Search Results (33)

The crystallization of soluble salts is one of the most significant agents of deterioration affecting porous building materials in historical architecture. This process not only compromises the physical integrity of the materials but also results in considerable aesthetic, structural, and economic consequences. Soluble salts involved in these processes may originate from geogenic sources—including soil leachate, marine aerosols, and the natural weathering of parent rocks—or from anthropogenic factors such as air pollution, wastewater infiltration, and the use of incompatible restoration materials. This study examines the role of capillary rise as a primary mechanism responsible for the vertical migration of saline solutions from the soil profile into historic masonry structures, especially those constructed with calcareous stones. It describes how water retained or sustained within the soil matrix ascends via capillarity, carrying dissolved salts that eventually crystallize within the pore network of the stone. This phenomenon leads to a variety of damage types, ranging from superficial staining and efflorescence to more severe forms such as subflorescence, microfracturing, and progressive mass loss. By adopting a multidisciplinary approach that integrates concepts and methods from soil physics, hydrology, petrophysics, and conservation science, this paper examines the mechanisms that govern saline water movement, salt precipitation patterns, and their cumulative effects on stone durability. It highlights the influence of key variables such as soil texture and structure, matric potential, hydraulic conductivity, climatic conditions, and stone porosity on the severity and progression of deterioration. This paper also addresses regional considerations by focusing on the context of Spain, which holds one of the highest concentrations of World Heritage Sites globally and where many monuments are constructed from vulnerable calcareous materials such as fossiliferous calcarenites and marly limestones. Special attention is given to the types of salts most commonly encountered in Spanish soils—particularly chlorides and sulfates—and their thermodynamic behavior under fluctuating environmental conditions. Ultimately, this study underscores the pressing need for integrated, preventive conservation strategies. These include the implementation of drainage systems, capillary barriers, and the use of compatible materials in restoration, as well as the application of non-destructive diagnostic techniques such as electrical resistivity tomography and hyperspectral imaging. Understanding the interplay between soil moisture dynamics, salt crystallization, and material degradation is essential for safeguarding the cultural and structural value of historic buildings in the face of ongoing environmental challenges and climate variability. Full article

Sustainable architectural heritage conservation focuses on preserving historical buildings while promoting environmental sustainability. It involves using eco-friendly materials and methods to ensure that the cultural value of these structures is maintained while minimizing their ecological impact. In this paper, the use of the hydroxyapatite (HAp) in various combinations on masonry samples is presented, with the aim of identifying the ideal solution to be applied to an entire historical building in Banloc monument. The new solution has various advantages: compatibility with historical lime mortars (chemical and physical), increased durability under aggressive environmental conditions, non-invasive and reversible, aligning with conservation ethics, bioinspired material that avoids harmful synthetic additives, preservation of esthetics—minimal visual change to treated surfaces, and nanostructural (determined via SEM and AFM) reinforcement to improve cohesion without altering the porosity. An innovative approach involving hydroxiapatite addition to commercial mortars is developed and presented within this paper. Physico-chemical, mechanical studies, and architectural and economic trends will be addressed in this paper. Some specific tests (reduced water absorption, increased adhesion, high mechanical strength, unchanged chromatic aspect, high contact angle, not dangerous freeze–thaw test, reduced carbonation test), will be presented to evidence the capability of hydroxyapatite to be incorporated into green renovation efforts, strengthen the consolidation layer, and focus on its potential uses as an eco-material in building construction and renovation. The methodology employed in evaluating the comparative performance of hydroxyapatite (HAp)-modified mortar versus standard Baumit MPI25 mortar includes a standard error (SE) analysis computed column-wise across performance indicators. To further substantiate the claim of “optimal performance” at 20% HAp addition, independent samples t-tests were performed. The results of the independent samples t-tests were applied to three performance and cost indicators: Application Cost, Annualized Cost, and Efficiency-Cost-Performance (ECP) Index. This validates the claim that HAp-modified mortar offers superior overall performance when considering efficiency, cost, and durability combined. Full article

Historic monument buildings represent, in a three-dimensional form, the expression of civilization, culture, and progress across various historical periods. Restauration works on such structure must achieve a performance level that preserves the value expression of parameters associated with criteria derived from both the historical substance and the requirements for strength and stability. National and international regulations (such as UNESCO conventions) play an essential role in heritage consolidation. These frameworks set standards for conservation practices and promote the importance of protecting historic heritage, which is an expression of cultural identity and community history. The research findings presented in the paper refer to a case study, Costache Conachi Manor, a building classified as a historic monument, located in Galați County, Romania. The investigations concern the processes and methods used to identify the current condition of the building, which includes the structural aspect and the materials used, in order to ensure compatible restoration works while respecting and enhancing originality. Overall, these advanced research techniques not only help to accurately characterize the materials used in the historic Costache Conachi Manor masonry structure but also play a vital role in developing knowledge of restoration and conservation practices. Full article

