Historic Brick Research Articles

Origin and technology of the Georgian brick at Fade Mansion, Dublin, built c. 1728

This paper studies the provenance and firing technology of the Fade Mansion brick. The microstructure was studied with scanning electron microscopy (SEM), mineral associations and transformation were determined with X-ray diffraction (XRD) and petrographic analyses. The results evidenced that the bricks were made with a decalcified, silica-based clay of glacio-fluvial origin, gathered locally. This agrees with the position of the Mansion on a terrace of the River Liffey, and with previous research on historic bricks made with boulder clay. They were fired in kilns in an oxidising atmosphere. The rubbers at window heads reached lower temperatures which resulted in low vitrification, leading to weathering. Initial vitrification structures generally concur with the occurrence of clay minerals, indicating temperatures of c. 800°C. Continuous vitrification is associated to the disappearance of clay minerals, the sintering of hematite and/or high-temperature phases and mica transformation, indicating a wide temperature range >950-1200°C, which agrees with the inconsistent brick properties.

Practical Application of the Similarity Law of Structures in the Reconstruction of the Surface Layer of Bricks

This paper discusses the results of experimental studies on the selection of the repair mixture compound for recreating the surface layer of the historical brick of the 18th century architectural monument “Commercial Bank” in Arkhangelsk. According to the research results, it was found that the historical brick has a relatively higher density and increased calcium content than the modern one. The characteristics of the surfaces of the analyzed materials based on the component indicators of specific surface energy showed that the brick of 1859, characterized by the highest degree of destruction, has the maximum value of the polar energy component. This fact may indicate a greater hydrophilicity of the surface in relation to atmospheric water and, as a result, a more intensive degradation process. It is established that the composition of the repair mixture with the addition of brick crumbs in the amount of 50 % has a value of the polar part of the surface tension equal to similar parameters for historical bricks (1786 and 1859) after their preliminary priming. The use of this mixture to recreate the surface layer of the brick will allow atmospheric water to pass freely through the repair compound and the body of the brick, without concentrating on the interface and without causing its destruction and detachment when drying.

Material Properties of Historic Brick in the Former Lake Chicago Basin

Material Properties of Historic Brick in the Former Lake Chicago Basin

Antifungal Activity of Polyoxometalate-Ionic Liquids on Historical Brick.

Moulds inhabiting mineral-based materials may cause their biodeterioration, contributing to inestimable losses, especially in the case of cultural heritage objects and architectures. Fungi in mouldy buildings may also pose a threat to human health and constitute the main etiological factor in building related illnesses. In this context, research into novel compounds with antifungal activity is of high importance. The aim of this study was to evaluate the antifungal activity of polyoxometalate-ionic liquids (POM-ILs) and their use in the eradication of moulds from historical brick. In the disc diffusion assay, all the tested POM-ILs inhibited growth of a mixed culture of moulds including Engyodontium album, Cladosporium cladosporioides, Alternaria alternata and Aspergillus fumigatus. These were isolated from the surfaces of historical brick barracks at the Auschwitz II-Birkenau State Museum in Oświęcim, Poland. POM-IL coatings on historical brick samples, under model conditions, showed that two compounds demonstrated very high antifungal activity, completely limiting mould growth and development. The antifungal activity of the POM-ILs appeared to stem from their toxic effects on conidia, as evidenced by environmental scanning transmission electron microscopy observations. The results herein indicated that POM-ILs are promising disinfectant materials for use not only on historical objects, but probably also on other mineral-based materials.

