• Resources Recycling
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• v.19 no.3
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• pp.16-23
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• 2010

Coal briquette use has dramatically increased because of high oil prices. Hence, it is necessary to develop an environment-friendly recycling technique of the coal briquette ash. The coal briquette ash contains a large amount of an unburned carbon content and a mullite with high thermal property, so it is considered to be used as raw materials of sintered eco-brick. This study aimed to investigate on how the unburned carbon affects properties of the sintered eco-brick. The eco-brick was mixed with the ratio of 50 wt% coal briquette ash having the unburned carbon 10.5 wt% and 50 wt% cullet, then being sintered at $950^{\circ}C$, which of the compressive strength was in line with the first class of the sintered clay brick standard(KS L 4201). In particular, the compressive strength of the sintered eco-brick was equal to the first class of the KS L 4201 despite the increase of mixing ratio for coal briquette ash with 1.0 wt% unburned carbon to 70 wt%.

• Proceedings of the Korean Ceranic Society Conference
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• 2004.04b
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• pp.49.3-49.3
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• 2004

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.175-176
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• 2023

The masonry structure is constructed by cement mortar binding material of brick objects and uses reinforced hardware(connected hardware or wall tie) together when building. However, over time, the corrosion of reinforced steel and the deterioration of joint mortar as well as bricks cause the risk of collapse. In particular, when the externally decorated brick wall is installed on the concrete girder for each floor, the angle bracket is not constructed or corroded, the full-layer weight load is applied to the wall of 0.5B, which is an example of full-scale or collapse. As a result of the evaluation, it was confirmed that the performance was improved compared to the existing bracket, and we plan to carry out a real-life test and long-term performance review of the building using the bracket in the future.

• Journal of the Korean Ceramic Society
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• v.15 no.4
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• pp.213-223
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• 1978

The purpsoe of this study was to produce domestic stamping materials; sling mass which could be used as unburned refractory for iron melt'ladle. Batch compositions were based on Belgian Ladelite; mineral compositions were composed of 84 wt% of quartz and 16 wt% of clay, and particle sizes were divided into 12 wt% of 1410/297㎛, 18wt% 297/149㎛, 20wt% of 149/74㎛, 11wt% 74/44㎛ and 39wt% 44㎛ under. The effect of variable batch compositions were also investigated such as substitution of pyrophylite or industrial grade alumina for quartz and of zircon for portion of quartz and clay, increase of clay and addition on sericite. Samples were pressed at 100kg/㎠ with 7.4wt% of water or 7.4wt% of 4 wt% PVA solution. Dried and Fired properties of samples such as linear shrinkage, apparent porosity, modulus of rupture, refractoriness and corrosion resistance to blast furnace slag were investigated. The results are summarized as follows. 1. Dried samples are shrinked, but fired at 700-1400℃ expanded. Samples fired at 700-1000℃ and 1200-1400℃ tended to expand with incresing of firing temperature, but fired at 1000-1200℃ tended to shrink with increase of firing temperature. 2. Apparent porosity of samples fired at 700℃ is increased, but fired at 1200-1400℃ decreased with increasing of firing temperature. 3. Modulus of rupture of samples fired at 700℃ is decreased, but fired at above 700℃ increased with increasment of firing temperature. 4. Dried samples with 7.4 wt% of 4 wt% PVA solution better improve modulus of rupture than with 7.4 wt% of water, but the firing strength of the sampels fired at 700-1000℃ is showed reversely. 5. In quartz-clay system, mineral phases of samples fired at above 1200℃ are consisted of α-quartz, α-cristobalite and mullite. Respectively as firing temperature was rising up, intensity of α-cristobalite and mullite is in creased. 6. Quartz-Kibushi clay system, Kimcheun quartz(substitutuion of portion of industrial grade alumina for quartz) Hampyeung clay system and pyrophyllite-clay system are better in corrosion resistance to blast furnace slag than burned pyrophyllite brick. 7. 84 wt% of pyrophyllite-16wt% of clay system is superior in modulus of rupture and corrosion resistance to blast furnace slag to 84 wt% of quartz-16 wt% of clay system.

• Advances in concrete construction
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• v.13 no.3
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• pp.215-221
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• 2022

Considering their similar mass densities, an attempt was made to optimize the mix design of micro-concrete that used barite sand as an aggregate by substituting marble powder (5%, 10%, 20%, 30%, 40%, 50%, 70%), clay brick powder (30%, 50%, 70%), and fly ash (30%, 50%, 70%) for the concrete (by mass) to form specimens for shaking table tests. The test results showed that for these three groups of materials, the substitutions had little effect on the density. The barite sand played a decisive role in the density, and the overall density of the specimens reached approximately 2.9 g/cm³. The compressive strength and elastic modulus decreased with an increase in the substitution rates for the three types of materials. Among them, the 28 day compressive strength values of the 40% and 50% marble powder groups were 11.73 MPa and 8.33 MPa, respectively, which were 58.7% and 70.7% lower than the control group, respectively. Their elastic modulus values were 1.33×10⁴ MPa and 1.42×10⁴ MPa, respectively, which were 39.1% and 35% lower than those of the control group, respectively. The 28 day compressive strength values of the 50% and 70% clay brick powder groups were 13.13 MPa and 5.8 MPa, respectively, which were 53.8% and 79.6% lower than the control group, respectively. Their elastic modulus values were 1.54×10⁴ MPa and 1.19×10⁴ MPa, respectively, which were 29.7% and 45.4% lower than those of the control group, respectively. The 28 day compressive strength values of the 50% and 70% fly ash groups were 13.5 MPa and 7.1 MPa, respectively, which were 52.5% and 75% lower than those of the control group, respectively. Their elastic modulus values were 1.36×10⁴ MPa and 0.95×10⁴ MPa, respectively, which were 37.9% and 56.6% lower than those of the control group, respectively. There was a linear relationship between the 28 day compressive strength and elastic modulus, with the correlation coefficient reaching a value higher than 0.88. The test results showed that the model materials met the high density, low compressive strength, and low elastic modulus requirements for shaking table tests, and the test data of the three groups of different alternative materials were compared and analyzed to provide references and assistance for relevant model testers.

