Study Cases of Steel Plate Epoxy Bonded Reinforced Concrete Beams with End and Intermediate Anchored Bolts

Abstract

A main drawback of external strengthening in reinforced concrete beams by bonding steel plates to the concrete tension surface is the interfacial debonding failure between a steel plate and a concrete beam that leads to the loss of composite action. This is due to the induced large shear and peeling distributed forces at a small region near the ends of the steel plate. To avoid or prevent this mentioned situation, results which found in the experiments with an additional installation of the anchored bolts in the reinforced concrete beams strengthened by epoxy bonded steel plate have been indicated that a significant increase in both the load carrying capacity and deflection of the beams can be achieved. Nevertheless, the failure by debonding is still occurred which can be observed from the load-deflection relationships. The experimental results have also been shown that the use of bolted anchorage system can prevent the occurrence of full debonding failure due to premature end peeling of the steel plate and also improves the performance of the strengthened beam. The mode of failure is changed from the brittle mode for beams without anchorage to the ductile mode for beams with anchorage, which is a good failure mode.