Predicting the Freeze-Thaw Damage Initiation in Concrete Facades with Different Surface Types

With statistical methods and by analysing a comprehensive database of concrete facade condition investigation reports and utilising the newly developed Relative Freeze-Thaw Exposure (RFE) Index, this article presents a novel service life model to estimate the probability of freeze-thaw damage initiation as a function of time. The model provides property owners with cost-effective baseline information for scheduling facade repairs and planning the extent of necessary restoration work.The model considers different geographical locations, facade directions and used surface type. It was initially applied to current climate conditions, but it also allows to calculate the probability of freeze-thaw damage initiation with future climate scenarios.The results showed that freeze-thaw damage initiates most rapidly in painted concrete facades. In contrast, the damage occurs significantly later in unpainted plain concrete facades, due to their greater ability to dry between rain events. This highlights the issue of neglected maintenance in painted concrete facades, as they should be recoated approximately every 15 years. The second shortest service life was predicted for clinker-tiled surfaces. This is due to their characteristic tendency to allow wind-driven rain to penetrate the concrete through the seams, while the dense tiles prevent the concrete dry efficiently.