• Journal of the Korea Institute of Building Construction
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• v.15 no.2
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• pp.161-167
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• 2015

Nowadays, all the world face to the global warming problems due to the emission of $CO_2$. From the previous studies, recycled aggregates were used as an alkali activator in blast furnace slag to achieve zero-cement concrete, and favorable results of obtaining strength were achieved. In this study, gypsum and incineration waste ash were used as the additional alkali activation and effects of the gypsum and incineration waste ash to enhance the performance of the mortar were tested. Results showed that although the replacement ratio of 0.5% of incineration waste ash and 20% of anhydrous gypsum resulted in the low of mortar at the early age, while it improved the later strength and achieved the similar strength to that of conventional mortar (at 91 days).

• Journal of the Korean Recycled Construction Resources Institute
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• v.3 no.2
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• pp.165-170
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• 2015

Pipe-rack structures supporting high temperature and pressure are of great importance to ensure the safety of the operation of the plants. If some damage occurred in the pipe-rack structure, the facilities not only bring damage to the commercial property, but also result in economic losses. Specially, since pipe-rack structures are exposed to various environmental conditions, it is essential to evaluate the thermal behavior of the structure caused by environmental conditions for the appropriate design and maintenance of the pipe-rack structure. Thus, based on a selected, typical pipe-rack structure, a thermal-stress coupled analysis was conducted to evaluate the temperature distributions and thermal stresses of the structure. For this, this study accounted for the operating condition of the pipe and the effect of environmental conditions, Yeosu in South Korea and Saudi Arabia in the Middle East. The results of the study showed the need for accounting for a variance in the environmental factors to evaluate the thermal behavior of the pipe-rack structure along with the working condition of pipe.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.4
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• pp.333-340
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• 2019

Red mud is an industrial by-product produced during the manufacturing aluminum hydroxide (Al(OH)3) and aluminum oxide(Al2O3) from Bauxite ores. In Korea, aproximately 2 tons of red mud in a sludge form with 50% moisture content is produced when 1ton of Al2O3 is produced through the Bayer process. Neutralization of red mud will help to reduce the environmental impact caused due to its storage and also lessen significantly the ongoing management of the deposits after closure. It will also open opportunities for re-use of the residue which to date have been prevented because of the high pH. Moreover, attention to liquefied red mud(LRM) that does not require heating and grinding process for recycling is needed. In this paper, characteristics of compressive strength for cement paste with content of LRM neutralized by nitric acid and sulfuric acid. The results showed that compressive strength of cement paste with neutralized LRM is higher than that of cement paste with LRM.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.461-461
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• 2018

우리나라를 포함하여 전 세계적으로 기후변화로 기인하는 기상변동성 증가 등의 원인으로 물, 식량, 에너지의 시공간적 불균형이 발생할 것으로 전망되고 있다. 특히 미국 캘리포니아 2012-2015 대가뭄, 우리나라의 2013-2015 대가뭄 등 물부족의 위험 가능성이 증폭됨에 따라, 이와 관련된 에너지와 식량 등의 연계자원들도 기존의 방법과 같이 관리되고 활용하는 것에 한계점이 도달하고 있다. 기후변화와 같이 기상학적 스트레스 증가와 더불어, 국제적으로 인구증가 및 도시화가 확대될 것으로 전망되며, 한국, 미국, 중국, 인도 등에서 물안보에 대한 우려가 현실로 다가오고 있으며, 세계경제포럼(world economic forum)의 "전 지구적 위험도 인지 조사"에서도 물, 식량, 에너지 위기에 대한 심각성을 강조하고 있다. 물, 식량 그리고 에너지는 서로 밀접한 연관성을 가지고 있으며, 개별 분야에서의 문제는 그 자체의 위기로 그치지 않고 다른 타 분야의 위험도를 증폭시키는 원인으로 작용하게 된다. 과거와 다르게 교통, 물류 등의 발달로 물, 식량 및 에너지의 국가간 의존도가 더욱 증가하는 방향으로 전개되고 있으며, 세 가지 자원의 연계성 강화는 결국 상호위기를 선제적으로 대응할 수 있는 방법으로 전망된다. 따라서 물안보 및 물복지 실현을 위한 물과 에너지의 저비용, 고효율의 최적화 방안은 상당히 중요한 요인이 될 수 있다. 이를 위해 본 논문에서는 자원간 Trade-off, 평가 등 에너지소비를 줄이고 에너지 효율성을 증가하며 에너지 절약형 기술에 개발에 중점을 두는 방안을 찾아야 한다. 또한 원예시설 및 관개 기술의 개선에 따른 물과 에너지 소비량 비교 분석, 시설원예 산업의 에너지 생산성 및 절약형 기술 등 에너지-물-식량 분야의 상호연결을 정량화하고 최적화하는 방안들을 지속적으로 모색해야 할 필요가 있다.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.3
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• pp.348-355
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• 2021

