• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2006년도 춘계 학술대회 개요집
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• pp.304-306
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• 2006

Positioning the workpiece accurately and preventing the weld distortion, tack welding is often performed before main welding in the construction of welded structures. The weld bead size of the tack weld is determined according to the workpiece thickness, weld length, weld joint type etc. However, this tack weld deteriorates the final weld bead profile, so that the grinding process is usually adopted for the uniform weld bead profile. In this study, an experimental method for the selection of optimal welding condition was proposed in the fillet weld which was done over the tack weld. This method uses the response surface analysis in which the leg length and the reinforcement height of weld bead were chosen as the quality variables of weld bead profile. The overall desirability function, which was combined desirability function for the two quality variables, was used as the objective function for getting the optimal welding condition. From the result, it was revealed that a uniform weld bead can be obtained by adopting the optimal welding condition which was determined according to the method proposed.

• 대한토목학회논문집
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• 제41권6호
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• pp.737-744
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• 2021

최근 택코트 부착성능의 중요성이 높아지며 시공과정에서의 택코트 손실을 방지하기 위해 동시포설공법이 제안되고 있다. 동시포설공법은 아스팔트 페이버에 택코트 살포장치를 부착하여 택코트 살포와 동시에 아스팔트 혼합물을 포설하는 공법이다. 노후 콘크리트 포장의 아스팔트 덧씌우기 포장은 강성포장 위에 연성포장이 적용되기 때문에 이질적인 재료에 따른 부착성능의 확보가 더욱 중요하다. 이에 따라 동시포설공법으로 적용이 가능하고 이질적 재료에도 충분한 부착성능을 나타내는 택코트 재료가 필요하게 되었다. 본 연구는 동시포설공법을 위해 개발된 택코트 재료의 기초성능을 평가하기 위해 다양한 조건의 부착강도 실험을 수행하였다. 부착성능 평가결과 양생조건과 택코트 손실에 의해 부착성능에 차이가 발생함을 알 수 있었으며, 개발 재료는 동시포설공법과 동일한 시공조건 모사 실험에서 기존 재료 대비 인장접착강도 1.21배, 전단부착강도 1.99배 높은 부착성능을 나타내어 동시포설공법에 적용하기에 적합한 것으로 나타났다.

• Journal of Welding and Joining
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• 제24권5호
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• pp.29-36
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• 2006

In this study, an experimental method for the selection of optimal welding condition was proposed in the fillet weld which was done over the tack weld. This method used the response surface analysis in which the leg length and the reinforcement height were chosen as the quality variables of the weld bead profile. The overall desirability function, which was combined desirability function fur the two quality variables, was employed as the objective function for getting the optimal welding condition. In the experiments, the target values of the leg length and the reinforcement height are 6m and zero respectively for the horizontal fillet weld of 10mm thickness mild steel. The optimal welding conditions could predict the weld bead profile(leg length and reinforcement height) as 6.00mm and 0.19mm without tack weld and 6.00mm and 0.48mm with tack weld. from a series of welding test, it was revealed that a uniform weld bead can be obtained by adopting the optimal welding condition which was determined according to the method proposed.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2004년도 추계학술발표대회 개요집
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• pp.289-291
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• 2004

The purpose of this study is to identify the effects of the length of tack weldment on the rotational distortion at the one side SA butt weldment using experiment. The maximum rotational distortion at the end of the SA weldment decrease with an increase in the length of tack weld length, while the maximum rate of the distortion increases. This result indicates that the increase of the length of the tack weldment at the one-side SA butt weldment does not prevent the hot cracks.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 추계 학술논문 발표대회
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• pp.173-174
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• 2018

In this study, the objective of this study was to evaluate the adhesive characteristics of existing self-adhesive rubber asphalt sheet, butyl sheet and acrylate sheet in a low temperature environment through Tack Rolling Ball Test to obtain basic data on acrylate. As a result of this experiment, in the case of the self-molding rubber asphalt sheet and the butyl rubber sheet, the compound of the sheet was frozen in the low temperature environment and the iron bead was separated. On the other hand, the acrylate sheet did not freeze the acrylate even at 0 ℃, It is confirmed that the measured value is shown by Ball Test.

