• Nuclear Engineering and Technology
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• 제48권5호
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• pp.1230-1236
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• 2016

This study aims to determine the effect of fly ash with a high replacing ratio of clay on the radiation shielding properties of bricks. Some interaction parameters (mass attenuation coefficients, half value layer, effective atomic number, effective electron density, and absorption efficiency) of clay fly ash bricks were measured with a NaI(Tl) detector at 661.6 keV, 1,173.2 keV, and 1,332.5 keV. For the investigation of their shielding behavior, fly ash bricks were molded using an admixture to clay. A narrow beam transmission geometry condition was used for the measurements. The measured values of these parameters were found in good agreement with the theoretical calculations. The elemental compositions of the clay fly ash bricks were analyzed by using an energy dispersive X-ray fluorescence spectrometer. At selected energies the values of the effective atomic numbers and effective electron densities showed a very modest variation with the composition of the fly ash. This seems to be due to the similarity of their elemental compositions. The obtained results were also compared with concrete, in order to study the effect of fly ash content on the radiation shielding properties of clay fly ash bricks. The clay fly ash bricks showed good shielding properties for moderate energy gamma rays. Therefore, these bricks are feasible and eco-friendly compared with traditional clay bricks used for construction.

• Journal of radiological science and technology
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• 제3권1호
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• pp.67-72
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• 1980

To shield the radiation, we can make use of various materials, but the scattered rays can be caused by the shielding materials. The degree of the scattered rays production is influenced by the nature of the shielding materials and the energy of the radiation, therefore to choose the proper shielding material is the most important matter in radiation protection. Authors made an experimental study on the scattered rays generated from the shielding materials, and obtained the results as follows: 1. In the ranking of the scattered rays production: Cement bricks, black colored fire bricks, and red colored fire bricks were marked the first the second, and the third ranking respectly, and the last order was lead plates. 2. In the relative ranking of the scattered rays production by energy increase: Lead plates were marked the first order, the next and third order were red colored fire bricks and black colored fire bricks respectly, and cement bricks were marked the last order. 3. The scattered ray ratio of lateral-back point per lateral point were generally decreased by energy increment. The diminishing orders were that lead plates were the first order, and the next and the third order were red colored fire bricks and black colored fire bricks respectly, cement bricks were marked the last order.

• Journal of Korean Society of Environmental Engineers
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• 제31권3호
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• pp.217-222
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• 2009

This study was conducted to search possibilities of the use of sludge from waterworks industry in the manufacturing of red clay bricks. Different compositions of the sludge were added into the raw materials of the bricks and required engineering characteristics of the manufactured bricks were examined. Compressive strength, plasticity, and surface absorption of the recycled bricks were analyzed and were compared with the bricks quality standard rules and regulation for quality assurance of the product. Compressive strength of the bricks made in a ratio 75% clay, 5% sludge and 20% silica was found 261.3 $kg_f/cm^3$ and that was comparable with first grade bricks standard. Compressive strength of the bricks made in a ratio 70% clay, 10% sludge, and 20% silica was found 249.9 $kg_f/cm^3$ while it was decreased to 217.3 $kg_f/cm^3$ when bricks were made in a ratio 65% clay, 15% sludge and 20% silica. However, these values of compressive strength were in agreement with the bricks quality standard. Surface absorption of the bricks made by the mixing of 20% silica with varying amount of sludge, i.e., 5%, 10%, and 20% was found 10%, 9.65% and 10.92% respectively. These values satisfied the quality standard of bricks of grade 1 and 2. Recycling of proper amount of sludge in bricks making could produce bricks of high engineering characteristics.

• Journal of architectural history
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• 제22권6호
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• pp.59-66
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• 2013

This study progressed an investigation on the cause of the efflorescence phenomenon of bricks in Suwon Hwaseong Fortress, which is designated as a UNESCO World Heritage by using diverse scientific analyses. The samples were taken in Hwaseong and analyzed using XRD and SEM-EDS for the material identification of efflorescence. We observed under a polarizing microscope and measured absorption factors for the basic investigation for traditional bricks. As a result of material identification, soluble salt($Na_2SO_4$, $KNO_3$) and insoluble salt($CaCO_3$) were detected. There was no big difference between original bricks and repaired bricks under the polarizing microscope. However, in terms of the water absorption rate, bricks which were used for repair nowadays showed low water absorption rate(1%). In conclusion, soluble salt and insoluble salt appeared due to an effect of an air pollution and joint mortar. Soluble salt was removed in the rainy season, but insoluble salt was not removed. As a result of the efficiency and safety tests for chemicals removing efflorescence, chemical E is likely to be the suitable chemicals for the efflorescence phenomenon of traditional bricks in Suwon Hwaseong Fortress. In the future, consideration whether the use of lime is available or not should be studied through comprehensive researches including repair work, construction work and the environment factor with lime. Also, physical, chemical identifications of repairing bricks will be required.

