Facade cladding of marble has, in several cases, suffered from problems with bowing panels that also loose strength. When not exchanged or repaired there is an obvious risk of panels falling down with time.
The project objectives are to develop a laboratory test method for the detection of marble with a potential risk of bowing and to develop a field site investigation method. In addition an equipment with sufficient precision to measure the development in bowing on the actual building cladding from year to year should be developed.
The laboratory method presented has proven good correlation with field observation of damaged buildings. Problematic stone types observed on buildings tend to show a clear bowing in the laboratory, while the reference materials did not show any bowing. A measuring rig, the “Bow-meter” has been developed to measure the amount of bow on the facade. The reproducibility of this equipment in use is better than 0,2 mm. The coefficient of variation is better than 0,8 %. A method for inspection of buildings is also presented. Further investigations and refinement of the methods will be done within a five year long, European, R&D project called TEAM (Testing and Assessment of Marble and limestone).