Optimum Design And Whole-working History Analysis Of Prestressed Reactive Powder Concrete Low-height T Beam

As a new kind of composite material, owing to its high mechanical properties such as high strength, high tenacity, high durability, volume stability and so on, Reactive Powder Concrete (RPC) has attracted much international attention. At present, lots of research result of RPC concentrate on material matching optimization and basic mechanic property research. In order to fill in the blank in the field of RPC structure of our country, under the fund of research and develop subsidy of Ministry of Railways, School of Civil Engineering and Architecture(Beijing Jiaotong University) has developed railway span of 20m prestressed RPC Low-height T Beam, which has been used in the actual project.The dead-load experiment indicates that the railway span of 20m prestressed RPC Low-height T Beam developed by Beijing Jiaotong University can be up to the required mechanics index, and also exceed it a lot. So, optimization design and the whole history analysis for the Low-height T beam have extremely important meanings to offer the design theory and design method for application of RPC in bridge engeneering.Firstly, based on Optimization design module of ANSYS, with the use of Subproblem Approximation Method and First Order Optimization Method, this paper optimizes the size of span 20m prestressed RPC(Reactive powder concrete, short for RPC )T beam. Objective function is the total cost of RPC and prestress wire. State variables are the maximum principal tensile stress and the maximum compression stress. Design variables are the thickness of upper plate, bottom plate, and web plate of T beam and the cross-section area of prestress wire. As a result, with the mechanical property and material usage of T beam optimized, the total cost of RPC low-height T beam is reduced.Secondly, through the program programmed by myself, this paper carried the whole history analysis on RPC low-height T beam. The analysis has two parts: first, non-prestressed RPC low-height T beam analysis; second, prestressed RPC low-height T beam analysis. In the first part, this paper analyzes the relationship between bending moment and compression strain of top of T beam under different ratio of reinforcement, stress distribution of the section of T beam, crack resistance, simplified calculating method of limit bearing capacity and crack resistance. In the second part, this paper analyzes the bending moment of section under three different ratio of reinforcement and prestressed reinforcement.Finally, it disposes and analyses the dead-load experiment data.This paper, as a tentative result, offers the reference for the RPC's application and study in its structural field in the future.