Technological peculiarities of strengthening RC members with prestressed FRP laminates

There is a general agreement on the benefits of using FRP materials for structural retrofitting. Full potential of this high strength material can be implemented by the process of prestressing. However, prestressing has a number of nuances and can be compromised. Therefore, based on the results of a recent experimental study and the experience of other authors, the peculiarities and issues of prestressing FRP laminates are summarized. Current paper includes the steps from the surface preparation, anchoring to commissioning. Also, a novel prestressing system for retrofitting of reinforced concrete members with externally bonded FRP laminates is disclosed. The advantage of the proposed system lies in the fact that efficient corrugated surfaces are employed for compression of FRP reinforcement. Usually, the result of using corrugated surface steel grips would be a fractured laminate, therefore plane surfaces are common in commercially available prestressing systems.