• Journal of Korean Society of Environmental Engineers
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• v.39 no.8
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• pp.449-455
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• 2017

Process input data including material and energy, process output data including product, co-product and its environmental emissions of the reference and target processes were collected and analyzed to evaluate the process performance. Environmentally problematic input/environmental emissions of the manufacturing processes were identified using these data. Significant process inputs contributing to each of the environmental emissions were identified using multiple regression analysis between the process inputs and environmental emissions. Optimum combination of the end-of-pipe technologies for treating the environmental emissions considering economic aspects was made using the linear programming technique. The cement manufacturing processes in Korea and the EU producing same type of cement were chosen for the case study. Environmentally problematic input/environmental emissions of the domestic cement manufacturing processes include coal, dust, and $SO_x$. Multiple regression analysis among the process inputs and environmental emissions revealed that $CO_2$ emission was influenced most by coal, followed by the input raw materials and gypsum. $SO_x$ emission was influenced by coal, and dust emission by gypsum followed by raw material. Optimization of the end-of-pipe technologies treating dust showed that a combination of 100% of the electro precipitator and 2.4% of the fiber filter gives the lowest cost. The $SO_x$ case showed that a combination of 100% of the dry addition process and 25.88% of the wet scrubber gives the lowest cost. Salient feature of this research is that it proposed a method for identifying environmentally problematic input/environmental emissions of the manufacturing processes, in particular, cement manufacturing process. Another feature is that it showed a method for selecting the optimum combination of the end-of-pipe treatment technologies.

• Economic and Environmental Geology
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• v.3 no.1
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• pp.17-24
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• 1970

The purpose of this report is to prepare a data for the economic evaluation on the Goobong Limestone Mine which is located at the south-eastern corner of the Yongchun Quadrangle scaled in 1:50,000. The accessibility from the mine to railroad was considered in two ways. One is to Dodam Station on Central Railway Line and the other is to reach Songjung-ni village which is near Sangyong Station on Hamback Railway Line. The distance of the former way is 26.7km and the later is 24.2km. Geologically the mine is situated near the base of the Greast Limestone Series which strikes generally $N25^{\circ}{\sim}30^{\circ}E$. The series comprises six different formations from older to younger; Pungchon Limestone Formation and Whajol Formation of Cambrian age, and Dongjum Quartzite Formation, Dumudong Formation, Maggol Limestone Formation and Goseong Formation of lower to middle Ordovician age. 82 samples; 48 from Pungchon Limestone Formation, 11 from Dumudong Formation, 15 from Maggol Limestone Formation and 8 from Goseong Formation, were taken from the series in the crossed direction to the general trend of the series as shown in geological map. They were chemically analyzed on the components of CaO, MgO, $SiO_2$, $R_2O_3(Al_2O_3+Fe_2O_3)$ and ignition loss as shown in table 2, table 3, table 4, and table 5. As seen from the tables, among the formations of the series, middle to upper parts of the Pungchon Limestone Formation and middle and upper parts of the Dumudong Formation have chemical composition as available source for the raw material of cement industry, not only that but also the part of the Pungchon Formation was highly evaluated as source for the flux of iron smelting and the raw material of carbide manufacturing because of its high purity of calcium carbonate.

• Korean Journal of Construction Engineering and Management
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• v.24 no.6
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• pp.66-73
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• 2023

The construction industry suffers losses due to failures in demand forecasting due to price fluctuations in construction raw materials, increased user costs due to project cost changes, and lack of forecasting system. Accordingly, it is necessary to improve the accuracy of construction raw material price forecasting. This study aims to predict the price of construction raw materials and verify applicability through the improvement of the Data Refactor technique. In order to improve the accuracy of price prediction of construction raw materials, the existing data refactor classification of low and high frequency and ARIMAX utilization method was improved to frequency-oriented and ARIMA method utilization, so that short-term (3 months in the future) six items such as construction raw materials lumber and cement were improved. ), mid-term (6 months in the future), and long-term (12 months in the future) price forecasts. As a result of the analysis, the predicted value based on the improved Data Refactor technique reduced the error and expanded the variability. Therefore, it is expected that the budget can be managed effectively by predicting the price of construction raw materials more accurately through the Data Refactor technique proposed in this study.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.4
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• pp.383-388
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• 2019

