• Journal of the Korean Ceramic Society
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• v.52 no.2
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• pp.159-164
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• 2015

We manufacture artificial lightweight aggregates (ALWAs) using bottom-ash as the primary raw material. We coat the ALWA surfaces with low-melting point materials in order to enable them to bloat, which is essential to reduce the bulk density of the aggregate. Then, we sinter the prepared aggregates at 1000, 1100, and $1200^{\circ}C$ using either the direct or two-step firing schedules. Finally, we evaluate the properties of the fired samples through analyzing their bulk density, water absorption, and microstructure. The surface-modified samples result in a reduction of their bulk density by $0.3{\sim}0.4g/cm^3$ regardless of the firing method used. Based on these results, we conclude that this approach could provide a viable method for the mass-production of ALWAs from industrial waste such as bottom-ash.

• Journal of the Korea Concrete Institute
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• v.27 no.5
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• pp.531-539
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• 2015

Properties of normal-strength mortar containing coarsely-crushed coal bottom ash considering standard particle size distribution of fine aggregate were investigated. Mortar containing raw bottom ash was applied as a reference. By crushing the bottom ash with a particle size larger than fine binder but smaller than fine aggregates, i.e., coarse-crushing, water absorption and specific gravity of the particles could be controlled as similar levels to those of natural fine aggregates. Workability and strength of the mortar were not changed and even increased when the coarsely-crushed bottom ash was added considering standard particle size distribution in Standard Specification for Concrete, while those were decreased when raw bottom ash was added without any treatment. When a replacement ratio of coarsely-crushed bottom ash was less than 30 vol.%, there were no significant decrease in dynamic modulus of elasticity and dry shrinkage of the mortar.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.327-332
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• 2003

The incinerated municipal waste can be classified into two general types of ash; fly ash and bottom ash. The fly ash is appointed as specified waste, because it contains harmful heavy metals, ie Pb , Cd, etc. more than permitted standard index. The purpose of this study is to manufacture the non-sintering artificial aggregates using municipal waste incineration fly-ash and to evaluate their applications as coarse aggregates in concrete interlocking block. The test results of water absorpsion, strengths of the concrete block using artificial aggregates showed that the artificial aggregates could be used in part of 10-20% as coarse aggregate in concrete block.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.625-632
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• 2021

In this paper, the applicability of bottom ash to insulation concrete was investigated to increase the utilization of bottom ash. Bottom ash was used as the aggregates in porous concrete and extensive experiments were conducted to investigate the characteristics of porous concrete using two types of bottom ash aggregates. The water-binder ratios of 0.25 and 0.35 were chosen and concrete specimens was produced with the compaction of 0.5, 1.5, and 3.0MPa to analyze the material properties at different compaction conditions. After concrete specimens were cured for 28 days at water tanks, unit weight, total void ratio, and thermal conductivity were measured. Based on the measured experimental results, the relationships between the unit weight, total void ratio, and thermal conductivity of porous concrete containing bottom ash was presented.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.17 no.6
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• pp.277-282
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• 2007

The artificial lightweight aggregate (ALA) was manufactured using coal bottom ashes produced from a thermoelectric power plant with clay and, the sintering temperature and batch composition dependence upon physical properties of ALA were studied. The bottom ash (BA) had 13wt% coarse particle (>4.75mm) and showed very irregular shape so should be crushed to fine particles to be formed with clay by extrusion process. Also the bottom ash contained a many unburned carbon which generates the gas by oxidation and lighten a aggregate during a sintering process. Plastic index of green bodies decreased with increasing bottom ash content but the extrusion forming process was possible for the green body containing BA up to 40wt% whose plastic index and plastic limit were around 10 and 22 respectively. The ALA containing $30{\sim}40wt%$ BA sintered at $1100{\sim}1200^{\circ}C$ showed a volume specific density of $1.3{\sim}1.5$ and water absorption of $13{\sim}15%$ and could be appled for high-rise building and super-long bridge.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1756-1767
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• 2008

Recently, a global trend has been established to facilitate the use of waste materials in geotechnical engineering applications. In Korea, where there is the need to save natural resources as these may become scare in the near future and to prevent excessive ground excavation for natural aggregates. The annual production of scrap tire and bottom ash has sharply increased in recent years. Therefore, it will be good waste resource recycling, if we can utilize the above wastes as fill materials in soft ground. In this study, based on the proven feasibility of bottom ash and tire shred-soil mixtures as lightweight fill materials, tire shred-bottom ash mixtures were suggested as a new lightweight fill material to replace the conventional construction material(soil) with bottom ash. Therefore, the main objective of this research is to investigate the feasibility of tire shred-bottom ash mixtures in order to estimate their suitability for the use of lightweight fill materials. So we carried out the performance tests of 2 large scale embankment which were made with tire shred-bottom ash mixture and the conventional fill material(weathered soil) respectively.

