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Tidal exchange, capillary rise, water condensation-evaporation cycles, and crystallizationof salts are the main causes of damage in historic brick buildings in Venice. The present studyaddressed these issues by proposing a study of twenty-three brick samples collected on the mainfaçade of the Santa Maria dei Servi Church (14th century). The color, mineralogical composition, and texture of these samples were studied using standard methods such as spectrophotometry,X-ray powder diffraction (XRPD), optical microscopy (OM), and field emission scanning electronmicroscopy (FESEM). The presence of carbonates (calcite and dolomite) and newly formed silicatephases, such as gehlenite and diopside, provided indications of the temperatures reached during firing and suggested the absence of a good standardization in the production process. Meanwhile,XRPD and hyperspectral analysis (HA) detected sulfates (e.g., gypsum and mirabilite) as the mainweathering products due to the salt decay process that affects monuments in the Venice lagoonenvironment. Moreover, secondary phases, such as Mg- and Ca-zeolites, occurred in bricks where thegroundmass observed by OM was more vitrificated, and the XRPD patterns displayed the highestamorphous content. On-site mapping of sulfates and chlorophyll by HA was also performed on themain façade of the Church, highlighting the large presence of salts and biodeterioration.

Deliverable D4.3 presents the work of research and technical development for designing a novel method for monitoring and predicting material decay in cultural heritage. It focuses on the microclimate and climate factors affecting the weathering of stone and timber used as building materials in diverse environmental settings. An apparatus for long-term field exposure tests was expressly designed in its hardware and software components. That supports the monitoring of the microclimate characteristics of selected stone and wood samples, installed in Italy and Norway at different orientations. The data series of surface temperature and humidity measured on the sample surfaces are to be compared with other microclimate and climate datasets recorded at different scales and from different sources and equipment (“smart tags”, weather stations, and regional stations of environmental monitoring). In such a way, the differences between standard climate time series and microclimate series at the scale of both the whole buildings and their discrete component materials can be determined. A correlation is also established between the environmental settings and the material properties and durability. In fact, the apparatus is also designed for the quantification of natural ageing. A series of preliminary laboratory analyses (colorimetry, profilometry, and μ-XRF) were conducted for measuring sample color, surface topography, and chemical composition. The relevant datasets are to be compared with the results of the same analyses repeated in the next years, so to verify changes in material properties and reconstruct the relevant deterioration trends. The results will feed the HT Simulator Tool and will constantly update the HRAP platform, supporting the modelling of the decay and assessment of the vulnerability of historical building materials, to the benefit of the scholars and stakeholders involved in the protection of cultural heritage from environmental stresses and climate change.

Carbonate rocks (limestones, marbles) are among the most commonly used building materials (both as dimension and ornamental stones), and are highly vulnerable to weathering, especially in polluted areas. One of the main issues in the evaluation of cultural heritage vulnerability is the quantification of the deterioration rate. With this goal in mind, and in the frame of the HYPERION Project, the water-driven recession of stone in cultural heritage was simulated and measured in the laboratory by exposing a set of carbonate rocks, historically exploited and used in northern Italy, to accelerated ageing tests by immersion in rainwaters with different compositions. The tests were run cyclically in an environmental test chamber, alternating wetting and drying phases; at fixed intervals, the recession of each sample was quantified by bulk weight-loss measurements and surface mapping at the confocal microscope. The relationship between the different mineralogy and texture of the stones and the rate and areal development of their recession was investigated, finding that, besides water pH, calcite grain size is the most important controlling decay factor. Correction coefficients were also calculated for obtaining more reliable recession estimations from recession equations known in the literature. The findings of this study can be exploited for predicting stone deterioration in cultural heritage constrained by the relevant environmental context and the expected future climate change., SGI-SIMP 2022 Meeting, September 19-21, 2022, Torino, Italy

