Maurizio Masieri

The innovative properties of the nano - materials can have advantageous application in the restoration and conservation of the cultural heritage with relation to the tailoring of new products for protection and consolidation of stone. Their potential use in this field needs to be assessed taking into account specific requirements such as effectiveness, harmfulness and durability. This paper reports on the experimental activity concerning the application of a nanosilica based product for the consolidation of stones having high porosity. The study deals with the assessment of the suitable methods and amounts of product to be applied and the determination of several basic requirements in order to evaluate the properties of the treated stone, such as the surface distribution and the penetration depth within the porosimetric network, the stone surface colorimetric parameters, the superficial strengthening effects, as well as the behaviour with respect to the capillary water penetration a...

Since the last decades, chemical treatments have been widely used for surface conservation of stone artefacts. Many case studies with a sufficient time laps from their realization, are now available for a monitoring activity in order to evaluate the in situ performance of the conservation works carried out in the past. The knowledge of the behaviour of the conservation treatments in real conditions can also be helpful to correlate their real performance with the results of wide laboratory assessments. The monitoring activity is also an important tool for detection of the new conservation needs of the artefacts in view of planning the monument's maintenance. In this work we focus the attention on the evaluation of stone protective treatments with reference to the water-repellency of the treated stone surface and its evolution over time, as a tool for the monitoring of the performance over time. As it is known, "in situ" verification of the effects of stone surface conse...

This paper reports a study of the effects of fire on the decorative stucco elements consisting of painted mouldings and decorations in the Petruzzelli Theatre in Bari (Southern Italy),. The Theatre was built at the end of the nineteenth century. In 1991 a fire caused serious damage to both materials and structure.

Visible damage to the decorations included various deterioration patterns. The fire-related effects on both plaster and painted surface layers were subjected to in-depth investigation under laboratory conditions by focusing on mineralogical, chemical and microstructural alterations. Methods used included Optical Microscopy, Environmental Scanning Electron Microscopy coupled with X-ray microanalysis, X-ray Diffraction, Fourier transform infrared spectroscopy and simultaneous Thermogravimetry - Differential Scanning Calorimetry.

De-hydration of the gypsum binder and oxidation of the iron compounds caused new mineralogical phases to form in the stucco plaster. In some cases, microscopic observation suggested that calcination of the lime binder may have occurred in thin layers under the surface. Significant microstructural modifications were detected in the form of cracks and microcracks, due to thermal shock and gypsum dehydration. Phase transformations affected the structural integrity and the colour properties of the stucco plaster to different extents, up to a maximum depth of around 2.5 cm, while fissuring due to thermal shock penetrated to greater depths.

Fire-related damage in the surface paint consisted of colour changes and/or disruption of the painted layers due to thermally-induced chemical reactions involving mineral pigments; detachment and burning of the painted layers from the direct action of flames, as well as accumulation of combustion deposits on the surface were also observed.

The innovative properties of the nano - materials can have advantageous application in the restoration and conservation of the cultural heritage with relation to the tailoring of new products for protection and consolidation of stone. Their potential use in this field needs to be assessed taking into account specific requirements such as effectiveness, harmfulness and durability. This paper reports on the experimental activity concerning the application of a nanosilica based product for the consolidation of stones having high porosity. The study deals with the assessment of the suitable methods and amounts of product to be applied and the determination of several basic requirements in order to evaluate the properties of the treated stone, such as the surface distribution and the penetration depth within the porosimetric network, the stone surface colorimetric parameters, the superficial strengthening effects, as well as the behaviour with respect to the capillary water penetration a...

In this study, two commercial sacrificial anti-graffiti systems, provided as water emulsion, were applied on a highly porous stone. The behavior of the anti-graffiti treatments was investigated by means of differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy in attenuated total reflectance mode (ATR-FTIR), colorimetric tests, and water static contact angle measurements.
The presence of a protective coating enhanced the removal of paint sprayed on the stone. However, penetration of the staining agent below the surface, due to the high porosity of the substrate, caused difficulties in eliminating the paint. In fact, repeated cleaning procedures, involving hot water, mechanical action, and chemical removers, did not allow a complete removal of the paint.
The examined systems behaved against graffiti in different ways. No affinity between the wax-based product and the paint was observed; nevertheless, this behavior did not result in good anti-graffiti performances. On the contrary, the penetration of the paint into the fluorine-based coating yielded a good anti-graffiti effectiveness, since the stain was easily eliminated from the surfaces.
The anti-graffiti coatings survived in limited areas after the cleaning processes, although the studied compounds are suggested as sacrificial products. Such behavior may affect the maintenance activities, when the surface is no longer protected and the coating need to be renewed, since compatibility problems, as well as harmful accumulation, could occur because of further treatments on these surfaces.