Correlation between Physical-mineralogical Properties and Weathering Resistance Using Characterisation Case Studies in Historic Indian Bricks

ABSTRACT This paper correlates the durability of bricks in various environments to their physical and microstructural characteristics. Micro-analytical and physical characterisation techniques were employed to find the raw materials and firing temperature of the historic bricks. Mercury Intrusion Porosimetry (MIP) and Scanning Electron Microscopy (SEM) helped in finding the effects at microstructure level with the variation of raw materials/firing temperature. The results showed that historic bricks fired at high temperature and made with non-calcium clays possessed superior physical characteristics and survived several centuries without any significant weathering. Also, differences in the state of conservation of the bricks were examined in cases where similar bricks were exposed to different conditions. The calcium-rich bricks fired at low temperature had a poorer degree of vitrification, but the weathering resistance again varied with respect to exposure conditions. Such bricks were found severely deteriorated when exposed to salt, and the extent of damage and damage patterns were also dependent on the kind of salt. Poorly fired bricks, which were not exposed to much salt, were found with minor external weathering traces such as powdering of edges. MIP results showed that the cores of bricks remained unaffected in spite of the external powdering. It could be generalised that poorly vitrified structure with a large number of small pores is more susceptible to salt crystallisation. Understanding the micro-characteristics of historic bricks helps in tracing back the manufacturing factors, which are indeed important in deciding on efficient replacement/protective treatments for the structure.

Characterization of Historic Bricks and Binder at Vat Phou World Heritage Site in Lao PDR and Selection of Compatible Replacement Units for Restoration

Characterization of Historic Bricks and Binder at Vat Phou World Heritage Site in Lao PDR and Selection of Compatible Replacement Units for Restoration

Impact of Surface Treatment of Historic Bricks on the Process of Water Vapours Diffusion

The article is dealing with impact of selected types of surface finish of historic bricks on their diffusion properties, i.e. on the process of their spontaneous self-drying. Within the pilot experiment was monitored diffusion flow of water vapours going from humid brick fragment through its surface finish to the surrounding environment. Brick fragment was saturated with water to a degree usually corresponding to common humidity of uninsulated underground brickwork of historic buildings. Surrounding environment had parameters of common heated object for residential or administrative purpose or an object for storage of things sensitive to impact of high relative air humidity. Test results proved that any surface finish of the brickwork, even its hydropohobisation is significantly slowing down process of drying of the masonry compared to the speed of drying of the untreated brickwork. It is evident from the course of lines of diffusion flows that the process of water vapours diffusion is most intense at the beginning of the period (about 5 to 10 days) and after this period the diffusion flow speed goes to a long-term stabilisation of diffusion flow speed, in such a way that its course is in average corresponding to linear functional dependence on time. In conclusion of the article we introduce on practical example calculation of real time of drying up of the masonry in historic building selected space flooded with flood water where is now running process of natural drying without additional humidity sources.

Characterization of building materials used in the construction of historical Al-Omariya mosque minaret in Mosul's old city, Iraq

During the Mosul 2016–2017 battle, a lot of historical buildings, especially those located in the Mosul's old city, were extremely destroyed or subjected to considerable damage. This paper focuses on studying the current state of historical minaret of Al-Omariya mosque, dated to the 16th century in Mosul's old city. The minaret shows the loss of the dome and severe damages at mid of its trunk. Restoration of such a building is an urgent priority, and great attention should be paid to revival this minaret. Among the most crucial challenges facing the restoration of historical buildings is obtaining alternative building materials that satisfy the compatibility requirements with the original materials. The current study addressed this problem by characterizing the historical brick and mortar of the minaret. Characterization of these historical building materials includes physical and mechanical properties, chemical and mineralogical compositions as well as microstructural features. Micro-analyses were obtained by carrying out a series of complementary tests: X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Ion Chromatography (IC) and Mercury Intrusion Porosimetry (MIP). The physical and mechanical tests indicated that the studied building materials are weak: low apparent density equal to 1.63 (g/cm3) for brick and 1.55 (g/cm3) for mortar, high total porosity of about 35% for brick and 31% for mortar, tensile strength and unconfined compressive strength of the brick limited to 0.65 (MPa) and 7.02 (MPa), respectively. Data analysis from XRD and IC tests was matched and the results confirmed that the historical brick contains calcite, quartz, and gypsum minerals, while the historical mortar contains gypsum as the main composite with other minerals of calcite and quartz. SEM revealed the bricks have a typical morphology due to the firing. It is observed from the MIP test results that there is an abundance of mesopores with diameter ranged from 0.01 μm to 1 μm for the brick and from 0.5 μm to 5 μm for mortar. Result analysis from this research work provides valuable information about the intrinsic features of the historical brick and mortar. This is, in turn, provides main guidelines that support the restoration of the minaret. It is suggested that the outputs of this study will contribute to the practical repair to the historical minaret of the Al-Omariya mosque by appointing the crucial criteria for selecting new brick and mortar used as alternative building materials in future conservation and intervention strategies.

