The Research Of Temperature And Crack Control On Mass Concrete Of The Bank Pier Of Feilong-island Bridge

In recent years,with the development of the national traffic and the expansion of bridge construction,the issue about the hydration heat control of mass concrete has attracted great attention of bridge engineering.Releasing steam heat from the mass concrete structures while solidifying leads to produce the temperature change and contraction.In bridge construction,inappropriate measures lead to thermal stress of concrete over the anti-crack strength,resulting in concrete cracking and impact the concrete work.Although the concrete dam design and construction of mass concrete in the heat of hydration temperature field of research has made substantial progress, but it is very necessary that the study which we combine the characteristics of a bridge between the various factors gives a more accurate calculation on the temperature field.This paper introduced systematically the temperature control program and monitor analysis of the results on mass concrete construction of main tower bank pier of feilong-island bridge in Jiangxi province.The project has achieved effective control of mass concrete construction through the choice of pouring concrete,the set of cooling pipes,the implementation of conservation measures and the real-time monitoring throughout the construction process.After the concrete was moulded, there was no crack in the bank pier.Practice shows that the temperature control method is effective.The main research work of this paper includes such aspects:(1) This paper introduces the basic theory of the heart of hydration analysis and considers the main influence factor of mass concrete temperature stress on the basic theory.This paper also analysis the temperature function principle,temperature crack development mechanism,danger,method of crack control in mass concrete and summaries the choose of different calorific indexes in mass concrete.(2) This paper introduces the detailed process what the temperature control about heat of hydration in mass concrete,analyzing and comparing the measured data with calculation results trough the feilong-island bridge project.(3) This paper has simulation analysis with the bank pier mass concrete by the finite element software,in accordance with the actual layout of the cooling pipes, water flow situation,the boundary conditions,the actual construction process factors. This paper has gotten many useful conclusions through the analysis about the data and the calculating results in temperature field.(4) This paper proposes and demonstrates the Effective temperature control measures can be more effective to lower the center of mass concrete temperature, making concrete a more uniform temperature change,reducing the temperature difference between inside and outside the concrete.