SERVICEABILITY OF CONCRETE BEAMS PRESTRESSED BY CARBON FffiRE REINFORCED PLASTIC .RODS

This paper describes an experimental program undertaken at the University of Manitoba to study the serviceability of concrete beams prestressed by carbon fibre reinforced plastic (CFRP) rods. The experimental program consisted of eight concrete beams prestressed by CFRP rods and two concrete beams prestressed by conventional steel strands. The beams were tested using two static concentrated loads which was cycled three times between a lower load level equivalent to 80% of the cracking load of the beam and an upper load level equivalent to 60% of the predicted strength of the beams which is equivalent to 1.5 to twice the cracking load depending on the prestressing leveL The beams were tested to examine the various limit states flexural behaviour, as well as to investigate the different modes of failure of concrete beams prestressed by CFRP reinforcement. The parameters considered in this experimental program were the prestressing ratio and the degree of prestressing. The findings of this experimental study, combined with available information, were used to propose design recommendations of concrete beams prestressed by CFRP rods.