Getty Conservation Institute 321d ago

Full Lecture Title — Long-Term Hygromechanical Effects of Freezing Treatment for Disinfestation of 18th-Century Wooden Sculptures This presentation investigates the hygromechanical effects of a disinfection freezing treatment ofwooden sculptures from the Isnard organ (1743) at the Madeleine Church in Aix-en-Provence(France). The sculptures were mechanically monitored before, during, and after freezing treatment. Following French regulations, the wooden artifacts were sealed in bags and frozen at -25°C for 24 hours, with a controlled decrease and increase in temperature to prevent reaching the dew point. This procedure ensures that the moisture content remains unchanged. While current research on freezing-induced damage primarily focuses on the immediate impacts, this in-situ monitoring tackled long-term effects. Mechanical testing, such as displacement and strain, was implemented across five field campaigns to analyze physical changes due to unstable climate conditions in the church. It monitored the objects for three months before and after the treatment both unstable and stable climatic conditions, and for three days during the treatment. Crack openings in the radial direction of the wood, as well as bulk swelling and shrinkage in both the radial and tangential directions were recorded in-situ. Results confirm previous studies when comparisons are made under stable climatic conditions. However, under long-term unstable climatic conditions, the strain shows notable differences before and after freezing treatment, suggesting a potential impact of the treatment on the structural behavior of the wooden sculptures. Presenters: Cécilia Gauvin: Science and Mechanics in Conservation of Heritage Gilles Tournillon: Science and Mechanics in Conservation of Heritage and Atelier Tournillon Leila Sauvage: Science and Mechanics in Conservation of Heritage, The Rijksmuseum, and University of Amsterdam