A(3) The additives (

Mediante modern terminology, the additive is per material “added sopra small quantities sicuro a liquid or granular material to produce some desired modification preciso its characteristics” (ISO 6707–1:2020), while the admixture is per material “added durante small quantities before or during verso mixage process sopra order preciso modify the characteristics of a mixture”. However, the difference between the two terms lies mainly con that the additive is added during the manufacturing of the cement, while the admixture is added to the concrete during mixage. Moreover, the Adherent EN 934–2 standard states that the admixture for concrete should be in an amount not greater than 5% by mass, compared with the cement. Therefore, under the current rules, the adjonction of materials, such as ground ceramic fragments, in considerable proportions would fall into the category of aggregates and not that of additives.

However, one of the main aims of the archaeometric study on ancient mortars and plasters is onesto reconstruct the production’s phases and the supply modalities of each component. Mediante this case, the term additive, used con its etymological sense (from addere, puro add) has the advantage of clearly recalling the difference between verso primary component (frequently sand) and an added component (i.e. the additive) mediante the aggregate. This is the meaning we have given esatto the term additive con this article. Still, the explanation provided above accounts for the fact that modern terminology partly overlaps and partly articulates itself differently, based on the contemporary world’s different needs. It follows that, as long as terminological uncertainties persist, it is always good sicuro specify the choice made durante the description of the results.

Hence, after having accurately characterised the main components (aggregate and binder), the following question concerns the possible presence of additives: “are there any deliberately added materials?”. If yes: “which types of materials were added?” and “where did they come from or how were they made?” (other questions concern suitability and functionality and are reported mediante the dedicated paragraphs).

Puro properly solve this question, it is necessary, perhaps even more than sopra previous cases, sicuro know which types of additives were used onesto facilitate-or even allow-their identification during the analysis of the “study’s object”

The prime of inclusions puro improve the final product’s affermazione was verso common practice that frequently left recognisable traces per literary sources and archaeological evidence. Consequently, citable examples are numerous and provide us with an extremely varied picture durante which inorganic and organic materials are enlisted. Therefore, it is possible preciso formulate the characterisation question in terms of: “are the additives of an inorganic or organic nature?” (we will see later that there are additional difficulties per this second case).

For this reason, we present a shortlist of inorganic and organic additives (and admixtures); however, we refer onesto the other contributions for the necessary insights on their characteristics and properties (Arizzi and Cultrone 2021; Ergenc et al. 2021).

Beginning with inorganic additives, the most common were natural and artificial pozzolans that are defined as “siliceous or siliceous and aluminous materials which sopra themselves possess little or mai cementitious value but will, con finely divided form and con the presence of moisture, chemically react with calcium hydroxide at ordinary temperatures onesto form compounds possessing cementitious properties” (Dodson 1990).

Natural pozzolans are volcanic origin materials, such as the volcanic ashes from the region of Pozzuoli from which they take their name (pozzolan s.s.). These are often found mediante the mortars/plasters of sites located within or close onesto volcanic regions (Lagna et al. 2009; Ozkaya and Boke 2009; Villasenor and Graham 2010; Kurugol and Gulec 2012), but when they are found per sites far from supply areas, archaeometric research is called upon preciso localise their origin and reconstruct the trade routes that allowed their import and usage. The provenance question may thus remain confined to the scale of the site and its territory or expand puro long-scale range imports and cross other issues such as those concerning the methods and extent of the promozione of raw materials sopra per given tavolo mytranssexualdate period (di nuovo.g. “what was the diffusion of these materials?”; “what were the routes and commercial methods involved in the transport of these important raw materials?”).

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