Ancient Bricks Research Articles

Fluorinated B-72 hybrid silver doped modified nanoparticle as a coating for biological corrosion protection of ancient bricks

In this paper, a superhydrophobic organic-inorganic composite coating containing fluorinated B72 hybrid methyl-modified silica/(Ag doped TiO2) by hexamethyldisilazane (HMDS) (H-SiO2/Ag/TiO2) was prepared by means of a mild and an environmental friendly method. Transparency, adhesion, hardness tests and photocatalytic performance were measured to determine the content of Ag in TiO2 which the TiO2/AgNO3 ratio is 0.008 g/mL. The synthesized Ag/TiO2 nanoparticles were characterized by X-ray diffraction (XRD), Raman spectra and transmission electron microscope (TEM). The highest contact angle of coated ancient bricks was 148.66° and the color change value of ΔE⁎ before and after coating was <5 which is within an acceptable range. The physical properties such as apparent porosity and water vapor permeability (ΔMp) were studied. After weathering from acid, alkali, salt, water and ultraviolet radiation, the bricks coated by the composite coatings still have good hydrophobicity that the contact angle were >120° and minor degree of surface corrosion comparing with the ancient bricks. The inhibitory effect of the composite coating on Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), and that on algae (Chlamydomonas and Dunaliella) were studied through bacteriostasis test and algae comparative experiments, respectively. Finally, the mechanism of the composite coating on antibacterial and anti-algae was studied. The results showed that the appearance of the ancient bricks was not changed after coating, and the anti-weathering, antibacterial and anti-algae properties of the ancient transformation were increased.

Study on the mechanical behavior of millennium-ancient bricks based on microscopic characteristics

The wide performance variation and inability for destructive testing make accurately determining ancient brick mechanical properties crucial for assessing structural safety in ancient masonry. This paper uses multiscale modeling with microscopic finite element analysis to quantitatively assess ancient brick macroscopic stress–strain relationship and compressive strength based on microstructural characteristics. The basic parameters such as porosity, pore size distribution, mineral composition and volume ratio, and microstructure characteristics of ancient bricks were obtained by corresponding methods. The Mori-Tanaka homogenization theory was applied to derive a three-phase equivalent brick matrix using elastic moduli and Poisson’s ratios of quartz, kaolinite, and montmorillonite at the microscale. The Representative Volume Element model with pores was created based on this matrix and pores, integrating Drucker-Prager plastic damage for finite element analysis of ancient brick mechanical behavior. The results indicate that stress–strain curves from the multi-scale micromechanics model resemble macroscopic experimental curves and maintain consistent peak strength. This shows that combining microscopic testing with finite element simulation for analyzing the mechanical properties of ancient bricks is feasible, providing a new non-destructive means of obtaining these properties.

Exploring in the Ancient Urban Center of Samatata: Initial Documentation of Archaeological Discoveries in the Lalmai Hill Range, Cumilla, Bangladesh

The study aimed to investigate the Lalmai Hill range in Cumilla, Bangladesh, which was the capital center of ancient Samatata, to uncover new archaeological sites. Over the years a total of 50 archaeological sites have been identified on the hills' flat tops and slopes through multiple phases of exploration conducted by the Archaeological Survey of India's Eastern Circle, the Department of Archaeology and Museums of Pakistan, and the Department of Archaeology under the cultural ministry of the Bangladesh Government. The archaeological sites discovered provide a captivating glimpse into the 7th to 8th century AD. This era is characterized by significant cultural and societal transformations, making it a compelling and pivotal period to explore. While most of these sites were discovered in the northern and middle parts of the Hill range, this study specifically focused on the southern part. Through several field surveys, a new archaeological site was discovered in the south zone of the Hill range. The findings revealed ancient bricks, wall structures, and potshards, indicating the presence of past human activities at the site. These findings provide insights into the historical and cultural significance of the region. Further exploration and excavation of this site and other potential areas within the Lalmai Hill range are warranted to enrich our understanding of the past culture and unearth other hidden treasures

Experimental study on weathering mechanism of ancient bricks in Jiayuguan Wei-Jin tombs, Gansu, China

