01555138

Component

https://doi.org/10.3141/2506-08

The current tendency in the asphalt paving industry is to increase the use of recycled asphalt pavement (RAP) and recycled asphalt shingles (RAS). However, a major concern that limits the use of RAP or RAS is the uncertainty about how much of the aged binder in RAP or RAS can be blended into virgin binder. Studies have focused on the diffusion between old and new binders. However, little research has been conducted to determine how much recycled binder could be mobilized and made available to coat aggregates. This study developed a laboratory procedure to quantify the rate at which aged binder was mobilized for recycled mixtures containing up to 80% RAP and 10% RAS. A new term, "large molecular size percentage (LMSP)," was derived from gel permeation chromatography testing and used to characterize recycled and virgin binders as well as their blends. Blending charts were generated for virgin–aged binder blends containing 0% to 100% RAP or RAS binder in LMSP. The relationship was found to be linear between LMSP and RAP or RAS binder content. An experiment was conducted to validate the method proposed for determining the mobilization rate. The results showed that the RAP binder mobilization rate decreased with the increase in RAP percentage in the mixture, which could be close to 100% at low RAP contents (10% and 20%); the rate dropped from 73% to 24% when the RAP percentage increased from 30% to 80%. For RAS, the mobilization rate reached a peak at 5% RAS content and then started to decrease with the increase in RAS content.

01596058

15-5141

English

pp 72–80

2015

Transportation Research Record: Journal of the Transportation Research Board

9780309369299

Print

Figures (9) ; References (17) ; Tables (2)

Asphalt mixtures; Binders; Blending; Laboratory tests; Recycled materials; Shingles

Highways; Materials; Pavements

TRIS, TRB, ATRI

Dec 30 2014 1:43PM

• Biomodification of Rubberized Asphalt and Its High Temperature Properties
• Characterization of Adhesion and Healing at the Interface Between Asphalt Binders and Aggregate Using Atomic Force Microscopy
• Correlating Laboratory Test Methodologies to Measure Skid Resistance of Pavement Surfaces
• Development of an Analytical Model to Predict the Field Permeability of Asphalt Pavements
• Effect of Mineral Fillers on the Oxidative Aging of Asphalt Binders: Laboratory Study with Mastics
• Effect of Recycling Agents on the Laboratory Performance of Asphalt Mixtures Containing Recycled Asphalt Shingles
• Effect of Water Content on Binder Foaming Characteristics and Foamed Mixture Properties
• Fatigue and Rutting Evaluation of Laboratory-Produced Asphalt Mixtures Containing Reclaimed Asphalt Pavement
• Fatigue Performance Evaluation of Rubberized Porous European Mixture by Simplified Viscoelastic Continuum Damage Model
• Improved Methodology to Evaluate Fracture Properties of Warm-Mix Asphalt Using Overlay Test
• Laboratory Tests and Numerical Simulations of Mixing Superheated Virgin Aggregate with Reclaimed Asphalt Pavement Materials
• Nanomechanical Evaluation of Vapor-Conditioned and Unconditioned Asphalt
• Numerically Supported Experimental Determination of the Behavior of the Interlayer Bond in Asphalt Pavement
• Precision of the Hamburg Wheel-Track Test
• Use of the Resilient Modulus Test to Characterize Asphalt Mixtures with Recycled Materials and Recycling Agents