• Journal of the Korea Concrete Institute
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• v.21 no.3
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• pp.265-273
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• 2009

There have been numerous studies to develop eco-friendly concrete. The attempt to reduce the amount of cement used is suggested as one of the solutions for eco-friendly concrete. To decrease the usage of cement, the pozzolan reaction materials are used as a mineral admixture. Hwang-toh, which is broadly deposited in Korea is a well known environment friendly material and the activated hwang-toh, which has the property of pozzolan reaction, is alternatively used as a mineral admixture of concrete. The purpose of this study is to investigate the drying shrinkage of hwang-toh concrete mixed with recycled PET fiber. Therefore, drying shrinkage experiments are performed to analyze mechanical property of hwang-toh concrete mixed with recycled PET fiber. Test results showed that the drying shrinkage is controlled by hwang-toh admixture and PET fiber.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.32-33
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• 2015

Depending on the industrialization, construction market has grown buildings are based on concrete will continue to increase. But the problems of environmental pollution come to the fore with the indiscriminate use of concrete and rapid development. In addition, carbon dioxide(CO₂) in the process of producing cement being emitted a large amount of has been caused a serious problem of environmental pollution. This trend is being actively conducted research to reduce the use of cement. In this study, eco-friendly materials, such as flats, Blast-furnace slag by mix and cement review the mechanical characteristics of the mudflats eco-friendly cement mortar to reduce the usability of the review were seen as a green building material.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.3
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• pp.152-159
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• 2010

Recently, the public interest in eco-friendly material and structure has been increasing and many Hwang-toh researches are being actively performed. Hwang-toh is one of the traditional environment friendly construction materials used as a construction and plastering material. Hwang-toh has many advantages as construction material due to its high heat storage capacity, auto-purification, antibiotic ability, and infrared ray emission characteristics. But, currently it has not been developed into construction material and used in modern construction due to its low strength and dry shrinkage cracking prone characteristics. According to the recent researches and study results, Hwang-toh can be used as a natural pozzolanic material like fly-ash or pozzolan. In this study, mechanical properties and structural flexure behavior experiments of slag, recycled PET fiber, and Hwang-toh added concrete are carried out. The test results showed that drying shrinkage of concrete mixed with Hwang-toh has lower compressive strength and elastic modulus than those of control cement concrete specimen, but it has the similar flexural behavior in reinforced concrete beams.

• Journal of Environmental Science International
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• v.16 no.9
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• pp.1099-1102
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• 2007

This paper presents eco-friendly planting method to overcome the problems of existing concrete retaining wall and gabion retaining wall, respectively, based on the examination on existing concrete and gabion retaining wall. Prior to doing this, proper design method was provided through pull out test. Planting method using gabion metal net and L shape green net retaining wall were compared and analyzed. According to this study, it is confirmed that reduction of construction period and economical profit in construction can be achieved by both manufacturing at the factory and self procurement at the job site as well as the use of metal net, which is applied as a substitution of existing strengthening material. For the effect of planting method, the use of L shape green net retaining wall shows superiority to environment-friendly gabion retaining wall in its ability to rootage and germination of the grass. The L shape green net retaining wall had excellent performance in helping rootage of grass and prevention of soil leakage, and even if raining period, remarkable damage of planting mat does not occur when planting mat is applied.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.2
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• pp.170-178
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• 2015

In this study, it was developed eco-friendly alkali-activated slag fiber reinforced concrete using ground granulated blast furnace slag, alkali activator (water glass, sodium hydroxides), and steel fiber. Eight reinforced concrete beam using alkali-activated slag concrete were constructed and tested under monotonic loading. The major variables were mixture ratio of alkali activator, mixed/without of steel fiber. Experimental programs were carried out to improve and evaluate the flexural performance of such test specimens, such as the load-displacement, the failure mode, the maximum load carrying capacity, and ductility capacity. All the specimens were modeled in scale-down size. The reinforced concrete beams using the eco-friendly alkali-activated slag fiber reinforced concrete was failed by the flexure or flexure-shear in general. In addition, the maximum strength increased with the adding the mol of sodium hydroxide, and the specimen reinforced the steel fiber showed the value of maximum strength which is increased by 15.8% through 25.9%. It is thought that eco-friendly alkali-activated slag fiber reinforced concrete can be used with construction material and product to replace normal concrete. If there is applied to structures such as precast concrete member and production of 2nd concrete product, it could be improved the productivity and reduction of construction duration etc.

