Conservation Of Historic Structures Research Articles

Methodology for the Application of 3D Technologies for the Conservation and Recovery of Built Heritage Elements

ABSTRACT The advent of 3D technologies unlocks new possibilities for capturing, analysing and preserving the intricate details of heritage sites. However, these technologies also raise technical and ethical challenges regarding the preservation of authenticity, integrity, and reversibility. This paper firstly analyses the ethical boundaries for the application of 3D technologies to cultural heritage through scrutinizing the extant literature and gathering the advantages and shortcomings of these technologies vis-à-vis traditional approaches. A comprehensive methodology is proposed for the restoration and conservation of historical structures using photogrammetry and 3D printing. By harmonizing technological potential with the ethical responsibilities of heritage conservation, the proposed framework promotes a balanced approach that not only addresses labour shortages of restoration specialists but also opens a realm of possibilities for cost reduction and superior quality control. In addition, the consistent nature of automation ensures that restoration and conservation tasks will be undertaken with meticulous precision, minimising material waste. Ultimately, this work is an insightful contribution that aims to shift rehabilitation and conservation of heritage sites towards automation not only to meet the needs of the moment but to propel us into a future where efficiency and sustainability are seamlessly intertwined.

Comparative Analysis of Non-Invasive Measurement Methods for Optimizing Architectural Documentation

Architectural documentation not only plays a critical role in the conservation of historical structures, but also enables their detailed comprehension of the structure. This study aims to assess the most effective methods for drawing and modeling architectural structures and present their advantages and disadvantages. Measurements play a significant role in this context, and today's technology offers the potential to accelerate this process and enhance accuracy. However, the application of these technologies can impose additional burdens such as elevated expenses, the requisite for specialized personnel, and the management of substantial data volumes. Therefore, determining the appropriate measurement method in line with the quality of architectural documentation is essential. For this study, the Mosque of Kurşunlu Complex in Eskişehir was selected for its historical and topographical attributes which enabled all methods to be examined. The data produced via terrestrial laser scanning, aerial photogrammetry and terrestrial photogrammetry methods were examined in terms of the production of drawings and models for different analysis methods such as structure, daylight and building acoustics, as well as survey drawings required for the architectural documentation processes of the building. The study concluded that no single method could produce holistic data on its own, and the best results for comprehensive documentation were achieved by integrating terrestrial laser scanning and aerial photogrammetry. Furthermore, for products that do not require comprehensive data, photogrammetric methods were more efficient.

Review: O'Neil Ford on Architecture

Review: <i>O'Neil Ford on Architecture</i>

Preliminary Investigations of Compatible Nanolime Treatments on Indiana Limestone and Weathered Marble Stone

ABSTRACT The conservation of historic structures must be carried out through treatments that use materials which are compatible with the originals. In recent years, nanolime has been considered one of the most promising products for the consolidation of calcareous substrates due to its characteristics of high compatibility with the treated substrate and durability. The effectiveness of nanolime products has been proven for superficial consolidation treatments (e.g. plasters and wall-paintings), and research nowadays is focused on the study of the in-depth consolidation effectiveness of porous substrates. The aim of this paper is to undertake preliminary investigations of compatible nanolime treatments for Indiana limestone (US) and a weathered marble. Nanolime was synthesized by anion exchange resins and dispersed in isopropanol and ethanol. The consolidation effectiveness is assessed by studying changes in porosity, drilling resistance, surface cohesion and aesthetic appearance (colour). Results showed that nanolime yielded the highest consolidation effectiveness when treated samples were kept in high relative humidity environments (~75%RH) or regularly sprayed with carbonated water in a laboratory environment (~50%RH). These results suggest that for an on-site consolidation treatment with nanolime in dry environments, treated surfaces could be regularly sprayed with carbonated water to increase consolidation effectiveness.