Selective demolition of masonry unit walls with a soundless chemical demolition agent

A soundless chemical demolition agent was applied for selective demolition to unit masonry [2 full-scale concrete brick walls in Type N mortar and 2 wallettes in lime mortar – 1 historic brick and 1 concrete brick]. Typically, cracking began shortly after 9 h and ultimately produced an average crack length of 418 mm per hole and an average maximum 5.22 mm crack width. Samples in Type-N mortar exhibited slower but significantly more cracks and wider cracking. Ninety-three percent of cracking occurred within 4 days. No masonry units were damaged and partial demolition was successful, although selective unit removal was not due to confinement.

Innovation building materials in energy-saving wall systems of historical buildings in Saint Petersburg

The article notes that the main heat losses during major repairs of buildings of historical development are associated with low thermal resistance of external wall fences, due to the lack of thermal insulation of balcony doors. The purpose of the study: to show a significant reduction in costs in the capital reconstruction of former apartment buildings, of which there are more than one and a half thousand in St. Petersburg, due to the use of innovative thermal insulation materials. Methods: thermal imaging, laboratory research. Results: as a result of studying the humidity regime, the experimental section of the wall, determining the dew point, resistance to vapor permeability, air permeability, and construction properties of historical bricks, the authors suggest that buildings of historical development follow the rule that provides for insulation of the external walls of these buildings from the inside.

Diagonal shear behavior of historic walls strengthened with composite reinforced mortar (CRM)

Composite reinforced mortar (CRM) represents an innovative strengthening solution for existing masonry structures. CRM is comprised of a composite grid embedded within an inorganic matrix (mortar) and it is applied as externally bonded reinforcement of masonry members. The composite grid bears the tensile stresses whereas the inorganic matrix is responsible for the stress-transfer between the composite grid and the substrate. CRM showed promising results in improving the mechanical properties of different masonry members, such as walls and arches. However, a full understanding of the mechanical behavior of CRM strengthened masonry members is still missing, which hinders the formulation of reliable CRM design guidelines. In this paper, an experimental investigation of the in-plane behavior of masonry walls made by historical bricks and strengthened with a CRM comprised of a glass fiber composite grid embedded in a lime-based mortar is presented and discussed. The parameters studied are the wall dimension and type (double leaf with and without diatoni). Furthermore, the effect of steel anchors on the strengthened wall capacity is investigated. The results obtained are finally analyzed using simple analytical formulations.

Diagonal Compression of Masonry Walls Strengthened with Composite Reinforced Mortar

The use of inorganic matrix composites to strengthen and retrofit existing masonry and concrete structures has been gaining increasing interest in the last years. Among them, composite reinforced mortar (CRM) systems are a promising solution to increase the shear and flexural capacity of masonry panels. CRMs are comprised of a relatively thin inorganic matrix layer reinforced with a bi-dimensional grid made with high-strength fibers impregnated with an organic matrix. They are compatible with the substrate due to the use of inorganic matrix, have good durability and high-strength-to weight ratio due to the use of reinforcing composite materials. CRM systems are still in their infancy and limited research is available in the literature. In this paper, masonry walls constructed with historical bricks typical of the north of Italy were strengthened with a CRM system including a glass composite grid and a lime-based mortar and were subjected to diagonal compression. Three walls were strengthened with the CRM and one was used as a control specimen. The results obtained showed that the CRM system significantly increased the shear strength of the masonry panels subjected to diagonal compression.

