A Case Study of the Design, Installation, and Early Performance of a Nineteen-Millimeter

A CASE STUDY OF THE DESIGN, INSTALLATION, AND EARLY PERFORMANCE OF A NINETEEN-MILLIMETER SUPERPAVE MIX Maupin, GW, Jr

Abstract

An attempt was made to design and construct a coarse matrix high binder (CMHB) mix. When the design of the CMHB mix was unsuccessful a coarse 19.0-mm Superpave mix was substituted. This report describes the attempted design of the CMHB mix, as well as the design, construction, and early performance of the Superpave mix. Construction problems with the Superpave mix included low gyratory voids on field samples and tenderness during compaction. Mix adjustments in the gradation and asphalt content failed to remedy the problems. The tenderness also contributed to inadequate pavement density. Although field samples indicated low gyratory voids, no overconsolidation as would be evidenced by bleeding has been observed. Therefore, it appears that this mix was able to contain more asphalt than was predicted by the gyratory voids. The average rut depth of all sections was about 4 mm after 27 months.