Material aging effects on the in-plane lateral capacity of tuff stone masonry walls: a numerical investigation

Recent studies have shown how the variability of material properties affects the nonlinear behaviour of unreinforced masonry (URM) walls. To preserve the historical built heritage, variations in structural capacity of URM buildings associated to aging and deterioration of masonry should be quickly predicted, by integrating with structural health monitoring and risk management. In this study, relationships between structural capacity features and material properties are numerically investigated for single walls, based on a structural modelling strategy that was experimentally validated on full-scale URM walls. The paper proposes an evaluation of the effects of degradation of material properties on the macroscopic descriptors of single masonry walls, such as peak strength and stiffness, also considering the uncertainties in the estimate of those properties. The authors do not attempt to model the physical processes of material aging with time, but assume certain levels of material degradation and investigate their effects on the structural response and capacity. Force-displacement curves and failure modes are associated with the overall nonlinear response of masonry walls due to progressive deterioration of material properties. Regression models are then proposed to predict variations in the peak load-bearing capacity and in -plane lateral stiffness when the mechanical properties of the constituents changed