• Journal of the Korea Concrete Institute
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• v.17 no.1 s.85
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• pp.141-147
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• 2005

The development of automobile, vessel, rail road, and machine industry leads an increase of foundry production used as their components, which cause a by-product, waste foundry sand (WFS). The amount of the WFS produced in Korea is over 700,000 tons a year, but most WFS has been buried itself and only $5{\~}6\%$ WFS is recycled as construction materials. Therefore, it is necessary for most WFS to research other ways which can be used in a higher value added product. The study on recycling it as a fine aggregate for concrete or green sand has been in progress in America and Japan since 1970s and 1980s respaectively. In this study, two types of WFS were used as a fine aggregate for concrete. Nine types of concrete aimed at the specified strength of 30 MPa were mixed with washed seashore coarse sand in which salt was removed, and WFS and then appropriate mixture proportion of concrete was determined. Moreover, basic properties such as air contents, setting time, bleeding, workability and slump loss of the fresh concrete with WFS were tested and compared with those of the concrete mixed without WFS. In addition, both compressive strength of hardened concrete at each ages and tensile strength of it at the age of 28 days were measured and discussed.

• Journal of Fashion Business
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• v.23 no.5
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• pp.124-136
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• 2019

Capstone design is a creative and comprehensive educational program requiring practical adaptation skills for the industry. The purpose of this study was to analyze the results of design development, lectures and curriculum satisfaction for textile fashion products based on four years of capstone design curriculum from 2015 to 2018. The curriculum consists of 26 groups of 72 students and a total of 26 final results were obtained via industry-university cooperation. The materials for product design development included differentiated clothing, leisure goods, bags, dog goods, smart goods, interior goods and recycled products based on textiles. The degree of satisfaction with lectures involving the capstone design class was very high, with 4.2 out of 5.0 when the number of students was less than 10. However, when the number of students was 20 or higher and the number of students was large, the level of satisfaction was below 3.88. Therefore, the capstone design class comprising less than 10 students was better at individual teaching and teamwork. In terms of satisfaction with capstone design curriculum, the respondents indicated that the teaching method addressing the needs of industry and academia facilitated practical learning. It was very helpful in improving competency related to the design and development majors and future employment. The capstone design curriculum was effective in the training for practical design development and planning.

• Journal of the Korean Society of Food Culture
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• v.36 no.5
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• pp.441-454
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• 2021

This study analyzed consumer needs for the development of elderly-friendly HMR products in China. In developing the products, items needed to be improved, types and packages of the necessary products, additional improvements and food preferences were investigated. According to the demographic characteristics of elderly Chinese consumers, these was analyzed as well. A survey was conducted on a total of 370 elderly people, and data analysis was performed using SPSS 18.0 program. Items related to product quality safety, such as "marks of origin by ingredient", "rich nutrients", "expansion of letter size of packaging", "rich nutrients" and "clear manufacturing date and expiration date", were required to develop HMR products. The types of products that should be developed were porridge and noodles, and the packaging types that should be developed were eco-friendly packaging and recycled packaging. In addition, "low-calorie HMR", "development of various seasonings", "use of eco-friendly food ingredients" and "HMR to digest easily" should be improved. The demand for product improvement and food preference showed significant differences according to the degree of education, monthly income and oral health. The results were intended to prepare basic data for setting the direction when developing elderly-friendly HMR.

• Journal of the Korean Society for Marine Environment & Energy
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• v.16 no.1
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• pp.53-59
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• 2013

Since 1990s, the major recycling methods for mechanical recycling of FRP(Fiber Reinforced Plastics)boats has involved shredding and grinding of the scrap FRP in a new recycled product. But still it leads to secondary problem such as air pollution, unacceptable shredding noise level and few limited applications. This study is to propose a newly advanced method which is more efficient and environment friendly waste FRP regenerating system. As extracting FRP layer and making the recycled fiber for recycled-fiber reinforced concrete(RFRC) from waste FRP, the recycling process has some merits in a sense of the recycling energy and the environmental effects. In this study, for those tasks, spectro-chemical differentiation method and coloring water-soluble dye treatment makes the roving layer more distinguishable photophysically. Also that has remarkably reduced safety hazards and energy. Using the mechanical properties of polymers and composite, FRP with the orthotropic and laminated plastic structure has been easily separated in the new extracting system. Also the new method has introduced five kind of separating manuals for the some different compositions of FRP boats. The roving fiber of laminated glass-fiber layer is as good as the polyvinyl fiber which is cost-high commercial fiber to increasing strength of concrete products. The early study has shown the effectiveness of laminated glass-fiber layer which also is chemical-resistant due to the resin coating. These results imply that more efficient and environment friendly recycled glass fiber can be better applied to the fiber reinforced concrete(FRC) substitute and this study also has shown wide concrete applications with RFRC from the waste FRP boat.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.4
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• pp.88-94
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• 2012

This study is conducted to utilize waste concrete powder made as a by-product manufacturing high quality recycled aggregate. The blaine fineness of the used waste concrete powder was 928 and $1,360cm^2/g$. As the main characteristic of waste concrete powder, it showed an angular type similar to cement, but hydrated products were attached on the surface of particles. In addition, the size of the particles of waste concrete powder was larger than OPC and in terms of chemical components it had higher $SiO_2$ contents. The viscosity of the paste that mixed waste concrete power decreased by 62% at the most, compared to the paste that only used OPC, and the final set time was delayed about two hours. As composition rates of waste concrete powder increased, the flow value decreased by 30% at the most according to the comparison with mortar that only used OPC, and sorptivity coefficients increased by 70%. The compressive strength of mortar decreased by 73% at the most as composition rates of waste concrete powder increased. According to the test results, it is desirable to use waste concrete powder by combining OPC appropriately(below 15%).

