2011‐02‐28
1
Alan Carter, Ph.D.École de technologie supérieure
Flexible Pavement Research Symposium – Feb. 23 2011
Outline of the presentation
IntroductionBackground
CIRSCORE
ObjectivesResultsResults
Czech RepublicQuebec
Conclusion
2011‐02‐28
2
Right thereg
École de technologie supérieure (ETS)
2011‐02‐28
3
Research Subjects
Thermal cracking of HMAUsage of RAPFatigue resistance and complexmodulusPavement designAsphalt Shingles in HMAAsphalt Shingles in HMACold recycling
Thermal cracking of HMA
PG58-28
Binder No. of freeze-thaw
cycles
Vitreous transition
(oC)
Failure temp. (oC)
Failure stress (MPa)
PG58 28
Water 8 -17.5 -31.8 4.0
Brine 8 -15.3 -27.7 2.38
2011‐02‐28
4
Research Subjects
Thermal cracking of HMAUsage of RAPFatigue resistance and complexmodulusPavement designAsphalt Shingles in HMAAsphalt Shingles in HMAWarm mixesCold recycling
RAP in HMA
70 ºC
2
3
4
5
6
7
*/si
nδ, 7
0ºC
(kP
a)
0
1
2
RBB--UH RBB-HM RBB-HC RBB-HNC
G
2011‐02‐28
5
Research Subjects
Thermal cracking of HMAUsage of RAPFatigue resistance and complexmodulusPavement designAsphalt Shingles in HMAAsphalt Shingles in HMAWarm mixesCold recycling
ComplexModulus
10, 3, 1, 0.3, 0.1, 0.01 and 0.03 HzCompression isine wave
-35, -30, -20, -10, 0, 10 and 20oC
2011‐02‐28
6
Complex Modulus120°
Epoxy glued
120°120°
Epoxy gluedaluminum
caps
Extensometer spring CIR sample
Research Subjects
Thermal cracking of HMAUsage of RAPFatigue resistance and complexmodulusPavement designAsphalt Shingles in HMAAsphalt Shingles in HMAWarm mixesCold recycling
2011‐02‐28
7
Pavement design
FPD AASHTO AI MEPDG
EB14 SMA EB14 SMA EB14
SMA EB14 SMA
Asphalt surface course (mm)50 50 50 50 50 50 50 50
Asphalt Base (mm)p ( )137 91 137 158 224 224 229 216
Granular Base (mm) 150 150 150 150400 400
150 150Granular sub-base (mm)
250 250 250 250 250 250
Research Subjects
Thermal cracking of HMAUsage of RAPFatigue resistance and complexmodulusPavement designAsphalt Shingles in HMAAsphalt Shingles in HMAWarm mixesCold recycling
2011‐02‐28
8
Asphalt shingles in HMA
Tear-off shinglesV i bilit f diff tVariability from different sourcesEffective binder content
Research Subjects
Thermal cracking of HMAUsage of RAPFatigue resistance and complexmodulusPavement designAsphalt Shingles in HMAAsphalt Shingles in HMAWarm mixesCold recycling
2011‐02‐28
9
Warm mixes
Let’s try to go lower!
ESG14LEA+ Sasobit
(1)
ESG14LEA+ Sasobit (2)
ESG14LEA+ Sasobit
(3)
ESG14LEA
Binder additive
1,8% Sasobit
150°C
1,8% Sasobit
140°C
1,8% Sasobit
130°C -130°
CAgg. 120°C 100°C 90°C 90°C
3,5% 3,5% 3,5% 3,5%Sand
3,5% water
23°C3,5% water
23°C3,5% water
23°C3,5% water
23°C
Cure 80°C 80°C 80°C 80°C
2011‐02‐28
10
Flexible pavement rehabilitation
What is Full Depth Reclamation(FDR)?
FDR is a pavement rehabilitationtechnique in which the full flexibletechnique in which the full flexible pavement section and a predeterminedportion of the underlying materials are uniformely crushed, pulverized or blended, resulting in a stabilized base course; further stabilization may becourse; further stabilization may beobtained through the use of availableadditives
2011‐02‐28
11
FDR
2011‐02‐28
12
Quebec’s paved road network
MTQ ≅ 33 000 km Municipalities ≅ 92 000 km
Average rainfall: 1 000 mm / yearFreeze depth: 1,2 to 3mNumber of days below freezing: 147 to 218Number of days below freezing: 147 to 218
2011‐02‐28
13
FDR done in Quebec (MTQ)
120
140)
40
60
80
100
120
(7
200
m2
/ km
)
FDRFDR stab.
0
20
1990 1995 2000 2005
Km
YEAR
Homogeneity
12000
6000
8000
10000
Load
(N)
Average: 9 377N
COV: 11%
0
2000
4000
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Samples
2011‐02‐28
14
FDR mix design
Based on Marshall stability and coating
Total water(% ωtot)
Residualbinder
added (%)
Addedcement
(%)
In-Place FDR - emulsion 4,0 to 6,5 1,8 to 3,5 0,8 to 1,5
In-Place FDR - foam 4,5 to 6,5 2,4 to 3,0 0,8 to 1,5
In-plant FDR - emulsion 4,0 to 8,0 1,4 to 2,2 0,8 to 1,5
2,2
2,7
1,0
1,0
FDR Mix Design
Use of Superpave Gyratory Compactor
2011‐02‐28
15
FDR Mix Design
Use of Superpave Gyratory Compactor
FDR Cure
In QuebecQC l t t d ft 2 3 d (38 C)QC samples tested after 2-3 days (38oC)Need to meet Marshall stability (dry and wet)
Problem○ Fails in lab – really good in field!
2011‐02‐28
16
FDR Cure (CTU)
1,5 2 % cement
1
TS a
t 5o C (M
Pa)
7 air
3 air + 8 ec 7 air + 21 ec
28 air
0
0,5
7 21 28
Days
IT
14 air + 14 w
FDR Lab vs Field
2 tests sectionsDiff t l i t tDifferent emulsion contentDifferent gradation
Even when coveredwith 2 layers of HMAwith 2 layers of HMAhigh variabilityEffect of temperature
2011‐02‐28
17
FDR
On-going workR t tiRepresentative cureEffect of cold temperatureCaracterisationPavement design
Thank you
Alan [email protected]
