Microenvironmental characterization of rendered autoclaved aerated concrete

The long-term behaviour and physical and mechanical properties of external walls made of rendered autoclaved aerated concrete (AAC) show a great variety under different exposure conditions related to climate and geography. The performance of the porous system depends greatly on its moisture characteristics and the severity of the agents acting within its microenvironment. In order to gather systematic data on the actual in-service performance of rendered AAC walls, an international research programme was initiated to provide continuous microenvironment monitoring of rendered AAC blocks naturally exposed on a test rack and rendered AAC test panels mounted at the field exposure station. In the experimental study, a comparison is made between the environmental exposure data at local and micro levels, and the performance assessment of different rendering systems based on the data and results of continuous moisture measurements at micro scale is presented.