• 콘크리트학회지
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• 제10권4호
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• pp.153-161
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• 1998

콘크리트 구조물은 자연적인 혹은 인위적인 온도의 승, 강하로 인하여 동결-융해 작용을 받게 되어 구조물의 성능저하를 야기시킨다. 현대에 들어서면서 콘크리트의 내구특성을 파악하기 위한 연구적 요구가 증가되고 있다. 따라서 폐주물사 콘크리트를 실제 구조물에 적용하기 위해서는 내구특성에 대한 연구가 반드시 이루어져야 한다. 폐주물사를 혼입한 콘크리트의 내구특성을 파악하기 위한 동결-융해 실험은 폐주물사의 잔골재 치환율, 물-시멘트비, AE제 사용 여부를 주요 변수로 하여 실시하였다. 원형공시체를 제작하여, 동결-융해 시험기에 넣어 -18~4$^{\circ}C$로 급속 동결-융해를 진행시키면서 매 23싸이클마다 동탄성계수를 측정하였다. 실험결과 AE제를 첨가했을 때 물-시멘트비가 적을수록, 폐주물사의 치환율이 클수록 전반적으로 강도가 증가하는 것으로 나타났으며, 물-시멘트비가 증가함에 따라, AE제를 사용한 콘크리트가 동결-융해 저항성이 증가하는 것으로 나타났다. 특히 폐주물사 치환율이 50%일때가 동결-융해 저항성이 가장 좋은 것으로 나타났으며 그 다음으로 25, 0% 순으로 저항성이 좋은 것으로 나타났다. 따라서 폐주물사 콘크리트가 내구성이 우수한 것으로 나타나 폐주물사를 콘크리트에 재활용할 수 있는것으로나타났다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.289-292
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• 2003

CFRD face slab concrete has a much capability to occur crack due to drying shrinkage and vibrator compaction etc. Because crack of concrete induces structural problem and decrease durability of concrete, it is need to reduce crack of concrete. In the experimental study it was analyzed that the effect of curing of concrete and compaction on CFRD face slab concrete. As a results, it was found that control of construction condition into curing of concrete and compaction improved on construction efficiency of face slab concrete.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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• pp.57-60
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• 2006

The purpose of this study is to assess performance of prepacked DFRCC material compared with the DFRCC material which is made by using general mixing method. From 4r-point bending test, bond strength test and chlorine ion penetration test, flexural stress, -deflection relations, bond strengths, and durability assessment have been obtained. From the experiments, premixed DFRCC shows relatively good performance.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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• pp.523-524
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• 2009

본 연구는 최근 부각되고 있는 지속가능성능 평가를 내구성 설계에 도입하여 염해를 입은 RC구조 물의 목표 내용연수를 달성하기 위한 최적 보수 내구성 설계기법의 가능성에 대하여 살펴보고자 한다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1995년도 가을 학술발표회 논문집
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• pp.30-34
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• 1995

There are carbonatiion, salt attack, freezing & thawing and alkali-aggregate reactions as the cautions of durability lowering of concret structure. Generally, these cautions complicatedly lower the durability of structure and among these cautions the most serious problem is salt attack and carbonation. This study is intending to get the carbonation phenominon, that among cement calcium hydroxides change into calcium carbonate by responding to carbon mitrogen in the air.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.605-608
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• 2006

This paper presents experimental results for durability performance of GFRP composite exposed to various environmental conditions. Specimens were conditioned for 7 environmental cases and immerged up to 150 days. A total of 720 specimens were prepared and tested for tensile strength for each immersion time. The results indicate that the tensile strength of the conditioned specimens was significantly reduced, regardless of the environmental factors considered, due to the degradation of GFRP.

• 콘크리트학회논문집
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• 제12권1호
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• pp.113-125
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• 2000

The purpose of this study was to examine the durability characteristics of controlled low strength material(flowable fill) with high volume fly ash content. Flowable fill refer to self-compacted, cementitious material used primarily as a backfill in lieu of compacted fill. The two primary advantages of flowable fill over traditional methods are its ease of placement and the elimination of settlement. Therefore, in difficult compaction areas or areas where settlement is a concern, flowable fill should be considered. The fly ash used in this study met the requirements of KS L 5405 and ASTM C 618 for Class F material. The mix proportions used for flowable fill are selected to obtain low-strength materials in the 10 to 15kgf/$\textrm{cm}^2$ range. The optimized flowable fill was consisted of 60kg f/$\textrm{m}^3$ cement content, 280kgf/$\textrm{m}^3$ fly ash content, 1400kgf/$\textrm{m}^3$ sand content, and 320kgf/$\textrm{m}^3$ water content. Subsequently, durability tests including permeability, warm water immersion, repeated wetting & drying, freezing & thawing for high volume fly ash-flowable fill are conducted. The results indicated that flowable fill has acceptable durability characteristics.

• 한국세라믹학회지
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• 제47권5호
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• pp.373-380
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• 2010

In this study, we studied on the durability of restorative cement mortar for deteriorated concrete at complex deteriorated conditions as variation of temperature and of humidities. We made a comparison between restorative materials with insulation function and restorative materials without insulation function in items of compressive and bending strength and permeability of water, durability for carbonation, salt damage, diffusion coefficient of salt at complex deterioration conditions like change of temperature, change of humidity, For insulation, we used close-pore type Alumino-Silicate lightweight aggregate and substituted 12 wt% and 15 wt% out of original restorative cement mortar without insulation function. As a result, it was found that original restorative cement mortar without insulation function fail to meet Korean Standard on polymer modified cement mortar for maintenance in concrete structure, but restorative cement mortar with insulation function is in contentment Korean Standard to meet excellent than restorative materials without insulation function for durability at complex deteriorated conditions.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 추계 학술논문 발표대회
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• pp.13-14
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• 2015

Carbonation is the results of the interaction of carbon dioxide gas in the atmosphere with the alkaline hydroxides in the concrete. in other words, of the hydrates in the cement pastes, the one which reacts with readily is Ca(OH)₂, the product of the reaction being CaCO₃ and which decreases the alkalinity of concrete. Consequently, RC structure is deteriorated due to steel corrosion in concrete. As the importance of maintenance of reinforced concrete structure recently has emerged, the attention of durability of structure has been increasing. There are many studies about durability decline especially due to the carbonation. In order to study carbonation progress after surface repair of carbonated concrete, each carbonation penetration velocity from different repair materials of concrete structure is compared through the experiment of carbonation accelerating CO₂ concentration to 100%. As carbonation infiltration progress is predicted through this study, the counterplan of service life evaluation will be prepared on selection of repair materials of concrete structure.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2005년도 춘계 학술기술논문발표대회 논문집
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• pp.165-169
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• 2005

The fire damage of building wouid effect on the safety of structure. When the reinforced concrete structure is heated by high temperature due to the fire, the structural resisting-force will be decreased. In a way, it is a requirement to use high strength concrete for high rise building. Particularly, fire resistance properties of high-strength concrete is more important than normal strength concretes. The fire outbreak of a high strength concrete by sudden temperature rise is a main problem, and causes crack by thermal stress, loading to the deterioration of the durability. In this study, normal and high strength mortar were exposed to a high temperature environment. And than fundamental data for the character change of concrete heated highly were presented by measuring compressive strength of concrete with polypropylene and vinylon fiber, before and after heating. As the results, it is proven that high strength mortar with polypropylene and vinylon fiber for prevents deterioration of durability by fiber.