Study On Reasonable Mixture Ratio Of Concrete In Cold Area And Marine Environment

Qing Long He bridge and Na Chao He No.2 bridge located in Bohai Bay where the concrete structure suffered water erosion and frost damage all the year round so that the concrete structure there is lack of durability.In order to ensure the durability of the concrete structure in cold area and marine environment,at the background of the project of Qing Long He bridge and Na Chao He No.2 bridge in Cao Fei Dian economic development zone,this thesis tries to find out a concrete mixture ratio design method which is suitable for cold area and marine environment through theory and experimental research.The main research contents and conclusions of the thesis are as follows:1.The author introduces the composition of concrete and its impact on concrete performance.When high-performance concrete take durability into first consideration,the choose for mineral admixture plays a vital role.After analyzing previous researches on mineral admixtures,this thesis proposed to choose the composite admixture of fly ash and slag powder as the raw material of high-performance concrete in cold area and marine environment.2.This paper introduces common design methods of high-performance concrete proportion.By the contrast analysis,this thesis finally chooses overall calculation method to research the design method of high-performance concrete proportion in cold area and marine environment.3.Based on overall calculation,the author calculates the mixture ratio of C45 intensity level of high-performance concrete,then carries out a testing experiment according to the mixture ratio.On the basis of the experimental results,the author finds out the deficiencies of overall calculation when confect the concrete proportion in cold area and marine environment and points out the revised overall calculation method.4.Based on the mixture ratio benchmark and combined with experiment.this thesis gets the reasonable numerical value range of correction factor y.By means of revised overall calculation method,the author calculates high-performance concrete proportion of c50 and c55 intensity level and designs a confirmatory experiment based on the calculated results of mixture ratio.The applicability of revised overall calculation method has been proved through experiment result.