Summary |
This thesis presents a practical method of analysis for temperature dependent response of composite concrete section, in both statically determinate and indeterminate structures. The evaluation of the temperature effects in a structure involves two aspects of calculations, which are to predict the temperature distributions through the structure and to calculate the strain and stress levels induced by these temperature distributions. The mechanisms of heat transfer occur on the concrete bridges is investigated and a fifth-degree parabola curve is selected to present the temperature distribution along the cross-section in this thesis. The theory used in the analysis of thermal response is based on the theory proposed by Priestley (1978). It also takes the aging effect into account using Age-Adjusted Effective Modulus Method. The elastic modulus is replaced by age-adjusted effective modulus which is affected by two factors, namely creep coefficient φ(t, [tauz]) and aging coefficient χ(t, τ) . The details of analysis of the thermal stress and strain in statically determinate and indeterminate bridge are discussed and described in several cases. A computer program which used in the thermal analysis is also described. To predict the time-dependent effects on concrete section, the creep and shrinkage effects are modeled using the aging-adjusted effective modulus method, couple with a relaxation procedure. |