This study focuses on the ancient bricks of Wei-Jin tombs in Jiayuguan, Gansu, China, analyzing the deterioration of the bricks under the long-term influence of natural environments and human activities. Currently, the ancient bricks exhibit various degradation diseases such as cracks, exfoliation, fracture, weathering, and microbial erosion, severely affecting the integrity of the cultural relics. Through on-site investigation and characterization testing, the physical and mechanical properties, compositional elements, pore size distribution, and thermal characteristics of the ancient bricks were analyzed. Indoor simulation experiments were conducted to study the impact of different types of environmental erosion cycles (such as H2O, HCl, NaOH, Na2SO4) on the performance and structure of the ancient bricks, the patterns and causes of deterioration were also studied. The results indicate that the cyclic effects gradually transform the porosity of the ancient bricks into lateral microcracks, which continue to expand, leading to varying degrees of degradation of performance. The extent of the impact of these cycles on the properties of ancient bricks is in descending order: Na2SO4, HCl, NaOH, H2O. H2O, NaOH, HCl, Na2SO4.

Reconnaissance archaeomagnetic study of ancient bricks from Northern Poland

In total, 24 brick samples for archaeomagnetic studies were taken from ten historical buildings constructed between c.1280 AD and 1630 AD in northern Poland. Eight of them are from the gothic period. The Thellier–Thellier archaeointensity protocol was used in order to determine the ancient intensity and inclination registered by the bricks. In total, 28 representative specimens from 16 bricks gave successful archaeointensity determination with category B of results quality. For 25 of them the corrections for anisotropy of thermoremanent magnetization and cooling rate were introduced. A large number of specimens classified as category C (48%) is due to a high value of relative additivity check error d(AC) caused most probably by the presence of multi-domain magnetite. The curvature parameter k exceeds the limit value in 11 specimens. However, in the same sample specimens with k higher than 0.270 have provided very similar values of archaeointensity than those with k below this limit. Corrected data are convergent with the Central European master curve of archaeointensity. The corrections of raw data reduce their dispersion at specimen/sample level in most of sites.

Rehydroxylation of calcined swellable clay minerals at ambient conditions

Thermal treatment of clay minerals is used to produce building materials like supplementary cementitious materials (SCM). New, environmentally friendly binders, that are alkali activated materials (AAM) or geopolymers can be produced with calcined clay minerals, too. Four typical reactions occur during thermal treatment of clay minerals, namely dehydration, dehydroxylation, breakdown of structure, and recrystallization of high temperature phases. Heating to temperatures below the breakdown of structure makes rehydration and rehydroxylation of the clay minerals possible, ass observed in ancient bricks and pottery. As swellable clay minerals or mixtures of different clay minerals come into focus as precursors for geopolymers or as SCM, it is important to pay attention to rehydroxylation in this context as well. This work studied the rehydration and rehydroxylation of three different homoionic (Na+, Ca2+, Mg2+) exchanged trans- and cis-vacant dioctahedral smectites at equal relative humidity (75% r.H.) at different temperatures (22, 40, and 60 °C) after calcination at 700 °C. Simultaneous thermal analysis was used to determine the amount of H2O uptake (after 4, 24, 48, 72, and 168 h) due to rehydroxylation. Rehydroxylation between 8.7% for a Na+ exchanged sample and up to 37.3% for a predominantly Mg2+ exchanged sample took place within 7 d. The process of rehydroxylation could be further verified by X-ray diffraction, these measurements should be part of future studies. The α-free isoconvertional approach resulted in Ea of rehydroxylation in the range 32–90 kJ/mol for Ca2+ exchanged samples.

Comparative study on material properties of ancient fired clay bricks of China

The city wall is a military defense building of an ancient city and a unique landscape architecture of a modern country that has extremely important historical, artistic, and scientific values. Most ancient Chinese walls were built of bricks and have been severely damaged and degraded by environmental and human influences. To protect these historical building monuments, it is necessary to determine scientifically the material properties of the bricks used in the ancient walls. In this study, the physical and mechanical properties, chemical element composition, mineral composition, micromorphology, and pore structure of 20 ancient fired clay bricks from four different regions, including white and blue wall bricks from Nanjing, blue wall bricks from Xi'an and Linqing, and the Great Wall bricks from Beijing, were compared using various modern analysis and testing methods. The results show that talc could be one of the raw materials to produce white bricks and the firing temperature of some white bricks could exceed 1200 ℃. The ancient blue bricks were mainly composed of quartz and feldspar, whereas the ancient white bricks were mainly composed of quartz and long prismatic and rod-like enstatite. The solid density and compressive strength of the white bricks were higher than that of the blue bricks. The proportion of pores larger than 10 µm in all ancient bricks is less than 10%. The pores smaller than 0.1 µm is less than 6% at higher firing temperatures. The results of this study can provide scientific guidance for the restoration and conservation of fired clay bricks of ancient city wall.

