Characterization of Gypsum Renders in the Paris Region and Determination of the Traditional Fabrication Process

Author(s): Jean Ducasse-Lapeyrusse, Véronique Vergès-Belmin
Paper category: Proceedings
Book title: Proceedings of the 5th Historic Mortars Conference
Editor(s): José Ignacio Álvarez, José María Fernández, Íñigo Navarro, Adrián Durán, Rafael Sirera
ISBN: 978-2-35158-221-3
e-ISBN: 978-2-35158-222-0
Publisher: RILEM Publications SARL
Publication year: 2019
Pages: 186-200
Total Pages: 15
Language : English

Abstract: This study aims to characterize traditional gypsum renders to understand their traditional fabrication process. A large sampling campaign covering the historical region of Paris and all building typologies from the 16th century to the early 20th century was conducted. The cross- sections of renders were first observed with the naked eye and then under the microscope to characterize the number, thickness, and granular typology of their layers. X-ray diffraction analysis and mercury intrusion porosimetry were performed on each render layer and the proportion of each crystallized phase was estimated using the Rietveld method. Calcite and quartz contents vary from building to building and even between two layers in a single render. On average, however, their content is low and gypsum appears to be the main and often the only component. Usually, only calcined gypsum is used to make renders, especially for the most prestigious urban monuments. For these types of buildings the renders are made up of several layers. These layers are applied successively and prepared with a single coarse plaster powder sieved at different grain sizes and mixed at specific water ratios.

Online publication : 2019
Publication type : full_text
Public price (Euros) : 0.00