RCC Sensitivity Analysis On The Thermal Stress For Aggregate Linear Expansion

In the mass concrete construction the thermal stress have great influence on safety and function of construction n. The problem of thermal stress and a need for temperature control in the mass concrete construction also occur in the roller compacted concrete dams(RCCD).With the fast developing of roller compacted concrete technique in building dam, the demands of thermal stress become more and more. The approaching principles are often taken for thematersal of dam building, especially aggregate. If the linear expansion coefficient of the local rock is too large,the thermal stress will become larger with the higher temperature of the compounded concrete. Therefore,it should be clear about how to select aggregate and whether the selected aggregate meet the demands of the temperature control for the mass concrete.Based on the heat conduction theory and the three-dimensional finite element(3-D FEM) theory,the3-D FEM theory formulas of temperature field are deduced; based on the heat stress theory and the 3-D FEM theory and creep theory of concrete,the3-D FEM theory formulas of thermal creep stress field are deduced in this paper. Study method is to adopt ANSYS-international large-scale general-purpose finite element software to realize the simulation calculation of the RCC thermal stress for Aggregate linear expansion. In this paper the thermal creep stress field, in roller compacted concrete gravity dam during construction and operation, are simulated by a type example. Changes of thermal stress of dam heel, upstream face, dam center, dam toe, downstream face for the difference of linear expansion coefficient aggregate used in the dam. The rule is summarized and the practical conclusion is drawn. The paper provides a certain theoretical research for the selection of different linear expansion coefficient of concrete aggregate in practice engineering and further theoretical research.