Radiocarbon Dating of Historical bricks: Exploring the unprotected archaeological mounds in the environs of excavated site of Nalanda

Nalanda was a renowned Buddhist monastery which is believed to have been active for 800 years from around 4th/5th to 12th centuries AD. We know about the site from the accounts of 7th century Chinese traveler (Xuanzang) and later from 19th century British surveyors (Buchanan, Cunningham and Broadley). There are many studies on this site, recent one among them is a geospatial analysis which has revealed a larger extent (~7.25 sq. km) of the site compared to what is protected at present as World Heritage (WH) inscribed by UNESCO (0.23 sq. km. as core zones and 0.58 sq. km. as buffer zone) and has identified several unprotected archaeological mounds in the vicinity. Since we have a range of period when the site was active, it is possible that the dates of structures in each unexcavated mound are decades or centuries apart. To understand the time sequence in which the site existed one could use absolute dating method. This paper reports result of preliminary dating analysis using the Accelerator Mass Spectrometry (AMS) technique on bricks collected from unprotected mounds in the environs of Nalanda. This paper also reports methods and issues in sample collection, preparation and discusses challenges to overcome in future efforts.

Experimental Investigation on the Performance of Historical Squat Masonry Walls Strengthened by UHPC and Reinforced Polymer Mortar Layers

Strengthening historical brick masonry walls is important because these walls are major load-bearing members in many architectural heritages. However, historical brick masonry has low elastic modulus and low strength, historical masonry walls are prone to surface treatment or other structural intervention, and some of the walls lack integrity. These characteristics make effective strengthening of historical masonry walls difficult. To address the issue, strengthening layers made up of ultra-high performance concrete (UHPC) are potentially useful. To investigate the strengthening effect of the UHPC layers, the authors constructed three squat walls using historical bricks and mortar collected from the rehabilitation site of a historical building, and strengthened two of the walls with a UHPC layer and a reinforced polymer mortar layer respectively. The three walls were broken down by horizontal cyclic force along with constant vertical compression, and then the unstrengthened one was strengthened in-situ by a UHPC layer and was tested again. The experimental results indicate that the UHPC layers significantly improved the in-plane shear resistance and cracking load of the squat walls, without decreasing the walls’ ultimate deformation. They effectively strengthened both moderately and severely damaged historical masonry walls, because the UHPC filled the existing damages and improved the integrity of the masonry substrate. In addition, the UHPC layers intervened the historical walls less than the reinforced polymer mortar layer. Therefore, the UHPC layers are efficient in strengthening historical squat masonry walls.

Failure and overhaul of a historic brick tower

Failure and overhaul of a historic brick tower

Reducing disaster risk to life and livelihoods by evaluating the seismic safety of Kathmandu's historic urban infrastructure: enabling an interdisciplinary pilot

Kathmandu’s medieval cities and shrines are exceptional architectural and artistic achievements underpinned by centuries of seismic adaptation. They host urban infrastructure of tangible and intangible value and play vital roles of cohesion in the life of thousands of people. They also represent portals where the heavens touch earth and individuals can commune with guiding deities. The 2015 Gorkha Earthquake and its related aftershocks were a human disaster, killing 9,000 people and displacing 2.8 million. Generating 7.6% of Nepal’s GDP through tourism, Kathmandu’s iconic skyline was dramatically altered by the earthquake. It destroyed 500,000 homes and undermined the sustainability of Nepal’s tourist industry and its 400,000 employees. However, it was also a cultural catastrophe damaging 403 monuments in Kathmandu, key elements within the Valley’s historic urban infrastructure. Their collapse caused multiple fatalities and first responders demolished others fearing that they might also fall and injure residents and visitors. With Overseas Development Assistance pledges of $2.5 billion US dollars, Nepal’s Government approved the rehabilitation of much of Kathmandu’s historic infrastructure but there is continued tension between interpretations of Sendai’s ‘Build Back Better’ framework and the obligation to preserve the authenticity and intangible values of its UNESCO World Heritage Properties. Many risk reduction strategies implemented in Kathmandu are demolishing historic buildings and rebuilding them in modern materials; while other monuments have been hybridised with metal bracing or concrete reinforcement. Mud mortars are frequently being replaced by cement and lime, although the resultant inflexibility is not necessarily seismically advantageous. Most monuments have been, or are being, rebuilt without research and analysis of why they collapsed, while their foundations, which in many cases preserve sequential experimental adaptations offering examples of practical seismic-resistant foundations which could be applied to other structures, are being demolished without record or research. With donor liability fears, contractors privilege modern materials, despite successful histories of vernacular systems. Costly historic bricks have been landfilled, causing supply chain delays and increased environmental impact from kilns. Residents, craftspeople and tour operators and businesses have been frequently excluded from decision-making but the risk to them, and their livelihoods, remains. Building on an interdisciplinary north-south partnership, we have piloted the integration of archaeology and geoarchaeology with 3D visualisation and geotechnical and structural engineering to co-produce and disseminate a methodology to assess, evaluate and improve the seismic safety of historic urban infrastructure within Kathmandu's UNESCO World Heritage Properties, reducing direct risk to life and livelihoods, while respecting and preserving Kathmandu’s authenticity and traditions.

