Structural health monitoring of structures repaired with FRP

Sprayed FRP is a novel method developed at the University of British Columbia which has been very successful in repairing damaged structures is Sprayed FRP. The key to a successful and optimal usage of FRP in strengthening and rehabilitation is in our ability to understand and effectively engineer SubstrateFRP bond. In this paper, performance of FRP as a repair material is studied by structural monitoring of the substrate and the FRP sprayed patch. In this study, 35x10x10 cm concrete beams are sprayed with FRP and tested under fourpoint loading. The substrate and repair material response to loading is monitored using strain gauges carefully installed at different locations of the structure. Ten 10-mm one-directional and two bi-directional strain gauges are used. Data is obtained using data acquisition machine and converter software. The load-stain curves for the strain gauges are graphed. The measurements at the gauges located at the same level are compared and strain divergence is discussed. Possible approaches are discussed to model the gradual process of bond interface. This is the basis for a comprehensive damage model capable of predicting the performance of repaired structures under various static and earthquake loading. A field performance of these repairs will also be discussed. The case study is a bridge in Victoria, British Columbia, which was repaired by sprayed FRP and has been monitored over the past three years by the materials group of UBC under Dr. Banthia’s leadership.