01661569

Component

During asphalt mixture production, the bulk specific gravity (Gsb) of mixture aggregate is not routinely measured to determine voids in the mineral aggregate (VMA) because it requires multiple tests and extended testing time. Instead, state agencies have used several alternatives to determine VMA of plant produced asphalt mixtures. The objective of this study is to determine the effect of these methods on the VMA determination during production. This study compared the results of four methods for determining Gsb of Reclaimed Asphalt Pavement (RAP) aggregate and six methods for calculating VMA of plant-produced mixtures. Materials, including virgin aggregate, RAP, and plant mix, were sampled during production from 10 projects in Florida. Properties of the sampled materials and mixtures, including Gsb of the virgin aggregate and RAP aggregate, the maximum specific gravity (Gmm) of RAP and plant mix, the bulk specific gravity (Gmb) of compacted mix, and asphalt content, were determined through laboratory testing. The Gsb of RAP aggregates and VMA of mixtures were determined using the methods evaluated, and their effects on Gsb and VMA were investigated. The study results indicated that Gsb of ignition-extracted RAP aggregate and the total aggregate blend can be used to calculate the VMA of the mix during mix design and production if it has been adjusted to account for the effect of the ignition method on the aggregate material.

This paper was sponsored by TRB committee AFK10 Standing Committee on Critical Issues and Emerging Technologies in Asphalt.

18-04574

English

17p

2018

Transportation Research Board 97th Annual Meeting

Digital/other

Figures; References; Tables

Asphalt content; Asphalt mixtures; Plant mix; Reclaimed asphalt pavements; Specific gravity

Ignition method; Maximum specific gravity; Voids in mineral aggregate

Florida

Highways; Materials; Pavements

Transportation Research Board Annual Meeting 2018 Paper #18-04574

TRIS, TRB, ATRI

Jan 8 2018 11:07AM