MICROSTRUCTURE AND SURFACE PROPERTIES OF FRESCOES BASED ON LIME AND CEMENT: THE INFLUENCE OF THE ARTIST'S TECHNIQUE

摘要

Frescoes are known to be the most durable form of mural painting. The traditional technique, widely used throughout history, consists of applying water-dispersed pigments on a fresh lime plaster, which hardens through a carbonation reaction. At the beginning of the 20th century, Portland cement was used by some mural artists to obtain similar painting plaster. Although involving different setting mechanisms, cement-based frescoes show the same aspect and durability as lime-based frescoes. Using microstructure characterizations of ancient frescoes (lime- or cement-based) and laboratory reconstructions, this paper offers a description of the mechanisms responsible for the adhesion of pigments and the hardening of surface.