Atmospheric deterioration of ancient and modern hydraulic mortars

• Published in: Atmospheric environment (1994) Vol. 35; no. 3; pp. 539 - 548
• Main Authors: Sabbioni, C., Zappia, G., Riontino, C., Blanco-Varela, M.T., Aguilera, J., Puertas, F., Balen, K.Van, Toumbakari, E.E.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 2001; Elsevier Science
• Subjects: Applied sciences; Atmospheric pollution; Belgium; Buildings. Public works; Concretes. Mortars. Grouts; Corrosion; Durability. Pathology. Repairing. Maintenance; Environmental damage; Ettringite; Exact sciences and technology; General (composition, classification, performance, standards, patents, etc.); Hydraulic mortars; Italy; Materials; mortar; Pollution; Spain; Sulphation; Europe; Atmospheric pollution; Ettringite; Environmental damage; Hydraulic mortars; Sulphation; Scanning electron microscopy; Mortar; Construction materials; Old building; Masonry; Experimental study; Material weathering; X ray diffraction; Optical microscopy; Experimental result; Failure analysis; Environment impact; Air pollution
• ISSN: 1352-2310; 1873-2844
• DOI: 10.1016/S1352-2310(00)00310-1

Different types of ancient and recent hydraulic mortars were collected from well-documented archaeological, historic and modern buildings in various geographical locations (urban, suburban, rural and maritime) of Italy, Spain and Belgium, representative of different environmental impacts, types and degrees of deterioration. A synthesis of the characteristics of the collected samples is presented, along with the identification of the formation products that occurred on the sample surfaces as a result of the reaction of the mortars with atmospheric pollutants. The analyses were performed by means of optical microscopy (OM), X-ray diffractometry (XRD), scanning electron microscopy (SEM-EDX) and ion chromatography (IC). The results obtained prove that sulphation processes takes place on hydraulic mortars, leading to gypsum formation on the external surface of the samples. Through the reaction of gypsum with the aluminate hydrate of the binder, ettringite formation was found to occur on a cement-based restoration mortar sampled in Antwerp.