Analysis Of Temperature Distribution On Concrete Box Girder Bridge At High Latitudes Region

The influence by the cold air from Siberia is very powerful to Harbin due to the location of Harbin between 44°04'～46°40'north latitude. So Harbin is the coldest region among the whole area with the same latitude. The frequently cold wave through Harbin leads to a larger annual and month temperature difference, and a larger temperature difference in a day. The large temperature difference in concrete box girder is resulted by the combination of solar radiation, the seasonal temperature difference, the cold wave, the heat of concrete hydration and the concrete's relatively low thermal conductivity. This large temperature difference creates significant stresses that can be larger than the stresses due to other applied loads and dead loads. For concrete box girders, because of their thin sections and concrete's low tensile strength, cracking can occurs and the durability of concrete can be reduced.Two concrete box girders consisting of a single box with two cells and a single box with four cells used on Harbin Songpu Bridge were measured in the field. The climate characteristics of a year in Harbin were collected to analyze the influence by them to concrete temperature. The vertical and lateral temperature distributions and thermal stresses in concrete box girders were analyzed using the measured data. Compared to the concrete box girders consisting of a single box with a single cell from other papers, it can be droved that the heat of concrete hydration are influenced by some factors such as the type of the cross section, the setting temperature of concrete, the lower air temperature and the code wave. By consulting the formula for the heat of hydration of mass concrete, the complex exponential function was used to calculate the heat of concrete hydration of concrete box girder. Based on heat transfer theory, ABAQUS program was used to model the heat transfer and determine the temperature distributions in the concrete box girders during concrete setting. The two coefficients in the complex exponential function were determined based on the experimental results, and a feasible method for calculating temperature field was obtained.