Flexural behaviour and ductility of HSC beams prestressed with AFRP tendons

This paper presents experimental results on the flexural behaviour and ductility of High Strength Concrete (HSC) beams prestressed by Aramid Fibre Reinforced Plastic (AFRP) tendons. The study showed that the load-deflection relationship of HSC beams pretensioned with AFRP tendons, varied linearly before cracking and almost linearly after cracking with a reduced stiffness. An increase of concrete strength led to an increase in cracking moment, but did not necessarily result in an increase of the ultimate moment capacity. The sustained service load had little effect on the ultimate flexural strength. The study also showed that at failure, the deflections of AFRP beams were less than those with steel strands. The deflection at ultimate of beams with AFRP decreased with the increase of concrete strength. On the other hand, the HSC beams absorbed more energy than Normal Strength Concrete (NSC) ones. A new definition of an overall factor expressed as a combination of the strength factor and energy factor, appears to be a suitable indicator of ductility of beams prestressed with AFRP tendons.