with steel plates are lowered down. Among the reinforcement methods in the present study, the best reinforcement method to improve anti-explosion performances of the beams is the beam strengthened with steel plates on the top and bottom of it. The optimal size of reinforcement length of steel plate is about 80 cm by comparing the different reinforcement lengths of steel plates in the same explosion case. To some extend, this study could provide some basis for evaluating anti-explosion performances and scheme design of structural strengthening of the beam.