This contribution presents one of the research directions of the project WATERISKULT (https://wateriskult.geoscienze.unipd.it), involving the decay of underwater archaeological sites, in particular of submerged structures and artifacts made of stone. The pilot sites of this project are located in the western, central, and eastern Mediterranean Sea, and include the Roman complex of Baia in Italy, the Hellenistic harbor of Amathus in Cyprus, and the Roman port structures of Anse des Laurons in France. Diving and sampling campaigns were organized therein in the first half of 2023, and were followed by laboratory analyses that explored the state of conservation of different archaeological stone materials (limestones, marbles, tuffs, sandstones, etc.). Microscopic techniques were applied for investigating the stone composition, biofouling, and chemical alteration, observing the surface and stratigraphic features of the sampled materials. Moreover, 3D morphometric techniques allowed for the quantification of the physical damage of the archaeological surfaces. The analytical results were combined with site-specific topographic information collected during the dives and environmental data provided by seawater monitoring agencies. In that way, the interaction between ancient materials and the underwater environment was explored, discussing the relationship between deterioration and a range of different stone and seawater properties.

How to cite: Germinario, L., Moro, I., Crocetta, F., Tomasin, P., Moschin, E., Cibecchini, F., Demesticha, S., Gallocchio, E., Gatt, J., and Mazzoli, C.: Stone decay in the underwater environment: examples from Mediterranean archaeological sites, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-1188, https://doi.org/10.5194/egusphere-egu24-1188, 2024.

Interaction between the historical built environment and environmental pollution can result in the accumulation of weathering crust on building material surfaces. A subgroup of weathering crusts are black crusts, which consist of gypsum layers formed by sulfation on calcium-rich substrates. These crusts occur more often and are more pronounced in polluted environments such as urban settings. As a result, they can incorporate particulate matter, polyaromatic hydrocarbons, and heavy metals. Black crusts can act as non-selective passive samplers, accumulating distinct layers of air contaminants depending on historical pollution levels.
Existing studies provide only coarse-resolution reconstruction of pollution, differentiating solely between inner and outer crust layers. Just a few explore the correlation between different periods of exposure to pollution and the variation of the composition of these crusts. This study focuses on the stratigraphic analysis of black crusts to assess their potential as a reliable geochemical archive for the reconstruction of past anthropogenic pollution within urban settings.
Following technological developments in transportation and combustion, the composition of pollutants in the atmosphere has evolved over the centuries, likely reflected within weathering crusts where pollutants accumulate. For the identification of past air pollution signatures, lead can serve as a useful tracer due to its isotopes, their presence is the result of different historical pollution sources. Variations in the ratios of lead isotopes provide a means to attribute and differentiate among these pollution sources. For lead isotope analysis, high-resolution laser ablation mass spectrometry will be used to distinguish between 206Pb, 207Pb, and 208Pb.
This study deepens the understanding of localized pollution levels in urban settings, allowing the implementation of conservation interventions including cleaning and consolidation, strategies to mitigate the impact on human health, local ecosystems, and biodiversity, and to support urban planning.

How to cite: Deboli, S., Visschers, S., Astray Uceda, B., Šípková, A., Wilhelm, K., and De Kock, T.: Black Crusts as Geochemical Archives: Preliminary Results from Antwerp, Belgium, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-4340, https://doi.org/10.5194/egusphere-egu24-4340, 2024.

Lake Tana is the largest lake in Ethiopia and the source of the Blue Nile. The lake is protected as a natural heritage site. It is surrounded by wetlands that provide a sanctuary to a diverse set of flora and fauna some of which are endemic to the region. It is also a culturally significant area. Surrounding the lake and on the islands are found tens of stone built monasteries, churches, bridges and palaces built in the Gondarine period (17^th and 18^th Century AD) and earlier. However, these buildings are subjected to biological growth in many different types that cause  discoloration and  degradation. The short and intense rainy season contributes to the nature, diversity and intensity of biological colonization of these stone structures. Biofilms, fungi, mosses, lichen and higher plants can be observed, while also small animals such as mites and rodents are agents of bio-deteriorative process. While micro-organisms alter the visual appearance, roots of higher plants are responsible for more severe physical decay on the site and building level, increasing also the impact of moisture-related weathering in decayed locations. However, micro-organisms can also alter the surface properties of materials, like water absorption and retention, and it is currently not well understood to what extend these contribute to the observed forms of degradation, like chipping, fissuring, cracking, etc. 

