Experimental Study of Flexural Strengthening of Two-way Reinforced Concrete Slabs Using Punched Steel Plates

Document Type : Research Article


1 civil engineering department, faculty of engineering, ferdowsi unversity, mashhad

2 department of civil engineering, faculty of engineering, ferdowsi university of Mashhad


RC slabs are the structural members responsible for carrying and transferring loads. RC slabs need to be strengthened as a result of different reasons such as changing of function and corrosion of steel bars. The most widely utilized approach in strengthening these slabs has been the usage of steel plates. However, the concerns in using these plates consist of their immense weight as well as their unreliability in being properly connected to the concrete slabs. This study focuses on using punched steel plates as a strengthening factor for concrete slabs since they have reduced weight and allow an easier and more reliable connection. For the experiment, two-way RC slabs with the dimensions of 120 cm and the thickness of 8 cm are strengthened through punched steel plates and are placed under a semi-concentrated loading effect. The effect of plates’ thickness, the arrangement and the area of the punched holes, and the connection type in the performance of the strengthening system are studied through load-displacement graphs and are analyzed in dissipated energy and ductility. The results showed that the punched strengthening plates increase loading capacity, energy absorption, and the ductility of the two-way slabs up to 62%, 253%, and 220%, respectively. Also, it was shown that the arrangement of the holes and the connection type of the strengthening plates have a significant effect on the performance of the strengthening system. Failure state control in experimental models showed that the failure mode in using epoxy resin is the debonding of the steel plate, while the failure mode in using expansive bolt is pulled out of the bolt.


Main Subjects

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