Evaluation of bond strength of tack coat materials in field: Development of pull-off test device and methodology
Document Type
Article
Publication Date
1-1-2009
Abstract
The results presented in this paper are part of NCHRP Project 9-40 on the Optimization of Tack Coat for Hot-Mix Asphalt Placement. This paper presents the development of a new test device, the Louisiana Tack Coat Quality Tester (LTCQT), for evaluating the quality of the bond strength of tack coat in the field. LTCQT is a modification of the ATacker device. A test matrix was developed to evaluate the reliability and the repeatability of the LTCQT in the field. Three emulsified tack coats (CRS-1, SS-1h, and Trackless) and an asphalt cement (PG 64-22) were evaluated over a wide range of temperatures and at a residual application rate of 0.23 L/m2. Two key test parameters were determined to characterize the mechanical responses of tack coats: the optimum testing temperature and the maximum tensile strength test. Results indicated that the LTCQT can successfully be used in the field to measure the quality of the bond strength of tack coat and to distinguish between the responses of the evaluated tack coats. A good correlation was observed between the absolute viscosity of residual tack coat material and the tack coat tensile strength. This study shows that the softening point can be an adequate parameter to determine the optimum temperature for the tack coat pull-off test, and therefore pull-off testing at the softening point temperature of the residual binder material is recommended for field tack coat evaluation.
Publication Source (Journal or Book title)
Transportation Research Record
First Page
1
Last Page
11
Recommended Citation
Mohammad, L., Bae, A., Elseifi, M., Button, J., & Scherocman, J. (2009). Evaluation of bond strength of tack coat materials in field: Development of pull-off test device and methodology. Transportation Research Record (2126), 1-11. https://doi.org/10.3141/2126-01