Automated operational modal analysis and ambient noise deconvolution interferometry for the full structural identification of historic towers: A case study of the Sciri Tower in Perugia, Italy

Structural Health Monitoring (SHM) based upon Operational Modal Analysis (OMA) constitutes an increasingly mature and widespread technology in the conservation of historic structures. Such techniques, while proved effective for assessing the global integrity of structures, may fail at detecting local damage with little influence on the modal features of the system. In this context, the analysis of propagating waves throughout the structure features a synergistic approach to OMA with superior capabilities for data-driven damage identification. Although some promising results have been reported in the literature on the application of Seismic Interferometry to reinforced-concrete structures, works concerning the continuous monitoring of ambient vibrations in historic structures are virtually non-existent. In this light, this paper proposes the coupled application of automated OMA and Ambient Noise Deconvolution Interferometry for the full structural system identification of historic structures, and evaluates the advantages of this technology through a validation case study of the Sciri Tower in Perugia, Italy. A continuous vibration-based monitoring system deployed in the tower during three weeks allows us to assess the effectiveness of the proposed approach. The reported results demonstrate the robustness of the monitoring system for identifying environmental effects on the spatial distribution of wave velocities, and shed light into the dispersion relation of the tower.

Trends of plant communities growing on the Etruscan tombs (Cerveteri, Italy) related to different management practices

Vegetation management of archaeological sites is a recurrent problem when considering the conservation of historic structures and biodiversity. In the UNESCO site of the Etruscan necropolis “La Banditaccia” (Cerveteri, Italy), several plants grow on the ancient tumuli, which are subjected to different management practices. In order to assess the influence of interventions on plant colonisation, a comparative analysis of several tumuli was performed, through structural, chorological, phytosociological and statistical evaluations. This investigation identified and defined an ecological gradient among the tumuli. The cover values of Therophytes and Hemicryptophytes decreased by half with regular cutting, while those of Geophytes and Phanerophytes increased. Mesophilic field plants (MFP), both ephemeral and perennial, represented the most abundant group. Mediterranean bushes and forests (MBF) showed a positive trend from the entrance to the last tumuli of the necropolis. This trend was clearly defined by PCA, and it seems community changes were caused by the absence of mowing activities and to a lower tourist frequentation. SIMPER analysis highlighted which species on each tumulus mainly influence their dissimilarity. This knowledge, when combined with the evaluation of the potential risk of the different plant communities growing on the tumuli, can help to identify the best management practices.

Studies in vernacular architecture in Afghanistan: training in conservation of historic structures in Kabul Old City

This paper discusses the research in pre-war decades in Afghanistan into vernacular architecture – styles and character of regional constructions – as well the recent efforts in training for and conservation of traditional buildings in Kabul Old city.

Necessity of “Historic Cultural Heritage and Conservation” Course in Interior Architecture Education

For five decades, academics and architects have been debating the subject of historical conservation techniques. Nowadays, much of building activities take place in historic areas. Most of the architects and interior architects are engaged to renovation or restoration of historical buildings. Architectural education is considered to be a complex process. Teaching the historical cultural heritage and conservation of historic structures constitutes an important part of architectural education. So, it is essential for students of architecture and interior architecture to be aware of the philosophy of conservation of historic cultural heritage. The course of “Historic Cultural Heritage and Conservation” which is about cultural heritage and principles, takes place in the undergraduate curriculum in the architecture and interior architecture departments of Izmir University. By this course knowledge of conservation, and restoration techniques were introduced. While students were taking this course also they were working on a studio project about a case study of an historical building. This paper considers the students’ approach to conservation and reuse of old warehouse building, in the scope of studio project. The aim of this paper is to show how the students were referred to conservation techniques on their studio projects while taking “Historic Cultural Heritage and Conservation” course.

