Updating coupling method of hydration heat temperature damage for concrete box girder

In order to prevent the earlier crack and temperature dash phenomenon of pier-on mass for concrete box girder during construction, hydration heat temperature damage model for concrete was studied, the time-dependent effect for modulus of elasticity and boundary conditions were comprehensively considered, an updating coupling method of hydration heat temperature damage for the girder was put forward by using linear iteration method, the whole damage field with the variation procedure of temperature load was computed, and the damage laws were analyzed based on the time-dependent relation curves of the field. Comparison between calculated result and measurement result shows that the deviation of the hydration heat temperatures is less than 10%, the appearing time of the difference peak value for the hydration heat temperature delays about 32 h compared with the temperature peak value, the peak values of the equivalent strain for the girder and the temperature difference appear synchronously, the hydration heat temperature damage degree is linear to the equivalent strain, their time-dependent effect laws are similar, so the model is feasible.