Study On Mixture Ratio Optimization And Performance Of High Performance Concrete Applied To Beijing-Shanghai High-speed Railway (from Dezhou To Jinan)

The Beijing-Shanghai high-speed railway is the highest standard, largest scale and the longest constructed in one stage in the world at present. It is the biggest project since the new China’s establishment. There are247bridges about1061km which are80.5%in total length. All the bridges used high performance concrete.The material-selecting, mix design, construction control and etc., are the critical of the properties of high performance concrete. Design the appropriate parameters of mix proportion and play the high workability and high durability become the problems to be solved urgently.In this paper, the compression strength and durability of high performance concrete was studied for the section of Dezhou-Jinan of Beijing-Shanghai high-speed railway. The related influencing factors of compression strength and durability were analyzed and some useful conclusions were obtained for the construction.(1) The mix design was studied using the orthogonal test method. The factors, such as the water-binder ratio, the total amount of binder and the dosage of mineral, were studied on the high performance concrete at different ages. And the parameters of mix proportion were given in the study. The water-binder ratio is0.37, the total amount of binder is380kg/m3and the dosage of mineral is40%. The water-binder ratio is the significant factor in three factors from the3d to56d. Its influence increased with time. The dosage of mineral is the significant factor at the early age at3d and7d. Its influence decreased with time. The total amount of binder is the significant factor at3d, but it decreased after7d and it became the indistinctive factor. The influence of the total amount of binder is the smallest one in the three factors.(2) The results indicated that the water-binder ratio becomes smaller, the frost resistance becomes better, the chloride-penetration resistance becomes smaller and the anti-permeability becomes better. The dosage of mineral and the total amount of binder exist an optimum value each other.(3) Under the guidance of the results and based on the engineering practice, the appropriate high performance was produced. The practice shows that the concrete can not only satisfy the requirements of bridges of high-speed railway, but also saved the engineering cost.