Laboratory Evaluation of Tensile and Shear Strengths of Asphalt Tack Coats
Woods, Mark Everett
AdvisorBuchanan, M. Shane
CommitteeWhite, Thomas D.
Asphalt tack coats are applied during pavement construction to ensure bond between pavement layers, thus providing a more durable pavement. A prototype tack coat evaluation device (TCED) was developed to evaluate the tensile and torque-shear strength of tack coat materials. Three emulsions (SS-1, CSS-1, and CRS-2) and one asphalt binder (PG 67-22), commonly used as tack coats, were evaluated using the TCED at various application temperatures, application rates, dilutions, and set times. A laboratory bond interface strength device (LBISD) was developed to assess interface shear strength of laboratory-prepared specimens. Mass loss testing was performed to evaluate moisture evaporation and visual breaking properties of emulsions. Study results indicate application rate, tack coat, and emulsion set time significantly affect TCED strength. Application rate also affected evaporation rate of emulsions.