Retrofitting and Rehabilitation in Steel Moment-resisting Frame with Prestressed Concrete Slab against Progressive Collapse Potential

Diaphragms are a fundamental part of the earthquake-resistant system, and in terms of rigidity, it is essential to transmit dynamic loads on a base of the structure. Also, floor openings on the response of buildings against progressive collapse are issues that have received less attention. In this study, floor opening surfaces and their positions on the progressive collapse potential of steel moment-resisting frame (SMRF) buildings were investigated according to the alternate load path method. Moreover, to retrofit and rehabilitate the two-way reinforced concrete (RC) slabs against a progressive collapse, two strategies, prestressed concrete slabs and installing carbon fiber reinforced polymer sheets on the surface of the old concrete slab, were proposed and six-story SMRF buildings were simulated using the finite element method. The maximum axial force around the removal column is 20% greater than the corresponding values on the floor opening is in the corner of the plan and the appropriate performance of the prestressed concrete slab leads to the load distribution in the ceiling diaphragm.