• Economic and Environmental Geology
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• 제55권6호
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• pp.571-582
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• 2022

In this study, the raw material and tempers of bricks used in three brick tombs built in Gongju, during the Ungjin period of Baekje were investigated. The royal tomb of King Muryeong, the 6th tomb in the royal tombs, and Kyochonri brick tomb remained in Gongju and the bricks of each site had different shape and physical properties despite their similarity in raw materials. As the results of the mineralogical and microstructural analysis, the bricks of the royal tombs were made of refined raw materials, and were infrequently added crushed bricks(grogs) as a tempering material. On the other hand, thick and elongated pores of bricks from the Kyochonri brick tomb were frequently found, and the remains of plant carbonization are observed in their microstructures. Since the pores are mainly distributed in a thickness of 0.3 to 1 mm, it is estimated that bricks were produced by adding a certain size of the plant to refined soil, and grogs also were added as a tempering material. In particular, it was found that adding plants and grogs in raw materials of bricks caused thick pores or cracks in the internal structure. Since the bricks of the Kyochonri brick tomb have internal cracks and low firing temperature, the ultrasonic velocity of the bricks was lower than that of the royal tomb bricks. It means that the mechanical strength of these bricks were relatively low. Accordingly, it is estimated that the tempering materials, firing temperature, and internal structures of bricks can affect durability of the brick, and it can be thought as a difference in the manufacturing technology of brick making.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 한국주거학회 2002년도 추계학술발표대회
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• pp.97-102
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• 2002

The Purpose of this study was to investigate the exterior materials of super high-rise housing more than 30 stories which were built in New York City between 1924 and 2004. The result of examining 153 buildings was as follows; Exterior materials of super high-rise housing which were used bricks, of the salt-glazed bricks, terra-cotta and ceramic tiles, jumbo bricks and bricks were preferred among them. The colour of bricks was yellow, yellow ochre, clear brown, brown, dark brown, orange, vermilion and red. Exterior materials of super high-rise hotel and hotel apartment were bricks and ceramic tiles in the early days but stones, curtain wall and glass(green glass, green-tinted glass, brown-tinted glass, black glass) after 1980s. The main colour of buildings extended gray, green, blue-tinted brown-tinted and black.

• Nuclear Engineering and Technology
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• 제56권2호
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• pp.666-672
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• 2024

In the present work, a new brick series based on the Vietnamese white clay minerals from the Bat Trang was fabricated to be applied in the radiation protection applications during the decommissioning of the nuclear power reactors. The bricks were constructed under various pressure rates varied from 7.61 MPa to 114.22 MPa. The influence of pressure rate on the physical and γ-ray shielding properties were investigated in the study. The experimental measurement for the material's density using the MH-300A density meter showed an enhancement in the prepared bricks' density by 22.5 % with increasing the applied pressure rate while the bricks' porosity reduced by 31.2 % when the pressure rate increased from 7.61 MPa to 114.22 MPa. The increase in the fabricated bricks density and the reduction in their porosities enhances the bricks' linear attenuation coefficients as measured by the NaI (Tl) detector along the energy range extended from 0.662 MeV to 1.332 MeV. The linear attenuation coefficient increased by 13.8 %, 17.6 %, 17.0 %, and 17.1 % at gamma ray energies of 0.662 MeV, 1.173 MeV, 1.252 MeV, and 1.332 MeV, respectively. The enhancement in the linear attenuation coefficient increases the bricks' radiation protection efficiency by 10.22 %, 14.48 %, 14.09 %, and 14.26 % at gamma ray energies of 0.662 MeV, 1.173 MeV, 1.252 MeV, and 1.332 MeV, respectively.

• Proceedings of the Korea Concrete Institute Conference
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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• pp.81-84
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• 2005

We investigated the effect of inorganic impurities such as clay bricks and asphalt concrete in recycled aggregate on the properties of lean concrete. The optimized moisture content of lean concrete with clay bricks increased, because the absorption ratio of clay bricks is high. On the other hand, lean concrete with asphalt concrete produced an opposite result owing to low absorption ratio. The results showed that inorganic impurities did not have a significant effect on compressive .strength of lean concrete containing below 30$\%$ clay bricks and below 10$\%$ asphalt concrete.

• Proceedings of the Korea Concrete Institute Conference
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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• pp.113-116
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• 2005

This study is contents about Separation ASCON, the Tiles and the Reds Bricks using the heavy suspension. The specific gravity of ASCON, the Tiles and the Reds Bricks are under 2.3. So we make the heavy suspension which the specific gravity is 2.3 and we separated ASCON, the Tiles and the Reds Bricks.

• Journal of the Korean Ceramic Society
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• 제15권4호
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• pp.193-198
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• 1978

Test-bricks were prepared from an artifically graded Ham Kang sand and a commercial CaO and autoclaved for 6 hours at $16 kg/cm^2$ pressure $(203^{\circ}C)$. Bricks were tested for compressive strength, free lime, saluble silica and amount of water absorption. Physical properties of bricks were very much depended on the size distribution of sand particle and the amount of soluble silica in bricks.