Study Of Temperature And Temperature Crack In Mass Concrete Of High-rise Building's Foundation

Mass concrete has been largely using in hydraulic structure for all along; however, it is being used in construction works more and more with the development of modern economy, such as the foundation for large-size equipment, the raft foundation in high-rise building. Study on mass concrete is approaching to mature. But when it comes to the crack control of mass concrete, especially in construction works, it remains a great number of problems to be resolved. At the same time, there are no general applicable theory and code instead of reference to hydraulic structure. So it is necessary to study on mass concrete in high- rise building.On one hand, the stress in mass concrete is caused because of the difference between internal temperature and external one. On the other hand, with the concrete solidifying, the tensile stress will appear due to concrete's shrinkage restrained by base rock. Once the stress resulted from both above exceeds the ultimate tensile strength of concrete at the same age, temperature crack of concrete is sure to appear, which will decrease bearing capacity of foundation and durability of concrete, and cause safety crisis of high-rise building.In this paper, the first, based on the mechanism of concrete crack, the cause, main factors, and measures are analyzed. The second, temperature field of mass concrete is theoretically studied. The results simulated from FEM software Ansys indicates that interaction between concrete and soil should be considered enough when mass concrete temperature field of foundation in high-rise building is calculated. And the choice range of hydration coefficient is determined on calculating mass concrete of foundation in high-rise building. At last, combining the test data with the Ansys result, some measures about crack-controlin construction are summarized.It can be referred to the study on mass concrete of foundation in high-rise building for interaction between concrete temperature field and soil temperature field considered, choice range of hydration coefficient determined, and measures about crack-control in construction summarized in this paper.