• International Journal of Highway Engineering
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• v.18 no.6
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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 $0.45{\ell}/m^2$.

• Journal of Welding and Joining
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• v.24 no.5
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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.

• International Journal of Highway Engineering
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• v.19 no.2
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• pp.97-102
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• 2017

PURPOSES : Emulsified asphalt is critical for road construction. The objective of applying asphalt emulsion as an adhesive is to prevent the phenomenon of debonding between the upper and lower layers. The quantity and veriety of bituminous material can be varied according to the type of pavement and site conditions. The objective of this study is to reveal the optimum application rates of the emulsified asphalt materials by types of tack-coats using Interface Shear Strength(ISS). METHODS : In the research, emulsified asphalt was paved on the surface of the divided mixture. The specimens of paving asphalt emulsion were utilized to evaluate the bond strength of tack-coat materials. In the evaluation process, NCHRP Report 712 was utilized to investigate the Interface Shear Strength, which reflects the bond capacity of asphalt emulsion. Then, the optimum residual application rates by tack-coat types were determined using regression analysis. RESULTS :As a consequence of squared R values investigated from 0.7 to 1 as part of the regression analysis, the tendency of predicted ISS values was compared with the results. The optimum residual application rates of AP-3, RS(C)-4, QRS-4, and BD-Coat were determined to be $0.78{\ell}/m^2$, $0.51{\ell}/m^2$, $0.53{\ell}/m^2$, and $0.73{\ell}/m^2$, respectively, utilizing 4th regression analysis. CONCLUSIONS :Based on the result of this study, it was not feasible to conclude whether higher residual application of tack-coat material leads to improved bond capacity. Rather, the shearing strength varies depending on the type of pavement.

• Steel and Composite Structures
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• v.14 no.1
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• pp.41-55
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• 2013

Fiber reinforced polymers (FRP) materials are increasingly being used for strengthening and repair of steel structures. An issue that concerns engineers in steel members which are retrofitted with FRP is stress experienced due to temperature changes. The changing temperature affects the interface bond between the FRP and Steel. This research focused on the effects of cyclical thermal loadings on the interface properties of FRP bounded to steel members. Over fifty tests were conducted to investigate the thermal effects on bonding between FRP and steel, which were cycled from temperature of $-11^{\circ}C$ ($12^{\circ}F$) to $60^{\circ}C$ ($140^{\circ}F$) for 21-36 days. This investigation consisted of two test protocols, 1) the tensile test of epoxy resin, tack coat, FRP and FRP-steel plate, 2) tensile test of each FRP compound and FRP with steel after going through thermal cyclic loading. This investigation reveals an extensive reduction in the composite's strength.

• Korean journal of food and cookery science
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• v.11 no.3
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• pp.237-243
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• 1995

"Woomegi Dduck" is one of Korean traditional pan fried rice cake made from glutinous rice by Tack-joo(rice wine) or boiling water. The optimum conditions for the preparation of "Woomegi Dduck" were investigated. The Hardnes, Cohesiveness, Gumminess, Chewiness, Adhesiveness of "Woomegi Dduck" added Tack-joo or boiling water measured by Rheometer, didn′t have significant difference between samples. The result of color test was L-Value, a-Value, b-Value and E Value of Woomegi Dduck added boiling water and 20％ rice flour were high. The best recipe of Woomegi Dduck was glutinous rice flour 50g, rice flour 20g, Tack-joo 30$m\ell$, or boiling water 25$m\ell$, sugar 10g.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.6
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• pp.737-744
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• 2021

Spray paving minimizes material lost during the construction or repair of a road surface, and it can be done in conjunction with tack coating. This approach involves applying the asphalt mixture at the same time as spraying the tack coat by attaching a spraying device to the asphalt paver. When applying an asphalt overlay to an aged concrete surface, it is important to ensure the adhesion performance between different material properties. Accordingly, there is a need for a tack coat that can be applied by spray paving and that exhibits good adhesive performance on different materials. In this study, bonding strength tests under various conditions were performed to evaluate the basic performance of a tack coat developed for use with a spray paver. The bonding performance of the tack coat was observed to be affected by curing conditions and material lost during construction. The test results also showed that the tensile and shear bonding strengths of the developed tack coat were 1.21 and 1.99 times higher than those of a conventional one, respectively. As a result, the developed tack coat is considered suitable for application to spray paving.

