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Double-layer renders were formulated for ensuring salt migration, ancient masonries conservation and environmental sustainability. Thus, natural hydraulic lime as binder and recycled aggregates from render wastes were selected. The properties were adjusted by adding an air-entraining agent in the inner layer and different percentages of water-repellent admixtures in the outer layer. The systems were applied on bricks and subjected to rising damp-evaporation cycles, for investigating their behaviour and properties in respect to NaCl migration. Mono-material prismatic render specimens were also studied. Water vapour permeability, capillary absorption, drying behaviour, compressive strength, mechanical resistance, conductivity and porosity of each formulation were evaluated. Good durability was observed whenever the render layers had different microstructure, either there was salts deposition within the lower layer,or if there was tefflorescences formation. If the layers had similar structure, deposition of salt at the brick-render interface occurred causing damages to the substrate.

This research concerns the structuring of a suitable method for the removal of oil (Fuel Oil 120 cSt) from traditional bricks and Istrian Stone, materials commonly found amongst embankments and buildings of North Adriatic coastal cities. A cleaning protocol, based upon non-toxic products, was developed in consideration of its compatibility with historical, architectural surfaces. The contamination effects of oil on Istrian stone and fired clay bricks was studied, followed by a range of cleaning treatments using bulk sorbents, surfactant solutions and N,N-dimethyl-octanamide. The application was executed using the products singularly, combined or in succession. The succession of sorbent, solvent and surfactant solution demonstrated good capability of removal and was then applied on macrosamples of brick masonry showing good results.

This work proposes a new analysis procedure aiming to study the effects of ceramic firing condition on the final product in order to distinguish the influences of the local production techniques. Particle packing, microstructure, porosity, as well as morphology of ceramic matrix are correlated to native material composition and firing temperature. These physical properties have been considered and investigated comparing the results obtained by Mercury Intrusion Porosimetry (MIP), Scanning Electron Microscope (SEM) and X-ray micro Computed Tomography (X-ray μCT). Recent measurements on archaeological and art materials by the innovative and nondestructive X-ray μCT method show promising results in Cultural Heritage field. This technique offers the advantages to provide information by images of the inner part of the object and to preserve its integrity. In this preliminary study home-made ceramic samples obtained from calcite-rich clay and subjected to different firing temperatures (in the 400°C-1000°C range) have been analyzed. SEM, MIP and X-ray μCT have provided complementary information regarding the effects of firing condition on physical properties and microstructure of ceramic mixture. SEM images show a more compact and vitrified morphology in samples fired at 900°C and 1000°C, in according to the melting temperatures of minerals. The results obtained by MIP, regarding the open porosity, show cumulative volume increase with firing temperature due to the presence of carbonate-rich clay which promotes high porosity over 600°C [6]. A more complete evaluation of the total porosity (open and close) is given by X-ray μCT measurements. The imaging elaboration of X-ray μCT results allowed to evaluate and calculate total porosity, pore size distribution and shape, Feret’s diameter and tortuosity.

The combined action of several physical, chemical and biological factors cause the weathering of stone widely employed in the field of Cultural Heritage. These deterioration processes were well studied and the results have promoted the research and the development of novel types of consolidation treatments to overcome the limitations of traditional ones and to meet the requirements of the historic building substrates. During the collaborative project NANOMATCH [1], different consolidating agents for carbonate supports, as alkaline alkoxides, were synthesized and applied. In particular, calcium alkoxides are metallorganic compounds that, dissolved in an organic solvent, penetrate within the porous substrate and, reacting with moisture and carbon dioxide of the atmosphere, form a calcium carbonate coating on the pore walls [2]. In this study, calcium ethoxide with formula Ca(OEt)2, is characterized, tested and applied on carbonate stone with different porosity, properly selected among those widely employed in Italian Cultural Heritage. Its performance as stone consolidant product was investigated and compared with that of a commercial one, the nanolime Calosil E50. The kinetic of carbonation process of Ca(OEt)2 was evaluated with ?FT-IR and, to understand how the humidity can affect the final product, XRD was used. Preliminary results of the performance of this consolidating treatment applied on carbonate stones regarding the changing in mechanical characteristics- drilling resistance, ultrasonic velocity- and the observation of the coating- photocolorimetric measurements- are here reported and discussed.

