ROMANS’ ESTABLISHED SKILLS: MORTARS FROM D46b MAUSOLEUM, PORTA MEDIANA NECROPOLIS, CUMA (NAPLES)

Roman mortars from a mausoleum (named D46b) belonging to the archaeological site of Porta Mediana necropolis, in Cuma (Naples, Southern Italy) have been studied by means of petrographic, mineralogical and micro-chemical analyses. The aim of this research is to fill the knowledge gap regarding mortar-based materials used in Roman age within this wide archaeological site. Two typologies of mortars (bedding and coating) were collected from mausoleum’s masonry. They were lime-based with addition of pozzolanic materials, according to Vitruvius’ recipe. Raw materials, such as volcanic sand and limestones, mainly from local sources, were preferentially used as aggregate, both for great availability and good properties. As regard production techniques, the multi-layer feature of the coating mortars, once again shows the great knowledge of the building art. Each layer is the result of a precise choice, as shown by the differences both in texture and petrographic features. Data from detailed mortars characterization have infer the outstanding skill of Roman craftsmen, as already proved by extraordinary durability of buildings. The research was very useful not only to increase the knowledge of this ancient culture but also to planning conservative actions, that, through mortar reproduction or the research of suitable materials, can promote the safeguard of this invaluable heritage.