The Research Of Hydration Heat Temperature Effect And Temperature Control Measures On The Zero Block Concrete Of Long-span Continuous Rigid Frame Bridge

With the stress of temperature on the deepening of the bridge, box girder Zero block hydration heat issue has been more and more attention in the pre-cast block number zero due to the heat of hydration and outside the box girder will have a greater temperature gradient, thereby forming temperature stress caused by temperature cracks easily, and zero block as the main force component, its quality is directly related to the construction of the bridge safety and durability of the whole bridge.In this paper, refer to a large number of hydration heat temperature effects related to the academic papers and books, and summarized, with a main span of zero block as the object of study for the three span continuous rigid frame bridge with 75 m, the specific work and achievements are as follows:(1) Through large amounts of data on-site monitoring to study variation zero block of hydration heat temperature field and analyze the causes.(2) Using finite element analysis software MIDAS/FEA build a solid model Zero tranches segment, the development process of hydration heat temperature field simulation, combined with data on the variation of the measured high-strength concrete hydration heat temperature field to summarize, find now there are norms and finite element software to calculate the heat of hydration of high strength concrete and practical terms there is a big difference, but according to research on the use of high-strength concrete hydration rate correction, so that the finite element analysis of the structure in good agreement with the measured value is calculated in order to the area offers the same type of bridge reference.(3) In order to achieve the purpose of controlling the temperature cracks, according to the heat conduction theory and the law of concrete hydration heat measured data found on the original construction program optimization, we propose two practical construction program, using the finite element simulation analysis shows that the two optimization can significantly reduce the peak temperature, reducing the temperature cracks appear.(4) Finally, the hydration heat temperature control measures are discussed, respectively, from the design and construction made concrete and feasible measures to crack control.