The present study evaluated experimentally the effects of the type and content of plastic fine aggregates on cement mortar in order to utilize waste platics as raw materials of concrete. The two kinds of plastics, LLDPE and HDPE were used, and the mixing rate of plastic fine aggregates was increased 0, 25, 50, 75, 100%. The mortar of LLDPE fine aggregate and HDPE fine aggregate showed similar tendency in flow and material separation resistance, density and water absorption, compressive strength and flexural strength by age. The flowability of mortar mixed with plastic fine aggregates was increased up to 50% but decreased at 75% or more. The material separation resistance of mortar with plastic fine aggregates was also dramatically decreased. On the other hand, due to the low density of plastics, the density of mortar decreased with the mixing of plastic fine aggregates. Due to the low adhesion between plastic fine aggregates and cement, the compressive strength by age was decreased in proportion to the mixing ratio of plastic aggregate, but the flexural strength of each age decreased with maintaining a certain level at 50% or more of plastic fine aggregate content.

• Journal of the Korean GEO-environmental Society
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• v.22 no.3
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• pp.5-13
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• 2021

Due to population growth and industrial development, the amount of industrial waste is increasing every year. In particular, in a thermal power plant using finely divided coal, a large amount of coal ash is generated after combustion of the coal. Among them, fly ash is recycled as a raw material for cement production and concrete admixture, but about 20% is not utilized and is landfilled. Due to the continuous reclamation of such a large amount of coal ash, it is required to find a correct treatment and recycling plan for the coal ash due to problems of saturation of the landfill site and environmental damage such as soil and water pollution. In recent years, the use of a fluid embankment material that can exhibit an appropriate strength without requiring a compaction operation is increasing. The fluid embankment material is a stable treated soil formed by mixing solidifying materials such as water and cement with soil, which is the main material, and has high fluidity before hardening, so compaction work is not required. In addition, after hardening, it is used for backfilling or filling in places where compaction is difficult because higher strength and earth pressure reduction effect can be obtained compared to general soil. In this study, the possibility of use of fluidized soil using high water content cohesive soil and coal ash is considered. And it is intended to examine the flow characteristics, strength, and bearing capacity characteristics of the material, and to investigate the effect of reducing the earth pressure when applied to an underground burial.

• Korean Journal of Organic Agriculture
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• v.20 no.4
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• pp.475-490
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• 2012

Since 1997, Korean Ministry of Knowledge Economy and Ministry of Environment have established data on some 400 basic raw and subsidiary materials and process like energy, petro-chemical, steel, cement, glass, paper, construction materials, transportation, recycling and disposal etc by initiating establishment of LCI database. Regarding agriculture, Rural Development Administration has conducted establishment of LCI database for major farm products like rice, barley, beans, cabbage and radish etc from 2009, and released that they would establish LCI database for 50 items until 2020 later on. The domestic LCI database for seeds, seedling, agrochemical, inorganic, fertilizer and organic fertilizer etc is only at initial stage of establishment, so overseas LCI databases are brought and being used. However, since the domestic and overseas natural environments differ, they fall behind in reliability. Therefore, this study has the purpose to select organic farming materials, survey the production process for various types of organic farming materials and establish LCI database for the effects of greenhouse gas emitted by each crop during the process. As for selecting methods, in this study organic farming materials were selected in the method of direct observation of material and bottom-up method a survey method with focus on the organic farming materials admitted into rice production. For the basic unit of carbon emission amount by the production of 1kg of organic farming material, the software PASS 4.1.1 developed by Korea Accreditation Board under Ministry of Knowledge Economy was used. The study had the goal to ultimately provide basic unit to calculate carbon emission amount in executing many institutions like goal management system and carbon performance display system etc in agricultural sector to be conducted later on. As a result, emission basic units per 1kg of production were calculated to be 0.04968kg-$CO_2$ for oystershells, 0.004692kg-$CO_2$ for expanded rice hull, and 1.029kg-$CO_2$ for bordeaux mixture liquid.

