Research On Strengthening Reinforced Concrete Beams With Prestressed CFRP Sheets

Carbon fiber reinforced plastic(CFRP) has been used widely in strengthening of concrete structure as a new material.But the character of high strength in CFRP can't fully exert with general strengthening method.Some scholars and scientific research institutes performed some experimental study in strengthening reinforced concrete beams using prestressed CFRP sheets.Experimental results show that the character of high strength in CFRP exert effectually, restrain the expansion of crack and distortion,improve greatly the performance of the beams, with the strengthening method.The more study of strengthening reinforced concrete beams with prestressed CFRP sheets is important and valuable.Numerical simulation and calculation in theory are done for the beams strengthening with prestressed CFRP sheets in this paper base on the present experimental results. First,using strip-partitoning method and programming in matlab language,the numerical caculations of the relation curve between moment and curvature are done for the beams strengthened with non-prestressed and pretressed CFRP sheets,base on the assumption of plane section, non-bonding slip and non-peeled destroy.Secondly,nolinear finite elemeant analysis by ANSYS are done for the beams strengthened with prestressed CFRP sheets base on the three assumptions before mentioned ,the analysis are all done for the relation curve between load and displacement, the distribution of material stress,the distribution of cracks.Lastly,calculation formula of flexural capacity and deflection are proposed. The effect of load history is taken into account.The method and formula confirmed by that results of numerical simulation and calculation in theory are in good agreement with the experimental results.