• Resources Recycling
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• v.25 no.4
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• pp.23-31
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• 2016

It was found that there was no problem in recycling by-products (waste rock and tailings) from Yangyang iron mine themselves through matter conversion because they are not hazardous according to results of KSLT method. In case of using tailings as sub-materials of cement, it recommended the use of less than 3% tailings dosage not to exceed 0.6% of total alkali ($R_2O$) content based on standard quality of portland cement (KS L 5201). Non sintered eco-brick corresponding to class 1 quality of recycled clay brick (KS I 3013) can replace 15% of cement with tailings and 100% of general fine aggregate with waste rock from iron mine. As mentioned above, recycling the by-products (waste rock and tailings) as sub-materials of cement and non sintered eco-brick could gain both environmental and economic benefits, that is, reduction of scale and maintenance cost of tailing ponds, decrease of energy use and $CO_2$ emission.

• Resources Recycling
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• v.8 no.1
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• pp.23-28
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• 1999

Firing characteristics, transverse rupture strength, and heat capacity were studied of the heat-reservoir refractory materials made of red-firing clay, mill scale, and water glass. The firing shrinkage increased with increase of the clay proportion in samples. The volume of fired bodies showed shrinkage by drying up to $300^{\circ}C$, steady expansion in the 300-$700^{\circ}C$ range due to phase transition of iron oxides. and drastic expansion above $1200^{\circ}C$. Flexural strength decreased from 5.6 Mpa to 2.35 Mpa with the decrease of the ratio of clay to mill scale from 1:1 to 1:3 Heat capacities changed from 1.1 Joul/g$^{\circ}$C to 1.35 Joul/g$^{\circ}$C with the ratio of millscale to clay ratio from 1:1 to 1:3. Mill scale in the specimen appears to exist as liquid phase during firing. Firing the specimens in air leads to the eruption of the molten mill scale to the sample surfaces. Contrarily, firing samples in a refractory sagger with a cover suppressed the eruption of the molten mill scale to the surfaces. The addition of mill scale gave rise to porous sintered bodies which would delay cooling rates of heat-reservoir brick.

• Nuclear Engineering and Technology
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• v.56 no.2
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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.

• Resources Recycling
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• v.11 no.2
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• pp.36-44
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• 2002

The waste garnet powder as a raw material for clay bricks was studied its recycling. The physical strength of clay bricks are closely dependent both on the contents of $SiO_2$, $Al_2$$O_3$, and $Fe_2$$O_3$in clay and on the viscosity of it. Although the garnet power has very high contents of $SiO_2$, $Al_2$$O_3$, and $Fe_2$$O_3$, it could not substituted to clay because of its low viscosity. Therefore the substitution of sand with waste garnet powder was considered to influence positively on the strength of clay bricks .Mixing ratios of {clay-sand}, {sand-garnet powder}, and {clay-sand-garnet powder} based on weight were controlled in the production of clay bricks. The properties of clay bricks such as compression strength, moisture absorption, shrinkage, and specific gravity has been evaluated. It was shown that the optimal mixing combination was found to be { clay(50%)-sand(30%)-garnet powder(20%)} as a weight basis. The present study indicated possibilities to produce commercially clay bricks with the waste garnet powder. An economical benefit will be produced in viable in view of recycling waste garnet powder.

• Earthquakes and Structures
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• v.23 no.1
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• pp.13-21
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• 2022

Masonry constructions exhibit uncertain behaviors under dynamic effects such as seismic action. Complex issues arise in the idealization of structural systems of buildings having different material types and mechanical properties. In this study, the structural behavior of a vaulted masonry building constructed using full clay brick and lime-based mortar and sitting on consecutive arches was investigated by experimental and numerical approaches. The dimensions of the structure built in the laboratory were 391 × 196 cm, and its height was 234 cm. An incremental repetitive loading was applied to the prototype construction model. Along the gradually increasing loading pattern, the load-displacement curves of the masonry structure were obtained with the assistance of eight linear displacement transducers. In addition, crack formation areas, and relevant causes of its formation were determined. The experimental model was idealized using the finite element method, and numerical analyses were performed for the area considered as linear being under similar loading effect. From the linear analyses, the displacement values and stress distribution of the numerical model were obtained. In addition, the effects of tie members, frequently being used in the supports of curved load-bearing elements, on the structural behavior were examined. Consequently, the experimental and numerical analysis results were comparatively evaluated.