• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.4
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• pp.106-113
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• 2010

We were tried to draw a conclusions related to additive amount of gypsum in blast furnace slag in the study. In the result, fluidity of concrete decreased with an increase of gypsum and was not satisfied with KS standard in the cases of natural gypsum and limestone sludge more than 2.6% addition. Early compressive strength of concrete containing desulfurized gypsum, fluosilicic acid gypsum and phosphoric acid gypsum were improved respectively but calcined lime sludge and lime powder were not influenced on strength. If available, additive gypsum should be managed less than 2.0% owing to low fluidity. In low temperature, fluosilicic acid gypsum was to advantages on the fluidity while desulfurized gypsum was in high temperature. There also are conclusions that additive gypsum was to be 2.6% in winter and in summer; it's to be fewer than 2.6%.

• Journal of the Korean Recycled Construction Resources Institute
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• v.3 no.4
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• pp.328-334
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• 2015

Building insulation materials use for the purpose of energy saving. Insulation materials can be classified inorganic and organic insulation materials. Inorganic insulation is used for fire resistive performance parts and organic insulation is used for thermal performance parts. Meanwhile, organic insulation is due to toxic gas emission in fire. Inorganic insulation is too heavy and low thermal performance than organic materials. This study is focused on evaluation of the physical properties of inorganic foam material using industrial by-products such as waste glass powder and fly ash. From the test result, inorganic foam materials for the applicability of fire-resistance and insulation light-weight materials.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.4
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• pp.365-372
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• 2018

3D printing technology of construction field can be divided into structural materials, interior and exterior finishing materials, and is mainly done by extruding and adapting. Particularly when it is applied as an exterior materials, it is mainly applied to an unstructured exterior materials and high accuracy is required. The exterior materials can be used as a cement composite materials, it is suitable also for a additive type manufacturing, and the role of a redispersible polymer powder is important. But, high temperatures, redispersible polymer cement base material beget dehydration and micro crack of cement matrix. In this research, we developed a EVA, EVCL redispersible polymer cement base material applicable as a 3D printing exterior materials, confirmed density and strength characteristics for application as an exterior materials, a flame retardancy test for improving the fire resistance of buildings and confirmed its possibility. From the test result, developed EVCL redispersible polymer cement mortar showed good stability in high temperatures. These high temperature stability is caused by the ethylene-vinyl chloride binding. Thus, this result indicates that it is possible to fire resistant 3D printing interior and exterior finishing materials.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.4
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• pp.547-552
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• 2022

In this study, we secured a technology for manufacturing expanded glass of uniform quality by using general tempered glass, that is, window glass, among automotive glass that is scrapped, and verified whether the manufactured expanded glass can be used for lithium battery fire suppression. The process of manufacturing expanded glass using waste glass is generally divided into Crushing → Milling → Granulation → Expansion → Cooling. With several trials a nd errors. It is obtained a yield of 0.5 ø mm to 2 ø mm spherical particles of 80 % or more. By comparing the surface analysis and physical properties, a more suitable sample was selected as a fire extinguishing agent for lithium batteries, and it was confirmed that the result of the adaptability test for lithium battery fire was satisfactory.

• Journal of the Korea Institute of Building Construction
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• v.14 no.1
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• pp.54-60
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• 2014

The purpose of this study is to examine whether cementitious powder separated from waste concrete can be used as an alternative raw material to limestone and reduce the usage of natural resource (limestone) and $CO_2$ emission based on recycling cementitious powder from waste concrete. Experiments actually analyzed the chemical composition of cementitious powder and performed hyperthermia analysis, measurement of free CaO and XRD analysis to measure the degree of recovery of hydration in the model of cementitious powder manufactured based on chemical composition. These were performed in each cementitious powder model at different calcination temperatures such as $900^{\circ}C$, $1200^{\circ}C$, $1300^{\circ}C$, $1400^{\circ}C$ and $1450^{\circ}C$. Through the experiments, it was found that the recovery of hydration was at a level which can be used as the alternative raw material for limestone, but the replacement ratio was directly affected by the degree of mixing of fine aggregate in less than $150{\mu}m$, which cannot be separated from cementitious powder. It was shown that there was no difference in the production of compounds involved in hydration at calcination temperatures of $1200^{\circ}C$ or higher. Therefore, to pursue the replacement of limestone and reduction of greenhouse gas by recycling cementitious powder, the development of technology to efficiently separate aggregate fine powder is required.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.242-243
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• 2014

In this study, industrial by-products including blast furnace slag, incineration ash and waste gypsum were used with recycled fine aggregates to manufacture the zero-cement mortar. The replacement ratio of anhydrite gypsum was fixed as 0, 10%, 20% the replacement ratio fo WA1 was fixed as 0.5% and 1.0%, respectively. It could be identified that when the replacement of gypsum was 20% and WA1 of 1.0%, the strength could be in the range of normal strength.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.222-223
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• 2014

In this study, industrial by-products including blast furnace slag, incineration ash and waste gypsum were used with recycled fine aggregates to manufacture the zero-cement mortar.The replacement ratio of dihydrate gypsum and anhydrite gypsum was fixed as 0 and 10%, the replacement ratio fo WA1 was fixed as 0.5% and 1.0%, respectively. It could be identified that when the replacement of gypsum was 10% and WA1 of 1.0%, the strength could be in the range of normal strength.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2003.05a
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• pp.89-94
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• 2003

Recently, the study to reduce and recycle industrial waste is underway vigorously in the various fields of industry according to the conservation of environment and resources. In construction work, the disposal problem of its waste and environmental disruption have already been serious all over the world. However the recycle of waste concrete is still at an early stage, recycled aggregate from waste concrete have only used those as subsidiary road fillers. The research institute and the company make the study that it is about the properties of recycled aggregate and those structural capacity since 1990. Through the experimentation last year, we know that strength and fluidity of recycle cement are inferior to normal cement, and admixing aggregate powder deteriorates its strength. The purpose of this study is to search for appropriate heating time and to improve performance of the recycle cement while heating hardened cement which is crushed, we investigate separating aggregate from hardened cement by preheating and improvement of strength and fluidity inrecycle cement which contains admixture.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.148-149
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• 2014

The aim of this research is to contribute on investment of less cement mortar or concrete in normal strength range using additional hydration of BS with stimulating effect of FGD and OPC based on the previous research result of the BS and RFA using cement mortar. As a test, the composition for normal strength range of mortar was evaluated with 0, 10, and 20 % of FDA and 0, 20 % of OPC replacement.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.30-31
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• 2013

In this study, characteristics of the concrete replaced in large amount with blast furnace slag is analyzed by the microscopic analyses in the process of the mock-up testing to apply to the actual practice in the area of the general strength by activating a small amount of cement(25%) replaced in large amount of finely powered blast furnace slag.