Non-linear hygrothermal failure analysis of an external clay brick wall by FEM – A case study

This paper presents the case study of a detailed analysis of the failure of an external clay brick wall that had been built in 1995. The failure involved the collapse of a considerable part of the outer wall as well as sizeable cracks in the remainder. To determine the cause of the collapse, a preliminary investigation and field survey were carried out, followed by laboratory tests. The diagnosis from the data collected was supplemented by sophisticated non-linear finite element models, which considered both thermal and hygrothermal behaviour of the bricks with which the wall had been built. Moreover, a parametric study and a search for optimal value based on the design of experiments and goal optimisation analysis is done to obtain the hygrothermal behaviour of the existing wall. In this way, transforming our experience in numerical simulation into knowledge, the causes of the external wall failure have been determined. Next, the lessons drawn from the study are given in the final section.

Research highlights
► Failure assessment using sophisticated non-linear finite element models and experiments.
► Search for optimal value based on the design of experiments and goal optimization analysis.
► Vulnerability of masonry walls due to the hygrothermal behaviour of clay bricks.
► Numerical model of masonry walls including a detailed contact-mortar brick model.
► Non-linear coupling analysis to reproduce a complex wall behavior: hygro-thermal-structural.