Variability in Long‐Term Concrete Deformations

Abstract

The deformation properties of concrete significantly influence the behavior of complex concrete structures. These properties are subject to large variabilities and it is therefore not possible to accurately predict the structural response. The sources of these variabilities are first examined, and an example is then presented of the long term deformation calculations in a multiple span bridge. Finally, a procedure using the finite element method, is proposed for predicting the variability in the shortening of the bridge. A number of analyses are performed for selected combinations of material properties, and the deformation at different time steps are calculated. Polinomial models are then fitted to the results at each time step. These models are used to calculate the distribution of the response, the confidence limits and estimates of the decomposition of the variance of the response. The results indicate that the variability in the response can be reduced by performing selected tests on the actual material, and using that data to adjust the numerical material models.