Assessment of risk of freeze-thaw damage in internally insulated masonry in a changing climate

Abstract

Buildings are susceptible to gradual changes in climate and to extreme events. The scale and severity of climate change are expected to be spatially heterogeneous. There is a necessity to consider changing climate in the operation and maintenance of buildings, as buildings have a long-term service life. In this study, the impact of climate change on the risk of freeze-thaw damage for internally insulated masonry wall in two regions in Switzerland (Zurich and Davos) for two future periods is investigated. A hygrothermal model that considers coupled moisture and heat transport in freezing and non-freezing building materials is used. The risk of freeze-thaw damage is evaluated with an indicator, called the FTDR Index. Climate projections under A1B and A2 emission scenarios from ten different climate model chains are chosen to cover a wide range of possible future climates. The risk of freeze-thaw damage at Zurich is relatively high in the reference period. An increase in air temperature in the cold period that leads to less freeze-thaw cycles is the main reason for the lower risk of freeze-thaw damage in the future periods. By comparison, the risk of freeze-thaw damage at Davos is low in the reference period. An increase in temperature and precipitation in the cold period is the main reason for the higher risk of freeze-thaw damage in the future periods at Davos. In the face of climate change, the future requirement on frost resistance of building materials and components at Davos should take the future climate loading into account.