Experimental insight in the mechanical behaviour of aged masonry specimens

In the structural mechanics field, the complex problem concerning the assessment of masonry behaviour is continuously studied in order to obtain structural analyses as accurate as possible and to enable to properly evaluate the safety of existing and historical buildings. Many are the difficulties concerning this task and a lack of knowledge is especially evident in presence of environmental decay. Investigations are needed e.g. to evaluate the consequences of moisture and salt-related decay on the masonry mechanical properties such as strength and elastic modulus. These issues were addressed experimentally throughout a vast laboratory campaign carried out via non-destructive and mechanical tests on several 1-header thick masonry specimens subjected to accelerated ageing cycles to simulate diverse decay levels. As an example, compression mechanical tests were carried out on the aged specimens, up to their brittle failure. In addition to instrumentation by traditional wired monitoring systems, the specimens were monitored during the mechanical tests via contactless image correlation method, employing an innovative testing set-up – developed by the authors - which overcomes the preparation of the masonry surface. This paper reports example results in the form of mechanical parameters’ distribution maps and graphs from mechanical testing on two aged brick masonry specimens monitored via imaging technique aimed at obtaining a better understanding of the weak points and mechanical behaviour of decayed masonry both at a global and local scale.