This poster aims to address some of the key challenges of managing cultural heritage sites found in a complex, evolving and vulnerable ecosystem, i.e. Lake Tana. Factors such as intense rainfall, humidity, the state of the structures, intensification of agriculture and the perspectives of local communities and stakeholders will be evaluated.

How to cite: Demssie, A., De Kock, T., Ortega-Saez, N., and Gemeda, B.: Biodeterioration of historical buildings and sites in north of Lake Tana, Ethiopia: a preliminary investigation, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-7547, https://doi.org/10.5194/egusphere-egu24-7547, 2024.

Built heritage is a vital component of urban environments and is rich in cultural and economic values. These buildings are abundant in city centres and have been the site of development for several centuries. They have created dense urban environments, exhibiting strong urban heat island effects. Ground-based vertical greening is a widely used green initiative in dense urban environments to mitigate the current climate stressors due to its small footprint and its ability to cover a large surface area with vegetation. The impact of this green initiative on the materials and structural integrity of built heritage is currently poorly understood and thus the focus of this research.

Several studies have already proven the efficacy of ground-based vertical greening in fostering a more stabilized condition on the underlying wall surface, characterized by reducing the amplitude of temperature and relative humidity fluctuations and the amount of solar irradiation. More stable conditions can imply a lower risk of common degradation processes, such as freeze-thaw weathering and salt crystallization, in historic building materials. 

Since the extent of the vertical greening performance and the deterioration of building façades strongly depend on the orientation of the façade, part of this research aims to establish a relationship between those two variables while considering the orientation of a building façade. Monitoring case studies in the historic city centre of Antwerp during summer develops an understanding of the shading performances of vertical greening and characterises the boundary conditions, such as orientation or leaf area index (LAI), that signify the extent of efficacy. The current case studies reveal a positive correlation between the LAI and the shading potential of vertical greening and highlight the significant role of orientation in mitigating the environmental parameters on the wall surface, as the cooling processes of vegetation mainly depend on the amount of solar irradiation. More specifically, the highest leaf area index and a south or west orientation show us the most significant cooling behaviour during the day which can reduce the risk of salt crystallization the most. The shading performance of vertical greening is only one of the several mechanisms determining the impact of vertical greening on the local environment and the subjected historic materials. 

How to cite: De Groeve, M., Kale, E., Orr, S. A., and De Kock, T.: The influence of orientation and leaf area indices of a vertical green wall on historic building materials, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-16698, https://doi.org/10.5194/egusphere-egu24-16698, 2024.

Ongoing urbanization has increased the impact of the urban heat island effect, air pollution, and noise pollution while limiting the space for green areas. Therefore an urgent action is required to mitigate these environmental risks. Vertical Greenery (VG) has emerged as a sustainable and viable solution across diverse contexts, but it is generally not always accepted for historic buildings by experts. The scepticism is rooted in concerns about the potential adverse effects on conservation practices and heritage values. Contrary to expert concerns, VG on historic buildings is seen as a response to reducing the urban heat island effect in high environmental risk areas by the users.

We conducted a comprehensive study in Antwerp (Belgium), a city actively advocating for VG solutions. We selected three neighbourhoods, namely Historical Centre, Oud Berchem, and Borgerhout Intra Muros Zuid, where air pollution, noise, and heat stress are above the risk level. We documented the VG implementations in these three neighbourhoods through the use of GIS and field survey methods. The prevalence of VG in case sites was analysed based on factors such as the heritage status of buildings and the morphology of streets, which could pose challenges to the implementation of VG.

The results suggest that VG is present in up to 14% of all buildings in the selected neighbourhoods. While in the Historical Centre, 59% of the buildings with VG have a heritage designation. As such, narrow streets and heritage designation do not prevent VG implementation in densely built neighbourhoods with green space deficits.

While this study provides site-specific results, the analysis methods we used can guide policymakers and urban planners to explore VG's adaptability to historic buildings in the development of effective integration strategies.

