• 한국응용과학기술학회지
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• 제22권4호
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• pp.371-378
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• 2005

In the previous study, three kinds of monomers and the functional monomer, acetoacetoxyethyl methacrylate (AAEM), which could improve the film property and cross-linkage, were polymerzied into acrylic resin copolymers (HSA-98-20, HSA-98-0, HSA-98+20) containing 80% solid content. In this study, the high-solid coatings(HSA-98-20C, HSA-98-0C, HSA-98+20C) were prepared by the curing reaction between acrylic resins containing 80% solid content and isocyanate at room temperature. Various properties were examined for the film coated with the prepared high-solid coatings. The introduction of AAEM in the coatings enhanced the abrasion resistance and solvent resistance of coatings, which indicated the possible use of high-solid coatings for top-coating materials of automobile. The curing times measured by viscoelastic measurement were 350, 264, and 212 min for HSA-98-20C, HSA-98-0C, and HSA-98+20C, respectively. This shows that the curing times become shorter with increasing $T_g$ values.

• 한국응용과학기술학회지
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• 제31권2호
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• pp.197-202
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• 2014

Positive plate was composed of lead hydroxide via reaction between lead oxide and $H_2O$ and lead sulfate was formed of the reaction of lead hydroxide with sulfuric acid. And its density is $3.8g/cm^3$, $4.0g/cm^3$, $4.2g/cm^3$ and $4.4g/cm^3$ by controlling volume of refined water. Curing of positive plate is done for low ($45^{\circ}C$, 40hr, over 95% of relative humidity) & high ($80^{\circ}C$, 40hr, over 95% of relative humidity) temperature, which created 3BS & 4BS active materials. Experimental result of DOD with 100% life cycle test shows that it was not related to the density of active materials but to the low & high temperature aging of active materials. The test makes us to understand that the crystallization which is made by curing of active materials is a more of a main factor than density of active materials under the deep cycle using circumstances. The active materials which were from the high temperature curing are better for deep cycle performance.

• 한국구조물진단유지관리공학회 논문집
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• 제21권5호
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• pp.134-140
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• 2017

본 연구에서는 양생조건이 다른 압축강도 90 MPa 수준의 고강도 콘크리트 부재의 휨거동 실험을 수행하였다. 실험변수는 정상 및 저온 양생 조건, 인장 철근량 및 콘크리트 압축강도 수준 등을 고려하였다. 8개의 보 부재를 제작하여 휨 실험을 수행하였으며 균열 간격, 하중-처짐 관계, 하중-변형률 관계 및 연성지수를 파악하였다. 실험결과는 철근량이 증가함에 따라 균열 개수는 증가하고 균열간격은 감소하는 경향을 나타내며, 콘크리트 강도가 높을수록 균열개수가 줄어들기는 하지만 그 효과는 철근량보다는 상당히 작은 것을 알 수 있었다. 설계기준에서 제안된 평균 균열 간격 식과 비교한 결과, 실험결과가 제안식의 결과보다 약간 크게 나타났으나, 제안식은 콘크리트 강도 및 양생조건을 반영하지 못하는 문제점이 있다. 정상 양생된 부재들의 연성지수는 3.36~6.74이며, 저온 양생된 부재들의 연성지수는 1.51~2.82으로 나타나, 저온 양생된 부재들의 거동은 정상 양생된 부재들에 비해서 연성도지수가 저감됨을 확인하였으며, 본 연구와 기존 연구의 연성지수를 비교한 결과, 고강도 콘크리트 부재의 연성지수는 선행연구의 보통강도 콘크리트의 연성지수 보다 크게 나타났으나, 더 구체적인 결과를 파악하기 위해서는 추가연구가 필요하다고 판단된다.

• 한국건축시공학회지
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• 제17권2호
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• pp.175-181
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• 2017

