• 한국의류산업학회지
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• 제13권1호
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• pp.130-134
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• 2011

In the study, the physical properties of the raw sample, non-circular(+ type) DTY yarn(50d level) with absorption and quick-dry function, were examined before and after being twisted(1000T/M). The results are as follows: The shrinkage of non-cricular(+type) DTY yarn(50d/36f) at $180^{\circ}$ was about 6-7% with twisted samples, but the samples without twisting went 8 to 10%. The elongation of the non-twisted and twisted samples at $180^{\circ}$ and 30-minute treatment time reached 50% and 40%, respectively. The tenacity of non-cricular(+type) DTY yarn(50d/36f) was affected less by treatment temperature in the twisted condition.

• 보존과학연구
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• 통권31호
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• pp.131-140
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• 2010

This study shows the comparison of chemical compositions of main component with other bronze bells after the research on the component analysis by non-destructive XRF analysis. There are shrinkage cavities caused by the shrinkage defect and pores with pollutants on Bronze Bell of Heungguksa Temple with gamma radiation images and 77.3% of copper, 8.4% of tin and 10.9% of lead were determined as the main components of it with XRF analysis The tin content of Brozen Bell of Heungguksa Temple is less than those (11~18%) of other bronze bells but the lead content of that is higher. The lead content of it shows 10.91% which is quite high while generally the lead contents of other bells were controlled lower than 2.1%. Buddhist bells have the different lead content according to the period. The lead content was low until Silla Dynasty and Unified Silla period but it has been getting higher since some point of Koryo Dynasty. It is assumed that expensive copper and tin were replaced with lead.

• 한국농공학회지
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• 제42권6호
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• pp.115-121
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• 2000

The purpose of this research is to investigate properties and field application of non-shrinkage high strength concrete containing expansive additive. Before the field applications, several basic laboratory test are performed to evaluate the characteristics of air content, workability and strength of the concrete using calcium sulfa aluminate(CSA) expansive additive. As a result, high strength concrete using CSA expansive additive show similar workability and compressive strength to that normal concrete, and the optimum replacement ratio of them is obtained by 10% CSA expansive additive. Accordingly, it can be concluded that the use of CSA expansive additive is effective to prevent shrinkage crack and to achieve volume stability of concrete structure.

• Computers and Concrete
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• 제23권5호
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• pp.329-334
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• 2019

Traffic flow capacity of some old road bridges is insufficient due to limited deck width. In such cases bridge deck widening is a common solution. For multi-girder reinforced concrete (RC) bridges it is possible to add steel-concrete composite girders as the new outermost girders. The deck widening may be combined with bridge strengthening thanks to thickening of the existing deck slab. Joint action of the existing and the added parts of such bridge span must be ensured. It refers especially to the horizontal plane at the interface of the existing slab and the added concrete layer as well as to the vertical planes at the external surfaces of the initially outermost girders where the added girders are connected to the existing bridge span. Since the distribution of the added concrete is non-uniform in the span cross-section the structure is particularly sensitive to the added concrete shrinkage. The shrinkage induces shear forces in the aforementioned planes. Widening of a 12 m long RC multi-girder bridge span is numerically analysed to assess the influence of the added concrete shrinkage. The analysis results show that: a) in the vertical plane of the connection of the added and the existing deck slab the longitudinal shear due to the shrinkage of the added concrete is comparable with the effect of live load, b) it is necessary to provide appropriate longitudinal reinforcement in the deck slab over the added girders due to tension induced by the shrinkage of the added concrete.

• 대한토목학회논문집
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• 제26권5A호
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• pp.909-915
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• 2006

콘크리트의 자기수축을 예측하기 위해 기존 수화도와 자기수축의 진행 속도 차이를 불포화공극 생성 속도로 가정하고 시멘트 페이스트의 자기수축 실험을 통하여 물-결합재비에 반비례하는 불포화공극 보정계수를 산정할 수 있었다. 이를 자기수축 기여 성분과 미기여 성분이 고려된 변형 Pickket 모델을 이용하여 콘크리트의 자기수축을 예측하였으며, 실험값 및 기존 Tazawa 모델과 일치하는 경향을 나타내어 불포화공극 보정계수에 의한 자기수축 예측이 타당함을 알 수 있었다. 그러나 강도의 함수로 설정된 기존 CEB-FIP 자기수축 예측 모델의 경우 최종 자기수축률과 자기수축 발현 시간함수에 대하여 다소의 수정이 필요할 것으로 판단된다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
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• pp.793-796
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• 2008

