Research On Early Thermal Stress Analysis Of Concrete Structure And Redevelopment

With the rapid development of construction, the larger scale and increasing complexity in structure size, the impact of the temperature stress caused by the heat of hydration of cement in the early phase of Mass concrete pouring is increasing. It can cause micro-cracks, which will seriously affect the durability of the structure. Therefore, the study of the temperature stress in the early phase is very important. As the parameters which are affecting the temperature stress caused by the heat of hydration of cement in the early phase of mass concrete pouring are complex, many models are formulas based on experience, such as hydrothermal model of cement, early development of elastic modulus of concrete model, early concrete strength development model etc. To solve these problems, we discuss the study of the parameter model of temperature field and stress field in the early phase, and the further research of the finite element software ANSYS.This paper firstly introduced the research background and research purposes, and then introduced the relevant theories and concepts, mainly including hydrothermal model, Adiabatic heating model, Modulus model, ANSYS optimization module and the idea of secondary development.Secondly, this article focused on two engineering cases, comparatively analyzed the influence of different hydration heat model to the temperature stress field, and thoroughly analyzed the parameters which are affecting the distribution of the temperature field, it comparatively analyzed the influence to the temperature stress from the model of the early development of different concrete elastic modulus, and it compared considering the impact of creep to the stress field with not considering it.As there was no formula to use to obtain some of the thermal parameters, we did a reverse analysis of the them, in this paper it took the parameter identification of the surface heat coefficient as example, researched the feasibility of parameter identification using the ANSYS optimized model, applied 0-order optimizing method, compared and analyzed the optimized value with the actual value and the calculated value from the optimal model.Finally against the above models, with reference of an example, we developed a GUI for ANSYS, using UIDL, APDL. This GUI is simple and can be widely applied.