• 한국도로학회논문집
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• 제18권6호
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• pp.137-143
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• 2016

OBJECTIVES : Bituminous materials, such as tack coat, are utilized between pavement layers for improving the bond strength in pavement construction sites. The standards regarding the application of bituminous material are not clearly presented in the Korean construction guideline without RS(C)-4. Hence, the objective of this study is to determine the optimum content of bituminous materials by analyzing interlayer shear strength (ISS) from the direct shear tester, which was developed in this research. The shear strength of tack coat was defined with the sort of bituminous materials. METHODS : The mixtures for the shear test were made using marshall mix design. The specimens were vertically and horizontally separated for the direct shear test. The separated specimens were bonded using bituminous material. The objectives of the experiment are to determine the performance of bond and shear properties resulting from slippage, rutting, shovel, and corrugation of asphalt pavements. A machine based on the Louisiana interlayer shear strength tester (LISST) of NCHRP Report-712 was developed to determine the ISS. The applied types of tack coat were RS(C)-4, AP-3, QRS-4, and BD-coat with contents of $0.3{\ell}/m^2$, $0.45{\ell}/m^2$, $0.6{\ell}/m^2$, and $0.8{\ell}/m^2$, respectively. RESULTS : Table 2 gives the results of the direct shear test using the developed shear machine. The BD-coat type indicated the highest average ISS value compared to the others. Between the surface and binder course, optimum tack coat application rates for AP-3, RS(C)-4, QRS-4, and BD-Coat were $0.6{\ell}/m^2$, $0.3{\ell}/m^2$, $0.6{\ell}/m^2$, and $0.45{\ell}/m^2$, respectively. These optimum contents were determined using the ISS value. CONCLUSIONS : The ISS values of AP-3, RS(C)-4, and QRS-4 showed similar tendencies when ISS increased in the range $0.3{\sim}0.6{\ell}/m^2$, while ISS decreased when the applied rate exceeded $0.6{\ell}/m^2$. Similarly, the highest ISS value of the BD-coat was observed when the applied rate was $0.45{\ell}/m^2$. However, shear strength was similar to the maximum value of ISS when the tack-coat application rate of BD-Coat exceeded $0.45{\ell}/m^2$.

• 한국도로학회논문집
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• 제19권6호
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• pp.37-46
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• 2017

PURPOSES : A composite pavement utilizes both an asphalt surface and a concrete base. Typically, a concrete base layer provides structural capacity, while an asphalt surface layer provides smoothness and riding quality. This pavement type can be used in conjunction with rollercompacted concrete (RCC) pavement as a base layer due to its fast construction, economic efficiency, and structural performance. However, the service life and functionality of composite pavement may be reduced due to interfacial bond failure. Therefore, adequate interfacial bonding between the asphalt surface and the concrete base is essential to achieving monolithic behavior. The purpose of this study is to investigate the bond characteristics at the interface between asphalt (HMA; hot-mixed asphalt) and the RCC base. METHODS : This study was performed to determine the optimal type and application rate of tack coat material for RCC-base composite pavement. In addition, the core size effect, temperature condition, and bonding failure shape were analyzed to investigate the bonding characteristics at the interface between the RCC base and HMA surface. To evaluate the bond strength, a pull-off test was performed using different diameters of specimens such as 50 mm and 100 mm. Tack coat materials such as RSC-4 and BD-Coat were applied in amounts of 0.3, 0.5, 0.7, 0.9, and $1.1l/m^2$ to determine the optimal application rate. In order to evaluate the bond strength characteristics with temperature changes, a pull-off test was carried out at -15, 0, 20, and $40^{\circ}C$. In addition, the bond failure shapes were analyzed using an image analysis program after the pull-off tests were completed. RESULTS : The test results indicated that the optimal application rate of RSC-4 and BD-Coat were $0.8l/m^2$, $0.9l/m^2$, respectively. The core size effect was determined to be negligible because the bond strengths were similar in specimens with diameters of 50 mm and 100 mm. The bond strengths of RSC-4 and BD-Coat were found to decrease significantly when the temperature increased. As a result of the bonding failure shape in low-temperature conditions such as -15, 0, and $20^{\circ}C$, it was found that most of the debonding occurred at the interface between the tack coat and RCC surface. On the other hand, the interface between the HMA and tack coat was weaker than that between the tack coat and RCC at a high temperature of $40^{\circ}C$. CONCLUSIONS : This study suggested an optimal application rate of tack coat materials to apply to RCC-base composite pavement. The bond strengths at high temperatures were significantly lower than the required bond (tensile) strength of 0.4 MPa. It was known that the temperature was a critical factor affecting the bond strength at the interface of the RCC-base composite pavement.

