Filling in the Blanks: Documenting Concealed Fabric and Deterioration in Existing Structures

The need to develop a highly accurate set of “as-found” condition documents presents a significant challenge in the practice of architecture for any project involving an existing building. For the majority of new buildings, an adequate construction documentation package can be developed simply by applying industry standards along with carefully engineered and well-detailed methods and materials. In contrast, projects involving intervention in existing buildings require an in-depth understanding of the existing building, its methods of construction, and any deterioration that exists. This requirement is particularly critical in the practice of preservation architecture, when renovation, adaptive re-use, and/or restoration projects affect structures with physical fabric of intrinsic historic value. Existing guidelines, such as those of HABS, attempt to ensure that recording is performed in a useful manner that meets certain minimum standards; however, these address only visible conditions, those that can be measured and photographed and those where physical reality is fully observable. Advancements in technology have allowed a marked increase in the ability to understand both the layout of concealed elements, such as wood framing configurations, and the existence of deterioration mechanisms invisible to the naked eye. Unfortunately, these advancements have not necessarily corresponded with the development of standards and guidelines for systematically conducting this type of investigation. Based in part on the author’s experience as a preservation architect, this thesis outlines a methodology and approach for documenting concealed fabric and conditions in historic buildings

NonDestructive Techniques for the Assessment and Preservation of Historic Structures

The preservation of the built heritage has long been a public concern, mainly due to fears about the loss of identity, history and heritage of populations. The main concerns are the conservation and restoration of monuments that usually represent important events in the history of a city or a country. More recently, urban residents and policymakers have become aware of the abandonment or degradation of old city cores, leading to mischaracterisation of the buildings and ways of living. To preserve history and promote building and urban renewal, considering the basic principles of the preservation process, it is important to introduce the least possible disturbance. To start with, the diagnostic process is a key aspect, especially to investigate the construction characteristics and the damage to materials, and to find structural and nonstructural problems. To start any process, a visual inspection, a study and knowledge of the original construction methods and materials and historical repair techniques can help but may not be sufficient, and the use of conventional techniques to complement the information needed can result in an insufficient understanding or in extensive and unnecessary intrusions in the construction. In recent years, the rapid growth of science and research, combined with the industry and the need to gather more and accurate information, have led to the fast development of nondestructive testing methodologies that allow the architectural archaeology to be studied, the structural assessment to be supported and information to be given about the material properties. Each technique can be used for a specific purpose, but, in some cases, only a combination of techniques is reliable and gives an accurate interpretation of the data acquired. The fundamental contribution and aim of this book is to give a full overview of several case studies where different nondestructive techniques have been applied, in several cases using multidisciplinary approaches, which aim to highlight the importance of the information acquired and encourage the use of these techniques in future studies. The book brings together 16 chapters focused on nondestructive testing techniques applied at the urban building level and also applied to monumental buildings, archaeology and cultural heritage, bringing together more than 40 international researchers and experts in the field, who are the source of practical case studies supported by a theoretical background.info:eu-repo/semantics/publishedVersio

Development of ground penetrating radar image library for setup parameters.

A significant amount of effort has been put in developing tools to interpret Ground Penetrating Radar signals obtained during surveys. Currently, skilled and experienced users do most of GPR image interpretation. They use experience in deciphering what the GPR signals represent. A successful survey will not only depend on the choice of antenna used, but also on the operating parameters used for the survey. This study aims at providing a library of GPR images taken from known targets with known parameters. The targets include a set of different sizes of steel rebars. The library of GPR images is developed using known targets set in a sand box. Sand has proven to have the same properties as Portland cement concrete in response to GPR signals. The sand box simulates a concrete slab; it is used for ease of placement of different targets with various configurations. The developed library of GPR images will be used for training of GPR users and comparison studies of GPR operating parameters. In the future these images can be used for a pattern recognition algorithm development, or any other theoretical study pertaining to GPR image interpretation

Unveiling Ancestral Iconography: An Analysis of 13th C. AD Earthen Finishes Through Infrared Thermography at Fire Temple, Mesa Verde National Park

Infrared thermography has been an increasingly applicable diagnostic tool in the nondestructive testing of heritage objects. By measuring the surface temperature and emissivity, infrared thermography is measures heat radiation. Thermography has the ability to investigate objects without contact or causing any deleterious effects. This thesis aims to apply infrared thermography technology to evaluate earthen architectural finishes, and with the intent for subsurface identification of over-painted images. Evidence-based results from both passive and active thermography methods on test facsimiles will inform the efficacy of the technique on earthen finishes, and its applicability to in-situ testing on the north wall of Fire Temple at Mesa Verde National Park

Development of ground penetrating radar image library for setup parameters.

