• International Journal of Highway Engineering
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• v.19 no.2
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• pp.25-34
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• 2017

PURPOSES: The purpose of this paper is to evaluate interface performance while using various tack coat materials for asphalt overlay. METHODS : The evaluation was conducted with tracking test, permeability, and interface bond strength. Tracking test was conducted using an image processing technique, to investigate the susceptibility of the tack coat materials. BBS and pull-off test were conducted to evaluate bond strength. The permeability test was conducted to evaluate the effect of tack coat materials. RESULTS : Results reveal that the trackless tack coat material demonstrates less tracking compared to other materials. Moreover, both BBS and pull-off tests can effectively evaluate the bond strength at the interface. RSC-4 was measured less bond strength. Moreover, tack coat prevents water penetration through the surface and aids the extension of the surface life of asphalt pavement. CONCLUSIONS : Trackless tack coat demonstrated a high and consistent bond strength performance. The tack coat types demonstrate marginally different performance as function of curing times. Field applicability was tested based on visual observation. Therefore, these should be considered when trackless tack coat is slightly enhanced the pavement performance based on limited this study results. Finally, it is necessary to allow reasonable time for the tack coat to completely cure.

• International Journal of Highway Engineering
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• v.18 no.5
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• pp.1-9
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• 2016

PURPOSES : This study focuses on the evaluation of interface performance with varying surface texture and tack coat application in an asphalt overlay. METHODS : The evaluation is carried out in two phases: tracking test and interface bond strength test. Using an image processing tool, tracking test is conducted to evaluate the susceptibility of the tack coat material to produce excessive tracking during application. Using the pull-off test method, the bond strength test is performed to determine the ability of the interface layer to resist failure. RESULTS : Results show that the underseal application yields less tracking compared to other applications. However, the bond strength is barely within the minimum acceptable value. On the other hand, RSC-4 produces higher bond strength for all surface types, but the drying time is long, which produces excessive tracking. CONCLUSIONS : While underseal application may be suitable for a trackless condition, the bond strength is less appealing compared to the rest of the tack applications available. RSC-4 demonstrated a high and consistent bond strength performance, but more time is required for drying to avoid excessive tracking. Tack coat application and surface type combination produce varying results. Therefore, these should be considered when selecting suitable future tack coat application options.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.1
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• pp.27-32
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• 2009

The main objective of this study is to develop a test for measuring the bond shear strength between pavement layers. The research is also conducted to evaluate tack coat materials and application rate in porous pavement. The experiment includes using two types of emulsions (RSC-4, Modified Emulsion) and a asphalt binder type (HM-1). HM-1 was developed to be applied in porous pavement. The bond shear strengths were measured by a direct shear type device under various test conditions. The shear strength may not be appropriate in the evaluation of the bond shear strength, while the toughness of the test may be useful. In case of the tack coat application rate in porous pavement, RSC-4 has to be used a minimum amount of $0.8l/m^2$ and modified emulsion asphalt has to be applied a volume of use $0.5{\sim}0.6l/m^2$. HM-1, asphalt cement type, is far stronger bond shear strength than emulsified asphalt tack coat and had showed the excellent trackless property.