How to cite: Kale, E., De Groeve, M., Pinnel, L., Erkan, Y., Hacıgüzeller, P., Orr, S. A., and De Kock, T.: Mapping Vertical Greenery on Historic Buildings in Neighbourhoods with High Environmental Risks: A Case Study in Antwerp, Belgium, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-15931, https://doi.org/10.5194/egusphere-egu24-15931, 2024.

The European project SCORE (Sustainable COnservation and REstoration of built cultural heritage, GA 101007531) deals with a two-way assessment of impacts of the environment on building materials and of materials on the environment. Indeed climate conditions and atmosphere composition determine built cultural heritage (BCH) materials’ behaviour and, at the same time, BCH conservation processes (products and techniques) impact greenhouse gases emissions and eventually climate change.

This contribution presents a characterization of the effects of different climate conditions on several traditional restoration mortars, bricks and calcareous stones. A common strategy plan was designed in order to compare the results of weathering exposition experiments in several location: North of Spain, North-West of France, Denmark and Calakmul Biosphere Reserve in Mexico. Some of the presented results correspond to real conditions experiments started before the common exposition campaign but they will be presented because of their interest.

The exposition support is a frame with a plate surface of 1mx1m, placed at 1m height under two exposure conditions: inclination of 10° and at horizontal position. The exposition frame is oriented facing the predominant wind direction. For comparison we chose to expose two kinds of hydraulic lime mortars from Saint Astier company, bricks from Denmark and Mayan calcareous stone from Campeche area treated with Ca(Zn (OH)₃)₂·2H₂O nanoparticles (CZ) in order to improve their behaviour under the exposure conditions.  Mortar coupons had dimensions of 20 x 10 x  3 cm, while the stone samples ones were 5 x 5 x 3.5 cm. A first set of mortars consisting of two-layer sample was tested with a base of a salt protection mortar and a 1 cm upper layer with a finishing mortar. A second set of mortars consists of a monolayer of a masonry restoration mortar. In each specific site, local or recipe mortars have been also exposed. 

Samples have been characterized before exposition and at regular time intervals during the exposition period, that is not finished. Weight, hardness, deterioration patterns, colour and P wave velocity have been measured at different sample locations. Results indicate that in French locations commercial mortars become better than home-made ones, probably due to the absence of any additive in the home-made recipes. First results for the Spanish exposition site show that velocity measurements start detecting some points where layers begin to separate from each other. Some microcracks start to develop at the surface of one type of mortar respecting the monolayer one.  Finally colour changes have been detected in the two layers masonry mortar.

Such gradual (also visible) degradation has previously also been documented in laboratory examination of fired clay bricks submerged in liquids with varying pH (3,5,7,9,11) and varying duration up to more than one year (432 days). Increasing submersion duration resulted in increased degradation, whereas the different pH values representing exposure to various conditions (acid rain, traditional rain, connection with alkaline mortar) revealed different degradation patterns.

The stone coupons improve some of their properties due to CZ addition at initial periods, but they tend to decrease over time.

How to cite: Valdeon, L., Menendez, B., Reyes, J., and Rörig-Dalgaard, I.: Durability of Built Cultural Heritage Materials under different climate conditions, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-13376, https://doi.org/10.5194/egusphere-egu24-13376, 2024.

The European project SCORE (Sustainable COnservation and REstoration of built cultural heritage, GA 101007531) deals with a two-way assessment of impacts of the environment on materials and of materials on the environment. Indeed, climate conditions and atmosphere composition determine built cultural heritage (BCH) materials’ behaviour and, at the same time, BCH conservation processes (products and techniques) impact greenhouse gases emissions and then climate change.

The objective of this work is to study the feasibility of recycling old mortars and plasters from an existing building to extract the sand with the aim of reusing it to produce new mortars for the renovation of the built heritage. Old mortars and plasters were mainly made with "natural" sands, generally alluvium and river sands, available near the site. These sources of sand may no longer be available or have become scarce. The use of different sands from the original ones in restoration plasters has consequences on the aesthetic properties of the new plasters applied during the renovation, which often requires the use of additives and dyes. To solve this problem, one possibility is to extract the original sand from deconstruction mortars, taken for example from renovation sites.