In many noteworthy buildings in Venice we can observe a strong loss of material at the bottom of the façades (usually in the 1-2 meters from the soil level). Capillary rise, water condensation-evaporation sub-florescence of salts can induce scaling and cracking in bricks with a subsequent reduction of the thickness of the wall section and therefore of its load-bearing capacity. This work proposes a new approach to assess the vulnerability of historical brick masonry patrimony, the most used in Venice. This new approach provides for three main steps: i) the minero-petrographic characterization of the materials (bricks and mortars); ii) the 3D photogrammetric survey and the measurements of the cross-sections of brick walls; iii) the decay assessment. For this purpose, the Church of Santa Maria dei Servi (Cannaregio, 14th century) was selected as case of study. Color, mineralogy and texture of the bricks and mortars, and secondary weathering products were studied by means spectrophotometry, X-ray diffraction, optical and scanning electron microscopy, and hyperspectral analysis. 3D surface modelling by empirical descriptions based on photogrammetry was used for understanding the effects of water and salts interaction in the bricks wall of the main façade. Results will be useful to provide previsions of long-term deterioration of that monument and they can be implemented in other brick buildings in Venice, which have the same decay pattern., AIAr Meeting, Padova, June 29 - July 2, 2022

The EU-funded project Hyperion aims at developing a “decision support system for improved resilience and sustainable reconstruction of historical areas” facing the impact of climate change and extreme weather events, with the aid of sensor-based and modeling tools. An essential part of the project involves the quantification of the current decay of cultural heritage, which may shed light on how heritage materials interact with the environment, react to microclimate stresses, and resist to future climate change in weathering models and simulations. To that purpose, a novel experimental method based on the long-term monitoring of historical building materials, their deterioration, and the relevant environmental parameters in different geographic contexts, was designed. A selection of stone and wood materials historically used in different European countries are exposed outdoors to natural weathering, in the urban environment of Italy (Padova and Venice) and Norway (Tønsberg). In every location, the same set of samples are exposed at different orientations (North, South, and horizontal plane) and their surface microclimate parameters are being monitored with temperature and moisture sensors. The microclimate data series are compared with the climate data provided by both the complementary weather stations installed in each monitoring site and the stations of the official regional agencies of environmental monitoring. At the same time, the material decay is being measured by monitoring the changes in surface topography/recession, chemical composition, and color of each building material, that is, comparing the maps acquired before and during the exposure tests by 3D optical profilometry, micro X-ray fluorescence, and colorimetry. This investigation is expected to provide a solid base for developing models of future deterioration of cultural heritage and prediction of its endurance in a changing climate., AIAr Meeting, Padova, June 29 - July 2, 2022

This contribution presents the work of research and technical development for designing a novel method for monitoring and predicting the weathering of cultural heritage, in particular of stones and timber used historically as building materials. An apparatus for long-term field tests was designed in its hardware and software components with a twofold application: Exposure of a set of selected stone and wood specimens to natural weathering, at different orientations (North, South, and horizontal plane) and environmental settings (Italy and Norway). Non-stop acquisition of microclimate data series at different resolutions, down to the scale of the specimen surface, completed by datasets of regional stations of environmental monitoring. Complementary laboratory analyses aim at setting a reference point for the state of conservation of each material before the exposure tests, and monitoring the changes of surface recession/topography (by 3D optical profilometry), thus reconstructing the relevant deterioration trends. Within the framework of the EU-funded project HYPERION, this novel experimental approach is expected to help assessing the interaction of building materials with the environment and their weathering constrained by microclimate and climate variability; combining climate model simulations, the stresses brought about by climate change can also be assessed. The findings might represent a source of precious information for the activities and decision-making protocols of the stakeholders involved in the protection of cultural heritage. Powered by, EGU22-5898; EGU General Assembly 2022, Vienna, Austria & Online, 23–27 May 2022

An innovative experimental method for the long-term monitoring of outdoor microclimateand material decay at cultural heritage sites was developed to aid the formulation of new damagefunctions and models for climate-change risk assessment. To that end, an apparatus for field exposuretests was designed to monitor a variety of historical building materials in different environmentalsettings. The data series acquired, i.e., surface temperature and moisture, are compared with thecorresponding meteorological datasets on a local and regional scale. The apparatus is designed forsupporting also the monitoring of the physical and chemical changes caused by weathering. Thisnovel method is expected to provide insights into the interaction between historical materials and theenvironment, which can be exploited for the protection and conservation of cultural heritage.

