Research Team Reviews Techniques for Analyzing Historic Buildings

Historical structures are vital links to humanity’s art, architecture, and culture, but their preservation faces significant challenges. A research team from the Department of Civil Engineering at Çanakkale Onsekiz Mart University in Türkiye has published a comprehensive review titled “Materials Characterization of Historical Structures: A Review.” This study focuses on the characterization methods of building materials, which are crucial for effective restoration and conservation efforts.

The research identifies key gaps in the current understanding of historical building materials, such as natural stones and mortars. It highlights the need for a more holistic analysis of these materials and clearer guidance for selecting appropriate characterization methods. This lack of clarity can hinder scientific restoration efforts, making the findings of this review particularly timely and relevant.

Evaluating Characterization Techniques

The review systematically evaluates various analytical methods used for characterizing historical building materials. It synthesizes existing research findings and clarifies the strengths and limitations of each technique, providing researchers with a valuable resource for choosing methodologies. Key areas of focus include the objectives of material property determination, sampling and preparation processes, testing equipment characteristics, and analysis outcomes.

Four core categories of characterization techniques are emphasized in the study. The first, physical and thermal property analysis, employs methods like Mercury Intrusion Porosimetry (MIP) for assessing porosity and water permeability. For instance, MIP identified two main pore size distributions in mortars from Amaiur Castle: 0.01–1 μm and 1–10 μm. Additionally, Thermogravimetric Analysis (TGA) and Differential Thermal Analysis (DTA) are utilized to evaluate thermal resistance, revealing that calcite decomposes at temperatures between 600–900 °C, resulting in a mass loss of 20%–40% due to CO2 emissions.

Chemical property analysis techniques include X-ray Diffraction (XRD) to determine mineral composition, with calcite and quartz being predominant in many mortars. Other methods like X-ray Fluorescence (XRF) and Fourier Transform Infrared Spectroscopy (FTIR) allow for detailed elemental and qualitative analysis, highlighting critical components such as high concentrations of lead and zinc in the black crusts of Seville Cathedral.

Mechanical and Visualization Techniques

The review also discusses mechanical property analysis, which utilizes non-destructive techniques to evaluate the structural integrity of historical buildings. Methods such as Ultrasonic Pulse Velocity (UPV) and the Schmidt hammer are crucial, as they provide insights into concrete quality and compressive strength without causing damage to these irreplaceable structures.

Moreover, visualization techniques play a significant role in assessing material morphology and identifying hidden defects. Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDS) allows for microstructural analysis, while Infrared Thermography (IRT) aids in detecting moisture and cracks, as evidenced in Malatya Taşhoran Church.

The review draws on an extensive array of studies, including benchmarks from Roman-period structures in Portugal, 11th–14th century buildings in Spain, and Mamluk-period structures in Egypt. By employing multiple methods in tandem, researchers can achieve more consistent and reliable results, establishing a strong data-driven foundation for future investigations.

Ultimately, the paper authored by Mertcan Demirel, Alican Topsakal, and Muhammet Gökhan Altun provides essential insights that can lead to reduced costs in engineering and architectural analyses of historical structures. It also supports the development of scientifically grounded restoration projects, ensuring that these cultural treasures can be preserved for future generations. The full text of the study is available at: https://doi.org/10.1007/s11709-025-1222-3.