01587327

Component

Dynamic modulus (|E*|) is used to evaluate the response of asphalt concrete in mechanistic-empirical pavement design. Test values measured at different temperature/frequency combinations are used to create a mastercurve, which allows interpolating |E*| for any other condition. Tests are usually performed unconfined even though confined conditions may be more representative of field conditions. This paper describes test results for 4 mixes with a dense gradation used at the Honolulu International Airport. The different mixes were obtained by using two different asphalt binders, a PG64-22 and a polymer modified PG76-22, with and without the addition of a synthetic fibers for each binder. The synthetic fibers used consist of a mix of polyolefin and aramid fibers. The objective is to study the effects on the mastercurve of these different mixtures at different confinement levels (0, 69, 138, and 207 kPa) and different air voids levels (4%, 7%, and 9%). The benefits of confinement varied with the combination of binder type and air voids. For modified mixtures, |E*| was observed to increase significantly with confinement (normally at a decreasing rate) at high temperatures and low frequencies. These benefits are observed for all air voids. For unmodified mixtures, confinement increases substantially at lower and intermediate air voids but the benefits practically disappear at higher air voids. At low temperatures/high frequencies, the confinement effects are minimal. At high temperature/low frequencies, the modified binder increases the confined |E*| significantly but the fibers tend to reduce it slightly with respect to the control mix

This paper was sponsored by TRB committee AFK50 Standing Committee on Characteristics of Asphalt Paving Mixtures to Meet Structural Requirements.

01584066

16-2582

English

15p

2016

Transportation Research Board 95th Annual Meeting

Digital/other

Figures; References; Tables

Air voids; Aramid fibers; Bituminous binders; Confining pressure; Dynamic modulus of elasticity; Hot mix asphalt; Synthetic fibers

Honolulu International Airport

Master curves; Polyolefin fibers

Aviation; Highways; Materials; Pavements; I31: Bituminous Binders and Materials

Transportation Research Board Annual Meeting 2016 Paper #16-2582

TRIS, TRB, ATRI

Jan 12 2016 5:08PM