Stress Performance Analysis And Experimental Study On Hollow Slab Reinforced With CFRP

The prestressed concrete hollow slab with its characteristic of convenient construction is widely used in a highway bridge which has a small or medium size span. However, due to the environment deterioration and load addition, many cracks have already appeared in it to some extents. Strengthening the hollow slab with CFRP, which can enhance its carrying capacity and security, can bring a good many economic and social benefits to our country.Based on the former experimental study and theoretic calculation, finite element analysis has been done on the prestressed concrete hollow slab strengthened with CFRP in this paper. Main research is as follows:The impaction of mechanical characteristics has been analyzed by different direction and different amount of CFRP attached to the hollow slab. Study shows that the number of CFRP layers only do little help to the cracking load, whereas, the more layers are, the more carrying capacity it has under the balanced-reinforced condition; Calculative results show that under the condition of not changing the amount of CFRP and reliable anchoring, the measure of pasting more layers of CFRP to the structure can be adapted, and it turns out to be a better way of strengthening structure.On the basis of balanced-reinforced destruction model I and balanced -reinforced destruction model II, a set of formulas to calculate the bearing capacity of bending have been given. The credibility of this method is validated. That the results of checking calculation by the formulas coincide with those by FEM shows that the formulas obtained in the paper are correct.Taking the prestressed model and the non-prestressed model in comparison, this paper analyzes the characteristic impacted by using different amount of prestress to the hollow slab. Research results show that the appropriate initial tensile intensity of CFRP ranges from 20% to 30%.