THE EFFECT OF PORE DISTRIBUTION IN HISTORIC MASONRY ON THE GROUTING METHOD AND GROUTING MIX SELECTION

The NAKI II DG16P02M055 research project incorporates extensive experimental and theoretical research into the effect of grouting on the physical and mechanical characteristics of brick, stone and mixed masonry. The focus of the research is on the verification of particularly the reinforcing effect of selected grouting agents based on hydraulic lime (nanolime), resins and silicates. Selected materials are used for the monitoring of the effect of grouting on changes in the porosity, pore distribution, absorption capacity as compared to ungrouted masonry, and the reinforcing effect of grouting on historic brick, sandy marlstone, sandstone, trachyte, limestone and mixed masonry with a lime binder for different types of grouting agents as compared to ungrouted masonry.

In-Plane Seismic Response Analyses of a Historical Brick Masonry Building Using Equivalent Frame and 3D FEM Modeling Approaches

ABSTRACT This article aims at contributing to the seismic performance assessment of a historic brick masonry building by finding a strength reduction coefficient through the use of linear and nonlinear modeling approaches, using Finite Element Method and Equivalent Frame modeling. To reduce the uncertainties, ambient vibration tests (AVT) were implemented. Series of simulations was performed using nonlinear dynamic analyses and incremental dynamic analysis curves were compared with the pushover curves. Results indicate that the mass-proportional pushover curve meets the mean of results obtained from IDA and the strength reduction coefficient falls into the range given in EN 1998–1 for unreinforced masonry.

Three-dimensional building façade segmentation and opening area detection from point clouds

Laser scanning generates a point cloud from which geometries can be extracted, but most methods struggle to do this automatically, especially for the entirety of an architecturally complex building (as opposed to that of a single façade). To address this issue, this paper introduces the Improved Slicing Method (ISM), an innovative and computationally-efficient method for three-dimensional building segmentation. The method is also able to detect opening boundaries even on roofs (e.g. chimneys), as well as a building’s overall outer boundaries using a local density analysis technique. The proposed procedure is validated by its application to two architecturally complex, historic brick buildings. Accuracies of at least 86% were achieved, with computational times as little as 0.53 s for detecting features from a data set of 5.0 million points. The accuracy more than rivalled the current state of the art, while being up to six times faster and with the further advantage of requiring no manual intervention or reliance on a priori information.

Petrographic and Thermal Characterization of Mortar from a Church Ruin in Cagsawa, Albay, Philippines

The Cagsawa Ruins is a crucial structure of the old church standing 38 km from Mt. Mayon in the province of Bicol. The ruins has been the result of the eruption of Mt. Mayon last February 1,1814. The remains have become a part of the province’s rich history and culture declaring it as one of the national treasures of the Philippines. Preservation is implemented to maintain the part that has remained from centuries ago. But apparently, the material used for preserving this important structure lacks compatibility with the original materials incorporated in the structure. Portland cement has been an alternative for lime mortars through which, in nature, are synthetic and are known to be the source of premature deterioration of soft, historic bricks. This cultural heritage is of importance to the history and must be preserved to its rightful material. By means of petrographic and thermal analysis it was proved that the aggregate from the mortar gathered from Cagsawa came from minerals and marine organisms that the decomposition of the elements confirmed that there are organic compounds present.