Galvanized corrugated steel sheets as an efficient material for torsional strengthening of RC beams

ABSTRACT Torsional deficiency is a critical issue in reinforced concrete (RC) beams, often leading to premature cracking and loss of structural integrity. This study proposes the use of anchored galvanized corrugated sheets (GCS) as a sustainable strengthening technique to enhance the torsional performance of RC beams. An experimental program was conducted on nine specimens, including two unstrengthened controls and seven beams strengthened with GCS. The investigated parameters were the orientation of GCS (horizontal, vertical, and inclined), sheet thickness, and bolt anchorage length (4D, 6D, and 8D, where D denotes the bolt diameter). The performance assessment focused on crack development, ultimate torsional capacity, torque–twist response, stiffness, and energy absorption. The results demonstrated that beams strengthened with inclined GCS achieved the highest improvement in torsional strength compared to horizontal and vertical orientations. Increasing sheet thickness and bolt length further enhanced structural performance. A finite element model (FEM) was developed and validated against the experimental findings, showing good agreement. A complementary parametric study confirmed that increasing the number of bolts can provide additional gains in torsional resistance. The proposed technique offers a practical and efficient solution for strengthening RC beams subjected to torsional stresses.