교량 신축이음장치의 파손 유형은 주로 후타재(무수축 모르타르)와 관련된 부분에서 많이 발생된다. 또 다른 문제는 중차량 통과에 따른 충격과 진동하중으로 인해서 신축이음장치를 후타재에 고정하기 위해서 사용하는 앵커 풀림 현상이다. 본 연구에서는 무수축 모르타르의 파괴에 따른 신축이음 장치의 파손을 방지하기 위해 탄성콘크리트를 개발하였다. 개발된 탄성콘크리트와 현재 주로 사용하고 있는 무수축 모르타르의 인발성능을 비교하였다. 또한, 후타재와 신축이음장치를 일체화하여 후타재의 파손을 방지하고 신축이음장치를 쉽게 교체할 수 있는 앵커 시스템을 개발하였다.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.822-823
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• 2006

The compaction and sintering behavior of zirconium titanate $(ZrTiO_4)$ was investigated by means of the measurement of sintering density and shrinkage, and the observation of microstructure. With increasing the content of $Al_2O_3$ additive, $Al_2O_3$-modified zirconium titanate samples fired at $1300^{\circ}C$ showed the anisotropic shrinkage behavior that the upper region of sintered body has higher sintering shrinkage than the low region. This difference of sintering shrinkage decreased with increasing firing temperature from 1300 to $1400^{\circ}C$. The SEM micrographs of powder compation show that the anisotropic shrinkage behavior is related with non-uniform density in a uniaxial compaction.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.457-462
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• 2003

It studies the non-structural crack factors that are produced in Steel Box Girder Bridge concrete floor plate using analytical method. It mainly studies humidity and design standard of concrete strength. It used MIDAS CIVIL Ver 5.4.0, a general structure analysis program that applies drying shrinkage rate of domestic road bridge design standard and standard value of creep coefficient, CEF-FIP standard equation and ACI standard equation from the aspect of creep, drying shrinkage and hydration heat to see the effect of the two factors on concrete crack and found the following result. The analytical results of this study showed that the initial stress, which was obtained by ACI standard, exceeds the allowable tensile stress between 5 to 18 days. This result means that even if a bridge is designed and constructed according to design standard, the bridge can have cracks due to various variables such as drying shrinkage, hydration heat and creep that produce stress in slab.

• 한국정밀공학회지
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• 제22권5호
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• pp.144-151
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• 2005

To predict the shrinkage of molded parts using numerical simulations, the mathematical model should be simplified to overcome the difficulties of formulation due to non-linearity of problems. So it is hard to predict the shrinkage exactly because of the simplification. In the present work, the neural network is used to predict the shrinkage which can implement nonlinear models very well. Comparison between the results of neural network and that of the commercial analysis software, ABAQUS, shows that the result of the neural network is in better agreement with that of the experiments.

• 복식문화연구
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• 제16권3호
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• pp.461-474
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• 2008

The purpose of this study was to present a making method of jeans pattern with high fitness after deriving the appropriate shrinkage rate by material and washing process. Research Method of jeans pattern was presented after applying the optimized shrinkage rate. According to the result of the exterior evaluation of test jeans, all 6 jeans were rated high with scores close to 3.5. Following the evaluation of satisfaction of usage by physical movement, the highest ranking was in the order of walking with normal steps, back bending $90^{\circ}$, chair sitting, climbing stairs, and squatting. The shrinkage rate by physical area showed the highest score in the order of pants length, waist circumference, thigh circumference, knee circumference, hem circumference, hips circumference. In addition, the shrinkage rate was higher in warp direction than weft direction after washing finishing. As for the result of addition and reduction of pattern measurements by parts of jeans, waist circumference was $2.5{\sim}5.2cm$, hips circumference was $-1.8{\sim}2.8cm$, thigh circumference was $-1.3{\sim}2.0cm$ and knee circumference was $-1.0{\sim}1.7cm$. Also, hem circumference was $-1.0{\sim}1.8cm$ and pants length was $2.9{\sim}6.2cm$. That is, this results showed a wide range of addition and reduction according to material and washing finishing.