Corroded Reinforced Concrete Bending Performance Degradation Finite Element Simulation

In recent years,durability of reinforced concrete structures is becoming increasingly prominent which have been attracted by worldwide academic organizations,scholars,engineers and technicians to pay attention to the research on the durability of RC structures.Some studies on finite element model and predication model of RC members are presented in this paper.The main contents are as follows.The section loss of steel bars and degradation of bond intensity were taken into consideration in this study,establishment of corroded reinforced concrete beam finite element model.The three-dimensional rod element was taken as the steel bar element, the eight-node solid element as the concrete element, and the nonlinear spring element as the bonding element between the steel bars and concrete. The bearing capacity of the reinforced concrete beam with corroded steel bars was simulated by making use of the large-scale finite element software ANSYS. Similarity of the ANSYS simulation results to experiment results manifested that the nonlinear finite element analysis for the reinforced concrete beam with corroded steel bars was reliable and accurate.In addition,Flexural carrying capacity of corroded reinforced concrete beams is modeled and calculated on the basis of the change of bond strength between corroded steel and concrete. At lower degrees of corrosion level,bond strength between steel and concrete doesn't have great changes with increasing degrees of corrosion, the mechanical behavior of the corroded RC beams is the same as that of the non-corroded ones, flexural carrying capacity of corroded RC beams can be calculated by conventional theory of the beam. When reduction of bond strength occurs due to higher degrees of corrosion, the mechanical behavior of the corroded RC beams lies in between that of the perfectly bonded and unbonded beam. It is different from the traditional way in RC beams, the interaction between cross sections of beams should be considered. In the present paper, the change of bond strength between corroded steel and concrete is considered, and on the basis of the condition of equilibrium of forces and compatibility of deformations forwhole beams,a calculation method for flexural capacity,conceptually explicit and widely applicable,was proposed,taking consideration of both corrosion degree and reinforcement index. The results were useful to perfect the calculation method of the flexural bearing capacity of corroded reinforced concrete beams.