Asphalt, widely used for road pavement, has different required physical properties depending on the environment to which the road is exposed. Therefore, it is essential to maximize the life of asphalt roads by evaluating the physical properties of asphalt according to additives and selecting an appropriate formulation considering road traffic and climatic environment. Dynamic shear rheometer(DSR) test is mainly used to measure resistance to rutting among various physical properties of asphalt. However, the DSR test has limitations in that the results are different depending on the experimental setting and can only be measured within a specific temperature range. Therefore, in this study, to overcome the limitations of the DSR test, the rheological characteristics were predicted by learning the images collected from atomic force microscopy. Images and rheology properties were trained through EfficientNet, one of the deep learning architectures, and transfer learning was used to overcome the limitation of the deep learning model, which require many data. The trained model predicted the rheological properties of the asphalt binder with high accuracy even though different types of additives were used. In particular, it was possible to train faster than when transfer learning was not used.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.425-432
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• 2021

In this paper, We produced supporting for ginseng cultivation facilities as a material recycling product of CPW(Complex Plastic Wastes, CPW) from households. And we analyzed the characteristics of material recycling products according to the amount of r-LDPE(Recycled low density polyethylene, r-LDPE) used. As a result, as the amount of recycled LDPE used increa sed, the tensile strength a nd elonga tion of ma teria l recycled products using CPW increa sed, but a sh decrea sed. When the recycled r-LDPE usage is 5% or more, the physical properties of the material recycling product using CPW stably satisfy the quality standard (GRM 3093-2021) of supporting for ginseng cultivation facilities.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.625-632
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• 2021

In this paper, the applicability of bottom ash to insulation concrete was investigated to increase the utilization of bottom ash. Bottom ash was used as the aggregates in porous concrete and extensive experiments were conducted to investigate the characteristics of porous concrete using two types of bottom ash aggregates. The water-binder ratios of 0.25 and 0.35 were chosen and concrete specimens was produced with the compaction of 0.5, 1.5, and 3.0MPa to analyze the material properties at different compaction conditions. After concrete specimens were cured for 28 days at water tanks, unit weight, total void ratio, and thermal conductivity were measured. Based on the measured experimental results, the relationships between the unit weight, total void ratio, and thermal conductivity of porous concrete containing bottom ash was presented.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.594-601
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• 2021

In order to expanding of the use of steel slag, a by-product of steel industry, as a road paving construction material, this present study confirmed the possibility of the rust formation of steel slag aggregate and evaluated the durability performance and the noise reduction characteristics of asphalt concrete mixture. As a result of conducting the rust formation test of aggregate, no rust was observed in both aggregate, so it is judged that the possibility of rust formation in the actual road water environment is very low. As a result of performing the moisture resistance test, all mixtures showed a tensile strength ratio exceeding 85%, satisfied the standard as asphalt mixture. In addition, the sound absorption coefficient of the steel slag aggregate mixture was measured to be higher than that of the general aggregate mixture. Accordingly, it is speculated th at th e steel slag aggregate mixture can more effectively respond to road noise reduction than the general mixture.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.2
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• pp.177-184
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• 2021

In this study, the effects of ground granulated blast furnace slag(GGBFS) and expansive additive(EA) on early strength mortar were examined for the purpose of reducing carbon and improving cement performance. As a result, ealry strength Portland cement(EPC) tended to decrease in flow compared to ordinary Portland cement(OPC), but binder with EPC and GGBFS was possible to obtain higher liquidity than OPC. EPC showed higher compressive strength and shrinkage than OPC. The compressive strength of specimen with EPC and GGBFS was reduced proportionally to the replacement ratio of GGBFS. The replacement ratio of GGBFS above the compressive strength equivalent to OPC was higher under low temperature conditions. The use of GGBFS resulted in high shrinkage compared to OPC, and this characteristic was even greater under low temperature conditions. The shrinkage of specimen with EA was decreased in early ages, but was higher than the OPC in long-term ages.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.4
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• pp.275-282
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• 2018

This study examines the ways to address environmental issues by utilizing activated loess to reduce the amount of cements that emit a large amount of carbon dioxide during the process of manufacturing, and by reusing the polysilicon sludge produced as a result of manufacturing polysilicon, one of the components for solar power generation panels. The findings of the experiment showed that the optimal replacement ratio of the polysilicon sludge is 20%, 35% for W/B, and 20% for the ratio of the fine aggregate addition. As it is deemed that utilizing the polysilicon sludge for reinforced concrete may lead to rebar corrosion due to the $CI^-$ contained in the sludge, it can be considered to use for unreinforced concrete or bricks.