• Magazine of the Korea Concrete Institute
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• v.14 no.6
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• pp.64-71
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• 2002

21세기라는 새로운 세기를 맞이하여 콘크리트 산업계는 시대의 변화에 부합하는 경영 방침이나 기술력이 요구되었으며 지금 까지 보다 더욱 힘든 환경을 맞고 있다고 생각된다. 예를 들어 환경 문제는 1992년의 환경과 개발에 관한 UN회의를 계기로 지구온난화, 해양오염, 산성비, 오존층 파괴, 열대림의 감소, 사막화 등에 대한 국제적인 관심이 커지고 있어서 21세기는 환경의 세기가 될 것으로 보이며 이에 따른 신속한 대책 수립이 요구되고 있는 시점에 와있다. 또한 자원 리사이클링과 환경에 관련된 각종 법령 등이 국가 차원, 혹은 지방 자치단체 차원에서 제정되고 있어 이에 대한 대응 방안이 요구되고 있다. 더욱이 여러 사회단체나 NGO 등의 압력으로 각종 공공사업의 수행에 있어서도 기본 이념인 편리성, 안전성, 내구성 공평성, 투명성 등에 덧붙여서 공해. 미관. 생태계, 건강, 복지, 문화 유산 등에 대한 배려도 요구되고 있으며 적용이 이루어지고 있는 추세이다.(중략)

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.3
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• pp.533-544
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• 2015

Unlike the concrete structure built on land, that exposed to the marine environment is greatly degraded in durability due to the exposure to not only the physical action caused by sea wind, tide, and wave, but also the harsh conditions, including the chemical erosion and freeze-thaw which result from $SO_4{^{2-}}$, $Cl^-$ and $Mg^{2+}$ ions in seawater. In the process of the large scaled construction of submerged concrete structures, of course environmental hazardous substance, such as alkaline (pH) and heavy metals, may be leached. Thus, this issue needs to be adequately reviewed and studied. Therefore, this study attempted to develop a CSA (Calcium Sulfo Aluminate) activator using electric arc furnace reducing slags, as well as the eco-friendly concrete for artificial reefs using electric arc furnace oxidizing slag as aggregate for concrete. The strength properties of the eco-friendly concrete exposed to the marine environment were lower than those of the normal concrete by curing 28 days. This suggest that additional studies are needed to improve the early strength of the eco-friendly concrete. With respect to seawater resistance of the eco-friendly concrete, the average strength loss against 1 year of curing days reached 8-9%. the eco-friendly concrete using high volume of ground granulated blast furnace slags and high specific gravity of electronic arc furnace oxidizing slag demonstrated the sufficient usability as a freeze-thaw resistant material. With respect to heavy metal leaching properties of the eco-friendly concrete, heavy metal substances were immobilized by chemical bonding in the curing process through the hydration of concrete. Thus, heavy metal substances were neither identified at or below environmental hazard criteria nor detected, suggesting that the eco-friendly concrete is safe in terms of leaching of hazardous substances.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.2
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• pp.729-737
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• 2013

The environmental load of concrete pavement can be categorized by temperature and moisture loads, which mean temperature distribution, and drying shrinkage and creep in the concrete slab. In this study, a method calculating the environmental load essential to mechanistic design of airport concrete pavement was developed. First, target area and design slab thickness were determined. And, the concrete temperature distribution with slab depth was predicted by a pavement temperature prediction program to calculate equivalent linear temperature difference. The concrete drying shrinkage was predicted by improving an existing model to calculate differential shrinkage equivalent linear temperature difference considering regional relative humidity. In addition, the stress relaxation was considered in the drying shrinkage. Eventually, the equivalent linear temperature difference due to temperature and the differential shrinkage equivalent linear temperature difference due to moisture were combined into the total equivalent linear temperature difference as terminal environmental load. The environmental load of eight civilian and two military airports which represent domestic regional weather conditions were calculated and compared by the method developed in this study to show its application.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.4
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• pp.316-323
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• 2023

The need for sustainable waste management has intensified the focus on recycling prestressed concrete sleepers used in railways. Given their high volume and environmental impact at the end of their service life, finding efficient recycling methods is crucial. This study explores current recycling approaches, particularly mechanical techniques, evaluating their advantages, limitations, and economic feasibility. Finally, an example of mechanical recycling was performed. The analysis results of the resulting recycled aggregates are suggested. Then, the non-cement concrete mixtures with recycled aggregates were designed, and their strength development was analyzed.

• Magazine of the Korea Concrete Institute
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• v.15 no.6
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• pp.14-16
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• 2003

• Magazine of the Korea Concrete Institute
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• v.24 no.6
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• pp.44-47
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• 2012

• Magazine of the Korea Concrete Institute
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• v.12 no.5
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• pp.17-22
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• 2000

• Magazine of the Korea Concrete Institute
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• v.17 no.4 s.87
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• pp.8-10
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• 2005

• Magazine of the Korea Concrete Institute
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• v.26 no.3
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• pp.22-25
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• 2014

• Journal of the Korea Concrete Institute
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• v.15 no.4
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• pp.574-584
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• 2003

The most common deterioration cause of concrete structures in urban environment is carbonation. Recently, the $CO_2$ concentration and temperature at atmosphere is sharply increased with time due to global warming phenomena. In this study, the climate scenario IS92a, which was suggested by the IPCC, is used to consider temperature and atmospheric $CO_2$ concentration change in the model of service life prediction. The modified mathematical solution, which was based on the Fick's 1st law of diffusion, was used to reflect concrete materials properties such as the degree of hydration of concrete with elapsed time, and important parameters, which associated with deterioration rate. The techniques of service life prediction are developed introducing the method of reliability and stochastic concept to consider microclimatic condition in Seoul, South Korea. From the result of service life prediction, concrete containing high W/C ratio is shown fast carbonation rate due to $CO_2$ concentration increase. It is concluded that the deterioration of concrete structures due to carbonation is insignificant problem on the conditions that below W/C 55%, well curing concrete.