Effect of Rejuvenated Binder on the Pavement Rutting Performance at Different Aging Levels

Hesham A Ali,Greg Sholar,Howard Moseley,Mojtaba Mohammadafzali,Farshad Haddadi

doi:10.1155/2020/9693821

Abstract

The use of Reclaimed Asphalt Pavement (RAP) in virgin mixtures is an effective means of promoting sustainability. The objective of this research was to investigate the effect of rejuvenated binder on the rutting performance and moisture susceptibility of high RAP content mixtures. All mixtures were tested at three aging levels, one short-term aging level, and two long-term aging levels. The performance of the specimens and the level of diffusion were measured and compared, and the correlation between binder test and rutting test results was evaluated. Based on the results, the degree of diffusion is not a determining factor in the performance of the mixture. However, the amount of the rejuvenator and Superpave performance grading (PG) of the rejuvenated binder is the most effective parameter. Results indicate that the short-term aged recycled mix exhibits a better rutting resistance than the virgin mix when its HTPG is 6°C higher than the virgin mix.

Highlights

To prepare specimens for binder extraction, the Reclaimed Asphalt Pavement (RAP) and aggregates were heated to 165°C for 45 ± 5 minutes. en, the rejuvenator or/and binder was added to the heated RAP or aggregate specimens and mixed for five minutes. e extraction specimen weight was 1100 ± 20 grams
Only a very thin layer of asphalt remains on the aggregates. e extracted liquid was placed into a centrifuge with an 800 relative centrifugal force (RCF) for 30 minutes to make suspended fine aggregate sediment. e rotatory evaporator was used to separate the solvent from the binder. e binder extracted from the first, second, and third stages represents the outer, intermediate, and inner layers of the asphalt binder film coating the aggregates, respectively
dynamic shear rheometer (DSR) Test. e average Ih of the three aging levels for each specimen type is presented in Table 6. e lowest Ih belongs to the virgin binder with 0.87 and the highest belongs to R1 and R3, which contain rejuvenator RA1. e Ih of 0.87 means that for the control specimens, the outer layer of the virgin binder ages much faster than the rejuvenated binder in R1, R2, R3, and R4

Summary

Objectives

In this research, rutting performance and moisture susceptibility of the hot mix asphalt is evaluated to see the effect of rejuvenated RAP binder on the mixture’s short and longterm performance. Two parameters of HTPG and the homogeneity index are assumed to be the effective parameters. Us, different types and dosages of rejuvenators are used to get different PGs and degree of homogeneities in the binder coating the aggregates Two parameters of HTPG and the homogeneity index are assumed to be the effective parameters. us, different types and dosages of rejuvenators are used to get different PGs and degree of homogeneities in the binder coating the aggregates

Methods

Results

Conclusion