This study investigates structural integrity and proposes retrofitting solutions for the historical two-storey school building in Thrapsano, Crete, severely impacted by the September 2021 earthquake. An extensive methodology was adopted, incorporating field surveys, material characterization, finite element modeling, and experimental analysis. The assessment is focused on identifying structural damage, such as cracking and delamination in masonry walls, and evaluating the dynamic and static performance of the load-bearing system under seismic loads. Key interventions include grouting for masonry reinforcement, replacement of mortar with compatible materials, stitching of cracks, and the addition of reinforced concrete and metallic tie elements to enhance diaphragm action. Advanced numerical simulations, validated through experimental data, were employed to model the pre- and post-retrofit behavior of the structure. The proposed retrofitting measures align with Eurocodes 6 and 8, and the Greek code for masonry structures (KADET), aiming to restore the structural stability and improve seismic resilience while respecting the building’s historical significance. The results from the finite element analysis confirm the effectiveness of the interventions in reducing tensile stresses and improving load redistribution, ensuring compliance with modern safety standards. This case study offers a framework for the seismic retrofitting of heritage structures in a similar context. Full article

Condition surveys are an important part of the whole scientific research of torso buildings, which we understand to be buildings with usually missing roofs, wooden ceilings, doors, windows, and other envelope constructions along with damaged internal and external infrastructure and surfaces. The aim of the processed condition surveys is to gather basic data on the technical state of the buildings. Torso buildings are, in our environment, especially the ruins of castles and manor houses, but also some churches, the remains of industrial enterprises, or even others. The proposed condition surveys can be used at any of them, not only in our country, but also in any other country of the world. The processed system of condition surveys allows us to anticipate further damage to architectural heritage buildings caused by their aging. It can contribute in a major way to the identification of eventual construction risks and to anticipate them. Condition surveys are designed as a quick, cheap, and easy to handle way to gather the basic overview needed for undertaking a basic stabilization of the most endangered parts of the ruins. In the next step, further scientific research using instruments i.e., in laboratories, can be undertaken. It is also important to know which parts of the torso buildings are dangerous and can endanger not only visitors, but also scientists realizing research on site. The first goal of the project focused on bettering of the stability of the torso buildings, especially ruins of castles, which was granted by the Slovak Ministry of Culture to elaborate and prepare a system for the identification of the most endangered parts of the ruins, which are in danger of dilapidation soon. The second goal was focused on preparing source material for further scientific research of the torso architecture. Experts from the Faculty of Civil Engineering of the Slovak University of Technology, with the cooperation of experts from praxis and from the Architectural Heritage Protection Office prepared a system for judging the construction details of torso buildings from the point of view of their construction–technical state. The aim of this judging lies in identifying the parts of their constructions that are most endangered by decay. Based on the condition survey results, conservation activities can be organized to save valuable details of the torso buildings before destruction and to protect the visitors of such localities before injuries, maybe even tragic injuries. Full article

In the conservation of monumental heritage, the collection and utilization of information are of primary importance. The Heritage Building Information Modeling (HBIM) procedure harnesses the potential of three-dimensional models, offering significant advantages in accessing documentation, interoperability, multidimensionality of intervention design, cost evaluation, and maintenance management. Our attention here is focused on the Certosa di Pisa (Italy), a large historical complex built in the 14th century as a monastery of the Carthusian Order, currently in a state of deterioration and in need of restoration and re-functionalization. The multifaceted nature of this monumental complex, with its intricate interplay of architectural elements spanning different historical periods and featuring diverse techniques, poses a significant challenge for structural safety assessment. This case study presents an opportunity to explore an HBIM approach to streamline the diagnostic process and facilitate the intervention design phase. The goal is achieved by utilizing an accurate 3D model enriched with data from multiple sources and automating certain operations for a simplified safety assessment of masonry structures under both gravity and seismic loads. The usefulness of the HBIM methodology is highlighted as a valuable tool in the realm of cultural heritage structures for both practitioners and scholars alike. Full article

