Atmospheric deterioration of ancient and modern hydraulic mortars

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.

[1]  S. Sarkar,et al.  Advances in Cement and Concrete , 1994 .

[2]  B. Turpin,et al.  Identification of secondary organic aerosol episodes and quantitation of primary and secondary organic aerosol concentrations during SCAQS , 1995 .

[3]  G. Zappia,et al.  Black crusts on ancient mortars , 1998 .

[4]  J. Seinfeld.  Atmospheric Chemistry and Physics of Air Pollution , 1986 .

[5]  Koenraad Van Balen,et al.  Expert system for the evaluation of deterioration of ancient brick structures , 1995 .

[6]  J. Aguilera,et al.  Environmental Deterioration of Ancient and Modern Hydraulic Mortars , 1970 .

[7]  C. Sabbioni,et al.  Effects of carbonaceous particles and heavy metals on mortar-SO2 reactions , 1998 .

[8]  C. Sabbioni,et al.  Sulphite quantification on damaged stones and mortars , 1998 .

[9]  C. Sabbioni,et al.  Decay of sandstone in urban areas correlated with atmospheric aerosol , 1992 .

[10]  C. Sabbioni,et al.  Oxalate patinas on ancient monuments: the biological hypothesis , 1991 .

[11]  C. Sabbioni,et al.  Anion determination in damage layers of stone monuments , 1995 .

[12]  S. Martínez-Ramírez,et al.  Studies on degradation of lime mortars in atmospheric simulation chambers , 1997 .

[13]  Antoine Picon.  L' art de l'ingénieur , 1997 .

[14]  Tim Padfield,et al.  Science, Technology and European Cultural Heritage , 1992 .

[15]  C. Saiz-Jimenez,et al.  Deposition of anthropogenic compounds on monuments and their effect on airborne microorganisms , 1995 .

[16]  Agnes Kirsopp Michels,et al.  Ancient Roman Construction in Italy from the Prehistoric Period to Augustus , 1949 .

[17]  Cristina Sabbioni,et al.  Mortar damage due to airborne sulfur compounds in a simulation chamber , 1994 .