The Temperature-effects Analysis And Cracks Control Of Cast-in-place Reinforced Concrete Structure

As the rapid development of economic construction and enhancement of building technology, the cast-in-place reinforcement concrete structure is more and more extensively used in every field in civil engineering. Due to the temperature cracks commonly existing in the cast-in-place reinforcement concrete structure, the appearing of cracks will not only influence the beauty of building, but also serious influence the service life and durability of building and probably momentarily threat to people'life property safety. So it is very important to research the temperature effects and temperature crack controlling measures.The finite element software SAP2000 is used in this paper to analyze the temperature effects of the reinforcement concrete structures which were set of no temperature crack controlling measures, the expansion and contraction joints and the later poured bands respectively. The main researching contents of this article are as follows:Firstly, the finite element model of the reinforcement concrete structure without using any crack controlling measures is established by using the finite element software SAP2000. The temperature effects of the reinforcement concrete structure without using any crack controlling measures under different temperature loads are analyzed. The results showed that:the temperature deformation is minimum at the bottom floor, increased as the increasing of the layers of structures and reached the maximum value of temperature deformation at the top floor; under the shrinkage equivalent and seasonal temperature difference, the temperature force is maximum at the bottom floor, decreased as the increasing of the layers of structure; under the sunshine temperature difference, the temperature force is minimum at the bottom floor, increased as the increasing of the layers of structure and reached the maximum value of temperature force at the top floor.Secondly, this article established the finite element model of reinforcement concrete structure setting of the expansion and contraction joints. When the expansion and contraction joints are used in the structure, the rules of temperature deformation and stress of the reinforcement concrete structure members under different temperature loads are analyzed. Through the analyzing, we can conclude that the rules of temperature deformation and force of the structure setting of the expansion and contraction joint is similar as the structure without using any crack controlling measures. At the same time, the effect of expansion and contraction joints to reinforcement concrete structure is analyzed. The results showed that the expansion and contraction joints can effectively decrease the influence of temperature loads to the reinforcement concrete structure.Thirdly, this article established the finite element model of reinforcement concrete structure setting of the later poured bands. When the later poured band is used in the structure, the rules of temperature deformation and stress of the reinforcement concrete structure members under different temperature loads are analyzed. The effect of later poured band to reinforcement concrete structure members'temperature effects is analyzed. Through the analyzing, we can conclude that the rules of temperature deformation and force of the structure setting of the later poured bands is similar as the structure without using any crack controlling measures. At the same time, the effect of later poured bands to reinforcement concrete structure is analyzed. The results showed that the later poured bands can effectively reduced the influence of the shrinkage equivalent temperature difference to the structured, but can not reduce the influence of the seasonal and sunshine temperature difference.