• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.337-338
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• 2009

Use of the recycled fine aggregate as a material of structural concrete is not easy currently because there are some problems, such as of quality control and the uncertainty of chemical and physical property. Thus, the results indicate that it is possible to produce high quality recycled fine aggregate for structure by microwave heating technology, friction and abrasion action.

• Journal of Drive and Control
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• v.19 no.3
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• pp.16-22
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• 2022

Crushers are equipment that crush natural stones, to produce aggregates used at construction sites. As the crusher proceeds, the inner liner becomes worn, causing the size of the aggregate produced to gradually increase. The vision sensor-based aggregate analysis system analyzes the size and distribution of aggregates in production, in real time through image analysis. This study developed an algorithm that can segmentate aggregates in images in real time. using image preprocessing technology combining various filters and morphology techniques, and aggregate region characteristics such as convex hull and concave hull. We applied the developed algorithm to fine aggregate, intermediate aggregate, and thick aggregate images to verify their performance.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.6
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• pp.63-72
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• 2012

The high-flowing concrete requires additionally or excessively more expensive admixture than conventional concrete. So, the concrete has not to be widely used in practical field due to the increase of production price, need of additional facilities, and excessive development of concrete strength in associate with addition of too much cementitious material even though it has more significant advantages than conventional concrete. Thus, this study aims at developing high-flowing concrete with general strength unlike high strength which has been carried out in conventional study. To observe the role of aggregate in the concrete quantitatively and to increase the performance of high-flowing concrete effectively, parametric studies were carried out such as W/C, s/a, fineness modulus of aggregate, contribution degree of particle sizes, and the effect of 13mm aggregate and fine stone powder as a partial replacement of aggregates. And the effect of these factors on performance of the concrete was evaluated by measuring slump-flow and gap of penetration height in U-typed instrument. As a result, it was found that flowability of high-flowing concrete depends upon grading of fine aggregate more significantly than that of coarse aggregate and is enhanced greatly as fineness modulus of fine aggregate decreases and the value of s/a increases. In addition, the application of 13mm aggregate and fine stone powder are expected as a partial replacement of aggregate in order to increase the performance of high-flowing concrete more effectively.

• Economic and Environmental Geology
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• v.57 no.2
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• pp.119-128
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• 2024

In Australia & Canada, architectural rock and aggregate are one of the mineral resources, and related data and information provided integrated with them. In these countries, the provided data and information, through the information system of local government and national geological survey organizations, are interactive maps, geological and thematic maps, exploration data set, 3 dimension geological models, minning rights status, survey reports and related papers etc. However, in case of Korea, aggregate and architectural rock are not assigned as the kind of mineral resources in accordance to domestic mining law, and related geological data and information are not provided from comprehensive mineral information system established in public geoscience organizations. And the administrative and informative management are conducted separately through the different governmental organizations such as Ministry of construction, Korea forest service, geoscience institute & Korea Mine & Reclamation Corporation. For securing the supply of architectural rock and aggregate resources, and for the convenience of their development & utilization, the unified information system and governance reform for the related industry is needed.

• Journal of the Korea Concrete Institute
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• v.17 no.4 s.88
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• pp.595-602
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• 2005

The purpose of this study is to utilize recycled concrete aggregates as permeable pavement materials. This study evaluates mechanical properties and durability of porous concrete depending on mixing rates of recycled aggregates and polyme. As a result, void ratio and permeability coefficient of porous concrete for pavement increased a little as mixing rate of recycled aggregates increased. Void ratio and permeability coefficient increased a lot as mixing rate of polymer increased. As polymer was mixed $20\%$, national regulation of permeable concrete for pavement($8\%$ and 0.01cm/sec) was met. Compressive strength and flexural strength decreased as mixing rate of recycled aggregates increased but they increased a lot as mixing rate of polymer increased. Even when recycled aggregates were mixed $75\%\;with\;10\%$ polymer mixed, national regulation of pavement concrete(18MPa and 4.5MPa) was met. In addition, regarding sliding resistance, BPN increased as mixing rate of recycled aggregates increased. But BPN decreased as polymer was mixed. Compared to crushed stone aggregates, abrasion resistance and freeze-thaw resistance decreased as mixing rate of recycled aggregates Increased. When polymer was mixed, abrasion resistance and freeze-thaw resistance improved remarkably. Compared to non-mixture, $10\%$ mixture of polymer improved abrasion resistance and freeze-thaw resistance about $8.6\%$ and 3.8times respectively.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2004.05a
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• pp.227-231
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• 2004

• Magazine of RCR
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• v.15 no.2
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• pp.39-44
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• 2020

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.173-176
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• 2004

This study is contents about the method which separates ASCON, the tiles and the reds bricks in recycled aggregates. The method of separation used difference of specific gravity.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2005.05a
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• pp.136-140
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• 2005

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.22 no.6
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• pp.305-311
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• 2012

In order to recycle the coal bottom ashes (denoted as BA) produced from a thermal power plant, the artificial aggregates (denoted as AAs) containing BA and red clay were manufactured, and the physical properties of AAs were studied as a function of particle size of BA and batch compositions. As-received BA had 38 wt% coarse particles of above 2 mm and many unburned carbon mass and porous slag particles were co-existed. So the two particle sizes of BA, the fine (< 100 ${\mu}m$) and coarse (< 2 mm), were prepared by milling and screening process. The AAs containing fine BA sintered at $1100{\sim}1200^{\circ}C$ had the higher bulk density and lower water absorption compared to the specimen made of coarse BA. The inside core of AAs manufactured by using coarse BA showed nonuniform and porous microstructure, while the AAs made of fine BA had a uniform and dense microstructure. In this research, the AAs containing BA and red clay with various bulk density (1.2~1.7) and water absorption (13~21 %) could be manufactured by controlling the particle size of BA and batch compositions, so the AAs of various physical properties could be applied to the wide fields such as construction/building materials in near future.