• Journal of the Korea Institute of Building Construction
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• v.19 no.4
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• pp.313-322
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• 2019

This study is to compare and analyze the physical and strength properties of lightweight concrete using domestic lightweight aggregate by replacement ratio of artificial lightweight fine and coarse aggregate after considering low cement mixture and pre-wetting time. The slump, unit weight, compressive strength and split tensile strength of lightweight concrete with domestic lightweight aggregate were measured. As test results, the slump of lightweight concrete by replacement ratio of lightweight fine aggregate increased as the replacement ratio of lightweight fine aggregate increased. The unit weight of lightweight concrete using 100% of lightweight fine aggregate was about 10.4% lower than that of the lightweight concrete with natural sand. In addition, the unit weight of lightweight concrete by replacement ratio of lightweight coarse aggregate increased with the increase of the ratio of LWG10(5~10mm). The compressive strength of lightweight concrete with lightweight fine and coarse aggregate increased as the replacement ratio of lightweight fine aggregate increased. The compressive strength of lightweight concrete with natural sand and LWG10 was 30 to 31MPa regardless of the replacement ratio of the lightweight coarse aggregate after 7 days.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.249-252
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• 1999

Recently, the use of lightweight concrete in architectural structures are increasing. It is considered important to control the quality of lightweight concrete. The purpose of this study is to find mechanical properties of lightweight concrete using the expanded clay. Thus, slump, air content, compressive strength, splitting tensile strength, length change ratio, unitweight change ratio and absorption of lightweight concrete have been investigated. As a result, it was shown that proper expanded clay replaced by coarse aggregate in concrete was considered as a good replacement of lightweight concrete.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.11a
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• pp.113-116
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• 2008

In these days, properties of concrete has been demanded to be high performance because concrete structure was bigger and higher. So studies on high strength concrete and lightweight concrete has been frequently done. But lightweight concrete has been used to limited non-structural elements in th country. Lightweight aggregate mixed with lightweight concrete was only coarse aggregate in case of the structural lightweight concrete. In the country studies on the lightweight concrete was poor and unvaried. Also it is difficult to be practical use of lightweight concrete was that it has been expensive. It was study on the using fine lightweight aggregate with lightweight concrete to crushed by-products and wastes to get to make foamed glass with recycled glass. So it was tested by fine aggregate standard and mixed with.

• Journal of the Society of Disaster Information
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• v.6 no.1
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• pp.78-90
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• 2010

Exposure to the outside, the concrete is differential moisture distribution depending on the depth. Such a differential moisture distribution causes the differential drying shrinkage in concrete structures. This thesis is researched to compare the shrinkage of lightweight concrete depending on depth to normal concrete. It is used artificial lightweight aggregate which has 20% of pre-absorb value by lightweight concrete. When water-binder ratio is 30%, average shrinkage of lightweight concrete section decreased than normal concrete, but differential shrinkage of lightweight concrete section increased. However water-binder ratio is 40% and 50% average shrinkage and differential shrinkage of lightweight concrete section decreased than normal concrete.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.11a
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• pp.73-77
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• 2008

Structural lightweight concrete will reduced total loads of supporting sections and foundations in archtectural and civil structures. So, the lightweight concrete can be used widely for various purpose in the archtectural and civil structures. This paper were examined the influence of the mixing factor on the fresh and hardened properties of lightweight concrete that are used 2types of the differences properties of lightweight aggregates. According to types of lightweight aggregates, the case of synthetic lightweight aggregate are have need higher s/a; 2~4% on mixing proportion. Lightweight concrete was somewhat exhibit lower compressive strength than ordinary concrete. However it was not showed a marked difference. According to types of lightweight aggregates, the case of synthetic the lightweight aggregate are highest performance in fresh and hardened concrete.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04a
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• pp.129-136
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• 1998

In this study, lightweight aggregates were developed to see the possible application as a structural uses. For the evaluation purpose, several testings were conducted to compare the physical characteristics between the controlled lightweight aggregates and other lightweight aggregates purchased from different sources. The tests included property changes of fresh concrete and strength characteristics of hardened concrete for both normal and high strength ranges. In addition, a experiment was performed to analyze the freezing and thawing resistance of new lightweight aggregate concrete against other lightweight aggregate concrete against other lightweight aggregate concretes with some experimental parameters such as lightweight aggregates, curing conditions, and water-cement ratio. The test showed that the new lightweight aggregate could be used structural components. Continuous study will be planned for future evaluations.

