Modelling shear strength in joints between porous mineral building materials

Shear capacity in joints are determined by various models in the Eurocodes. Many different types of joints and materials in the Eurcodes together with different assumptions and material properties results in the different models. It is the purpose of this paper to make an overview of the various models used for porous mineral building materials like concrete, lightweight concrete and masonry and investigate and compare with the many tests performed over time, in order to improve and harmonise the models. Further the failure criteria of different structural joints, i.e. reinforced/non-reinforced, brittle/ductile failures, cracked/uncracked are investigated with the aim to determine which of the basic parameters in the models are related, and how, and to harmonise the parameters for the various failure criteria. Further a statistical approach will be applied to establish the characteristic values and corresponding variability of the parameters used in the models. This will be used both to evaluate if the chosen parameter is sufficiently reliable, i.e. whether the concrete strength or the tensile strength is the related parameter, and to propose a harmonised reliability level to be used across the various brittle materials and failure criteria. Requirements for the reliability level is introduced in order to illustrate how the partial factors can be calibrated using the results of the statistical analysis performed.