Temperature Cracks Control Mechanism And Finite Element Simulation Analysis Of Mass Concrete

With the continuous development of our country economy, high-level and tall building will be more and more used in the construction of city. While the existing relevant theories of mass concrete is mostly comes from the hydraulic structure, as the construction engineering field has its particularity. As tall and super-tall building of mass concrete crack problem, it has not yet formed a complete set of practical construction measures. At the same time, the corresponding theory and clauses in mass concrete construction code is not perfect, so the research of mass concrete of high-rise and super high building still has its extremely vital significance.In the process of concrete hydration, the cements produce a lot of hydration heat. As the coefficient of concrete thermal conductivity is low, a lot of heat accumulates in the concrete structure. This may easily make concrete structure to generate temperature difference between inside and outside structure. When temperature difference between inside and outside is too large to make the concrete to bear the tension, the concrete structure may generate a certain degree temperature cracks. The cracks will affect the durability of the structure, bring a certain hidden danger to the structure, reduce the bearing capacity of building foundation. Therefore, the temperature cracks control of mass concrete structure must be studied.Combined with the foundation engineering construction of twin towers in Guiyang, temperature control technology of mass concrete slab has been carried on the system research.(1) From the perspective of micro mechanics, the formation mechanism of mass concrete structure temperature cracks has been expounded, the influence of common factors for mass concrete temperature cracks generation has been analysed in the the construction process.(2) Through consulting many literature data, the calculation method of heat conduction equation and temperature field theory has been deduced. This paper calculates the temperature peak value and concrete temperature stress of mass concrete foundation slab. Then the calculation result may provide theoretical guarantee for engineering construction.(3) Combined with specific engineering, a complete temperature cracks control measures for mass concrete has been designed. The measures, such as concrete mix proportion design, concrete pouring measures, temperature detection measures and preliminary field tests so on, effectively prevent the generation of massive concrete foundation slab temperature cracks. After taking these measures, the project achieves the desired results.(4) Through using the finite element software MIDAS/GEN, finite element simulation analysis of concrete pouring process has been conducted in this project. The impact of temperature difference between the inside and outside of mass concrete structure from various factors in construction process is considered during the simulation analysis. The calculation result provide a reliable guarantee for construction in the project。Obtained from the project specific practice of the project: prevention work of mass concrete temperature cracks own characteristics of complexity and uncertainty, but by optimizing the mix proportion of concrete, taking reasonable construction organization, designing a comprehensive construction program and other measures are can effectively prevent the generation of mass concrete temperature crack, ensure the quality of the project construction.