Study On The Influence Of Key Construction Technology Of Box Girders On Durability Of HPC Used In Passenger Delivered Lines

The high-speed passenger dedicated lines has been wildly constructed for virtues of all-day operation safety,large transportion capablility,high speed,little enegy cost,low pollution. High Performance Concrete(HPC) using in box girders is aimed to obtain good endability ,however,during the process of construction ,many factors will affect the strength and endability of HPC. And during construction,the tempreture of concrete raises due to the heat produced by the cement hydration,while the surface temperature is lower,and the the temperature within inside and outside. And all of these maybe cause cracks.The effects of several factors such as weigh error, working capability of material, vibrating time, delay time, curing regimes on the strength and durability of conrete are investigated based on the construction of Shi-Tai passenger delicated line.Temperature changes inside box girders in 48hours after pouring are simulated using finite element method.The relationship between temperature and time is obtained. The analytical results are compared with experimental data partly. Four measures to control cracks caused by temperature are proposed.