We tested the proposed method on a site in Paris. Deconstruction mortars were crushed and the sand was recovered, characterized and used for the formulation of new mortars by adding lime and water. Washing methods with water and acid washing solutions have been tested in order to obtain sands free of debris and lime agglomerates. Citric acid was used because it presents good lime dissolution results and is quite easy to employ in restoration works. Microscopic observations were made to determine the effectiveness of each washing solution. Sands washed only with water show some remains of lime on the grain surfaces whereas washing the grains with citric acid solution (2 %) produces excellent results.

In addition, mortars formulations with different grain size of recycled sands were made. These formulations consist of a mixture of recycled sand, water and an additive lime in equal proportions. Specimens of 4 x 4 x 16 cm were produced and their mechanical properties were measured at 28 days of age. During the maturation time, the samples are kept in an environment with constant humidity and temperature, to optimize the conditions of hydration, carbonation and maturation.

The results obtained show that the mechanical properties of mortars made from recycled sand are acceptable and that these are intrinsically linked to the grain size and quality of the sands. The mechanical properties of mortars formulated with recycled sands of the right grain size are similar to those formulated with commercial natural sand. A large part of the recycled sand, after just washing with water, can be used in the formulation of new mortars with regard to standards and aesthetic properties.

How to cite: Menéndez, B., Yameogo, V., and Ghorbel, E.: Sustainability and cultural heritage conservation: re-use of sand from deconstruction renders, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-12505, https://doi.org/10.5194/egusphere-egu24-12505, 2024.

The increase in demand for natural resources due to the growth of the world population is generating an unprecedented increase in waste, and the unsustainability of this situation has induced the change towards a more environmentally friendly economy, the so-called “Green Economy”. Through the new policies for waste management, its reuse in other industrial processes is being encouraged, favouring “Zero Waste” initiatives. This aims to minimize the emission of greenhouse gases that could accelerate climate change, as well as to the reduction of associated energy expenditure. In Spain, two of the sectors that generate the most waste are construction and agriculture, especially linked to animal by-products not intended for human consumption (SANDACH, by its Spanish acronym). In line with these new trends, new initiatives are required to promote the reuse of this waste and the development of more sustainable construction products that involve the reduction of the carbon footprint. Therefore, the main goal of this work is to better understand the effect of adding natural fibres of animal origin, in this case cow hair and pig bristles, to lime mortars for their use both in modern construction and its application in repair historical mortars. In this way, we aim to achieve a double goal: on the one hand, to obtain information about the quality of the result of combining these products; and on the other hand, to reduce CO₂ production by avoiding the incineration of animal by-products not usable in other sectors, finally producing a more sustainable mortar. The specific objectives proposed are: 1) to compare the quality of lime mortars considering the addition of hairs, bristles or with combined proportions of both fibres, with respect to control samples without fibres; 2) to evaluate if the speed and degree of carbonation are affected by the addition of fibres; 3) to identify deterioration processes that may reduce the quality of lime mortars due to aging in the laboratory and outdoors; and 4) to establish optimal production and handling conditions in collaboration with regional or national companies interested in the use of this product. To achieve these goals, in this first stage we will present the preliminary results comparing a mortar without fibres as control sample, with 3 sets of samples with different fibre proportions (containing 10 g or 20 g of cow hair or pig hair per 2 kg), as well as a mixture of both types of fibres (5+5 g and 10+10 g per 2 kg). Based on these results, it will be possible to consider the possibility of increasing the quantity of fibres until reaching an acceptable limit of workability and usefulness without compromising the quality of these mortars.

Acknowledgements: This study was financially supported by the Research Project TED2021-132417A-I00 funded by MCIN/AEI /10.13039/501100011033 and by the European Union NextGenerationEU/ PRTR and E. Molina-Piernas acknowledges co‑funding from the European Social Fund (D1113102E3) and Junta de Andalucía.

How to cite: Molina-Piernas, E., Pacheco-Orellana, M. J., Domínguez-Bella, S., Martínez-López, J., and Sánchez-Bellón, Á.: Insight to the effect of adding cow hair and pig bristles to lime mortars: Towards obtaining more sustainable construction products recycling waste animal byproducts., EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-18747, https://doi.org/10.5194/egusphere-egu24-18747, 2024.