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.21 no.1
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• pp.19-26
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• 2015

The carton for liquid products are divided into 'gable top carton' and 'aseptic carton'. Currently, these packages are being recycled in the toilet tissue manufacturing process. The recycling of the carton aluminium laminate is the most important problem facing the recycling procedure of the carton packages due to the reduction in quality of recycled materials. The polymer structure with synthetic resins being used mainly in beverage packaging is also one of the important factors for the procedure for its recycling. The objective of this study was to investigate the package material and structure of the carton for liquid products through marketing research and suggest the supplementation in the work processes of production, use, and recycling. The results represent to improve the recycling profit and the quality of recycled materials when a laminated aluminium of carton for liquid products is replaced to the transparent polymer film. The improvement of the sorting and recycling process may help their recycling efficiencies. In addition, the limited use of synthetic resin molded packaging and increase of wood-pulp collection rate will provide the improvement of the recycling profit and the quality of recycled materials.

• Journal of the Korean Recycled Construction Resources Institute
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• v.3 no.3
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• pp.277-282
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• 2015

This study is conducted to utilize waste concrete powder (WCP) made as a by-product manufacturing high quality recycled aggregate. The blaine fineness of the used waste concrete powder was $928cm^2/g$. As the main characteristic of waste concrete powder, it showed an angular type similar to cement, but hydrated products were attached on the surface of particles. In addition, the size of the particles of waste concrete powder was larger than OPC and in terms of chemical components it had higher $SiO_2$ contents. For using WCP in soil cement-based pavement, the qualities, physical and chemical properties, of WCP should be researched. In the first step, the specified compressive strength of mortar for two types of clay sand soil and clay soil respectively was experimented to be 15 MPa and then optimum mixing ratio of chemical solidification agent were decided in the range of 1.5 - 3.0% in the replacement with cement weight content. In the second step, based on the prior experimental results, recycling possibility of WCP in soil cement-based pavement was studied. In the result of experiment the mixing ratio of WCP were 5, 10, 15 and 20% in the replacement with soil weight and the compressive strength of mortar was somewhat decreased according to the increase of the mixing ratio of WCP.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.2
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• pp.82-89
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• 2009

According to the great city development and the rapid growth of redevelopment project, waste concrete emission has been increased. Waste concrete powder is one of the by-product originated from the recycling of the waste concrete. The more making high quality recycled aggregate to use aggregate for concrete, the more waste concrete powder is producted relatively. Therefore, to realize the total recycling of waste concrete, development of recycling technology for waste concrete powder need very much. This technical note present the discharged process and the various properties of waste concrete powder. As the results, on the average, the maximum particle-size of waste concrete powder is less than $600{\mu}m$, and oven-dry density is less than $2.5g/cm^3$. And waste concrete powder contains more than 50% of $SiO_2$, 30% of CaO and 10% of $Al_2O_3$. Thus qualities of waste concrete powder is lower than those of high quality raw material for concrete. However, if it is processed by grading to the purpose, it will be used as resource of raw materials for construction field.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.2
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• pp.227-234
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• 2020

Under consideration of construction waste recycling, candidate secondary products applicable for the civil and construction areas can be reliably employed based on the recycling cost analysis. For the validation purpose, probability-based cost analyses were performed to estimate recycling cost profit considering uncertainties. When recycling construction wastes, the costs at each stage are fully dependent on target products to be adopted. To achieve commercialization of each product, its quality has to be improved with economic efficiency through accurate evaluation of input costs. Based on the probabilistic recycling cost analysis, the cost benefit for target products was estimated with waste classification cost, transportation cost to recycling treatment facilities and production cost. All necessary information on the cost analysis were collected from literature, disclosure, and existing recycling companies. In addition, a cost difference between recycled and non-recycled events was made. As a result, a probability-based recycling cost estimate for candidate secondary products was herein presented.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.4
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• pp.75-81
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• 2012

In case of crushing rock to produce materials for lean concrete subbase layer in concrete pavement, natural sand is used for the gradation adjustment of aggregates, and the percentage of natural sand used is 30%~40% of the weight ratio of aggregate mix. The supply of natural sand that is used in lean concrete as a fine aggregate is getting harder due to the current of exhaustion of source, and the cost for the purchase of natural sand is included in the cost of roadway construction. This study, therefore, was conducted in order to resolve the exhaustion of materials and economize in construction expenditure by the application of screenings, which is by-product of crushing rock in quarry, as an alternative to natural sand. As a result of a comparative analysis on the application of screenings and natural sand with typical types of rock that is produced in domestic, which was conducted in the first year, It is found out that the use of screenings as a fine aggregate showed better unconfined compression strength. Verification of actual application of screenings was conducted in the second year, after test construction and follow-up investigation. The compressive strength, compaction density, settlement of screenings applied case was higher than that of natural sand. Thus, it is expected that application of screenings to construction in field will contribute to the cost saving, material recycling and the protection of environment.