Keywords: concrete beams, carbon fibre reinforced polymers, CFRP wraps, FRP, durability, beam, aging, beam bending tests, carbon wraps, maximum load, deflections, crack width, deformability, deformation
Durability study on CFRP wrapped concrete beams under aging conditions
The main purpose of this paper is to study the performance and durability of concrete beams with wrapped carbon fibre reinforced polymer (CFRP) under accelerated and natural aging. Variation in mechanical properties of CFRP wrapped concrete beams due to aging through: 1) water immersion, salt and alkaline solution immersion at elevated temperatures (room, 43°C and 60°C); 2) natural constant 20°C; 3) outside weathering was studied. Different parameters evaluated during beam bending tests are: maximum load (moment), deflections, crack width, and deformability factor. Results of experimental/theoretical load (moment) ratios indicated a trend of reduction in load (moment) capacity with increasing temperatures. The ratios of load at each deflection limit to maximum load of beams aged in water decreased with both temperature and aging duration. In addition, the average deformation factors decreased with increase in temperature and aging duration. Accelerated and natural aging results were compared on the basis of stress-temperature-time superposition principles. Based on the correlation of natural aging to accelerated aging, 12.73% strength reduction in carbon wraps bonded to concrete beams is equivalent to about 77.5 years.