Why asphalt fails, and what stops it

Most asphalt that fails early was placed badly, not designed badly. The mix was right, the thickness was right, and the pavement underneath was fine. Something went wrong between the truck and the roller.

Temperature is the usual culprit. Asphalt leaves the plant hot and has to be placed and compacted before it cools past the point where the roller can still work it. If the truck waits too long, or the paver stops and starts, or the crew is compacting a mat that has already dropped below its working temperature, the result is a surface that looks fine on the day and ravels within a couple of years because it never reached density. Haulage from plant to site is not a logistics detail. It is a quality control.

The second culprit is the joint. Every place where one paving run meets another is a weakness, and a poorly made longitudinal joint is where water gets in and where the surface starts to break up. Good crews plan their runs to minimise joints, keep them away from wheel paths, and treat each one with the same care as the mat itself.

The third is what is underneath. Asphalt placed on a base that has not been proof rolled, or that has soft spots nobody found, will follow that base as it moves. The surface gets the blame; the preparation was the problem. So we treat proof rolling and base compaction as part of the surfacing package, not as somebody else's job that happened before we arrived.

None of this is complicated. It is a matter of doing the ordinary things properly, every time, with people who know why they matter.