Mechanical Properties Research Of Rectangular Reinforced Concrete Beams Strengthening By Steel Plate And Concrete Composite During Construction Stage

The steel plate and concrete composite strengthening(SPCCS)technique has been widely concerned by the strengthening industry because of it is convenient to construct and it has an advantage that it can obviously increase the rigidity and strength of the reinforced structure after reinforcement.The SPCCS technique is the application of the steel-concrete composite structure,which is an effective combination of the Increasing cross-section reinforcement method and the bolting steel plate reinforcement method in the bridge reinforcement method.By using the Mechanical Properties of steel plate and concrete and dealing with a reasonable structure interface,the SPCCS technique has become a new practical technology which can obviously increase the bearing capacity and the structural rigidity of bridge.At present,the relevant research about SPCCS technique was mainly aimed at the mechanical properties of the whole structure after reinforcement.In view of the characteristics of the beam to be strengthened that the bearing capacity and the structural rigidity are insufficient,the research about the mechanical properties of the beams to be strengthened during Construction stage is rare.In this paper,according to the technical characteristics of SPCCS technique,the numerical simulation is performed on the rectangular reinforced concrete beam reinforcement.The research was mainly concentrated at the following:Firstly,at the beginning,the composition and basic principle of the SPCCS technique was introduced,and the mechanical principle of the rectangular reinforced concrete beam in the reinforcement of the construction process by the impact of the factors was introduced.Secondly,a three-dimensional solid model of rectangular reinforced concrete beam was established by using the method of separate modeling with the finite element software ANSYS to analyze the drill hole of planting rebar at the bottom and the side of beams.The effect of different hole density,drilling diameter and drilling depth on the initial flexural Stiffness of the beam in the elastic-plastic phase,which can provide a reference for the design and construction of the SPCCS technique.Thirdly,in view of the most unfavorable stage of SPCCS technique during the construction of pouring concrete,the finite element method was used to build and analyze the concrete beam model with planting rebar at the different diameters and depth,so as to propose a correct design solution to install planting rebar on the concrete beam,and the correct design solution of the SPCCS technique was further improved by theoretical and numerical simulation analysis.