Research On Flexural Strengthening Method Of Reinforced Concrete Beams

A considerable part of the existing highway bridges was built in 80 s in our country.The bridge which has kept operating for more than 30 years accounted for about 40% of the total bridge.The industrial economy has brought great changes to the vehicle operation condition and the environment condition of the bridge,that has exacerbate the deterioration of the bridge condition.Reinforcement and reconstruction of bridge with safety hidden danger can restore its proper carrying capacity and improve durability.This paper carried out the experimental study on flexural strengthening of reinforced concrete hollow slab beams with representative active service.The effects of three kinds of reinforcement methods,which are bonded steel plate,prestressed carbon fiber board and carbon fiber board,are studied to improve the bending stiffness and bending strength of the beams and to restrain the development of cracks.The bending strengthening theory of carbon fiber board is discussed in combination with the standard.We can conclude from the results of the experiment as follows: The reinforcing effect of the steel plate method is the best;The reinforcing effect of pasting the prestressed carbon fiber sheet is a little worse than it;The reinforcing effect of the carbon fiber sheet method is the worst,but it still meets the requirement of strengthening design.MIDAS FEA was used to simulate the experimental beam.The simulation results of the experimental beam are close to the experimental results under the condition of considering the dispersion crack model,which can ensure the correctness of the testing process and results.Through the case of a bridge reinforcement,the method of quality inspection for the strengthening of carbon fiber sheet is introduced in this paper.We have done a load test on the bridge after the completion of the reinforcement.The results of bridge load test show that the reliability of carbon fiber sheet used in flexural strengthening of RC beams.The research results of this paper have a certain theoretical significance and practical value for the bending strengthening of concrete bridges.