An Integrated Analytical Approach to Define the Compositional and Textural Features of Mortars Used in the Underwater Archaeological Site of Castrum Novum (Santa Marinella, Rome, Italy)

Minerals

Luciana Randazzo¹  Michela Ricca¹  Silvestro Ruffolo¹  MauroF. La Russa¹  Marco Aquino²  Barbara Davidde Petriaggi³  Flavio Enei⁴ 

[1] Department of Biology, Ecology and Earth Sciences (DiBEST), University of Calabria, 87036 Arcavacata di Rende, Cosenza, Italy;Department of Environmental and Chemical Engineering (DIATIC), University of Calabria, 87036 Arcavacata di Rende, Cosenza, Italy;Ministero dei Beni e delle Attività Culturali e del Turismo—Istituto Superiore per la Conservazione e il Restauro, 00153 Rome, Italy;Museo del Mare e della Navigazione Antica, Castello di Santa Severa, 00058 S. Severa, Rome, Italy;

关键词: pozzolana;    hydraulic-type mortars;    minero-petrographic analysis;    restoration;   

DOI  :  10.3390/min9050268

来源: DOAJ

【 摘 要 】

This paper aims to carry out an archaeometric characterization of mortar samples taken from an underwater environment. The fishpond of the archaeological site of Castrum Novum (Santa Marinella, Rome, Italy) was chosen as a pilot site for experimentation. The masonry structures reached the maximum thickness at the apex of the fishpond (4.70 m) and consisted of a concrete conglomerate composed of slightly rough stones of medium size bound with non-hydraulic mortar. After sampling, for a complete characterization of selected mortar fragments, different and complementary techniques (stereomicroscopy, polarizing optical microscopy, and X-ray powder diffraction analysis) were carried out in order to: a) define the minero-petrographic features; and b) investigate their state of conservation. The obtained data allowed the determination of the main constituents of mortars from a compositional point of view. The raw materials, in fact, were quite homogeneous, as well as the ratio in which they were mixed, confirming the typical "recipe" used in Roman times to manufacture hydraulic-type mortars by adding pozzolana. At the same time, it was possible to identify the various degradation processes we were interested in, namely, biological colonization (bio-fouling) that develops differently according to environmental conditions. Based on characterization phase results, the research will help to develop adequate techniques for intervention (innovative tools and methods for the protection of underwater cultural heritage) with particular regard to cleaning and consolidating procedures to be carried out directly in situ.

【 授权许可】

Unknown