Study On Crack Control Of Mass Concrete

With the development of economy,urban infrastructure construction especially the realty estate have developed in a high speed in China since entering the 21 st century.The engineering construction scale of the high-rise buildings and the large-scale commercial multifunctional buildings in china is becoming larger and more complex,and the mass concrete structures are applied widely in engineering project.However,the construction time of mass concrete is long and the mass concrete is affected greatly by the environment,and a great deal of heat of hydration of cement is given off from the mass concrete structures during solidification process of the mass concrete structures.so,the temperature of mass concrete is hot in inner and cold in outer,it is easy to create temperature crack,which will affect the integrity of the structure,water resistance and using function of the structure.The temperature crack of mass concrete structure is becoming more and more prominent and puzzles engineers at present.Temperature control is the key technique in mass concrete construction,so it will be theoretically and practically significant to research on the measures for temperature-crack to prevent cracks and guarantee the safety.This paper take the measures of crack control for mass concrete in construction as research objects,analyze the causes for crack initiation and give some measures to prevent and control crack initiation.Through the example of mass concrete project in construction,some construction experience for crack control of mass concrete are summarized.The main works included in this paper are as fol ows:(1)The definition and the characteristics of mass concrete are introduced,the harm of temperature crack in mass concrete structure and the formation mechanism of temperature crack in mass concrete structure are analyzed,major factors concrete cracking in mass concrete structure are analyzed,which provides the means for control temperature cracking of the mass concrete structure.(2)The type of temperature stress and the development of temperature stress for mass concrete are introduced.The forecast method and formula of temperature and temperature stress for mass concrete are given.(3)Through the example of mass concrete project in construction,calculation of the forecast value of adiabatic temperature of concrete,the temperature of Inner concrete and the temperature stress for mass concrete of concrete foundation slab of Chu Tianfu project are calculated,and validate that the crack resistance of concrete meets requirements,some construction experience for crack control of mass concrete are given,which will provides some important experience for design and construction of similar projects.