• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.4
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• pp.131-139
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• 2021

This study assessed the use of zeolite with high absorption performance in landscape paving concrete as a substitute for aggregate. The absorption performance and strength properties of paving concrete were investigated according to the replacement rate of the zeolite coarse aggregate, and the mechanical properties were investigated through strength tests. The absorption rate of the zeolite aggregate was 14%, which is 2.5 times higher than that of general aggregate. When zeolite coarse aggregate is applied to paving concrete, the absorption rate increases according to the replacement rate. The absorption rate was 5.2% at a replacement rate of 50%, which was 42% higher than that of general paving concrete. The compressive strength increased to 20% of the replacement rate and decreased at a higher replacement, but all the strengths in the construction standard code were satisfied. The flexural strength satisfied the code up to a replacement rate of 10%, but the strength decreased with increasing replacement rate, and the splitting tensile strength was greater than that of paving concrete using general aggregate up to a 20% replacement rate. Overall, zeolite coarse aggregate can be applied as a substitute.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.3
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• pp.327-334
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• 2022

In this study, in order to evaluate the characteristics of mortar and concrete using wood chip cogeneration plant flooring as fine aggregate, mortar characteristics according to wood chip aggregate replacement rate and water-cement ratio as a substitute for crushed sand, and concrete characteristics according to wood chip aggregate replacement rate were compared and evaluated. The cement mortar flow according to the wood chip aggregate replacement rate showed a tendency to increase as the wood chip aggregate replacement rate increased, and the compressive strength and flexural strength increased as the wood chip aggregate replacement rate increased. The slump and air content of concrete increased as the aggregate replacement rate increased, and the compressive strength and tensile splitting strength of concrete tended to increase as the wood chip aggregate replacement rate increased. Accordingly, the possibility of using the flooring by the cogeneration plant as a fine aggregate for concrete was confirmed.

• Cement Symposium
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• no.32
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• pp.222-227
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• 2005

• Resources Recycling
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• v.17 no.1
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• pp.73-79
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• 2008

Along with the increased social infrastructures and reconstruction, the demand for aggregate, which is used in concrete, has rapidly increased. However, there are problems due to the exhaustion of natural aggregate resources, and strict restrictions. In this study, the possibility of using rapid chilled steel slag as a substitutive material of fine aggregate is determined from the property test and mechanical test for the concrete that is made with rapid chilled steel slag, which highly decreases the free CaO, the main problem of the steel slag.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.4
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• pp.267-274
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• 2018

Though the wet bottom ash has been used as a type of lightweight aggregate, dry bottom ash, new type bottom ash from coal combustion power plant, has scarcely researched. It is excellent lightweight aggregate in the view point of construction material. This study is performed to check the applicability of dry bottom ash as a fine aggregate in lightweight aggregate concrete, by analyzing various properties of fresh and hardened concrete. We get results that the slump of concrete is within the target range at less than 75% replacement rate of dry bottom ash, the air content is not affected by the replacement rate of dry bottom ash, the bleeding capacity is less than $0.025cm^3/cm^2$ at 75% under of the replacement rate of dry bottom ash, and the compressive strength of concrete show 90% or more comparing the base mix while initial strength development is a little low. Oven dry unit weight of concrete is reduced by 8.9% when replaced 100% dry bottom ash, and dry shrinkage tends to decrease depending on increase of replacement rate of dry bottom ash. Modulus of elasticity of concrete shows no decease at 50% over of the replacement rate of dry bottom ash, while modulus of elasticity of concrete decreases when the replacement rate increases further. The dry bottom ash, when used as a fine aggregate in lightweight concrete, can be used effectively without any deterioration in quality.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.473-476
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• 2008

The use of the recycled fine aggregate to the material of structural concrete is not easy currently because there are some problems, such as the difficulty of quality control and the badness of chemical and physical property other than river sand, crushed fine aggregate. To use of recycled fine aggregate, many researches on the recycling of recycled fine aggregate have been studying until today. However, the result of the research is little except for some results. Therefore, the purpose of this study is to confirm the possibility of use of recycled fine aggregate for raw material of plaster mortar. In this study, various tests were performed such as flow, air content, unit weight, bond strength, and compressive strength test to evaluate the effect according to the substitution of recycled concrete aggregate. The results of strength test showed that the concrete strength improved with the increase of replacement ratio of recycled fine aggregate. In the other side, flow and air content are decreased according to replacement ratio of recycled fine aggregate. The result of this study could be used as the basic data for the recycling of recycled fine aggregate.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2015.11a
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• pp.132-133
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• 2015

이 논문은 세라믹 비드를 일반 모르타르의 잔골재로 대체하여 사용했을 경우 모르타르의 압축강도에 변화를 확인하고자 수행하였다. 잔골재를 대체할 세라믹 비드의 입도분포를 확인하였고, 세라믹 비드의 잔골재 대체율을 10%, 20%, 30%로 설정하고 2가지 종류의 세라믹 비드를 이용하여 시험체를 제작하여 7일, 14일 28일의 압축강도를 측정하였다.

• Clean Technology
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• v.12 no.4
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• pp.238-243
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• 2006

The aggregate properties of chilled converter slag reformed by atomizing liquid converter slag were investigated. The properties of mortars with various replacement of standard sand by chilled converter slag as recycled fine aggregates were investigated. The particle shape of chilled converter slag by atomizing was a sphere with an open cavity which is enclosed with two layers like a bored coconut. Specific gravity, unit weight and fineness modulus increased with increasing the replacement, and solid content had the maximum at the replacement of 75% and water absorption rate had the minimum at the replacement. The hardened mortars with higher replacements have the higher specific gravity and the denser texture.

• Resources Recycling
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• v.10 no.2
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• pp.41-49
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• 2001

In this study, the properties of cement mortar and concrete using ceramic wastes as fine aggregates and coarse aggregates are considered experimentally. Flow value of mortar using ceramic waste as fine aggregates is increased more or less, and the com- pressive strength of mortar using ceramic wastes as fine aggregates is increased with elapsed age. The slump value of concrete using ceramic wastes fine aggregates and coarse aggregates is somewhat decreased. The compressive strength of concrete using ceramic wastes as fine aggregates and coarse aggregates is lower than that of OPC concrete in early age, but has gradually increased in long ages.

• The Journal of Engineering Geology
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• v.13 no.3
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• pp.345-358
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• 2003

Recently, the reuse of coarse aggregate derived from demolished concrete was introduced into practice with two environmental aspects: protection of natural sources of aggregate and recycling of construction waste. However, recycled aggregate has been used for the very limited application such as subbase material for pavement and constructional filling material because it was considered as low quality constructional materials. In the present study, in order to examine the possibility that recycled aggregate can be used for concrete mixing, we conducted various experimental tests to identify mineralogical, chemical and mechanical properties of recycled aggregate and to determine the workability and mechanical properties of recycled aggregate concrete (RAC). The cement paste and mortar contained in recycled aggregate significantly affect the basic mechanical properties of aggregate and the workability and mechanical properties of RAC. However, RCA mixed with the proper replacement ratio of recycled aggregate shows the comparable compressive strength and freeze and thaw resistance to those of normal concrete. Therefore, it is considered that recycled aggregate can be widely used for concrete if the cement paste and mortar can be efficiently removed from recycled aggregate and/or if the effective replacement ratios of recycled aggregate are applied for mixing concrete.