Experimental Study on Carbon Fiber Reinforced Polymer Strengthened Pre-Cracked Box Girders with Corrugated Steel Web

This paper presents an experimental study on carbon fiber reinforced polymer (CFRP) strengthened pre-cracked box girders with corrugated steel web subjected to bending. The research work covers the original crack and crack growth on the corrugated steel web, the influence of deflection and strain response. The results show that the flexural strength and load carrying capacity of the cracked corrugated steel box girders can be improved through the CFRP strengthening. As a result, the growth of the initial crack development is restrained efficiently. The new cracks are mainly located between the loading point and support. The ultimate failure mode is characterized as the shear failure on the bottom flange plate and the interfacial slippage between the web and the bottom flange. It is worth pointing out that the initial deflection of the strengthened corrugated steel web box girders is greater than that of the girder before strengthening. However, with the load increase, the former deflection is growing slowly until it becomes smaller than the latter, i.e., the strengthening enhances the stiffness of the box girder, at the same time the residual deformations are increased.