Abstract

The use of reclaimed asphalt pavement (RAP) in hot mix asphalt (HMA) has been increasing in the last few decades because of its cost benefits and because of a compelling need to preserve the environment and natural resources. It is commonly assumed that HMA containing RAP (HMA-RAP) has an improved resistance to permanent deformation (rutting) and decreased resistance to the fatigue cracking. This is due to the fact that asphalt binder contained in the RAP has been oxidized over the years and is typically stiffer than virgin asphalt binder. However, during the production stage of the HMA-RAP, the blending between aged and virgin asphalt binders would be incomplete or partial, which would lead to heterogeneous distribution of the aged and virgin asphalt binders within the asphalt mix with RAP. Therefore, the purpose of this article is to evaluate the effect of silo storage on the blending mechanism between virgin and RAP asphalt binders and the impact that this would have on performance of the mix. Two plant-produced asphalt mixes (HL-3 and HL-8), typically used in the province of Ontario for surface and base courses in flexible pavements, were considered in this study. The mixes were designed with 15 and 30 % RAP, respectively, and the samples were collected immediately after the production (0 h) or at different silo storage times (1, 4, 8, and 12 h). The temperatures of the collected materials were closely monitored and recorded. The findings of this research indicated that silo-stored samples exhibited some improvement in their rutting and fatigue resistance. The examination of the dynamic modulus master curves indicated that the rheology of the mixes evolved with silo storage and that blending between the aged and the virgin binders has been improved.