Comparative study on the similarity between ancient white bricks and the self-developed imitative white bricks

Many architectural heritages in China are built with ancient white bricks (AWB), which behave very differently from traditional blue and red bricks. Indeed, AWB buildings have undergone centuries of historical changes and weathering with time, and require urgent repair. Since replacing ancient bricks with imitative bricks when restoring heritage buildings has become a consensus, it is necessary to develop imitative white bricks (IWB) similar to AWB in many respects to be used for restoring ancient buildings. Therefore, this paper develops a novel IWB and analyses its similarity with the AWB by means of X-ray diffraction, X-ray fluorescence, mercury intrusion test, scanning electron microscopy, and ultrasonic pulse velocity. The results reveal that the self-developed IWB is highly similar to AWB in mineral and chemical composition, micro-morphology, internal appearance, apparent densities, water absorption rate, saturation coefficient, porosity, and these bricks are concentrated in micropores with similar radii. Besides, the durability is somewhat similar in terms of salt crystallization and resistance to freeze-thaw cycles. The IWB and AWB are classified as susceptible to salt crystallization, while good resistance to these white bricks' freeze-thaw cycles. The ultrasonic pulse velocity of the self-developed IWB along the height direction is close to the ultrasonic pulse velocity along other AWB directions. Besides, ultrasonic pulse velocity along the height direction is linearly correlated to the compressive strength of and the IWB and AWB, which has important reference significance for evaluating the mechanical properties of architectural heritages by ultrasonic non-destructive testing technology. These results can provide theoretical and technical support for the in-situ repair of damaged AWB and are significant for restoring and conserving brick masonry architectural heritages.

Pore structure and fractal dimension analysis of ancient city wall bricks in China

Comprehensive quantitative characterization of the pore structures of ancient city wall bricks is important for predicting the durability of historical masonry buildings. However, in most previous studies, only one or two methods were used to analyse the pore structures of fired clay bricks. In this study, mercury intrusion porosimetry (MIP), low-temperature nitrogen adsorption (LTNA), and low-field nuclear magnetic resonance (LF-NMR) were used to characterize the pore structure and fractal dimension of nine different ancient city wall bricks. The results show that the surface relaxivity of ancient bricks measured via the Hahn spin echo (HSE) in LF-NMR ranged from 1.55 to 1.75 μm/s. Furthermore, the porosity of the blue bricks measured via LF-NMR were much lower than that obtained via the gravimetric method owing to a higher number of paramagnetic iron mineral phases. LTNA was not suitable for describing pore size distribution of ancient bricks as the pore diameters were mainly concentrated in the range of 100–1000 nm. The pore structures of ancient bricks in dried and water-saturated states were different, the pore size of the white bricks obtained via LF-NMR was smaller than the MIP-derived pore-throat size by a factor of approximately 2.

Assessment of Traffic-Induced Ground Vibrations and Effects on Masonry Monuments in Ayutthaya Historical Park, Thailand

ABSTRACT This paper presents an assessment study of traffic-induced ground vibrations and their effects on masonry-type historic structures in Ayutthaya Historical Park, a UNESCO World Heritage Site in Thailand. The first objective is to propose a practical prediction of the attenuation rate of vibration for risk management of the monuments located along roadsides in the city. The attenuation of vibration waves traveling from traffic sources and the intensity of ground vibrations were determined by in situ vibration measurement. The results from the investigations in the Ayutthaya area were compared with those obtained from other sites having different characteristics of subsoil classified by the average shear wave velocity (Vs). It was found that the attenuation rates at a long distance from the source tend to be dependent on soil property in terms of Vs of subsoils. The attenuation curves derived from the regression analysis are proposed for risk management from the vibration of the heritage site. The second objective is to assess the effects of traffic vibrations on historic structures. The highest amplitude observed in Ayutthaya was within the recommended vibration criteria for historic buildings. In addition, finite element analysis of a 3D stupa model revealed that the stresses resulting from the ground vibration records induced by traffic was lower than the strength of ancient brick and mortar.

