Test And Analysis On Temperature Stress Of Large-size Cast-in-place RC Slabs

Due to the large plane size of the large-size cast-in-place reinforced concrete slabs, great amount of stress, which might lead to a number of tiny cracks that influence negatively the safety and usage of the slabs, might be generated because of the following factors including the shrinkage and creep of the concrete, the temperature differences that occur in distinctive seasons and indoors or outdoors. The frame of the central stadium in Tianjin Olympic Game Center was equipped with large jointless concrete slabs, and the technique of the later joint-filled slots was utilized during its construction to control the temperature stress. This article aimed to comprehend accurately the temperature stress of the large-size cast-in-place reinforced concrete slabs of the stadium. Multiple groups of concrete strain gauges were buried in the concrete slabs and the later joint-filled slots in order to observe closely how the stress was affected by the temperature together with the shrinkage and creep of the concrete slabs in the long term. In the meanwhile, the efficiency and reliability of the method that the later joint-filled slots was used to control the temperature stress was verified by setting up an analyzing model according to finite element measure.The main research and the consequent results of this article were listed as below:(1) The influence of temperature stress on the large-size cast-in-place reinforced concrete slabs of the Tianjin Olympic Game Center was analyzed via the experimental data. It is also been proven valid that the method of the later joint-filled slots was adopted to control the temperature stress of the concrete frame of the Tianjin Olympic Game Center.(2) This article summed up the distributing principle of the inner force and cracks when the reinforcing steel bars inhibited the shrinkage of the concrete in the slabs by using universal finite element software ANSYS to make calculation. Simultaneously, the distributing principle of temperature stress was studied in the similar way.(3) This article investigated the relationship between the temperature change of the slabs and that of the atmosphere, on the basis of which the stress distributing principle when there exists temperature difference between the upper and lower surfaces of the slabs was concluded.(4) In terms of the experimental tests and theoretical analysis in this article, some...