Conservation environment with high humidity content or exposure to liquid water are directly linked to degradation of cellulosic materials, such as paper and fabrics. This research had as main objective the development of formulations based on two water-repellent products commercially available: a fluoroacrylic co-polymer and a polydimethylsiloxane. The purpose was to test their applicability to paper and textiles, both ancient and modern. Different analytical techniques have been used: FTIR-ATR spectroscopy, colorimetric analysis, observations by SEM-EDX and light microscopy, contact angle measurement and mechanical strength. Applications were carried out by spray and immersion achieving a systematization of the method and the choice of non-toxic solvents. Two of the four formulations tested were prepared with the addition also of silica nanoparticles. The results highlighted the compatibility and effectiveness of fluoroacrylic polymer with low nanosilica percentages applied by immersion.

In the last years, significant research effortsin the cultural heritage area have been conducted towards environmentalimpact reduction of biocides and to improve theireffectiveness overtime.This paper proposes an approach based on encapsulation/incorporation of zosteric sodium salt, ZS, an environment friendly biocide, in silica nanocapsules. The aim of this work is the development of a material for controlled release of bioactive species to be incorporated into coatings. Porous silica nanocapsules have been fabricated by the one-step synthesis called dynamic self-assembly (DSA) [1]

Limestone, used in artistic and architectural fields because of its composition and textural characteristics, is particularly susceptible to decay. Its constant exposure to a combination of weathering factors, causes an increase in porosity and a loss of material cohesion. In order to deal with this deterioration process, Ca(OEt)2 as a novel product developed during the EC NANOMATCH project, is tested to consolidate four types of limestone widely employed within Italian Cultural Heritage: Noto stone, Lecce stone, Carrara marble and Vicenza stone [1]. Pore-space properties, such as pore-size distribution and connected porosity, are crucial factors in the evaluation of a consolidation product and, throughout this study, they are analysed with NMR relaxometry of water 1H nuclei. This technique, being both non-destructive and non-invasive, is able to obtain both longitudinal (T1) and transverse (T2) relaxation time distributions of water in the stones' pores, before and after the consolidation treatment [2]. The results demonstrate that T2 is more sensitive than T1 in detecting pores of small dimension for all lithotypes, but not for marble which gives results that are not easily legible due to its low open porosity and a small quantity of absorbed water. Combining relaxation data and micro-structural studies performed by MIP and SEM measurements, a better understanding is obtained of the changes within stone porosity. The results confirm that NMR technique could be a useful tool for the evaluation of consolidation treatment on stone.

We present a multi-analytical non-invasive approach for the characterisation of yellow paints used in three paintings from the International Gallery of Modern Art Cà Pesaro, Venice. The paintings selected for this study were executed in oil-based media between 1940 and 1960, they are unvarnished and have large monochromatic yellow areas. We focus on the identification of yellow pigments with a combined approach based on non-invasive portable X-ray Fluorescence spectrometry, complemented with VIS reflectance, remote-Fourier Transform Infrared and Raman spectroscopies. Different yellow pigments including Chrome yellow Naples Yellow and Cadmium-based yellow were identified. Their identification is of fundamental importance because several modern inorganic yellow pigments (in particular chrome and cadmium-based pigments) are known to exhibit peculiar degradation patterns, leading to noteworthy aesthetic changes in paint such as darkening and fading. This work highlights the suitability of non-destructive techniques for the characterisation of modern paints and the utility of an integrated approach to obtain useful information for preventive conservation. Results demonstrate the need to complement elemental data acquired using portable X-ray Fluorescence with suitable complementary molecular spectroscopic techniques.

Μη διαθέσιμη περίληψη Not available summarization Παρουσιάστηκε στο: Conservation of Architectural Surfaces: Stones and Wall Covering