Seismic Performance of Three Ancient Stupas in Anuradhapura, Sri Lanka

Ruwanweli, Abayagiri and Jetavana stupas situated in Anuradhapura, are three ancient wonders of Sri Lanka. Renovations and restorations of these stupas were started in early parts in the 20th century and carried out until recently. Considering their geometric proportions, cultural and social importance, there is an impending need to assess these stupas for seismic performance to avert any possible damages due to seismic activities that might occur in the future. Further, this requirement has become more important due to some researchers’ predictions on intraplate activities in the behaviour of ancient stupas with respect to possible earthquake accelerations. In this regard, two-dimensional numerical models of the three stupas were prepared using SAP2000 v.14: generalpurpose software package. Both static and dynamic analyses were performed on numerical models for self-weight and two recorded acceleration histories, respectively. Two acceleration histories are from Mahakandarawa, Sri Lanka and Manjil, Iran. Material parameters of ancient bricks were obtained from previous literature works and experimental test results conducted on similar bricks of another ancient stupa in Sri Lanka. Considering the past records of earthquakes that have occurred in Sri Lanka, it was understood that all three stupas are in the safe realm under magnitude 4.7 earthquakes (Peak Ground Acceleration of 5.48x10-5 g). Even referring to the stress distribution with magnitude 7.4 Manjil earthquake (Peak Ground Acceleration of 0.4 g), both Ruwanweli and Jetavana stupas are in safe zone.

Bhiṣvā Stūpa of Birgunj as an 'Ancient Stūpa'

An earthen mound, Bhiṣvā located on Birgunj, where Buddhist pilgrims stayed during the night between their journey from Lumbini and Bodhgaya. During the Rana period, Ranas assumed a trove of treasure and jewellery inside the earthen mound in the Terai region, excavated it, found ancient bricks and coals, and then left the digging of the hill. A sculptor expert from the Archaeology Department of Nepal declared the earthen mound Bhiṣvā stupa in 1977 without any scientific investigation. Later, Two Buddhist priests worshipped jivanyāsapūjā on the stūpa in 1978. After that, Hindu and Buddhist followers installed different Hindu and Buddhist images on the stupa at various times. The Department of Archeology has not done any research on it and has not declared it as a Stupa. It cannot be called a stupa without the declaration of an official institution, without mention in any Buddhist scriptures, and without any authentic document based on the words of people. But it can be called a stupa based on its shape and name.

Modified nano-SiO2/TiO2 hybrid fluorinated B-72 as antimicrobial and hydrophobic coatings for the conservation of ancient bricks

A transparent superhydrophobic organic–inorganic composite coating was prepared with fluorinated B72 as the base organic component and methyl-modified silica/titania (SiO2/TiO2) by hexamethyldisilazane (HMDS) as the inorganic component by a simple and gentle means to protect ancient bricks from the invasion of micro-organisms and the breakage of weathering. Contact angle, transparency, adhesion, and hardness tests were utilized to testify the content of TiO2 in the inorganic component. The modified SiO2/TiO2 and the composite coating were characterized by infrared spectroscopy (FT-IR), transmission electron microscope (TEM), and scanning electron microscope (SEM). 8% TiO2 in methyl-modified silica was proved to achieve the highest contact angle. Compared with the untreated bricks, the composite coating enhanced the performance of ancient bricks against weathering, bacteria, and algae. In detail, the inhibitory effect of the coating on Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) was studied by a bacteriostatic circle test and fluorescence staining, and the influence of the composite coating on algae was determined by comparative experiment as well. Finally, the mechanism of the coating on antibacterial and anti-algae was explored and summarized. The results demonstrated that the weathering process can be slowed by coating the bricks with silica-titania hybrid fluorinated B-72 without altering their outward appearance, thereby protecting ancient buildings without structural repairs involving cement, glues, or concrete which alter the original architect's concept.

