ANALYSIS OF SPALLING IN TUFFEAU: CASE STUDY OF THE CASTLES OF CHAMBORD AND CHAUMONT-SUR-LOIRE IN FRANCE

Sarah Janvier-Badosa (1) , Kévin Beck (2) , Malek Balawi (2) , Marie Ternoy (2) , Romain Janvier (2) , Xavier Brunetaud (2)

1 IJL - Institut Jean Lamour
2 GC - Génie Civil

The main historic monuments of the Loire Valley in France are built with tuffeau. This very porous and soft siliceous limestone presents many technical and aesthetic advantages justifying its wide use. Among the most damaging degradations of tuffeau, spalling is the most destructive one. This study aimed at verifying the profiles of gypsum content observed in spalling of tuffeau at the castle of Chambord during a previous study. Here, samples from both the Castle of Chambord and from the Castle of Chaumont-sur-Loire were collected, to provide more extensive and thus representative data for monuments made out of tuffeau in the Loire Valley. For all samples, in both castles, a systematic presence of gypsum was observed in areas subjected to spalling. The gypsum content is always very low at the surface and progressively increases (always around 1%) up to the depth of the zone where the crack is present, and then decreases along depth. No other salt was detected. This study also proved that preexistent cracking is not necessary for gypsum to crystallize. All these statements are totally in accordance with the previous study, hence allowing to confirm its representativeness.

Mots clés: Spalling; gypsum; limestone; tuffeau; case study

Domaines: Génie civil; Matériaux

Sarah Janvier-Badosa, Kévin Beck, Malek Balawi, Marie Ternoy, Romain Janvier, et al.. ANALYSIS OF SPALLING IN TUFFEAU: CASE STUDY OF THE CASTLES OF CHAMBORD AND CHAUMONT-SUR-LOIRE IN FRANCE. Fifth International Conference on SALT WEATHERING OF BUILDINGS AND STONE SCULPTURES (SWBSS 2021), Delft University of Technology Delft, the Netherlands, Sep 2021, Delft, Netherlands. pp.327-335. ⟨hal-03553016⟩