On 3 November 2023, a moment magnitude (M_W) 5.7 (Local Magnitude, M_L6.4) earthquake struck the western region of Nepal, one of the most powerful seismic events since 1505 in the region. Even though the earthquake was of moderate magnitude, it caused significant damage to several masonry buildings and caused slope failures in some regions. The field reconnaissance carried out on 6–9 November by the study team, following the earthquake, conducted the first-hand preliminary damage assessment in the three most affected districts—Jajarkot; West Rukum; and Salyan. This study covers the observed typical structural failures and geotechnical case studies from the field study. To have a robust background understanding, this paper examines the seismotectonic setting and regional seismic activity in the region. The observations of earthquake damage suggest that most of the affected buildings were made of stone or brick masonry without seismic consideration, while most of the reinforced concrete (RC) buildings remained intact. Case histories of damaged buildings, the patterns, and the failure mechanisms are discussed briefly in this paper. Significant damage to Khalanga Durbar, a historical monument in Jajarkot, was also observed. Medium- to large-scale landslides and rockfalls were recorded along the highway. The motorable bridge in the Bheri River suffered from broken bolts, rotational movement at the expansion joint, and damage to the stoppers. The damage observations suggest that, despite the existence of building codes, their non-implementation could have contributed to the heavy impact in the region. This study highlights that the local population faces a potential threat of subsequent disasters arising from earthquakes and earthquake-induced landslides. This underscores the necessity for proactive measures in preparedness for future disasters. Full article

The Old City of Dubrovnik’s historical urban heritage architecture, consisting of poorly to well-built irregular stone masonry construction, is at high risk of earthquakes. It was enlisted as a UNESCO World Heritage after the severely damaging 1979 M_w = 7.1 Montenegro earthquake. Retrofitting strategies to a certain degree of earthquake protection have been made to the monument heritage architecture after repeating destructive earthquakes for several centuries. The originally 13th-century Rector’s Palace underwent several major modifications throughout history after disastrous events: fire in 1435, a gunpowder explosion in 1463, and earthquakes in 1520, 1667, and 1979. The design and construction information were collected from historical records and studies performed by various researchers, including field measurements and laboratory tests. Based on the data gathered, the building’s resistance to destructive earthquakes in compliance with contemporary building codes was determined using simulations on a calibrated spatial structural model. The study revealed that the building’s critical parts are most susceptible to a certain degree of damage or even collapse. The presented case study is the basis for decision-making and implementing the building’s earthquake risk reduction measures. Additionally, it will serve as a guide for earthquake risk evaluation on similar buildings, even though they may differ in degree or detail. Full article

This paper presents the path of knowledge developed for assessing the structural safety of the Norman-age Pisan Tower, which is mostly incorporated into the Royal Palace in Palermo, Italy. Historical, geomatic, and mechanical investigations were conducted and the most relevant results are herein collected and presented. The research path was addressed to specific tasks: identification of the building, geometric surveys, recognition of the sequence of phases of building transformation, detection of the components of the load-bearing structure, structural diagnostic surveys, and investigation of the subsoil and foundations. The explicit vulnerabilities found were mostly confined to the Piazzi library floor, while implicit vulnerabilities were identified in the presence of false walls and in high loads and fillings on the vaults of the last levels. The results of the analyses allowed the individuation of the confidence factors to use in structural analysis models aimed at the assessment of the seismic safety of the building. Full article

H-BIM paradigms are constituted by 3-D informative contents documenting the current and past state of existing structures. Although the transversal vision and the multidisciplinary interpretation have been attributed to BIM models, in the field of monumental structures, these databases can be organized in different ways depending on the adopted protocol and classifications for the required output of the work. In this manuscript, an H-BIM approach targeted at collecting and providing useful information to execute seismic vulnerability analyses of monumental structures is presented. The BIM modeling followed a protocol based on the following steps: geometrical acquisitions, scan-to-BIM modeling, and informative data collection. The methodology has been applied to the oldest part of Palazzo Vecchio in Florence (IT), an important monumental masonry structure representing the political headquarter of the city since the Middle Ages. The parametric modeling was realized classifying the information according to structural perspectives based on the cognitive steps for the investigation of the existing structures. Finally, a seismic assessment has been realized through a simplified procedure developed for cultural heritage buildings. The outcomes of the evaluation are still part of the collected information of the H-BIM model, as an example of continuous improvement of the available contents of the database. Full article

Historic monuments in Greece represent part of the nation’s identity and, as such, they form a crucial part of local communities, not only culturally but also socially and economically. In the current paper, the design process of reconstructing a masonry two-story urban house from the late 19th century located in the historic center (Chorá) of a distant island in the Aegean Sea, Patmos, is discussed through related theories and actual design considerations. Chorá is protected as a UNESCO site; therefore, strict rules for the conservation of any structure enclosed within its boundaries apply. Analysis of the excavation findings and architectural drawings showing the current condition and the conservation proposal, together with the pathology of the building, as well as a structural analysis of the reconstructed structure, are thoroughly discussed in the present paper. These latter can serve as a record for the specific typology of the building and the processes engineers and architects must follow in order to obtain official permission to restore and even reconstruct collapsed parts of such traditional houses, while catering for climate change issues. The maintenance of the originality of the structure is of major importance and is thoroughly discussed, together with the detailed presentation of architectural and structural solutions serving this goal. Full article

