Abstract: Utilized the capability of electrical conductivity and piezoresistivity, CFRP alarm sensors are produced by two methods which are post-layered method and pre-layered method. This kind of sensor, which has the obvious merits such as the low cost, corrosion free, and its easy conformance with the test conditions, further can give different alarm sounds according to the rupture of different CFRPs, which means it can distinguish the work phase of the structure. The experimental research of five reinforced concrete beams for investigating the practicability of such an alarm sensor is presented in this paper. As a result, CFRP alarm sensors can give a good prediction to the macroscopical behaviors of reinforced concrete beams. Especially, the electrical resistance of CFRP will bring an obvious signal at the moment when concrete cracks and steel yields, which means that an alarm is given. It is concluded that CFRP alarm sensors is practical to reinforced concrete elements.
Key words: CFRP; sensor; structure health monitoring; alarm