Coupled Effect of Loading and Environment of Concrete Bridge in Service Life

Abstract

A numerical method is proposed to study load and the environment couple effect during the service of a concrete bridge. By studying the corrosion process of reinforcement bars, the strain of the bars is decomposed into two parts, elastic strain and corrosion strain, and their ratio is defined as the corrosion factor. The time-dependent constitution of corrosion of the steel bar is obtained by introducing a nominal elastic module. According to the virtual work principle, the finite element formulation of the reinforcement concrete element is derived, and the computation sequence determined using the time history method is illustrated. The nonlinear finite element program is realized by the Fortran program to numerically solve the problem, which is verified by testing a model of three reinforced concrete beams. The results show that both stiffness matrix and the additional nodal load of the reinforcement concrete element should be considered in the couple effect analysis. The proposed method can be used to predict long-term mechanical properties of concrete bridges.