imad al-qadi, university of illinois at urbana-champaign enad mahmoud, bradley university...
TRANSCRIPT
Best Practices for Implementation of Tack Coat
Imad Al-Qadi, University of Illinois at Urbana-ChampaignEnad Mahmoud, Bradley Universityhttp://ict.illinois.edu/Publications/report%20files/FHWA-ICT-12-004.pdf http://ict.illinois.edu/Publications/report%20files/FHWA-ICT-12-004.pdf
Problem Statement
Interlayer bond is critical to performance
Tack coat is the sole material bonding layers
Optimum tack coat application must be identified
Objectives
Assess laboratory performance of tack coats
Determine optimal residual application rate of tack coats
Evaluate field-optimal tack coat application
Optimize tack coat materials, application rate, placement methods, and surface preparation techniques
Research Performed
LABORATORY
Research Performed
FIELD
Research Performed
FIELD TEST
I-80 - 26 test sections 3 existing surfaces: milled HMA, milled
PCC, and fresh binder stone mastic asphalt (SMA)
Illinois 98 – 19 sections 1 existing surface – milled HMA
Findings
Specify tack coat application rate based on residual AC rate, not truck applicator rate
Developed optimal application rates for all possible surfaces
Identified methods for surface cleaning that provide best bond strength
Determined viable options for rapid set tack coats
Emulsions outperformed cutbacks
Why were Findings Important?
Identification of the optimum tack coat application rate will Ensure cost-effective and efficient
tack coat application Enhance pavement performance Help the industry to better optimizeresources
Recommendations
Based on this research, and the good correlation of laboratory and field results, new products in the future can be tested in the laboratory to determine their expected performance in the field
Implementation
Special Provision for selected projects
Worked with: Tack Coat Manufacturers Materials Personnel Construction Personnel HMA Contractors Applicator Manufacturers
Benefits
Improved Pavement performance Reduced
delamintation Improved rutting
resistance Faster opening to
traffic Some of the tested
products allow traffic over tack coat (trackless tack coat)
Questions?
Amy SchutzbachIllinois Department of [email protected]
Megan SwansonIllinois Department of
Transportation217-782-3547