Talking Asphalt: Workmanship matters – August 2012

As part of my consulting work, I routinely review and evaluate newly resurfaced pavements where the owner is concerned or dissatisfied. The original comment will be something like, “The pavement doesn’t look right.” Then the owner, contractor and I will look at the pavement, review any test data and try to determine if there is a significant problem.

Generally, there will be some visible distress. This could be non-uniform surface texture, segregation or poor joints. It could be tack or bonding problems, or a thickness issue or poor compaction. The task then becomes a matter of evaluating whether the concern is “cosmetic” versus “functional.” Is the reasonable life of the pavement compromised? Or, is it just sloppy workmanship? Either way, the owner is not happy; so workmanship matters!   

Most of the pavements that I have been asked to review have been serviceable, but the workmanship certainly could have been better. A little bit of attention to detail and craftsmanship could have avoided the situation. Here’s a reminder about some areas to really concentrate on.

For pavement overlays, the work starts with making sure any damaged or failed areas are repaired. The next step is cleaning the existing surface, followed by applying a uniform tack coat. I’ve seen several slippage failures that could have been readily avoided if the old pavement had been cleaned and then had a good tack application. The purpose of the tack is to promote bonding between the old and new layers. You can’t get a good bond if the old surface is dirty or has fuel spills or other contaminants, or if the tack is poorly applied.

Segregation is a functional problem, not a cosmetic one. Rough, open textured mats allow water to enter and lead to potholes and pavement break-up. The workmanship part of segregation control should be obvious. Handle the material at all times so that it moves in mass rather than allowing individual aggregate particles to rattle out. 

Joint construction is absolutely critical. A lot of complaints are about crooked, overlapped or rough joints. Clean, tight, well-compacted joints last longer (and certainly look better). Take the time to build a good joint. Also, avoid excessive handwork; let the paver do most of the work. Don’t throw the coarse material back on the mat.  

Compaction is another area to really do a good job. An asphalt pavement must be well compacted to provide good performance. A minor increase in the in-place air voids content of the pavement can make a major difference in its service life. Get the roller marks out, too.

Clean up the job before you leave. Remove any waste material or debris. If there are any problems, correct them before leaving. If additional work is needed, notify the owner when it will be done, and follow through on making the corrections.

As I’ve said before, asphalt work is not brain surgery; it starts with doing things consistently well. A big part of that is good workmanship.

Email Dwight at