Considerations on the identifiability of fracture and bond properties of reinforced concrete

This work tackles the issue of identifiability of fracture and bond properties in reinforced concrete. The basis for modeling of fracture is a computational model capable of describing damage and failure mechanisms in concrete, as well as bond-slip which is a result of degradation of the concrete-steel interface. The discrete approximation combines ED-FEM for concrete crack representation in each element and X-FEM representation of bond-slip along a particular reinforcement bar. The uncertain model parameters are modeled as random variables and identified via Bayesian inference with the help of observations from tensile tests on concrete tie beams with a single embedded reinforcement bar. We discuss how the choice of observation type affects the parameter identifiability and propose combinations which improve the estimation capabilities and reduce the discrepancy between the computed and observed quantities of interest.