Incorporation of Cracks in Finite Element Modelling of Existing Concrete Structures

Abstract

Transport infrastructures are fundamental in society and interruption in their service leads to large economic losses. However, inspection and maintenance work of said infrastructures need to be performed to ensure their safety, which traditionally involves limitation or interruption of their use. This paper treats the finite element modelling part of a framework for non-intrusive assessment of existing structures. In practice, the load history of a structure is rarely known in detail. Here, existing cracks due to previous loading is included from the start of the finite element (FE) analysis to circumvent this issue. The focus is on comparing the choice of different shear retention factors for discrete cracks based on comparison to experimental test results. The results indicate that the shear retention factor used for the discrete cracks does not influence the capacity, which remains the same for all considered values. It appears the anchorage force development of the bond-slip reinforcement does not rely on shear transfer in the discrete crack in the adopted FE model. Moreover, the results showed that combining both discrete cracks and a bond-slip relation implicitly including the loss of confinement due to corrosion-induced splitting cracks leads to excessively low capacity compared to experimental results. From the present study it can be concluded that the shear retention factor is of little importance for the considered FE model. However, it is emphasized that other modelling choices may entail other findings.