Historical buildings and monuments are largely made of brickwork. These buildings form the historical and artistic character of cities, and how we look after them is a reflection of our society. When assessing ceramic products, great emphasis is placed on their mechanical properties, whilst their durability is often neglected. However, the durability or resistance to weathering of masonry elements is just as important as their mechanical properties. Therefore, this work deals with predicting the durability of solid-fired bricks before they are used when reconstructing monuments and historical buildings. Durability prediction is assessed by identifying defects in the material’s internal structure. These faults may not be visible on the element’s surface and are difficult to detect. For this purpose, non-destructive electroacoustic methods, such as the resonant pulse method or the ultrasonic pulse method, were used. Based on an analysis of the initial and residual mechanical properties after freezing cycles, four durability classes of solid-fired bricks were determined. This work aimed to find a way to predict the durability (lifetime) of an anonymous solid-fired brick, expressed in terms of the number of freeze cycles the brick would last, based on non-destructive measurements. Full article

Masonry structures began to be built with the existence of human beings and are an inspiration for today’s structures. Monumental historical buildings built according to people’s religious beliefs have special importance among such structures. Despite being exposed to many natural disasters over time, such structures that have survived till today are an indispensable part of the historical heritage. Within the scope of this study, structural analyses were carried out for the historical Ulu Mosque’s minaret in Bitlis (Turkey), located in the Van Lake basin, using both on-site measurements and finite element methods. Detailed historical and architectural features were given for the minaret and the mosque. In addition to four different earthquake ground motion levels of 2%, 10%, 50% and 68%, structural analyses were deployed separately for seven different geographical locations in the same seismic risk area. Moreover, time history analyses were conducted using the acceleration records of the Van earthquake that occurred in the region. The minaret performance levels were determined by using the displacement values obtained. The study examined the different probabilities of exceedance and the changes in the regions with the same seismic risk. As a result of each structural analysis, base shear forces, displacement, period and maximum stress values were obtained for the minaret. The displacement, base shear force, and stress values increased as the exceedance probability decreased. While the same seismic and structural analysis results were obtained for the selected settlements in the same earthquake zone in this study, remarkable differences were observed for these settlements using the geographical-location-specific design spectrum. Full article

Gönpa Gang is an example of the traditional Buddhist architecture of Upper Mustang. It is also the first monument in Upper Mustang to be studied using the dendrochronological dating method. The gönpa is a two-story building of imposing size, made from simple elements of Tibetan architecture, namely masonry walls, timber posts, and beams. A total of 14 samples were collected from elements on both the ground and the first floor. The limited number of samples results from the cultural and religious character of the object under study. Only the elements consistent with the structure and the space arrangement, interpreted as original features, were examined. Microscopic observation and the analysis of the anatomical features of all 14 samples resulted in the identification of Himalayan pine (blue pine), Pinus wallichiana A.B. Jacks. Intra-annual density fluctuation, false rings, and missing rings were detected. From 14 samples collected in Gönpa Gang, 18 series were worked out. Thus, 15 series from 12 samples were synchronized and used for the development of the mean chronology, UMGG_m, with a total length of 160 rings. The chronology covers the period from 1524 to 1683. Examination of the Gang Gönpa wood resulted in the age determination of 13 elements. The results were compared with architectural stratification by Harrison and historical data from written sources. The timber used in the gönpa comes from the Southern Mustang area. The examined wood demonstrates a correlation with the timber used in the Upper Mustang historical buildings further north. Full article

Grouting of historic structures is a common procedure in many restoration projects, as the masonry in many cases requires additional strengthening. However, grouting of complex historic structures can also provide important information regarding the construction phases and the state of preservation of the internal structure of a monument, which may not be visible by the naked eye. This requires an innovative approach in order to reveal these aspects. In the current research, the data recorded from the grouting of the Holy Aedicule are implemented and analyzed, in order to obtain information regarding the construction phases of the complex Holy Aedicule structure, as well as information regarding the state of preservation of the internal structure behind the marble cladding that encloses it. The correlation of detailed grouting data with geospatial information allows for a more detailed analysis, which, coupled with ground-penetrating radar prospections, can provide critical information regarding the features of the internal structure. The results highlight the importance of this correlation to reveal information that may not be obtained through a typical approach. Thus, this study allowed for the development of an evolved interdisciplinary approach for the management of grouting data in a 2.5D environment, which can be applied in other historic structures and buildings. Full article