Physicochemical Characterization of Historical Coating Mortars – Case Studies in South Brazil

ABSTRACT

The intervention process in historical buildings involves the application of a scientific methodology for the materials characterization. In Porto Alegre — RS, Brazil, several buildings with patrimonial value from the nineteenth and early twentieth centuries were preserved. This study presents the physicochemical analysis of mortar coating samples obtained from two buildings, the commercial and residential building “Frasca House” (1911) and the Metropolitan Curia of Porto Alegre (1888). The visual investigation and aspects of the color and morphology of the samples were determined with a stereoscopic microscope. Chemical analyses provided information on the binder:aggregate proportion and qualitative soluble salts, correlated with deterioration caused by efflorescence. Microstructural analysis allowed to determine the nature of the binders, aggregates and fine particulates. It is expected to contribute, in restoration interventions, to the choice and quantity of materials compatible with the original evaluated here, preserving it and, thus, extending the service life of the building.

KEYWORDS:

• Characterization
• Frasca house
• historical building
• Metropolitan Curia
• mortar coating

Acknowledgments

This study was partially supported by the research teams Núcleo de Tecnologia da Preservação eda Conservação (NTPR/UFBA), Laboratório de Materiais eTecnologia do Ambiente Construído (LAMTAC/NORIE/UFRGS) and Laboratório de Materiais Cerâmicos (LACER/UFRGS).

Notes

¹ Couto, M. Tractado de architectura. 1631–1641, L. II, cap. IX, p. 37.

² Palladio, A. I. Quattro libri dell’Architettura. Veneza, Dominico de’Franceschi,1570, L. I, Cap. V, p. 8.

³ Plínio. Naturalis Historia. 77–79 d.C.

Additional information

Funding

This work was supported by the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPQ) and Programa de Cooperação Acadêmica em Defesa Nacional/Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (PROCAD/CAPES).