• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.19-20
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• 2013

Consider about aggregate's price, coarse aggregates from 13 to 25mm were widely used in ready mixed concrete company. But if only use 13 to 25mm aggregates in the concrete, gap grading problem would be occurred. When recycled aggregates from 13 to 25mm was used, continuous grading would increase the durability and strength for the concrete, meanwhile the construction waste materials would also be reused. In this paper, 5-13mm recycled aggregates was utilized, to analyse the fundamental properties for concrete, strength has been tested to evaluate the quality and reusing effect of the recycled materials.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04b
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• pp.683-686
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• 1998

In this paper, we carried out the fundamental experiments on the resistance of chemical attack of mortar using the electric are furnace slag as fine aggregate. The mortar specimens made from the EAF slag as fine aggregate were immersed in four sorts of chemical solutions, and measured to investigate the change of compressive strength and weight. As the results of this study, it was found that compressive strength and weight were increased with incresing replacement ratio of the EAF slag.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.269-274
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• 2000

As a result of the reduction of natural aggregate, most of developed country have been studied the utilization of Blast-furnace Slag(BFS) as aggregate of concrete. bur, in korea there are only basic study about these even though other country are using Blast-furnace Slag production of Ready Mixed Concrete. According, in this study, we carried out fundamental experiments in order to know the material properties of BFS and possibilities of the BFS as fine aggregate of concrete. It is included that analysis concerning material properties of BFS as like specific gravity, absorption. unit weigth, grading including investigation of the surface shape by SEM, also, analysis concerning properties of concrete with BFS as like air-content surface slump. compressive strength .etc.

• Proceedings of the Korea Concrete Institute Conference
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• 1996.04a
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• pp.12-17
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• 1996

It is true that aggregate strength is usually not a factor in normal concrete strength because, the aggregate particle is several times stronger than the matrix and the transition zone in concrete. In other words, with most natural aggregates the strength of the aggregate is hardly utilized because the failure is determined by the other two phases. But aggregate characteristics that are significant to concrete technology include porosity, grading or size distribution, moisture absorption, shape and surface texture, crushing strength, elastic modulus, and the type of deleterious substances present. Therefore, in the area of high strength concrete, concrete is much more influenced by properties of aggregate. This experiment is performed to investigate how kinds of aggregare influence on the workability of high strength concrete. In this experiment, four types of aggregate is used, that is crushed river aggregate, crushed stone, recycled aggregate of low strength and recycled aggregate of high strength. In this study, we scrutinize a fundmental study on the workability of high strength concrete according to kinds of aggregate.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.364-367
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• 2004

The purpose of this study is to investigate quality of recycled fine aggregate manufactured by drying manufacturing system which is the manufacture method of high quality recycled fine aggregate, and to analyze on the fresh, hardened and durability properties of recycled concrete using it. Therefore it is to present the fundamental data for structural application of recycled concrete. The results of this study are as follows; Quality of recycled fine aggregate by drying manufacturing system is improved, and compressive and tensile strength of recycled concrete using high quality recycled fine aggregate are similar to those of normal concrete. But, durability such as carbonation, salt damage and dry shrinkage show decreased somewhat.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.613-618
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• 2002

Steel slag produced in steel making process is divided with electric arc furnace slag and converter slag. Compared with the blast furnace slag, converter slag has the expansibility due to the reaction with water and free CaO. Therefore it is specified in Standard Specification for Concrete in Korea that steel slag aggregate must not be used in concrete. In this study, we treat electric arc furnace slag aggregate(EAFSA) for concrete before and after several aging process to reduce expansibility. The fundamental properties are measured, which are specific gravity, unit weight, abrasion value and immersion expansion ratio, as concrete aggregate. To understand the suitability of EAFSA for concrete, we made the concrete with EAFSA and then determined the strength and the volume change in EAFSA concrete. From the results EAFSA treated with steam aging process has potentiality for concrete aggregate.

• Journal of the Korea Concrete Institute
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• v.11 no.3
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• pp.101-111
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• 1999

Compared with the BF slag, the EAF slag has expansion due to the reaction with water and free CaO. Therefore it is specified in Concrete Specification that the FAP slag aggregated must not be used in concrete. Because of this reason it is unusual to use the EAF slag aggregate in concrete. The EAF slag aggregate treated with accelerated and water aging was comparatively satisfied with fundamental properties, which are specific gravity, unit weight, abrasion and immersion expansion ratio, as concrete aggregate. Therefore when we measured the compressive strength till 28 days, we found that the mortar and concrete replacing the natural aggregate with the EAF slag aggregate by 4 steps had better results than the concrete using the natural aggregate in a view of the compressive strength. But at 91 days, concrete using the EAF slag aggregate had no difference with it using the natural aggregate.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.1
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• pp.190-196
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• 2006

In the existed study, a fire outbreak in a reinforced concrete structure looses the organism by the different contraction and expansion of hardened cement pastes and aggregate, and causes cracks by thermal stress, leading to the deterioration of the durability. So accurate diagnosis of deterioration is needed based on mechanism of fire deterioration in general concrete structures. Fundamental information and data on the Properties of concrete exposed to high temperature are necessary for accurate diagnosis of deterioration. Therefore, This study is willing to propose fundamental data for quick and accurate diagnosis of deteriorated concrete structure by fire damage with making variable concrete test specimen, exposing high temperature environment, observing the explosive spalling and examining engineering property.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.101-104
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• 2005

It analyzed the supply status of fine aggregate and find the point of issue related alternative fine aggregate through researches and interviews. The conclusions of the study are as follows. 1. Ready mixed concrete manufacture used crushed fine aggregate (15.5$\%$) and recycled fine aggregate (1.5$\%$) for alternatives aggregate than 1.3$\%$ in 1991. It is not allowed to use a recycled fine aggregate in ready mixed concrete, but they used it. 2. All alternative aggregate are satisfied the Korean Standard, But they showed low properties of mortar compared to when it replaced with natural fine aggregate. So, it is needed to make another special Korean Standard to use alternative aggregate in normal concrete by mixing method to recover the workability and compressive strength.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.333-334
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• 2009

This study was investigated the fluidity properties of Normal concrete using Fine aggregate with Rapidly cooled Electric arc furnace oxidizing slag.