The present study explores the effect of activating solution concentration (4, 6 and 8 M NaOH) on mechanically and thermally pre-treated carbonate-high illite clay (LCR). Pastes were prepared with an alkaline solution/clay (S/B) ratio of 0.55, which were cured at room temperature and relative humidity > 90% in a climatic chamber. At two and 28 days, compressive mechanical strength was determined, and the reaction products were characterised by X-ray Powder Diffraction analysis (XRPD), Fourier-transform infrared spectroscopy (FTIR) and Scanning Electron Microscopy - Energy Dispersive X-ray spectroscopy (SEM/EDX). Results obtained showed that the presence of reactive calcium in the starting clay induces co-precipitation of a mix of gels: An aluminium-enriched C-S-H gel (C-A-S-H) and a N-A-S-H gel, in which sodium is partially replaced by calcium (N,C)-A-S-H. Pastes prepared with higher (6 or 8 M) activator concentrations exhibit a more compact matrix than the ones prepared with 4 M NaOH. The findings show that the use of a 6 M NaOH solution yields a binder with two days compressive strength >20 MPa and 28 days strength of over 30 MPa.

Ceramics are among the most studied findings, one of the best markers for providing technological and functional information in archaeological contexts. Their chemical-mineralogical characterization allows to answer a large number of historical-archaeological questions about classification, provenance, production technologies, trade routes, economic exchange, etc. The best methodological approach not only integrates morphological-stylistic studies to the archaeometric ones, but also includes a synergic instrumental strategy aimed both to take advantage of each different analytical technique to the best of its potentiality and to over step the problems connected to the preciousness and uniqueness of the objects. As far as the mineralogical and petrographical composition of preindustrial ceramics is concerned, its determination is crucial to answer provenance and technological issues like raw materials procurement and the production processes in this respect, equivalent firing temperature, redox atmosphere during firing are important factors that help in understanding the relevant mineralogical and micro-structural transformations. In this paper, we illustrate how an integrated approach of analytical techniques, tested on different classes of ceramics – pottery with spathic calcite, Apulian red figure pottery and technical ceramics – can provide answers to archaeological questions.