Girder 0 # Block Pouring Temperature Field And The Early Thermal Stress

With the enhancement of strength of materials and the development of theprestressing force technology, the span of the prestressed concrete continuous girderbridges constructed by cantilever method becomes larger and larger. At the same time, thestrength of concrete is much higher and the volume of the box girders near the piers ismuch bigger than before. It is important to solve the temperature problem caused by heatof cement hydration in order to reduce the cracks brought by temperature in cement duringthe placement of high strength box girders.Based on the prestressed concrete rigid frame bridge connecting the HengKun nationalhighway from FuNing to GuangNan in Yunnan province, the paper combines the fieldmeasurement method with finite element analysis in the research and educes thedistributive regularities of temperature and stress fields. Comparing with the two results,the finite element model in the paper is correctly made up to simulate the temperature fieldof the concrete in practice. It can be used to work out the forepart temperature stress ofthe concrete. Recur to finite element software, the paper reviews several factors that canaffect the temperature fields and stress fields of the concrete. These factors includeconcrete component, heat conductivity, thickness, atmosphere temperature, wind speed,construction technique, heat preservation measures, the time of backout moulding boardand so on. In the end, the paper get some helpful conclusions and practicably advances,which can afford references to other people on construction control and preventing crackof the similar bridge.