Microstructure and weathering mechanisms of natural cements used in the 19th century in the French Rhône-Alpes region

Title: Microstructure and weathering mechanisms of natural cements used in the 19th century in the French Rhône-Alpes region
Author(s): E. Cailleux, E. Marie-Victoire, D. Sommain, E. Brouard
Paper category : conference
Book title: Workshop Repair Mortars for Historic Masonry
Editor(s): C. Groot
Print-ISBN: None
e-ISBN: 978-2-35158-083-7
Publisher: RILEM Publications SARL
Publication year: 2009
Pages: 82 - 93
Total Pages: 12
Nb references: 16
Language: English

Abstract: Before the development of artificial Portland cements, natural cements were used as binders in concrete. In France, natural cements were extensively produced and marketed in the middle of the 19th century. In the French Alps near Grenoble, these kinds of cements were massively used in building construction as an alternative of stone. Some of them were characterised by an ochre colour and a rapid hardening. The first visual investigations of the 19th century buildings of this region made of natural cements showed a good state of preservation. Two kinds of damaging mechanisms were however identified: an erosion phenomenon developed on the surface of the majority of the buildings, involving a modification of the initial aspect and a spalling phenomenon observed only on a few buildings. In order to formulate a compatible repair mortar, the microstructure and the weathering mechanisms of these ancient cements were characterised. Samples were firstly taken from representative buildings. The hydrated phases were then identified by scanning electron microscopy observations (SEM) coupled with energy dispersive spectrometer analyses (EDS). Residual unhydrated clinker phases were also characterised after etching of polished cross-sections by optical microscopy observations. Weathering mechanisms were investigated using X-ray fluorescence, SEM observations and EDS analyses.

Online publication: 2009-06-08
Publication type : full_text
Public price (Euros): 0.00