References

1.
Cooley
L. A.
,
Kandhal
P. S.
,
Buchanan
M. S.
,
Fee
F.
, and
Epps
A.
, “
Loaded Wheel Testers in the United States: State of the Practice
,”
Transportation Research Circular
, no. 
E-C016
(July
2000
): 21.
2.
Izzo
R. P.
and
Tahmoressi
M.
, “
Use of the Hamburg Wheel-Tracking Device for Evaluating Moisture Susceptibility of Hot-Mix Asphalt
,”
Transportation Research Record: Journal of the Transportation Research Board
1681
, no. 
1
(January
1999
):
76
85
. https://doi.org/10.3141/1681-10
3.
Haas
R.
,
Tighe
S.
,
Dore
G.
, and
Hein
D.
, “
Mechanistic-Empirical Pavement Design: Evolution and Future Challenges
,” in
Annual Conference and Exhibition of the Transportation Association of Canada
(
Ottawa, Canada
:
Transportation Association of Canada
,
2007
).
4.
Lee
H. J.
,
Lee
J. H.
, and
Park
H. M.
, “
Performance Evaluation of High Modulus Asphalt Mixtures for Long Life Asphalt Pavements
,”
Construction and Building Materials
21
, no. 
5
(May
2007
):
1079
1087
. https://doi.org/10.1016/j.conbuildmat.2006.01.003
5.
Neubauer
O.
and
Partl
M. N.
, “
Impact of Binder Content on Selected Properties of Stone Mastic Asphalt
,” in
Proceedings of the Third Eurasphalt and Eurobitume Congress
(
Crowthorne, UK
:
Transport Research Laboratory
,
2004
),
1614
1621
.
6.
Oliver
J. W. H.
, “
The Influence of the Binder in RAP on Recycled Asphalt Properties
,”
Road Materials and Pavement Design
2
, no. 
3
(
2001
):
311
325
. https://doi.org/10.1080/14680629.2001.9689906
7.
Chen
J.-S
,
Wang
C.-H.
, and
Huang
C.-C.
, “
Engineering Properties of Bituminous Mixtures Blended with Second Reclaimed Asphalt Pavements (R2AP)
,”
Road Materials and Pavement Design
10
, no. 
sup1
(
2009
):
129
149
. https://doi.org/10.1080/14680629.2009.9690240
8.
Nahar
S. N.
,
Mohajeri
M.
,
Schmets
A. J. M.
,
Scarpas
A.
,
van de Ven
M. F. C.
, and
Schitter
G.
, “
First Observation of Blending-Zone Morphology at Interface of Reclaimed Asphalt Binder and Virgin Bitumen
,”
Transportation Research Record: Journal of the Transportation Research Board
2370
, no. 
1
(January
2013
):
1
9
. https://doi.org/10.3141/2370-01
9.
Di Benedetto
H.
,
de La Roche
C.
,
Baaj
H.
,
Pronk
A.
, and
Lundström
R.
, “
Fatigue of Bituminous Mixtures
,”
Materials and Structures
37
, no. 
3
(April
2004
):
202
216
. https://doi.org/10.1007/BF02481620
10.
Huang
B.
,
Li
G.
,
Vukosavljevic
D.
,
Shu
X.
, and
Egan
B. K.
, “
Laboratory Investigation of Mixing Hot-Mix Asphalt with Reclaimed Asphalt Pavement
,”
Transportation Research Record: Journal of the Transportation Research Board
1929
, no. 
1
(January
2005
):
37
45
. https://doi.org/10.1177/0361198105192900105
11.
Huang
B.
,
Zhang
Z.
,
Kingery
W.
, and
Zuo
G.
, “
Fatigue Crack Characteristics of HMA Mixtures Containing RAP
,” in
Proceedings of Fifth International Conference on Cracking in Pavements
(Paris, France: RILEM,
2004
),
631
638
.
12.
Moghaddam
T. B.
and
Baaj
H.
, “
The Use of Rejuvenating Agents in Production of Recycled Hot Mix Asphalt: A Systematic Review
,”
Construction and Building Materials
114
(July
2016
):
805
816
. https://doi.org/10.1016/j.conbuildmat.2016.04.015
13.
Shirodkar
P.
,
Mehta
Y.
,
Nolan
A.
,
Sonpal
K.
,
Norton
A.
,
Tomlinson
C. A.
,
Dubois
E.
,
Sullivan
P. F.
, and
Sauber
R. W.
, “
A Study to Determine the Degree of Partial Blending of Reclaimed Asphalt Pavement (RAP) Binder for High RAP Hot Mix Asphalt
,”
Construction and Building Materials
25
, no. 
1
(January
2011
):
150
155
. https://doi.org/10.1016/j.conbuildmat.2010.06.045
14.
Jiang
Y.
,
Gu
X.
,
Zhou
Z.
,
Ni
F.
, and
Dong
Q.
, “
Laboratory Observation and Evaluation of Asphalt Blends of Reclaimed Asphalt Pavement Binder with Virgin Binder Using SEM/EDS
,”
Transportation Research Record: Journal of the Transportation Research Board
2672
, no. 
28
(July
2018
):
69
78
. https://doi.org/10.1177/0361198118782023
15.
Liphardt
A.
,
Radziszewski
P.
, and
Król
J.
, “
Binder Blending Estimation Method in Hot Mix Asphalt with Reclaimed Asphalt
,”
Procedia Engineering
111
(
2015
):
502
509
. https://doi.org/10.1016/j.proeng.2015.07.123
16.
Carpenter
S. H.
and
Wolosick
J. R.
, “
Modifier Influence in the Characterization of Hot-Mix Recycled Material
,”
Transportation Research Record
, no. 
777
(
1980
):
15
22
.
17.
Kriz
P.
,
Grant
D. L.
,
Veloza
B. A.
,
Gale
M. J.
,
Blahey
A. G.
,
Brownie
J. H.
,
Shirts
R. D.
, and
Maccarrone
S.
, “
Blending and Diffusion of Reclaimed Asphalt Pavement and Virgin Asphalt Binders
,”
Road Materials and Pavement Design
15
, no. 
sup1
(
2014
):
78
112
. https://doi.org/10.1080/14680629.2014.927411
18.
Kriz
P.
,
Grant
D. L.
,
Gale
M. J.
,
Lavorato
S.
, and
Pahalan
A.
, “
Reclaimed Asphalt Pavement-Virgin Binder Diffusion in Asphalt Mixes
,” in
Proceedings of the 59th Annual Conference of the Canadian Technical Asphalt Association (CTAA)
(
Ottawa, Canada
:
Transportation Association of Canada
,
2014
),
375
400
.
19.
Alavi
M. Z.
,
He
Y.
,
Harvey
J.
, and
Jones
D.
,
Evaluation of the Combined Effects of Reclaimed Asphalt Pavement (RAP), Reclaimed Asphalt Shingles (RAS), and Different Virgin Binder Sources on the Performance of Blended Binders for Mixes with Higher Percentages of RAP and RAS, No. UCPRC-RR-2015-06
(
Davis, CA
:
National Center for Sustainable Transportation
,
2015
).
20.
Rad
F. Y.
,
Sefidmazgi
N. R.
, and
Bahia
H.
, “
Application of Diffusion Mechanism: Degree of Blending between Fresh and Recycled Asphalt Pavement Binder in Dynamic Shear Rheometer
,”
Transportation Research Record: Journal of the Transportation Research Board
2444
, no. 
1
(January
2014
):
71
77
. https://doi.org/10.3141/2444-08
21.
Jacques
C.
,
Daniel
J. S.
,
Bennert
T.
,
Reinke
G.
,
Norouzi
A.
,
Ericson
C.
,
Mogawer
W.
, and
Kim
Y. R.
, “
Effect of Silo Storage Time on the Characteristics of Virgin and Reclaimed Asphalt Pavement Mixtures
,”
Transportation Research Record: Journal of the Transportation Research Board
2573
, no. 
1
(January
2016
):
76
85
. https://doi.org/10.3141/2573-10
22.
Kennedy
T. W.
and
Huber
G. A.
,
The Effect of Mixing Temperature and Stockpile Moisture on Asphalt Mixtures, No. FHWA/TX-85/49+ 358-1
(
Austin, TX
:
Texas State Department of Highways and Public Transportation
,
1984
).
23.
Fontes
L. P. T. L.
,
Trichês
G.
,
Pais
J. C.
, and
Pereira
P. A. A.
, “
Evaluating Permanent Deformation in Asphalt Rubber Mixtures
,”
Construction and Building Materials
24
, no. 
7
(July
2010
):
1193
1200
. https://doi.org/10.1016/j.conbuildmat.2009.12.021
24.
Seo
Y.
,
El-Haggan
O.
,
King
M.
,
Lee
S. J.
, and
Kim
Y. R.
, “
Air Void Models for the Dynamic Modulus, Fatigue Cracking, and Rutting of Asphalt Concrete
,”
Journal of Materials in Civil Engineering
19
, no. 
10
(October
2007
):
874
883
. https://doi.org/10.1061/(ASCE)0899-1561(2007)19:10(874)
25.
Standard Method of Test for Determining the Fatigue Life of Compacted Asphalt Mixtures Subjected to Repeated Flexural Bending
, AASHTO 321 (
Washington, DC
:
American Association of State Highway and Transportation Officials
,
2017
).
26.
Bituminous Mixtures—Test Methods for Hot Mix Asphalt—Part 24: Resistance to Fatigue
, EN 12697-24 (
Brussels, Belgium
:
European Committee for Standardization
,
2007
).
This content is only available via PDF.
You do not currently have access to this content.