• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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• pp.313-316
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• 2006

The most serious cause of deterioration in the concrete structures is reinforcing corrosion due to the chloride attack and carbonation. Therefore, it is needed to protect durability and performance according to the appropriate materials and methods in the concrete structures. In general, several types of polymer and silicate are used as protecting deterioration agents of concrete structures, but these agents have many problems because of low durability and properties. The object of this study is to develop a preventing aging technology. The work involves the development of silicate type penetration reinforcing agent.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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• pp.229-232
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• 2005

Protective surface coating for concrete is available for applying to concrete structures for protecting chloride attack. However, the useful data obtained from real marine environment for surface coating materials is not sufficient yet in Korea and thus the engineers face many difficulties to apply the coating method in durability design. Surface-coated concrete specimens were fabricated and installed around the piers of Seohae grand bridge to observe long-term performance in actual marine environment. In this study, the results of durability of surface coatings for 3 years were reported.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2009년도 추계 학술논문 발표대회
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• pp.117-120
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• 2009

It has been gradually increased with the use of resin based membrane forming agent for curing method, which plays a role in protecting moisture evaporation by forming resin membrane at the surface of concrete. In this paper, tests were carried out to examine moisture retention capability of cement mortar applying membrane forming agent. Dosages and types of the membrane forming agent were varied. It is found that sheet curing sealed with the surface of concrete closely has favorable moisture retention capability. However, the application of membrane forming curing method had superiority in moisture retention capability at early stage but at later age, its capability is deteriorated. Hence, further study regarding altering application method was necessary to secure enhanced moisture retention capability.

• 콘크리트학회논문집
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• 제11권5호
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• pp.69-77
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• 1999

A spalling is defined as the damages of concrete exposed to high temperature during the fire by causing cracks and localized bursting of small pieces of concrete. It is reported that spalling is caused by the vapor pressure and polypropylene(PP) fiber has an important role in protecting from spalling. This paper is a study on the properties and spalling resistance of high-performance concrete with the kinds of aggregate and the contents of PP fiber. According to the experimental results, concrete contained no PP fiber take place in the form of the surface spalling and the failure of specimenns after fire test regardless of the kinds of aggregate. Concrete contained more than 0.05% of PP fiber with the aggregate of basalt does not take place the spalling, while the concrete using granite and limestone does the surface spalling. It is found that residual compressive strength after exposed at high temperature has 50~60% of its original strength. Although specimens after exposed at high temperature is cured at water for 28days, they do not recover their original strength.

• 한국구조물진단유지관리공학회 논문집
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• 제9권1호
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• pp.217-223
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• 2005

본 연구는 철근 콘크리트를 염해 및 중성화로부터 보호하여 철근의 부식을 방지하기 위한 3종류 표면 보호재의 성능을 평가한 것으로서, 표면 보호재를 사용한 시험편의 부식저항성능과 중성화 저항 성능을 평가하였다. 실험결과 3종류의 표면 보호재를 사용한 시험편에서는 철근의 부식저항성능이 매우 우수하게 나타났으며, 중성화 방지 성능도 우수하게 나타났다. 특히 발수성의 프라이머와 마감 코팅재를 함께 사용한 시험편은 철근의 부식과 중성화를 매우 크게 감소 시켰다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.807-810
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• 2005

In this study, MMA-modified paste of coating material for protecting the concrete structures was developed. The coating material was applied to cement concrete specimens by brush, roller and spray in each of which one, two and three layers to survey, by the cold-hot iterative test, the neutralization test, the chloride ion permeation test and the ante-abrasion test, the affect of painting methods and layers influencing on the durability of coating material. Results of the cold-hot iterative test showed that, regardless of the painting methods and layers, the defects such as crack or fuzz on surface were not produced. As the number of painting layers increased, the neutralization prevention as well as the chloride ion permeation prevention effects were increased. On the other hand, no difference was found between the painting methods. Reducing weight by abrasion of polymer paste coating material was $20\%$ comparing to that of cement mortar.

• Computers and Concrete
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• 제30권6호
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• pp.409-419
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• 2022

The purpose of this study is to examine the effectiveness of biological repairing mortars on restoring the structural performance of a sewage culvert deteriorated by sulfate attack. The biological mortars were developed for protecting concrete structures exposed to sulfate attack based on the block membrane action of the bacterial glycocalyx. The diffusion coefficient of sulfate ions in the biological mortars was determined from the natural diffusion cell tests. The effect of sulfate-attack-induced concrete deterioration on the structural performance of culverts was examined by using the moment-curvature relationship predicted based on the nonlinear section lamina approach considering the sulfuric-acid-induced degradation of the structure. Typical analytical assessments showed that biological mortars were quite effective in increasing the sulfate-resistant service life of sewage culverts.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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• pp.356-359
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• 2004

Recently, owing to the deterioration of reconstruction and the construction, much of the construction waste is discharged in our construction field, and the amount of construction waste are rapidly increased. These waste are raised to financial and environmental problems, so the method of reusing waste concretes has been studied and carried out many direction. Especially being want of resources, if waste concrete could be recycled as aggregate for concrete, it will contribute to solve the exhaustion of natural aggregate, in terms of saving resources and protecting environment. This study is that the floating properties of concrete with recycled coarse aggregate were investigated for the substitution of recycled coarse aggregate. The result of this study, floating properties increases and strength development of concrete is showing a clear strength increase effect compare to blast furnace slag non-mixing according to age passing in case of use blast furnace slag. The Quality of recycled coarse aggregate concrete was improved by water reducing.

• 한국방재학회 논문집
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• 제5권1호
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• pp.77-84
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• 2005

콘크리트 구조물의 성능저하, 노후화 및 용도 변경 등으로 구조물을 해체할 경우가 증가하면서 발생되는 폐콘크리트량이 급증하고 있는 추세이지만, 거의 대부분이 단순 매립용 재료로 사용되고 있다. 우리나라와 같이 부존자원이 부족한 나라에서 폐기되는 콘크리트를 포장 콘크리트용 골재로 재활용할 경우 콘크리트용 천연골재의 부족 현상 극본, 자원절약 및 환경보존 등에 크게 기여할 것으로 기대된다. 본 연구에서는 실제 구조물에 사용된 콘크리트를 해체하면서 발생한 폐콘크리트를 파쇄하여 제조한 재생골재의 혼합율을 각각 5단계로 변화시켜 제조한 재생 골재를 포장 콘크리트용 골재로 활용하기 위하여 실시한 실험결과에 대하여 고찰하였다.

• Advances in concrete construction
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• 제15권1호
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• pp.63-74
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• 2023

All production and consumption activities produce wastes, which often cause damage to our environment and multiple risks to the human health. The valorization of these wastes in concrete technology is a future solution that will allow finding other construction materials sources, optimizing energy consumption and protecting the environment. Among these wastes, there is the marble waste. Every year, huge amount of marble waste is discarded as dust or aggregates form, in open-air storage areas causing serious problems for the environment and public health. In this context, the incorporation of marble waste as a replacement of ordinary aggregates or cement in concrete composition is actively investigated by researchers. This paper presents a comprehensive review of published studies over the last 20 years, dealing the effect of marble waste on fresh and hardened properties of concrete. Most of the studies carried out have used marble waste as dust with substitution rates between 5 and 20%. Besides the economic and ecological benefits, this review showed that marble waste can improve the physical, mechanical and durability properties of concrete. This improvement depends on the form (dust, fine aggregate or coarse aggregate), substitution method (as cement or aggregates replacement) and substitution rate of marble waste. Additionally, the review results showed that the use of 10-15% of marble waste dust as cement substitution can lead to increase the compressive strength.