What effect does stopping and starting the paver have on the mat?

• A. It improves surface uniformity.
• B. It reduces material temperature.
• C. It speeds up production.
• D. It will create dips and bumps in the mat.

Answer: (D)

Stopping and starting the paver breaks the continuous flow of asphalt, causing temperature and viscosity changes at each restart. The mat cools and stiffens near the joint, and the screed has to reestablish a uniform surface as new material is fed in. This creates a weak transition zone and slight thickness differences, which show up as dips at the start of a pass and bumps where the old and new material meet. Continuous paving helps maintain uniform density and thickness, so interruptions lead to nonuniformities rather than improvements.