Abstract:

Directing to the insufficient of concrete beams strengthened with fiber reinforced plastics,the study is focused on prestressing to glassfiber reinforced plastics and bonding prestressed GFRP on the tension surface of concrete beams to improve the load-bearing capacity of concrete beams.Considering the low shear strength capacity of GFRP,the article studies the method of prestressing to GFRP and then,9 strengthened beams with different prestress and concrete grade are done in the experiment of bending strengthening.Strengthened beams with different bonding style on the side of concrete beams with the same prestress are also made in the experiment of shear strengthening.Experiment results show that concrete beams strengthened with prestressed GFRP can enhances the cracking moment and ultimate bearing capacity and strength utilization factor of GFRP and can also lead to a much slower growth of cracks and improve resistance to deformation.

Key words: prestress, GFRP plates, strengthen, concrete beam, experiment