In cold weather regions, hot air blasting is a popular crack cleaning method. Hot air blasting typically uses a compressed air heat lance that introduces gas and combustion to the compressed air to provide a jet of hot air to the treated area. However, hot air blasting introduces problems as well. Extreme caution must be taken to ensure the pavement is not overheated, which will result in the asphalt binder becoming brittle and leading to premature failure and may introduce more moisture from the frozen ground.
Care also should be taken to never allow use of direct flame methods, as the charring effect will lead to soot residues and cause poor initial bonding. Such direct flame problems occur frequently with current practices . In addition, hot air blasting does not clean de-icing chemicals that remain in and around the cracks. Furthermore, propane regulators often freeze in cold weather, thus delaying the sealing process.
