Analysis Of Hydration Heat Effects On Large Volume Cap Structure

With the rapid social and economic development, large volume concrete has beenwidely used in the field of civil engineering of high-rise and super high-rise buildings,long-span bridge, industrial buildings and other structures. Because of the large volumeconcrete in cement producing a lot of heat of hydration, and the thermal conductivity ofconcrete is relatively low, it is not easy to distribute the heat. Hence, the internal structure isin rapid warming and slow cooling, thus forms a large temperature gradient, which causesthe cracks. And the cracks will seriously affect the safety of the structure, beautifulappearance, permeability and durability. Therefore, research on the heat of hydration ofmass concrete has been paid more attention for the engineering structure. This paper isbased on the summary of others’ research, the definition of large volume concrete and thedevelopment of mass concrete at home and abroad is introduced, the temperature field oflarge volume concrete water to generate heat and stress field is analyzed by using the finiteelement method, the mechanism of the effect of heat of hydration of mass concrete isstudied on, the causes of the temperature crack of the large volume of cap are summed up.and the influence factors of large volume concrete hydration heat are analyzed. In the end,the control of pile cap mass hydration heat measures and detailed analysis of the controleffect of the corresponding are put forward. The main work in this paper is as follows:（1）A comprehensive introduction to the thermodynamic properties of concrete andin-depth analysis of the causes of mass concrete cracks（2）Acomprehensive introduction to the analysis of temperature field and stress fieldanalysis of the main theory, and puts forward the existing problems and solutions.（3）By using the finite element software MIDAS/FEA2013the bridge pile cap ofmass concrete is analyzed, and the temperature field on the surface of the body andhydration heat and stress distribution of the large volume cap is analyzed.（4）By changing the type of cement, cement quantity, pouring method, whether to setthe condenser tube or not, controlling molding temperature, whether the use of insulationmaterials and other parameters, Parameter analysis of hydration heat of mass concrete ismade, and the main factors that influence of large volume concrete hydration heat is studied（5）According to the above analysis results, effective measures are proposed to reducethe heat of hydration of mass concrete.