In order to create and make available the following: Design guidelines, recommendations for energy audits, data for analysis and simulation of the condition of masonry walls susceptible to biological corrosion, deterioration of comfort parameters in rooms, or deterioration of thermal resistance, the article analyzes various types of masonry wall structures occurring in and commonly used in historical buildings over the last 200 years. The summary is a list of results of particular types of masonry walls and their mutual comparison. On this basis, a procedure path has been proposed which is useful for monitoring heat loss, monitoring the moisture content of building partitions, and improving the hygrothermal comfort of rooms. The durability of such constructions has also been estimated and the impact on the condition of the buildings that have been preserved and are still in use today was assessed.
This paper summarises the current state of knowledge related to scarf and splice carpentry joints in flexural elements, also providing some examples of tensile joints. Descriptions and characteristics of these types of joints found in historical buildings are presented. In addition, issues related to forming carpentry joints in historic and heritage structures are discussed. Next, analyses and studies of flexural elements as well as selected examples of tensile joints described in the literature are presented. It is worth noting that authors of vast majority of the publications cited draw attention to the need for further research in this area. They acknowledge that existing descriptions are incomplete and insufficient for bringing about precise understanding and correct description of the static behaviour of these joints. Knowledge about designing and assessing static behaviour of existing carpentry joints is an important issue and is necessary to properly design and strengthen existing joints in historical timber structures.
The paper presents the results of an experimental investigation of stop-splayed scarf joints, which was carried out as part of a research programme at the Wroclaw University of Science and Technology. A brief description and the characteristics of scarf and splice joints appearing in historical buildings are provided, with special reference to stop-splayed scarf joints (so-called ‘Bolt of lightning’) which were widely used, for example, in Italian renaissance architecture. Analyses and studies of scarf and splice joints in bent elements presented in the literature are reviewed, along with selected examples of analyses and research on tensile joints. It is worth noting that the authors in practically all the cited literature draw attention to the need for further research in this area. Next, the results of the authors’ own research on beams with stop-splayed scarf joints, strengthened using various methods, e.g., by means of drawbolts (metal screws), steel clamps and steel clamps with wooden pegs, which were subjected to four-point bending tests are presented. Load-deflection plots were obtained for load-bearing to bending of each beam in relation to the load-bearing of a continuous reference beam. A comparative analysis of the results obtained for each beam series is presented, along with conclusions and directions for further research.
The paper presents a diagnosis of damage to heritage structures based on the case of the historic church in Kożuchów. The Church of the Purification of the Blessed Virgin Mary dates back to the thirteenth century and is an important sacral building in south-west Poland. Renovation and strengthening works have been conducted in recent years with the goal of structurally stabilizing the heritage building. The paper includes a short history of the building, as well as a review of contemporary diagnostic methods used in heritage buildings with emphasis on the methods used in the diagnosis of the discussed object. Correct diagnosis of the heritage building is the key to selecting an optimal design solution for supporting and strengthening the building structure. Pre-design analysis was based on a geotechnical assessment of ground conditions, identifying cracking patterns of walls and vaults, preparing a digital model using Heritage—Building Information Modeling technology and performing structural analysis. The main cause of cracking of the walls and vaults of the church is related to uneven subsidence and localized stability loss of the building’s foundations, resulting from differentiated soil and water conditions beneath the building. Based on the research and analysis, final conclusions and proposals for strengthening the structure were presented, including jet-grouting columns, tie rods and Fibre Reinforced Cementitious Matrix systems.
9 October 2024 in Civil and Environmental Engineering Reports
Widely used in civil engineering, GPR (ground penetrating radar) is increasingly being used to survey historic structures. However, there are still no conclusive directives on the use of GPR in the identification and diagnosis of masonry structures. The current state of the art allows only on the example of individual case studies, to draw conclusions about the effectiveness of the use of this tool. One such area, where the effective use of GPR has been experimentally confirmed, is the historic architectural survey of a heritage buildings. Due to diversity in the dielectric properties of individual construction materials, it is possible to observe on radargrams the change of electromagnetic wave patterns by materials from different phases. Traditional approach require extensive excavation efforts or core drilling, which may not always be acceptable for conservation reasons. Hence the GPR method could be interesting, non – destructive option for identification and diagnosis of historical masonry walls. The authors used the architectural survey and accompanying excavations at the former Piast Gymnasium in Brzeg to conduct a survey campaign using the GPR method. The brick walls of the building's nave have been scanned. The nave have undergone numerous alterations over hundreds of years. The GPR data has been subjected to adequate post-processing and then correlated with architectural surveys and validated on the basis of available excavations at the site. The authors highlight that GPR surveys, when combined with architectural investigations, offer a less invasive approach to examining historic structures, thereby mitigating the need for problematic excavation work.