The integrated use of non-destructive geomatic and geophysical techniques such as close-range digital photogrammetry, laser scanner techniques, thermography, sonic and ultrasonic methods, resistivity, etc... for the diagnostics of the stone building materials of architectural structures has become increasingly dependent on the integration of different disciplines of applied research. As is well known many historic monuments are characterized by severe damage due to temporal degradation, problems caused by differential settlements of the foundations and various types of natural hazards. Therefore it is of great interest to test and develop effective, integrated non invasive procedures to detect the conservation state of the building materials of historic structures, and identify and prevent their potential vulnerability in order to preserve their intrinsic characteristics for a long time.

For extensive applications, as well as for investigations on monuments or large architectural elements, scanning and digital high resolution images are particularly useful, thanks to their limited cost, high production and relatively simple reproducibility of the tests. These techniques give useful information on the shallow conditions of the investigated materials. Geophysical techniques such as the ultrasonic and resistivity methods are non-invasive and are considered the most appropriate to evaluate the internal structure and assess the quality of the stone materials of the architectural heritage.

This paper presents an integrated approach that combines advanced geomatic survey procedures, such as close-range photogrammetry (CRP) based on high resolution images and Terrestrial Laser Scanner (TLS) techniques with a few geophysical techniques such as the ultrasonic and resistivity ones in order to test the effectiveness of the integrated approach in providing an effective diagnosis of stone building materials in the Basilica di San Saturnino (Cagliari – Italy). This Basilica is the oldest monument of the town of Cagliari (Italy) and represents an interesting synthesis of different construction techniques with heterogeneous stone materials of different origins. CRP and TLS were applied to the investigated elements with the aim of obtaining a natural colour texturized 2D-3D model with a calibrated scale and coordinates. The geometrical anomaly and reflectivity maps derived from the data of the CRP-TLS survey show the presence of some anomalies worthy of attention, but they were referred to the shallow materials. A further investigation on site using the ultrasonic pulse velocity (UPV) and electrical resistivity techniques were performed to investigate the materials in depth. The results of the CRP and TLS techniques allowed the best design of the ultrasonic and electrical techniques and also proved to be useful in the data interpretation phase.

Acknowledgements: The authors would like to thank the Ministero della Cultura - DIREZIONE GENERALE MUSEI - DIREZIONE REGIONALE MUSEI SARDEGNA (ITALY) for their kind permission to work on the San Saturnino Basilica.

How to cite: Casula, G., Fais, S., Cuccuru, F., Bianchi, M. G., Ligas, P., and Cannas, L.: A multidisciplinary approach for the diagnostics of the stone building materials of architectural structures, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-2818, https://doi.org/10.5194/egusphere-egu24-2818, 2024.

Identifying and determining buried archaeological structure limits are crucial for archaeological prospection surveys. The archaeological prospection surveys can shed light on protecting cultural heritage. Magnetic is one of the most applied methods in archaeological surveys to plan the excavation process. It aims to identify buried temples, graves, city walls, and other structures by interpreting the data obtained from magnetic measurements, which is one of the non-destructive geophysical exploration methods. In the process of interpretation of magnetic data, many methods have been developed, such as Horizontal Gradient Magnitude, Analytical Signal, Theta Map, and Tilt Angle methods, which can generate information about the boundaries of potential subsurface features. By analyzing the gradients of the magnetic field data, inferences can be made to determine the edges of subsurface potential archeological structure distributions.

The Olympos is an important ancient city in Antalya (the south of Turkey) and contains many structures from the Byzantine period. This research aims to detect the pipe drain as a water system of the Episkopeion region in the Olympos ancient city. To this end, Tilt Angle (TA) and Edge detection field (ED) methods were tested on the magnetic map of the synthetic model. The horizontal boundaries of the potential pipe drain elements of the region were analyzed by applying the same procedures on the magnetic map obtained from the magnetic measurements on the area that has not been excavated in the Episkopeion archaeological excavation area. Magnetic measurements were carried out in 4 different regions within the Episkopeion area, and each area was numbered and analyzed separately. Combining the results obtained, an integrated visualization of the water system in the area was achieved.

Keywords: Archaeological Prospection, Edge Detection, Olympos, Tilt, Angle, Pipe drains.

How to cite: Deniz Toktay, H.: Edge detection of magnetic data: Preliminary results of application to Episkopeion region in Olympos Ancient City (Antalya), EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-19203, https://doi.org/10.5194/egusphere-egu24-19203, 2024.