• International Journal of Highway Engineering
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• v.15 no.4
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• pp.85-94
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• 2013

PURPOSES: The performance of tack coat, commonly used for layer interface bonding, is affected by application rate and curing time. In this study, bonding strength tests were performed according to the application rate and curing time of asphalt emulsion. Based on finding from this study, optimum application rates and curing times are proposed. METHODS: In order to investigate bonding characteristic of asphalt emulsion, tests were performed on both asphalt concrete pavement and portland concrete pavement. Also, asphalt emulsions were tested at the application rate of 0, 0.2, 0.4, 0.6, and $0.8{\ell}/m^2$ and at the curing time of 0, 0.5, 1, 2, and 24 hours. Pull-off test and shear bonding strength test, which commonly used for bonding strength measurement of asphalt emulsion, were adopted for this study. To assess field performance under different testing condition, asphalt emulsions were applied to in-service pavement. Throughout coefficient of determination analysis between material index properties from asphalt emulsion and mechanical response from bonding strength tests, performance correlativity was analyzed. RESULTS: Test results show that optimum application rate for asphalt overlay on asphalt concrete pavement (AOA) and asphalt overlay on concrete pavement (AOC) was $0.4{\sim}0.5{\ell}/m^2$ and $0.3{\sim}0.5{\ell}/m^2$, respectively. According to the curing time increment, tensile strength and shear strength of AOC were increased to 22~44% and 20~39%, respectively. AOA case also show strength increment in tensile strength (42%) and shear strength (9%). We tested the applicability of tack coat materials at the field sites, and our findings demonstrated that the bonding (for D and E) and rapid curing (for B, C, and D, E) performances were superior than others. Among material index properties, there was a high correlation between penetration ratio and bonding strength test result. CONCLUSIONS : Result show that interlayer bonding strength was affected by asphalt emulsion type, application rate and curing time. AOC required slightly higher application ($0.1{\ell}/m^2$) than AOA. Both AOA and AOC cases show higher strength at longer curing time. Up to 2hours of curing, rapid strength increments were observed, but strength increment ratio was decreased after 2hours of curing. From the observed correlation between penetration ratio and bonding strength, it is expected that penetration ratio can be used as one of important factors affecting bonding strength analysis.

• Journal of the Korean Graphic Arts Communication Society
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• v.22 no.2
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• pp.101-110
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• 2004

The local surface strength variation of coated papers were measured at various speeds on a number of coated paper samples to study the effects of speed and ink tack on coating pick. Coating pick phenomenon is observed in an ink transfer variation curve as a decrease in the slope of the curve. On the other hand, it causes an actual decrease in net ink transfer to paper with an increase in speed. The effect of speed on coating pick depends on ink tack, ink film thickness and surface properties of coating layer formation of paper. A novel device to measure the surface strength can rate the coating paper in a different order. Comparison are made between dry test of coating paper pick and wet coating pick test of printing in IGT printability tester. Coating formulation is the main key to prevent from coating pick. The binder level increases, the coating pick and the slop decrease. The piling on blanket in printing is a problem when the coating pick is occur on a local area rather than average surface strength of coated papers.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.959-960
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• 2009

• International Journal of Highway Engineering
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• v.20 no.3
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• pp.1-9
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• 2018

PURPOSES : In order to evaluate a crack resistance at cold joint, sealing tape was adopted to apply at cold joint instead of typical tack coat material(RSC-4). The sealing tape was made by hot sealing material. The crack resistance as function of environmental and traffic loading was measured with visual observation. METHODS : In this study, the crack resistance was evaluated as function of environmental and traffic loading. The freeze-thaw method was adopted for environmental loading of asphalt pavement. condition. The damage of cold joint under freeze-thaw action is initiated by ice expansion load and accelerated by the interfacial damage between new and old asphalt pavement. The traffic loading was applied with wheel tracking machine on the cold joint area of the asphalt pavement for 3 hours at $25^{\circ}C$. The evaluation of crack resistance was measured with visual observation. The freeze-thaw results shows that the sealing tape was significantly increased the crack resistance based on. RESULTS : To estimate the crack resistance at cold joint area due to the environmental loading, the Freeze-thaw test was conducted by exposing the product to freezing temperature(approximately $-18^{\circ}C$) for 24 hours, and then allowing it to thaw at $60^{\circ}C$ for 24 hours. The tack coat material(RSC-4) was debonded after 21 cycles of the Freeze-thaw test. The first crack was observed after 14 freeze-thaw cycle with RSC-4 material. But, the sealing tape was not debonded after 24 cycle test. Also, the sealing tape shows the better performance of the crack resistance under the traffic loading with wheel track test. The crack was generated the under traffic loading with RSC-4(tack coating), however, the crack was not shown with sealing tape. It indicates that the sealing tape has a strong resistance of tensile stress due to traffic loading. CONCLUSIONS :Based on limited laboratory test result, a performance of crack resistance using the sealing tape is better than that of general tack coat material(RSC-4). It means that the sealing tape is possible to extend a pavement service life because the crack, one of the main pavement distresses, will be delayed.