When Portland cement meets natural cement

Author(s): Elisabeth Marie-Victoire, Myriam Bouichou
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: 914-927
Total Pages: 14
Language : English

Abstract: The development of the Portland cement industry gradually replaced natural cement production by the end of the 19th century. But in the pivotal period in between, in some constructions, natural cement – which was still used for ornaments – could neighbour Portland cement used for the structural elements. In this paper, a critical combination of both types of cements in one of the first reinforced concrete buildings of Paris will be presented. In 2016, a restoration of the façades of François Hennebique’s headquarters built in the late 19th in Paris city centre was planned. After removal of the thick layers of paint accumulated over time, locally serious cracking was observed leading to a deeper diagnosis. Optical microscope observations and SEM examinations combined with EDS analysis evidenced a massive sulphate reaction in the Portland cement structural elements, probably due to the vicinity of high sulphate content natural cement. Combined with carbonation- induced corrosion, these two decay mechanisms strongly impacted the final restoration protocol.

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