Concrete-fiber-reinforced polymer interfacial bond monitoring with self-triggering sensors

摘要

External bonding with fiber-reinforced polymers is currently one of the most popular technologies for rehabilitation of concrete structures. However, the effectiveness of the technology largely depends on the strength of the bond between the fiber-reinforced polymer laminate and the concrete substrate. This article provides a system to monitor the loss of bond between the fiber-reinforced polymer laminate and the concrete. Fiber optic sensors are broadly accepted as a structural health monitoring device for fiber-reinforced polymer materials by integrating the sensors into the host material. A recent development in fiber optic sensor technology is the mechanoluminescence-based optoelectronic sensors. Concrete beams strengthened with multifunctional fiber-reinforced polymer laminates were tested in shear using these sensors to evaluate the bond strength of the composite system. The sensors showed response to shear stress transfer in the adhesive layer which was observed to be as low as 2MPa. The inclusion of sensors does not affect the bond strength (3.35MPa), for both beams with sensors and without sensors. Real-time failure detection of fiber-reinforced polymer-strengthened beams was successfully achieved in this study. In future, the scheme aims at providing a tool to reduce the response time and decision making involved in the maintenance of deficient structures.