01594359

Component

The bond strength between asphalt and aggregates is a crucial parameter in evaluating the capability of a binder to resist moisture-induced damage. The influences of different modifiers and additives on the bond strength and self-healing property of asphalt were investigated using the binder bond strength (BBS) test. Three new indices were introduced in the process, namely, the recovered bond strength, pull-off comprehensive strength, and healing ratio. Furthermore, the impact of the complex modulus on the bond strength was studied using dynamic shear rheometer test. Finally, the pull-off test results were compared with the findings obtained from the Hamburg wheel-tracking device (HWTD) test regarding the moisture sensitivity of mixtures under dry and wet conditions. Results indicate that styrene–butadiene–styrene (SBS), polyethylene (PE), polyphosphoric acid (PPA), and Gilsonite can improve the bond strength. Furthermore, both PPA and sulfur enhanced the adhesion strength of SBS-modified asphalt. The warm additive ethylene bis-stearamide wax (EBS) and rubber processing oil reduced the bond strength of asphalt. Besides, the 18% Asphalt Rubber and asphalt modified with 2% EBS exhibited a self-healing property that was superior to that of PE and Gilsonite modified asphalt. The complex modulus of asphalt was found to have a dual effect on the BBS test results: pull-off tensile strength increased with the complex modulus, while the healing ratio of bond strength decreased with the complex modulus. The comparison of the BBS and HWTD tests confirmed that the BBS test could address the mixture resistance to water damage.

This paper was sponsored by TRB committee AFK20 Standing Committee on Characteristics of Asphalt Materials.

01584066

16-2677

English

15p

2016

Transportation Research Board 95th Annual Meeting

Digital/other

Figures; Photos; References; Tables

Adhesion; Aggregates; Asphalt additives; Asphalt rubber; Bituminous binders; Bond strength (Materials); Styrene butadiene styrene; Sulfur

Complex modulus; Gilsonite; Modifiers (Asphalt); Moisture sensitivity; Polyethylene; Polyphosphoric acid; Self-healing (Materials)

Highways; Materials; Pavements

Transportation Research Board Annual Meeting 2016 Paper #16-2677

TRIS, TRB, ATRI

Jan 12 2016 5:11PM