• Journal of the Korea Concrete Institute
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• v.29 no.4
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• pp.399-406
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• 2017

CaO-based by-product, which consist of CaO, $SO_3$, $Al_2O_3$ and so on, has being used to raw materials of CaO compound. When It was applied to recycling water of remicon, concrete performance can be enhanced because hydration reaction of powder material is accelerated. In this study, activated-sludge, which was putted desulfurization gypsum of CaO-based in recycling water, was manufactured to verify effect of them, and then they was investigated by characteristics of cement matrix and mortar. As a results, they indicated reduction of setting time and high soundness in cement matrix, and acceleration of hydration reaction can be verified by XRD analysis. Also, it can be maintained good workability if water content by usage of desulfurization gypsum, which used for production of activated-sludge, was adjusted. In addition, it can be verified strength development by activated-sludge although cement content by usage of desulfurization gypsum was reduced.

• Journal of the Korean Geotechnical Society
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• v.19 no.2
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• pp.159-170
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• 2003

In this study, the mixed design of grout with hish strength.high permeation.high durability and environmental stability as the state of the art in material field was performed. Also, the subjects of grouting, grouting effects for ground conditions, and environmental effects were analyzed. According to these results, the fundamental data will be suggested as a design of grouting in the field application. The physical, mechanical and chemical characteristics with particle shape of the grouts were analyzed. Then, the gel-time of grouts, which is essential for workability and permeation range, were controlled. Also, the laboratory model grouting tests were performed to find the characteristics of solidification, permeation and durability with grouts. The ordinary portland, slag and microcement which have been used in the construction field were evaluated fur the environmental effects. To find the leaching of $Cr^{6+}$characteristics in cement grouts, $Cr^{6+}$ leaching tests were performed for the raw materials. Also, the results of leaching test were shorn by surrounding environment. Then, the unconfined compression strength tests were performed with the homo-gel samples, and the amount of changed $Cr^{6+}$ was measured by curing solution.

• Resources Recycling
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• v.30 no.5
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• pp.17-24
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• 2021

Natural aggregate regular exploitation has led to environmental and resource depletion issues; consequently, construction waste has become an important raw material in the supply of aggregate smoothly. The recycled aggregate produced in the most of recycled aggregate processing company in Korea has a high adhesion ratio of cement paste and mortar, which affects the water absorption ratio and density. Therefore, the quality of recycled aggregate needs to be improved. In this study, we improved the quality of recycled aggregate through the use of a multistage separation ball mill. This ball mill has a sieve which protects the ball mix and improves the motion. Products produced by using multistage separation ball mill were compared with various quality standard for utilization as recycle aggregate. Finally, we confirmed that the multistage separation ball mill can efficiently separate cement paste and mortar from natural aggregate and that it is suitable for the production of recycled aggregates.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.1
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• pp.92-99
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• 2021

CaO-based by-products composed of CaO, SO3, Al2O3, etc. are generally used as raw materials for CaO compounds. When applied to the recovered water of ready-mixed concrete, the hydration reaction of the powder material is accelerated and concrete performance can be improved. In this study, activated sludge was prepared to apply to the recovered water of ready-mixed concrete by mixing CaO-based hot-rolled slag(C12A7) in the recycling water of ready-m ixed concrete. Cem ent paste setting time and mortar compressive strength performance tests confirmed the effect on the hydration reaction. Therefore, the possibility of concrete application using activated sludge was confirmed.