Climate change is one of the most critical global challenges of our time. During the last century, the anthropic activity had a great impact not only on the environment, affecting even the conservation of cultural heritage. This is becoming a mandatory issue to be tackled by international and local administrations and heritage stakeholders. Stone is one of the natural materials most utilized in historical monuments. Although stone decay phenomena have been broadly investigated in the past, only few studies are moving towards the understanding and quantification of the short- and long-term effects of climate change. This research direction, however, is essential for supporting sustainable mitigation plans and the city management. The HYPERION project aims to fill this gap, improving the knowledge of measurable material- and climate-based parameters that influence stone decay rate. The project includes simulations of future scenarios and potential effects of changing climate patterns and air quality, extreme climate events, and multi-hazard circumstances in the historical urban context. In this contribution, we present the preliminary results of the study of selected building stones used in four European demonstration sites, in Italy (Venice), Greece (Rhodes), Spain (Granada), and Norway (Tønsberg). The basic petrographic and physical-mechanical investigation of the materials is combined with accelerated ageing tests under different environmental stresses (cycles of salt crystallization and freeze-thaw and interaction with rainwaters with different compositions) and field-exposure tests. The expected results will help refining adequate material-specific models of stone surface recession and support structural and hygrothermal simulations about the future decay of cultural heritage., Japan Geoscience Union Meeting 2021 JpGU21, May 30 - June 6, 2021

The Euganean Hills (Veneto, NE Italy) are the most important quarry district in Italy for the extraction of trachyte, which has been carried out in tens of quarries all through the centuries, from Pre-Protohistory and, more intensely, from the Roman age onwards. Trachyte of the Euganean Hills has an age-old tradition of usage as carving and building stone, mainly in northern and central Italy, e.g., for manufacturing diverse everyday items and funerary and votive artifacts, as well as for building infrastructure, monuments, and in public and private construction. An archaeometric study of Euganean trachyte is here presented following two main research directions. The first involves the identification of criteria for recognizing provenance quarry of trachyte used in archaeological and historical materials, supported by a petrographic and geochemical database obtained from samples collected in the entire area of the Euganean Hills. The petrographic provenance tracers involve mineralogical composition and textural features of phenocrysts and groundmass, whereas the geochemical tracers comprise major- and trace-element composition of bulk rock and phenocrysts, in particular of mafic minerals. Trachyte provenance can be most precisely determined by applying multivariate relations based on phenocryst chemistry, which can be analyzed even on small, altered archaeological samples. The provenance markers were tested in a provenance study of Euganean trachyte used in Roman public infrastructure in Veneto, including roads, bridges and forum squares. The results provide insights into the commercial, political and economic dimension of the management of trachyte quarries and development of extraction activities in the Roman times, as well as into ancient trades in northern Italy and the main routes of stone circulation. The second research topic addresses the investigation of weathering and durability of Euganean trachyte used as building stone. Weathering crusts and patinas were detected on trachyte in urban environment, and their mineralogical and microstructural characteristics, major- and trace-element chemical composition were analyzed. The alteration products, mainly involving surface enrichment in carbonates, heavy metals, and carbon, represent an informative indicator of environmental conditions, in particular air quality, and chemical stability of the rock-forming minerals of trachyte and neighboring jointing mortars. Trachyte durability was also examined by a petrophysical and mechanical characterization of quarry samples, providing elements for aiding quality assessment by conservators-restorers and building companies. Particular emphasis is placed on the properties related to absorption, transport, and retention of water and aqueous solutions, in liquid and vapor state. Depending on porosimetric characteristics, i.e., pore volume, size, size distribution, shape, and degree of interconnection, different trachyte varieties exhibit a relatively wide array of technical performances, diversely affecting their decay behavior.

Decay of trachyte used as building stone in urban environment was investigated through the analysis of crusts and patinas found on trachyte of the Euganean Hills in the Renaissance city walls of Padua, northeastern Italy. Mineralogical and microstructural characteristics of the alteration products, as well as major- and trace-element chemical composition, were determined by optical microscopy, SEM–EDS and X-ray mapping, XRPD, and LA-ICPMS. The results are discussed referring to environmental parameters, in particular concerning air quality and anthropic pollution sources. The influence of composition of the stone and other neighboring materials on specific weathering processes is also debated. The formation of crusts and patinas turns out to be mainly due to exogenous processes. Enrichment in heavy metals and carbonaceous matter derives from the deposition of particulate emitted during fuel combustion by road vehicles, domestic heating and, secondarily, industrial activities. The particulate is typically cemented by calcite, mainly mobilized after dissolution from nearby mortar joints, or iron, released by leaching from iron-bearing minerals, reprecipitated according to pH fluctuations. Gypsum layers were rarely observed. Generally, composition of the weathering crusts and patinas of Euganean trachyte proves to be an informative marker for the relevant environmental conditions and their evolution.