A significant amount of effort has been put in developing tools to interpret Ground Penetrating Radar signals obtained during surveys. Currently, skilled and experienced users do most of GPR image interpretation. They use experience in deciphering what the GPR signals represent. A successful survey will not only depend on the choice of antenna used, but also on the operating parameters used for the survey. This study aims at providing a library of GPR images taken from known targets with known parameters. The targets include a set of different sizes of steel rebars. The library of GPR images is developed using known targets set in a sand box. Sand has proven to have the same properties as Portland cement concrete in response to GPR signals. The sand box simulates a concrete slab; it is used for ease of placement of different targets with various configurations. The developed library of GPR images will be used for training of GPR users and comparison studies of GPR operating parameters. In the future these images can be used for a pattern recognition algorithm development, or any other theoretical study pertaining to GPR image interpretation

Técnicas de diagnóstico no destructives para edificios históricos: guías metodológicas y protocolos de operación

ABSTRACT: The aim of this End of Master Work is analysing the different methodologies and find out the most helpful norms to apply three specific non‐destructive techniques, namely: Active thermography, sonic pulse velocity test and ground penetrating radar for the detection and evaluation of decays in historic buildings, structures and elements. Nowadays, there is not a recognized source of knowledge to consult in order to apply these techniques for historical architecture. Some recommendations are given by specialized institutions as RILEM (International Union of Laboratories and Experts in Construction Materials, Systems and Structures) or DGZfP (German Society for Non‐Destructive Testing). Some initiatives tried to standardize the test procedures with no great success. The application procedures are currently applied on‐site most of the time with personalized methods and applying modifications according to the limitations of each test project. Official universal standards do not cover the special cares of a historical element requires. Therefore, a research about the most common procedures for active thermography, sonic pulse velocity test and ground penetration radar is compiled. The available knowledge is very dispersed. The amount of case studies articles and reports provide vital information to improve the test efficiency and many experts are glad to share their real experience with these technologies with other professionals. Diving into the literature and conversing with practitioners, it is noticeable the lack of standardization and the few standards that are applicable for building preservation, are usually not followed or even known. Why? Examining the available standards, it is clear the complexity of their structure. The limitations of their procedures invalid often their applicability on‐site, i.e. very complex calibration method which required specific equipment not offered out of the laboratory. Thus, the user finds other solutions to accomplish the test with relative success. For on‐site application, recommendation guidelines are usually more complete that the proper standards, but still not sufficient to increase the efficiency of the tests. Considering this report as an introduction to the three methodologies, there is still a lot of work to do in order to document and put together the isolated valuable information to improve the tests efficiency test on historical buildings.Máster en Investigación, Tecnología y Gestión de la Construcción en Europ

Building concrete structure assessment using image-based non-destructive technique

Buildings and infrastructures need to be maintained regularly throughout the entire of their operational life. The building structural health monitoring system is produced to prevent the occurring of hazardous incident. However, the health information of these buildings are not being recorded and reported by the construction and building industry. Hence, issue of deterioration of building structural concrete in recent years had become an alarming issue that highlighted extensively throughout the world. The building infrastructure management, rehabilitation or maintenance is needed indeed to extend the service lives of these buildings, especially those historical buildings that representing the landmark for a country. As such, assessment of building structural concrete health, especially the concrete cracks are crucial for ensuring the safety and health of the building as cracks are among the earliest symptoms of concrete structure degradation. Therefore, non-destructive geotechnical technique was introduced in this study to determine the physical conditions of the concrete and visual examination was conducted for results verification purposes. In doing this, experiment was conducted by exerting hydraulic load on a reinforced concrete beam to produce cracks in precast concrete beam. Then, the common used non-destructive electromagnetic (EM) device, ground penetrating radar (GPR) with 2 GHz high frequency bi-polar antenna was employed to scan the reinforced concrete beam to detect cracks. After that, visual inspection was conducted for validation of concrete cracks on the beam. The high similarity in the radar profile obtained by GPR and numerical model proved the advantages of utilizing non-destructive technique for inspection of building structural health, where the inner structure of the concrete can be taken into granted as well in the future through refinement of the results of this study. With such new benchmark, it opens up new application for GPR in civil infrastructure maintenance and managemen