• International Journal of Concrete Structures and Materials
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• v.5 no.2
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• pp.125-131
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• 2011

Five all-lightweight alkali-activated (AA) slag concrete mixes were tested according to the variation of water content to examine the significance and limitation on the development of cementless structural concrete using lightweight aggregates. The compressive strength development rate and shrinkage strain measured from the concrete specimens were compared with empirical models proposed by ACI 209 and EC 2 for portland cement normal weight concrete. Splitting tensile strength, and moduli of elasticity and rupture were recorded and compared with design equations specified in ACI 318-08 or EC 2, and a database compiled from the present study for ordinary portland cement (OPC) lightweight concrete, wherever possible. Test results showed that the slump loss of lightweight AA slag concrete decreased with the increase of water content. In addition, the compressive strength development and different mechanical properties of lightweight AA slag concrete were comparable with those of OPC lightweight concrete and conservative comparing with predictions obtained from code provisions. Therefore, it can be proposed that the lightweight AA slag concrete is practically applicable as an environmental-friendly structural concrete.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.181-182
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• 2016

We developed eco-friendly lightweight concrete in order to apply eco-friendly lightweight concrete into structural wall or slab of shallow depth urban railway system. However, since lightweight aggregate has different structural feature of porous and it has been overvalued at current KS standard when applied, we did compare the characteristics of freezing and thawing of normal weight aggregate concrete by comparative test method(KS, ASTM). According to test method, there was a big difference of dynamic elastic modulus in lightweight concrete rather than in normal weight aggregate concrete. The big absorption factor in lightweight aggregate is main reason for that. For more detail, in KS law in which only 14 days water curing is carried out, the big amount of moisture in lightweight aggregate is frozen and high heaving pressure occurs and finally that lead to destruction of lightweight concrete. Therefore, it is considered that in case of lightweight concrete, resistibility against freezing and thawing has been undervalued in domestic KS law compared to ASTM law, which is overseas standard. So, a variety of examination about testing criteria and rule would be necessary for exact assessment of lightweight concrete.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.179-180
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• 2016

This study has a purpose of producing precast concrete for rapid construction of urban railway system. However, previous precast concrete has problem of its weight itself and there has been a keen interest in effect of carbon emission reduction and eco-friendly in our society. Therefore, in order to solve these two problems, we are about to produce precast concrete using lightweight aggregate and eco-lightweight concrete, with which much mineral had been replaced. As a result, we could confirm that it was possible to produce RMC B/P production satisfying the requirement performance of eco-lightweight concrete, which is replaced with a great amount of mineral for reduction of precast concrete's weight and environmental performance. Also, by confirming the possibility of producing precast concrete which lightweight concrete is used, if producing precast concrete by using eco-lightweight concrete, it would be effective to avoid destruction of environment and much useful to use multiple tower crane when constructing. Afterward, we will proceed our study by constructing precast concrete at which eco-lightweight concrete is used for continuous quality improvement.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.271-272
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• 2010

This thesis is researched to compare the shrinkage of lightweight concrete depending on depth to normal concrete. It is used artificial lightweight aggregate which has 20% of pre-absorb value by lightweight concrete. When water-binder ratio is 30%, average shrinkage of lightweight concrete section decreased than normal concrete, but differential shrinkage of lightweight concrete section increased. However water-binder ratio is 40%, average shrinkage and differential shrinkage of lightweight concrete section decreased than normal concrete.