• 접착 및 계면
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• 제14권4호
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• pp.167-174
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• 2013

본 연구에서는 ink binder용으로 isophorone diisocyanate (IPDI)/polyether polyol/2-hydroxyethyl acrylate (HEA)계 UV 경화형 우레탄 아크릴레이트를 중합하였다. HEA/PETA 혼합 비율을 달리한 조성물의 UV 조사 시간에 따른 광경화거동을 FT-IR spectrophotometer, probe tack tester 및 Photo-DSC로 확인하였다. UV 조사 시간이 증가함에 따라 전환률 및 gel content는 증가하였으며 probe tack은 감소하였다. 반응성 희석제로 사용한 PETA 함량이 증가함에 따라 저장탄성률, 인장강도 및 초기분해 온도가 증가하였다. HEA/PETA 비율이 30/70인 경우 UV 경화 후 PMMA sheet에 대한 부착특성이 가장 우수하였다.

• 한국의류학회지
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• 제4권1_2호
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• pp.35-42
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• 1980

Gan Tack is meetings for marriage in Royal Families only. There are three selection courses before the final decision of one person, and it done with a view to finding the best person in the country. On the history of costume, it was greatly changed in Yungjo's period. In this thesis, I studied the costumes of king Yungjo, Jungsungwanghu who is the consort of Yungjo, Inwonwanghu who is the consort of the late king, Sunhigung who is a seraglio of Yungjo, Ongjus who are King's daughters by seraglios, Sanggungs who are court ladies, Yumo who is a wet nurse, and etc., for Gan Tack with Hyaegyunggung-Hong who is chosen the consort of Prince, and research the Dresses, which are Jugori, Chima, Dangui, Gonryongpo, and Wonsam. The girls who attend Gan Tack dress up Jugori whose color is yellow, Chima whose color is red, and Dangui whose color is green. King wears in Gonryongpo, the Consorts in Wonsam, and the court ladies and Ongjus in Dangui, of course, there are differences of the colors and ornaments on the ranks. Finally, I hope this thesis will be of great help to the costume of historical dramas.

• 한국도로학회논문집
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• 제17권3호
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• pp.35-47
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• 2015

PURPOSES : A tack coat has been utilized to increase the bond performance between the surface layer and base course (intermediate course) at various road pavement sites. This is similarly true in other nations. Based on this connection, the objective of the present study is to evaluate the properties of hot mix asphalt (HMA) mixtures with an RSC-4 or BD-Coat and determine the application rate of the tack coat. METHODS : The HMA specimens were manufactured using superpave gyratory compaction. The HMA mixtures were composed of a 5-cm thick surface layer and a 10-cm thick base course. An impact hammer resonance test (IHRT) and a static load shear test were conducted to evaluate the performance of the HMA mixtures with a tack coat. From these tests, the dynamic moduli related to the high-frequency resistance and interlayer shear strength (ISS) of HMA could be obtained. RESULTS : The results of the dynamic moduli of HMA are discussed based on the resonance frequency (RF). To check the accuracy of the IHRT, we conducted a coherence analysis. A direct shear test using the application of a static load test was carried out to evaluate the interlayer shear strength (ISS) of HMA. CONCLUSIONS : The maximum ISS was demonstrated at an RSC-4 application rate of 462 gsm, and the maximum dynamic modulus was demonstrated at an RSC-4 application rate of 306 gsm. By averaging the results of the ISS, the maximum ISS values were obtained when a BD-Coat application rate of 602 gsm was applied.