For the analysis of reinforced concrete structures, the effect of creep and shrinkage must be considered for checking the instability and serviceability. The objective of this research is to present a finite element method which is capable of simulating the behavior of reinforced concrete beams and plates at working loads, including the effects of nonuniform reinforcing, tensile cracking, shrinkage, and creep.
In general, two approaches by which we analyze the reinforced concrete structures using finite element method, are exist. One is layered approach, and the other is non-layered approach. In order to include the long term effects into structural analysis, the layered approach is suitable. But it has many disadvantages, for example, it needs an amount of computer memory and computing time due to a large number of total elements for claculation. For this reason, this study uses a non-layered approach for beam analysis.
But, for plate analysis, layered approach is inevitable, because crack developing direction is unknown. Therefore, we use a layered approach for plate analysis. This study uses VanZyl's Dirichlet series for creep, and ACI and BP model for shrinkage. But to predict more exactly long term deflections, more accurate creep and shrinkage model is needed.
Results of beam analysis fit well with experimental data, but, in case of plate, results can not be compared with experimental data due to lack of experiments. In both structures final deflections calculated by ACI model for shrinkage are larger than BP model.