01594655

Component

https://doi.org/10.3141/2574-07

As virgin pavement material sources become scarcer and costlier, the use of higher quantities of reclaimed asphalt pavement (RAP) in the production of new asphalt mixes becomes desirable. A major concern associated with the use of high percentages of RAP in new mixes is the interaction between age-hardened and new binders because the performance of the mix can be highly influenced by the properties of the composite binder. The objective of this study was to use asphalt binder testing and diffusion and aging theory to investigate the evolution of blending of virgin and RAP binders during asphalt mix production, storage, and placement. The rheological properties of a two-layer asphalt binder sample composed of virgin and simulated RAP binder and conditioned over time at different temperatures were measured with a dynamic shear rheometer. The conditioning process simulated the hot-mix asphalt (HMA) and warm-mix asphalt (WMA) time–temperature paths during mixing, storage, and placement. The diffusion and aging coefficients for the composite binder were estimated by comparing measured shear stiffness values with those predicted with a diffusion model and considering asphalt binder aging over time. The diffusion model was solved numerically with the finite control volume approach. On the basis of the preliminary laboratory test results, full blending of the age-hardened binder and the new binder was observed during HMA mixing and construction, while only partial blending was achieved during WMA production and construction. The blending of age-hardened and new binders could potentially be improved with the aid of warm-mix admixtures, rejuvenating agents, or both.

01616111

16-4454

English

0000-0002-8924-6212

pp 64–73

2016

Transportation Research Record: Journal of the Transportation Research Board

9780309441148

Print

Figures (8) ; References (33) ; Tables (6)

Age hardening; Bituminous binders; Blending; Hot mix asphalt; Mixing; Paving; Reclaimed asphalt pavements; Warm mix paving mixtures

Diffusion theory; Finite volume method

Construction; Highways; Materials; Pavements

TRIS, TRB, ATRI

Jan 12 2016 5:58PM

• Blending Measurements in Mixtures with Reclaimed Asphalt: Use of Scanning Electron Microscopy with X-Ray Analysis
• Detection and Estimation of Re-Refined Engine Oil Bottoms in Asphalt Binders: Texas Department of Transportation’s Approach with Wavelength Dispersive X-Ray Fluorescence Spectroscopy
• Direct Tensile Test to Assess Healing in Asphalt
• Effect of Polymer and Oil Modification on the Aging Susceptibility of Asphalt Binders
• Effect of Rejuvenators on Rheological, Chemical, and Aging Properties of Asphalt Binders Containing Recycled Binders
• Fatigue Performance of Re-Refined Engine Oil Bottom–Modified Asphalt: Laboratory Study
• High-Temperature Properties of Asphalt Binders: Comparison of Multiple Stress Creep Recovery and Performance Grading Systems
• Investigation on the Development of Asphalt Mixture Limit Criteria for Low-Temperature Cracking
• Measuring Adhesion Between Modified Asphalt Binders and Aggregate Minerals: Use of Particle Probe Scanning Force Microscopes
• Quantifying the Thermomechanical Response of Bitumen from Microphase Properties
• Rolling Thin Film Oven Test and Pressure Aging Vessel Conditioning Parameters: Effect on Viscoelastic Behavior and Binder Performance Grade
• Study of Evolution of Asphalt Binder Microstructure Resulting from Aging and Tensile Loading
• Study of Moisture Impact on Asphalt Before and After Oxidation Using Molecular Dynamics Simulations
• Temperature Effects of Linear Amplitude Sweep Testing and Analysis