This project is a fundamental necessity, given the fact that a majority of the nation’s structures are over 30 years old. With limited funds these structures won’t be able to be replaced for years to come. With increasing truckloads, the external composite strengthening approach is the only method of strengthening to prolong their life span. This investigation entails the testing required to determine the effects of the environment on the durability of external composite strengthening. The project will address the testing and performance evaluation of 81 FRP strengthened concrete beams and FRP coupon specimens subjected to various environmental conditions. These environmental conditions will include: (1) freeze/thaw, (2) repeated (fatigue) loading, (3) UV light, (4) water submersion/humidity, (5) saltwater, (6) alkali, and (7) dry heat exposure, as detailed in Table 1. The environmental exposures will be conducted in accordance with ASTM specifications
Two types of fiber-reinforced polymer (FRP) will be used in this investigation. The test beams will be constructed, strengthened and subjected (with CFRP coupon specimens) to specific environmental conditions. After the completion of these accelerated environmental exposures, proper instrumentation will be applied to the test beams. Each beam will be subjected to four-point flexural load tests up to failure. Loading and unloading will be conducted to determine the level of the dissipated energy. A 30x12x12 environmental testing chamber of several capabilities is under construction in the STC. Several laboratories and skilled technicians will be supporting the various activities outlined in this proposal.