• Journal of the Korea Concrete Institute
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• v.22 no.6
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• pp.851-858
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• 2010

In this study, waste glass and bottom ash were used as basic materials in order to secure a recycling technology of by-products which was mostly discarded and reclaimed. In addition, because softening point of waste glass is less than $700^{\circ}C$ and bottom ash includes combustible material, it was possible to manufacture low-temperature sintering lightweight aggregates for energy saving at $800{\sim}900^{\circ}C$ that it is as much as 20~30% lower than sintering temperature of existing lightweight aggregates. Thermal conductivity of newly-developed lightweight aggregates was 0.056~0.105W/m. K and its porosity was 40.36~84.89%. A coefficient of correlation between thermal conductivity and porosity was -0.97, it showed very high negative correlationship. With this, we were able to verify that porosity is key factor to affect thermal conductivity. Microstructure of lightweight aggregates by $CaCO_3$ content and replacement ratio of bottom ash in the variation of temperature were that $CaCO_3$ content increased along with pore size while replacement ratio of bottom ash increased as pore size decreased. Specially, most pores were open pore instead of closed pore of globular shape when replacement ratio of bottom ash was 30%, and pore size was small about 1/10~1/5 as compared with case in bottom ash 0~20%. In addition, open pore shapes were remarkably more irregular form of open pore in $900^{\circ}C$ than $700^{\circ}C$ or $800^{\circ}C$ when replacement ratio of bottom ash was 30%. We reasoned hereby that these results will influence on absorption increase, strength and thermal conductivity decrease of lightweight aggregates.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.3
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• pp.192-201
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• 2023

In this paper, the strength properties of porous concrete containing natural fine aggregates and bottom ash aggregates were investigated, The material properties of natural fine aggregates and bottom ash were identified then used as aggregates for porous concrete. The water-binder ratio was constant at 0.25, and the com paction level of 0.5, 1.5, and 2.5 MPa was applied to produce a porous concrete specimen. Test of unit weight, ultrasonic velocity, compressive strength, and flexural tensile strength were perform ed and analyzed. The unit weight, ultrasonic velocity, com pressive strength, and flexural tensile strength increased as the compaction level increased and also the replacement rate of bottom ash with sand(fine aggregate) increased. In addition, through regression analysis, the correlation between the unit weight, compressive strength, and flexural tensile strength of bottom ash porous concrete was presented. Unit weight and strength properties are proportional to each other and showed an increasing correlation. In addition, the correlation coefficient (R²) value of regression analysis was calculated based on the experimental results of this study and those of other research papers.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.99-100
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• 2015

Significant amount of bottom ash has been produced in the power plant located at southeast region of Korea, but those were abandoned in the pond site without any treatment. In these days, there is a strong move to enforce environmental regulations to protect surrounding nature, a lot of pressure is given to the power plant industry to remove hazardous chemicals from their waste material before landfill or site storage. The overall objective of this research is to separate hazardous chemicals from the bottom ash, and use it safely as sustainable construction material. In this specific study, magnetic separation of bottom ash was applied, and used as a fine aggregates to make mortar specimens. According to the results, it was found that the use of bottom ash decreased 28-day compressive strength. However, using non-magnetic bottom ash provides best results in terms of thermal conductivity, showing strong possibility to be used as heat insulating material.

• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.1
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• pp.99-109
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• 2015

In the construction industry, the interest for recycling aggregates is rising as more people demand for alternatives due to lack of supply of natural aggregates and environmental problems. However, in order for recycled aggregates to be used in infrastructures, stability and other factors need to be verified. Therefore, the objective of this study is to analyze the sensitivity of soil properties to secure slope safety according to various heights of embankment when bottom ash and dredged soil mixture is applied in the embankment. In most cases, all heights were safe for the slide for the embankment whether the water level is full or sudden draw down. The result of the sensitivity analysis revealed that the unit weight of embankments is highest among all factors to be considered. However, the sensitivity of the unit weight became smaller and the sensitivity of the friction angle of embankments increased with the height of embankments. The sensitivity of factors of core materials is very small because the core has weaker physical properties than those of the embankment. The effect of the height for each factor is different for each slope and water levels. The sensitivity of the unit weight of embankments is most affected when the height is 60m in the upstream slope. To conclude, bottom ash and dredged soil mixture can be applied in the embankment and different factors must be considered in different scale because the sensitivity depends highly on the height of embankments.