Roman brick production technologies in Padua (Northern Italy) along the Late Antiquity and Medieval Times: Durable bricks on high humid environs

Production technologies of Roman to Medieval times bricks on the city of Padua were addressed by means of a multi-analytical approach, consisting in Spectrophotometry, X-Ray Fluorescence (XRF), Powder X-Ray Diffraction (PXRD), Polarized Optical Microscopy (POM) and Scanning Electron Microscopy (SEM-EDS). The Early-Christian (5-6th centuries) and Romanesque (12-13th centuries) areas of the Basilica of Saint Justine of Padua (5/6-16th centuries), and the remains of the Roman necropolis (1-3/4th centuries) still preserved under the basilica, were selected to collect the bricks in order to define possible differences between the materials used for the various building phases. The walls are mainly shaped by yellow (with pale and dark hue) and beige colored bricks with an overall good conservation state. The ceramic bodies of this type of bricks showed the development of high-temperature phases but a low sintering degree was achieved. Moreover, secondary phases such as zeolites and calcite were formed, within almost the pale-yellow bodies and intensively precipitated through the groundmass of the beige bricks, respectively. Mg-rich calcareous clays and chloritic-illitic clays were used, firing temperatures of or over 900°C were reached and more porous ceramic bodies were produced when higher was the carbonate content on the raw clays. A lesser carbonate content of the base clays and/or the decrease in the firing temperatures were the main technological modifications progressively accomplished, leading to color changes on the ceramic bodies from yellow to beige hue. The Roman production technologies might be largely inherited by the brick makers during the Late Antiquity and Medieval times in the city and the reuse of more ancient bricks during the Medieval Times was confirmed. Such reuse operations have allowed to observe that under high humid conditions the yellow hue bricks have been rather good preserved, while when exposed to insolation and fluctuations of the environmental conditions a significant granular disaggregation -with the concomitance darkening of the color pastes- is developed. The color of bricks may entail an identifier of a specific construction period of the city and durable bricks from local clays, especially suitable for high humidity areas and that may preserve the aesthetical values of the city of Padua, may be currently produced.

Modified Nano-Sio2/Tio2 Hybrid Fluorinated B-72 as Antimicrobial and Hydrophobic Coatings for the Conservation of Ancient Bricks

Modified Nano-Sio2/Tio2 Hybrid Fluorinated B-72 as Antimicrobial and Hydrophobic Coatings for the Conservation of Ancient Bricks

Investigation of compression constitutive relationship of ancient brick masonry

Through uniaxial compressive strength tests on glutinous rice mortar, ancient bricks, and ancient brick masonry, the main mechanical properties of ancient masonry materials and the stress–strain relationship of ancient brick masonry were analyzed under uniaxial compression. Based on the compressive strength of the masonry, compressive strength of a single brick, and compressive strength of the mortar, the constitutive relationship of the ancient brick masonry in the Shanxi Province of China and the formulas for elastic modulus was established. The results reveal that the constitutive relationship of masonry under axial compression can satisfactorily fit the experimental data obtained for masonry under axial compression. The model provides a theoretical basis for the finite element simulation and durability evaluation of ancient masonry structures in the Shanxi Province of China.

Study of Structural Characteristics of Ancient Bricks With Neutron Radiography Facility at BTRR

Neutron radiography (NR) has been applied successfully to investigate different types of building materials, rock samples, sculptures, statues or monuments for since long. The utilization of neutron imaging for non-invasive investigations of cultural heritage objects is demonstrated on the example of ancient bricks found in Mahasthangarh and Sonargaon, two key archaeological sites in Bangladesh. The visualization of the internal structure of different brick samples, by means of Neutron Radiography (NR), has been experimented using the BTRR research reactor in Bangladesh - the only neutron imaging facility available in Bangladesh for R D purposes. Manufacturing building materials have become a very good option for business in developing countries like Bangladesh. Among the non-destructive testing (NDT) techniques, neutron radiography is the most common procedure to identify light and organic materials, homogeneity, any inclusion or voids or cracks etc. inside the structure. The radiographic images in a dry condition for individual samples have been investigated. The image analysis was performed using ImageJ software and texture features were extracted using gray level co-occurrence matrix implemented by MATLAB for acquiring qualitative and quantitative information from this inspection technique at a high level of accuracy. The results obtained by neutron imaging provide the statement that the brick sample from Mahasthangarh is more homogeneous inside.

Ancient mud bricks show adobe’s foundations 5,000 years ago

Ancient mud bricks show adobe’s foundations 5,000 years ago

Properties and Durability of Ancient Bricks

Properties and Durability of Ancient Bricks

The Current Experience of the Mechanical Properties of Ancient Brick

The Current Experience of the Mechanical Properties of Ancient Brick