Application Of High Performance Concrete In The Precast Prestressed Concrete Bridge In Railway

Concrete has been used for nearly 200 years,from ordinary concrete to high strength concrete,high performance and green concrete development gradually.Since the last century,concrete has become a preferred material of buildings,Bridges,water conservancy,roads and other modern engineering structure.As a society,application of railway bridges can save land and account for less fertile fields,while from the technical viewpoint,is mainly to control the problem of roadbed settlement.As the designed life of more than one hundred years of railway bridge is increasing,the proportion of application of prefabricated bridges using high-performance concrete if they could be in the right under the guidance of the theory of rational analysis and improve the use and can not only achieve the design of the "one hundred plan",and can avoid related engineering quality defects in the process of construction,in addition,the development of the reasonable and efficient use of high performance concrete,inevitably will drive the further development of the high-speed railway.The purpose of this paper is to research the mixture ratio of high performance concrete.Through discussion on precast beam curing system,choice the best concrete construction technology,to improve the efficiency of the simply supported beam production,quality,and reduce energy consumption,production cost.The current railway engineering used high performance concrete as the same as the general high-performance concrete with high workability,high durability,high construction and economical requirements.Prefabricated T beam used in railway engineering is the national production license shall be issued for factory production,different from the ordinary railway and other engineering construction.In order to improve production efficiency,reduce cost and ensure time limit for a project to improve the template turnover rate,and the national various prefabricated T beam averaged by the acceleration of the steam curing to achieve this purpose.This paper research and analysis on the production technology of prefabricated T beam,determine the construction process of concrete is the precast beam production process of the main factors influencing the pedestal turnover.By redesign of the concrete mixture ratio,composite mixed will prefabricated track of high speed railway the mixture into T Beam Precast concrete mix proportion.Prefabricated T beam was determined by the test of compound admixtures the optimal mixing proportion,and in the test to determine the design has reached the railway related specification of prefabricated T the requirements of high-performance concrete beams.For high performance concrete,sand ratio,water/cement ratio and the admixture are the main factors of concrete quality.Through experiment analysis on the main factors of 3d,7d,28d strength,found that the composite admixture are the main factors influencing the 3d strength of high performance concrete.Through optimizing the mixture ratio,achieve the growth in the early strength of parameters in the same time,new mixture preparation of high-performance concrete early strength than conventional steam curing of high performance concrete strength can meet the requirements of design and industry,and even new mixture production of precast beam slightly higher than the design requirements,and industry and the natural curing the construction process to replace the original steam curing process.New concrete construction technology not only changed the concrete curing process and improved product quality.At the same time,through economic analysis,using the new mixture ratio of the production process cost reduction was reduced than the original steam curing process,and due to the cancellation of steam curing system,had eliminated the dependence on the boiler in the original production process,reduce the energy consumption and the air pollution,etc.