TechBrief: The Use of Thin Asphalt Overlays for Pavement Preservation
Primary Topic: Materials-Asphalt
Description: This Technical Brief provides an overview of thin asphalt overlays placed as a pavement preservation treatment. This document defines thin asphalt overlays as dense graded mixtures placed less than 1½ inches in thickness. Gap-graded and open-graded mixtures may be specifically designed for thin placement but they are considered specialty mixtures and are not discussed in this document. Thin asphalt overlays placed for pavement preservation are functional overlays to extend the service life of the pavement and are not intended to add structural capacity. The key benefits of a thin asphalt overlay are improved ride, corrected rutting, impermeability, and reduced noise. Project selection, mix design criteria, construction considerations and expected performance are presented. Since some aspects of the technology are still evolving; best practices and areas of caution are included.
FHWA Publication Number: FHWA-HIF-19-053
Publication Year: 2019
Document Links: PDF (file size: 1 mb)