The History of Tack Coat Treatment

Bond coat (also known as tack coat) has been used since the early days of asphalt construction.  It is a widely accepted common practice in hotmix road construction.  Recent research by NCAT has confirmed its importance as one of the most cost-effective ways to prevent upper lift failure and placed new emphasis on proper application.  The study found that, at the time, industry standard application rates of bond coat were not sufficiently meeting the needs of effective road construction-- leading to premature road failure.  Researchers reduced that proper bonding may require up to twice the previously recommended amount, with new changes to recommended application rates and methods in order to increase compaction and better prevent road failure due to slippage between layers.