Spectroscopic Study of Poly(Vinylidene Fluoride)/Poly(Methyl Methacrylate) (PVDF/PMMA) Blend

Poly(vinylidene fluoride)/poly(methyl methacrylate) blends casted in the DMF could be used in the conservation of historic structures (monuments) exposed to atmospheric agents or as a coating to replace and maintain parts or missing pieces. This study deals with the effect of blending of PVDF to PMMA to enhance the properties and their properties were studied using the FTIR and UV-visible spectroscopy. In FTIR spectra, it was found that PVDF/PMMA blend casted in the Dimethylformamide (DMF) showed the superposition of the spectra of all compositions, with the exclusion of any chemical reaction between two polymers or the presence of the double bonds characteristic of PVDF dehydrofluoration. The UV-visible spectroscopy before and after exposure to artificial weathering, showed that the PVDF is very stable (the invariant absorbance values at 200 nm wavelength after the equivalent of two years of aging). In contrast, the absorbance of PMMA has changed at the same wavelength explaining its tendency of degradation.

Evaluation of environmental impact on historical stone masonry through on-site monitoring appraisal

This paper presents the design and application of an environmental monitoring system on the historical site of Odda’s Chapel in Deerhurst, Gloucestershire, UK, and the determination of hygroscopic behaviour of the original building materials to obtain long-term moisture content variation. The monitoring system provides a comprehensive profile of hygrothermal conditions in the walls at the locations where moisture conditions are potentially causing decay and damage. The system makes use of temperature and relative humidity sensing technology placed on the wall construction, providing continuous data including rainfall, wind-driven rain and runoff rain measurements. The relative merits and results of the designed system are evaluated and discussed, as well as the implications of its application in the conservation of historical structures. The environmental monitoring results show general deterioration in the shell of the building. Internal wall surface measurements are essential for the documentation of wall interior response and should be conducted across the wall section at several locations. The fact that 91% of in-wall recorded relative humidity (RH) values are greater than 75% RH throughout the monitoring period demonstrates the need for measures to conserve this historical stone masonry.

On the Dynamic Behaviour of Strengthened Stone Masonry Walls

Unreinforced stone masonry is common in heritage structures worldwide. Unfortunately, these structures are susceptible to failure or severe damage when subject to dynamic or seismic loading. Conservation of historic structures is a challenge as the heritage and cultural values need to be preserved while the advent of new seismic codes may require major strengthening to be implemented. The new seismic codes demand high seismic strength and ductility for such structures, whereas neither the strength nor the ductility of an existing stone masonry building can be quantified easily. The Parliament buildings of Canada fall into this category. Therefore, an extensive experimental program was carried out to investigate the dynamic and seismic behaviours of stone walls representative of Canada’s Parliament buildings. The walls were constructed of double stone wythes with the cavity between being filled with weak mortar, shards and small stones, constituting a rubble core of the walls. The experimental program included in-plane quasi-static, free vibration and high frequency loadings, together with out-of-plane shake table tests. The tests were aimed at investigating the integrity, strength, damping, stiffness degradation, and ductility of the walls. Different potential strengthening methods were assessed, methods that would minimize structural intervention and preserve the heritage values of the building. The methods involved different metallic anchors and traditional stone interlocking to tie the two outer wythes together. Fortunately, the stone walls exhibited satisfactory performance in all cases. In addition, the test results suggested that plain un-strengthened stone walls had strength and other characteristics similar to those of the rehabilitated walls, in the range of the imposed load scenarios.

Reflections on Water: Architectural Manifestations in the Historic and Cultural Quarter along Lake Pichola in Udaipur

