Evaluating the Performance of Tack Coat Materials in Saskatchewan Climate by Means of a Field Study and Laboratory Study – Part 1 Field Study

Tack coat materials are used to provide sufficient bond between an existing asphalt concrete
layer and a new asphalt concrete overlay and/or in-between two lifts of newly placed asphalt
concrete. Most of the time, agencies and contractors rely solely on emulsified bituminous
products for use as tack coats. Recent developments in tack coat materials are focusing on fast
curing and non-tracking emulsions. The objective of this project is to evaluate the performance
of several tack coat materials in Saskatchewan climate through a field study and a laboratorytesting
program. Ten test sections were constructed in August 2017 on a two-way, two-lane
rural highway (Highway 12) near Blaine Lake, Saskatchewan. Construction and installation of
the tack coat materials was completed over two days to eliminate any variability due to
weather conditions. A post-construction inspection was conducted in September 2017 to
document any surface distresses related to the construction process. A distress survey will be
conducted following the spring season of each year for 5 years. Core samples were collected in
September 2017 to evaluate the initial bond strength of the tack coat materials. Core samples
will be collected following the spring season of each year to evaluate the degradation of bond
strength over time. Findings from this project will be used to update the approved tack coat
materials list and provide recommendations and guidelines for construction best practices. This
paper introduces the experiment, discusses the products used, and provides a summary of
observations from the field component of the project.