Asphalt Overlay

Back to Glossary

Asphalt Overlay

What is Asphalt Overlay?

Asphalt Overlay, A resurfacing method that installs new hot mix asphalt atop an existing pavement to restore ride quality.

Description

Asphalt Overlay involves milling or cleaning an existing asphalt surface and placing a new lift of hot mix asphalt, typically 1.5–2 inches thick. Overlays correct raveling, oxidation, and minor rutting without full reconstruction, extending pavement life by 8–15 years. Key steps include tack coat application for bonding, adherence to profile grades, and proper compaction. Interlayers mitigate reflective cracking or stress-absorbing membranes.

FAQs

  • When is overlay preferred over full replacement?

    When base layers remain structurally sound and distresses are surface level.

  • What thickness is typical?

    Residential driveways 1.5 in, arterial roads 2–3 in.

  • Is milling always required?

    Milling improves smooth tie-ins at gutters and curbs but may be skipped on rural roads.

  • How long before traffic can use the new overlay?

    Generally, after cooling to below 140°F, about 2–4 hours.

  • What causes overlay slippage?

    Insufficient tack coat or contamination between layers.

  • Who designs the overlay mix?

    Pavement engineers specify gradation and binder grade.

  • Can overlays be recycled later?

    Yes, future milling recovers RAP for new mixes.

Fun Fact

Fun Fact: The world’s first asphalt overlay project was Pennsylvania Avenue in Washington  , D.C. in 1876, laid to reduce dust for the centennial celebrations.

CSI Code

32 12 16

NAHB Code

270