The aim of this paper is to undertake a critical appreciation of the historic cultural quarter along the eastern edge of Lake Pichola in Udaipur, which is a result of its unique context with the objective of understanding the forces that underpin this development, examine its existing state, and highlight key concerns. The main issues that were highlighted include preservation of existing traditions, conservation and adaptive reuse of historic structures, sensitive and participatory planning and design, formalising of street activities, provision of infrastructure, and administrative structures to deliver the project, and organisation of awareness programs for the local community. The aim of this study is to develop a critical appreciation of the historic core and cultural quarter along the eastern edge of Lake Pichola in Udaipur, which is a result of its unique climatic, social, and topographical context, to chart the changes to this context, to draw attention to past patterns of growth. The objective is also to understand the forces that have influenced and underpin this development, examine its existing state and highlight key concerns. The study is limited to the historic core along the waterfront and its related structures along the eastern bank of Lake Pichola in Udaipur. The study demonstrated that the historic core along the lake front is a result of evolution that has been guided by dominant determinants such as its socio-economic hierarchy/structure, political, cultural, and religious factors, climate, availability of materials and technology. The overall form, settlement pattern and the massing of buildings in Udaipur are dominated by its physical attributes and in consonance with the topography and landscape, and ordered by the generative force of its land form and the lake. It is, however, subject to severe developmental and environmental pressures as a result of intense tourism related and commercial activities, unwarranted and haphazard building activities, continuous neglect of residential properties, some of the historic fabric and surviving artefacts, and poor infrastructure. If this trend were to continue, the problems will intensify manifold causing serious threat to this valuable environment, its urban spaces and exquisite edifices. Preservation of this waterfront, which plays a decisive role in solving critical urban, social and economic problems in this city, is vital. The main issues identified for consideration in this context were preservation of existing traditions, conservation of historic structures and adaptive reuse of buildings, sensitive and participatory planning and design, formalising of street activities, provision of infrastructure and administrative structures to deliver the project, and creation of awareness and understanding amongst the local community

Turkish historical arch bridges and their deteriorations and failures

Preservation and conservation of historical structures are the major points for the continuity of history. Therefore, in order to develop suitable restoration projects without neglecting any of the unique cultural values, it is very important to determine the present conditions of these structures. In this paper, it is aimed to present architectural and engineering properties of Turkish historical arch bridges. For this purpose, deteriorations in construction materials, damage and failure patterns occurred in the masonry arch bridges are classified and discussed using some illustrated photos. Some restoration practices for the bridges have been carried out by Turkish General Directorate of Highways are briefly discussed.

Lime mortar and the conservation of historic structures

Lime and the lime mortars and plasters made from it have a long and successful history in building construction. However, the development of Portland cement in the 19th century gradually displaced or supplemented lime and much of the ancient trades knowledge has been lost, often to the detriment of masonry construction and conservation. The author has been associated with the conservation of many of Australia’s oldest masonry buildings and structures and, backed by research at the University of Newcastle, has been able to show that the best and most durable of the old mortars were accidentally or deliberately made with impurities which gave hydraulic properties and proportioning which aided carbonation. The ability to replicate the successful mortars and match mortar to the brick or stone now seems possible.

Historical studies on the five stone-masonry bridges over the Kotsuki river

The five stone-masonry arch bridges over the Kotsuki river in Kagoshima city were constructed around 150 years ago and were in use till recently. But two of them were washed out due to the record rainfall which fell in August 1993. Therefore it was decided to carry out river conservation works and move the three remaining bridges to a different place and preserve them there. This paper investigates the changing conditions of the five stone-masonry arch bridges in relation to the variations in social environment from a historical perspective. An attempt is made to understand the cultural significance of present civil engineering structures. The procedure for general agreem6nt regarding the preservation and conservation of historical structures is also discussed.

Conservation of Historic Buildings

Since its publication in 1982 Sir Bernard Feilden's Conservation of Historic Buildings has become the standard text for architects and others involved in the conservation of historic structures. Leading practitioners around the world have praised the book as being the most significant single volume on the subject to be published. This third edition revises and updates a classic book, including completely new sections on conservation of Modern Movement buildings and non-destructive investigation. The result of the lifetime's experience of one of the world's leading architectural conservators, the book comprehensively surveys the fundamental principles of conservation in their application to historic buildings, and provides the basic information needed by architects, engineers and surveyors for the solution of problems of architectural conservation in almost every climatic region of the world. This edition is organized into three complementary parts: in the first the structure of buildings is dealt with in detail; the second focuses attention on the causes of decay and the materials they affect; and the third considers the practical role of the architect involved in conservation and rehabilitation. As well as being essential reading for architects and others concerned with conservation, many lay people with various kinds of responsibility for historic buildings will find this clearly written, jargon-free work a fruitful source of guidance and information.