Stress Analysis of Concrete Structures Subjected to Variable Thermal Loads

A primary factor in the correct design of structures is predicting stress levels caused by thermal effects--both of which relate to aspects of the maximum stress limitation and the durability of construction. This technical paper presents a numerical method based on the finite-element method for the stress-strain analysis of concrete structures exposed to time- and space-variable thermal loads. Different environmental conditions can be simulated via appropriate boundary conditions imposed on the differential equations governing the phenomenon. The seasonal and daily variation of external temperature, in particular, is taken into account. Also considered by the proposed method is the heat generation phenomenon, which is the result of the hydration reaction of the cement and can cause significant temperature gradient and related mechanical stresses, especially in thick concrete casting. The stress-strain-thermal analyses of a concrete dam and a typical bridge section confirm the effectiveness and reliability of this numerical procedure in practical structural design.