본 연구는 초고강도 섬유보강 콘크리트의 인장강도 특성을 파악하기 위한 일환의 연구로서 직접인장시험에 의한 노치가 도입된 시험체의 인장성능을 파악하기 위하여 시험변수는 목표 설계기준강도 120, 150 및 180MPa를 대상으로 하였으며, 양생조건을 일반 수중양생과 $90^{\circ}C$ 고온증기 양생조건으로 하여 그 특성을 검토하였다. 전반적으로 노치타입의 직접인장강도 시험체는 기존 직접인장 시험체에 비해 중앙균열 유도가 효과적인 것으로 나타났으며 데이터를 직접 인장강도-변형률 그래프로 나타낸 결과 먼저 재령 측면에서는 28일에서 56일로 진행할 때의 강도 상승이 가장 높은 것으로 측정 되었으며, 양생조건 측면에서는 고온증기 양생의 경우 수중양생의 비해 초기 강도가 높으나 장기 재령에 가까워질수록 두 가지 양생조건의 직접인장강도 차이가 미비해지는 것을 알 수 있었다. 최대인장강도는 수중양생의 경우 모든 목표설계강도가 재령이 증가할수록 일정하게 증가하는 것으로 나타났으며, 증기양생의 경우 재령 7일에서 초기강도 발현 효과로 인해 상당히 증가하는 경향을 나타내었다. 초기균열 강도는 수중양생의 경우 재령경과에 따라 증가하며, 증기양생의 경우 7일에서 수중양생에 비해 높은 것으로 나타난 반면에 28일 강도는 저하하는 경향을 나타내었다. 이부분에 대해서는 강섬유의 배열상태 등의 검토가 필요할 것으로 사료된다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 춘계학술대회 논문집
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• pp.260-263
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• 1996

The thermally stimulated currents(TSC) are measured to know the behaviour of charging particles of epoxy composites at the temperature range of -160∼200[$^{\circ}C$] and to prove the variation according to curing time in this study. It is confirmed that the peak amplitude is inversely proportional to the curing time, and TSC are reduced is and T$\sub$m/ is moved to high temperature side according to the curing time because carboxyl radical is formed by thermal oxidation and motility becomes lack.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.817-820
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• 2006

This study investigated on the differentiation of microstructure of blast furnace slag concrete(BBSC) using Mercury Intrusion Porosimetry(MIP). From the test result, it was found that the BBSC did not show shortcomings of high temperature curing. The BBSC gives more fineness microstructure than that of plain concrete when it is cured same curing condition. The curing age making stable structure to poor surroundings was 28, 14, 7 days for blast furnace concrete cured at 5, 20, $30^{\circ}C$, respectively.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.785-788
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• 2006

This paper investigates the temperature history of slab mock-up specimens with various surface curing sheets, in order to determine a favorable surface curing method in hot weather condition. Test showed that insulating double bubble sheets+aluminum foil simultaneously on the upper section of a specimen prevented an increase of sudden temperature and a decrease of vaporization when placed during the hot weather condition. It also secured the high strength in early age. Therefore it is found that using the double bubble sheets+aluminum foil on concrete surface declined the plastic and drying shrinkage and inclined the early strength, thus improving the concrete quality.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1994년도 가을 학술발표회 논문집
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• pp.194-199
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• 1994

Frefab Construction known for durable construction skill prompting high productivity in developed country is not yet settled in Korea. This situation of prefab construction results from lack of skill, specialists and quality control. In introducing skill, all equipments are thoughtlessly imported without inside eudeavor for development. Regardless of production of goods, basic study for production of goods, construction and structure is not abailable. The object of this study is curing method in the production process of PC concrete product. From change of curing temperature and curing period which would be factors of product quality in PC concrete production, and research of optimized steam curing condition from relations between curing condition and strength development, basic data of concrete steam curing method will be presented.

• Journal of the Korean Wood Science and Technology
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• 제35권5호
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• pp.76-86
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• 2007

This study was conducted to investigate the effects of formaldehyde to urea (F/U) mole ratio on thermomechanical curing of UF resin adhesives with different F/U mole ratios. Thermomechanical curing of these UF resin adhesives was characterized using parameters of dynamic mechanical analysis (DMA) such as the gel temperature, maximum storage modulus, and peak temperatures of storage and loss modulus. As the F/U mole ratio decreased, the gel temperature of UF resin adhesives increased. The maximum storage modulus as an indicator of the rigidity of UF resin adhesives decreased with decreasing F/U mole ratio. The peak temperature of tan $\delta$ increased with decreasing F/U mole ratio, indicating that the vitrification occurred faster for high F/U mole ratio of UF resin adhesives than for the one of lower F/U mole ratio. These results partially explained the reason why UF resin adhesives with lower F/U mole ratio resulted in relatively poor adhesion performance when they were applied.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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• pp.227-230
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• 1998

The effects of post curing conditions on thermal properties of alumina filled epoxy resin system DGEBA/MDA/SN were investigated. As the post curing time increased at 15$0^{\circ}C$, the glass transition temperature increased from 121 to 124, slightly. As the heating rate increased, high thermal decomposing temperature (T$_{d}$) and most decomposing temperature (T$_{p}$) increased. For the case of post-cured system at 15$0^{\circ}C$ for 4 days showed lower values than virgin system. At the post curing condition the system must have been thermally degraded.ded.