• Hwankyungkyoyuk
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• v.20 no.4
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• pp.132-144
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• 2007

This study had the following aims: (1) To examine the significance of an eco-friendly environment based on the experiences of adventure sports participants, and to identify eco-friendly behaviors; (2) To review the characteristics of adventure sports that are held in a natural environment, as well as the existing problems in different adventure sports fields (3) To conduct an analysis of various eco-friendly behaviors and of the efforts that are being exerted to address a wide range of problems related to environmental pollution, by employing qualitative research methods, in a bid to ultimately present the symbiotic, coexistent, and harmonious relations between nature, sports, and humans. Ten individuals who were engaging in the adventure sports of scuba diving and paragliding were selected for the study, and the gathered data were analyzed based on the "surjection", "unit", "sign", and "subject" factors. The results of the analysis show that most of the adventure sports participants who were the subjects of the study believe that an eco-friendly environment helps protect and preserve nature, which is the basis of human life that adventure sports flourish in a natural environment that nature sustains adventure sports and that dealing carelessly with nature, or concentrating on the exploitation of nature for development purposes a real danger to its preservation. It was established in the study that keen adventure sports participants, or those who have a passion for and a thriving career in adventure sports, can do much to address environmental problems. The results of the study demonstrate that the link between sports and nature will promote a keen interest in and love for nature among sports enthusiasts as well as an awareness of the need to protect and preserve it, which will in turn lead them to develop a desire to do such. When these are realized, concrete images of eco-friendly behaviors will be seen on the part of a greater number of people.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.5A
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• pp.299-305
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• 2012

The objective of this paper is to obtain the basic data in order to develop an eco-friendly concrete through evaluation on the properties of polymer cement mortar and concrete using PVAc (Polyvinyl Acetate), as a kind of water-soluble polymer. For this purpose, the physical properties of cement mortar and concrete which does not contain the PVAc as the control batch were compared and analyzed with those using the PVAc. And then, the replacement amount of the PVAc was 3%, 6%, 9% and 12% by binder, respectively. And also, the properties of concrete using the PVAc were evaluated, by adding an antifoaming agent in order to control the air contents increasing with an increase of amount of polymer usage. As a result, in the case of polymer cement mortar using the PVAc, it presented that the compressive strength reduced, while the performance of flexural strength and drying shrinkage increased. When the replacement of the PVAc was 6% within concrete, the compressive, tensile, flexural strength and elastic modulus were increased.

• Resources Recycling
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• v.29 no.1
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• pp.53-61
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• 2020

This study aimed to develop a foam concrete material for a ground repair system that has low strength and low fluidity by using an eco-friendly binder, which substitutes industrial by-products for more than 90% of cement. Basic properties were evaluated after substituting a small amount of calcium sulfo aluminate (CSA) for the binder to improve the sinking depth rate and volume change, commonly found when it had a large amount of industrial by-products. The substitution rates of CSA for the eco-friendly binder used for the foam concrete were 2.5, 5, and 10%. Fresh properties, hardened properties, pore structure, and hydrates were analyzed. Experimental results showed that using only 2.5% of CSA could improve the deep sinking depth which occurred when using an eco-friendly binder. As a result, the weight difference between the upper, middle, and lower parts of cast specimens was improved even after being hardened. The addition of CSA also contributed to the formation of small, uniformly sized closed pores and improved initial strength. However, when the proportion of CSA increased, the long-term strength decreased. However, it satisfied the target strength when 5% or less of CSA was used. The results of this study revealed that it was possible to manufacture foam concrete with low strength and high fluidity for repairing ground satisfying target qualities by adding 2.5% of CSA to the eco-friendly binder containing a large amount of industrial by-products.

• Journal of the Korea Concrete Institute
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• v.20 no.5
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• pp.619-626
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• 2008

There have been numerous studies to develop eco-friendly concrete. The attempt to reduce the amount of cement usage is suggested as one of the solutions for eco-friendly concrete. To reduce the amount of cement usage, the pozzolan-reaction materials such as ground granulated blast furnace slag, fly ash, and meta kaolin are widely used as the mineral admixture. Hwangtoh which deposited broadly in Korea is a well known eco-friendly material and the activated Hwangtoh with pozzolan-reaction can be practically used as a mineral admixture of concrete. Meanwhile, PET fiber made of recycled PET bottle is a type of recycled material, which can be used to control micro cracks in concrete. But the study about concrete mixed with recycled PET fiber is insufficient and the research of Hwangtoh concrete mixed with PET fiber is urgently needed presently. In this study, experiment and analysis flexural behavior of Hwangtoh concrete blended with recycled PET fiber are carried out. The results are discussed in detail.

• Journal of the Korea Concrete Institute
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• v.25 no.3
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• pp.261-269
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• 2013

In this study, it was developed eco-friendly inorganic binding material concrete using ground granulated blast furnace slag and alkali activator (water glass, sodium hydroxides). Eight reinforced concrete beam using inoganic binding material concrete were constructed and tested under monotonic loading. The major variables were mixture ratio of alkali activator, type of admixture and admixture. Experimental programs were carried out to improve and evaluate the flexural performance of such test specimens, such as the load-displacement, the failure mode, the maximum load carrying capacity, and ductility capacity. All the specimens were modeled in scale-down size. The eco-friendly concrete using inorganic binding material encouraged alkali activation reaction was rapidly hardening speed and showed possibility as a high strength concrete. Also, the RC beams using new materials showed similar behavior and failed similarly with RC beam used portland cement. It is thought that eco-friendly inorganic binding material concrete can be used with construction material and product as a basic research to replace cement concrete. If there is application to structures in PC member as well as production of 2nd concrete product, it could be improved the productivity and reduction of construction duration etc.