Research On Bending Capacity Experiments Of RC Beams Externally Prestressed With CFRP Tendons

With the increase of service life, a large number of bridges have varying degrees of damage, even affect the running safety. So the appropriate measures must be taken to reinforce the bridges. External prestressing reinforcement technology is considered one of the most effective methods of bridge reinforcement. Carbon Fiber Reinforcement Polymers (CFRP) have advantages of high strength, light weight, non-corrosion and anti-fatigue. The reinforcement technology of external prestressing CFRP tendons, which is the combination of the advantages of external prestressing reinforcement technique and CFRP materials, will be widely used on the bridge reinforcement engineering. Based on the static load test of 13 trial beams(12 external prestressing reinforced beams with CFRP tendons and 1 un-reinforced beam), the paper mainly studied the influence factors of bending resistance capacity, ultimate stress increment of CFRP tendons, and the calculation method of the bending resistance capacity.According to the test results, this paper analyzed the bending resistance capacity, deformation, crack, strains of CFRP and steel tendons, and verified that the plane section assumption is also applicable. Otherwise, the influences of arrangement of external CFRP tendons, concrete strength, reinforcement ratio and load level were researched. And ten methods were adopted to calculate the ultimate stress of external CFRP tendons. The calculation results were compared with the experimental results, and the best appropriate calculation method was determined. It should provide the references for practical engineering applications. Finally, based on the calculation method of bending resistance capacity, the calculation results were in good agreement with experimental results.