Experimental Study On Bending Resistance Capacity Of Reinforced Concrete Beams Strengthened By External Prestressing And The Contrast Against It By Bonding Steel Plate

In this paper, the author study the mechanics performance of reinforced concrete beam strengthened by external prestressing and the contrast against it by bonding steel plate by the means of theoretics and experiment. Through this study, the author educes many valuable conclusions and put forward some advices for the design of beam strengthened by external prestressing.First, the author carried out static experiment on the 1:1 model of fixed support beam strengthed by external prestressing and by bonding steel plate. In this experiment, there are 6 fixed support beams. Three of them are strengthened by external prestressing, two of them are strengthened by bonding steel plate, and the other one is reinforced concrete beam as contrast experiment beam. In the experiment, the author get many conclusions on the fixed beam strengthend by the two means through analysing the experiment result, including strain, displacement, angle of rotation and damage character.Secondly, the author compares the two strengthening means in two aspects. They are mechanical property and the convenient of construction. It can be used for reference in selecting strengthening scheme .Once again, contraposing the specific case in engineering strengthening and the shortcoming in the strengthening concrete norm, the author puts forward modified means that designer should examine the internal force after esmating the prestressed tension rod sectional area and deduce the practical formula used in the examining. The formula is suitable for most engineering cast which consist of three disposal styles of tension rod-level tension rod, one break point strut-framed tension rod, two break points strut-framed tesion rod, and consider the boundary condition's effect on the strengthening. Its application also is convenience.Finally, by the experimental data and the programming calculation, the author study the eccentric compression and tension state on the control section of the two style of strengthened beam. Basing on the formula and the theory on reinforced concrete cross-section's eccentric compression and tension, the author programsABSTRACTcomposition that examine strengthened concrete cross-section's stress condition by matalb software. By this program and experimental data, the author analyzes the strengthening theory and the cross-section's bending resistance capacity of strengthened beam. In addition, this program can be used in engineering.