performance of stone matrix asphalt pavements in maryland
DESCRIPTION
Performance of Stone Matrix Asphalt Pavements in Maryland. L. Michael G. Burke C. Schwartz AAPT 2003 Lexington, KY. Maryland’s First SMA 1992 First Superpave 1995. 2001. 2002. 1999. 2000. 1996. 1997. 1998. Since 1996 Maryland has been designing SMA with SGC. 76-22. 70-22. - PowerPoint PPT PresentationTRANSCRIPT
Performance of Performance of Stone Matrix AsphaltStone Matrix Asphalt
Pavements Pavements in Marylandin Maryland
L. MichaelL. MichaelG. BurkeG. BurkeC. SchwartzC. Schwartz
AAPT 2003AAPT 2003Lexington, KYLexington, KY
Maryland’s First SMA 1992
First Superpave 1995
Since 1996 Maryland has
been designing SMA with SGC
1996 1997 1998 1999
2000 2001 2002
Since 1997 Maryland has been using PG Binders...
76-22 70-22 64-28
Ndesign 100VTM 4.0VMA 18.0External1.25Internal
1.16
GRADATION SPECIFICATION
0.075
0.15
0.3
0.6
1.18
2.36
4.75
9.5
12.5
19.0 mm100
82-88-60
20-28
14-20
9-11
12.5 mm100
90-9970-85
30-50
20-33
8-11
9.5 mm100
10070-90
30-50
20-30
8-13
19.0
COARSE AGGREGATEGap-Graded Mixes
TestProperty
LA Abrasion Loss,% Max.
Flat & ElongatedParticles, %
Retained on the #4 Sieve Max.
3:1
5:1
PV
Test Method
T96
D4791
---
---
MSMT 411
SpecificationLimits
30
---
20
5
8.5(d)
The Gap-Graded Specimen shall conform to the following
Hot MixAsphalt
Gap-Graded
Plant Control
VMA
18.0 Min.
17.0 Min.
VTM
4.0
±1.2
Ndes
100
AC
6.5 Min.
±0.4
Binder
70-22
Draindown% Max.
Stabilizer ByWeight of
Total Mix %
Specification
0.3
0.2 - 0.4
Plant Tolerance
0.3 Max.
±0.1
CHARACTERISTICSCHARACTERISTICS
Superpave SMASuperpave SMA
Rut ResistantRut Resistant
DurableDurable
Skid ResistantSkid Resistant
Reduced SprayReduced Spray
Reduced HydroplaningReduced Hydroplaning
Reduced SoundReduced Sound
DECISION POINTS FOR USING SMA DECISION POINTS FOR USING SMA
• 2000 ESAL’s per day
• 55 mph
• 2000 ESAL’s per day
• 55 mph
MD SMA LANE MILESMD SMA LANE MILES
NUMBER OF PROJECTS NUMBER OF PROJECTS BY MIX TYPEBY MIX TYPE
12.5 mm
19 mm
0
50
100
150
200
250
300
5.2 5.4 5.6 5.8 6.0 6.2 6.4 6.6 6.8 7.0 7.2 7.4
Asphalt Content (%)
Fre
qu
en
cy
0
10
20
30
40
50
60
70
5.7 5.8 5.9 6.0 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 6.9 7.0 7.1
Asphalt Content (%)
Fre
qu
en
cy
12.5 mm
19 mm
0
20
40
60
80
100
120
Air Voids (%)
Fre
qu
en
cy
010
20
30
40
50
60
7080
Air Voids (%)
Fre
qu
en
cy
12.5 mm
19 mm
0
50
100
150
200
250
15 16 17 18 19 20 21 22 23 24
VMA (%)
Fre
qu
en
cy
0
20
40
60
80
100
120
15 16 17 18 19 20 21 22 23 24 25 26
VMA (%)
Fre
qu
en
cy
12.5 mm
19 mm
y = 0.0082x + 0.0956
R2 = 0.0582
y = 0.0040x + 0.1054
R2 = 0.0664
0.00
0.05
0.10
0.15
0.20
0.25
0 1 2 3 4 5 6 7 8 9 10
Time Since Construction (years)
12.5 mm19 mm12.5 mm19 mm
y = 0.0082x + 0.0956
R2 = 0.0582
y = 0.0040x + 0.1054
R2 = 0.0664
0.00
0.05
0.10
0.15
0.20
0.25
0 1 2 3 4 5 6 7 8 9 10
Time Since Construction (years)
12.5 mm19 mm12.5 mm19 mm
RUTTING RUTTING PERFORMANCEPERFORMANCE
ROUGHNESS (IRI)ROUGHNESS (IRI)
y = -1.36x + 76.36
R2 = 0.01
y = 2.57x + 84.03
R2 = 0.04
0
50
100
150
200
0 1 2 3 4 5 6 7 8 9 10
Time Since Construction (years)
12.5 mm19 mm12.5 mm19 mm
y = -1.36x + 76.36
R2 = 0.01
y = 2.57x + 84.03
R2 = 0.04
0
50
100
150
200
0 1 2 3 4 5 6 7 8 9 10
Time Since Construction (years)
12.5 mm19 mm12.5 mm19 mm
FRICTIONFRICTION
y = -0.728x + 49.726
R2 = 0.025
y = 0.218x + 45.512
R2 = 0.005
20
30
40
50
60
70
0 1 2 3 4 5 6 7 8 9 10
Time Since Construction (years)
12.5 mm19 mm12.5 mm19 mm
y = -0.728x + 49.726
R2 = 0.025
y = 0.218x + 45.512
R2 = 0.005
20
30
40
50
60
70
0 1 2 3 4 5 6 7 8 9 10
Time Since Construction (years)
12.5 mm19 mm12.5 mm19 mm
CORRELATIONSAC AV VMA 0.075 mm 4.75 mm IRI/Year Rutting/Year Friction/Year
AC 1.00AV 0.29 1.00VMA 0.24 0.29 1.000.075 mm 0.06 0.18 -0.32 1.004.75 mm 0.10 -0.05 0.12 -0.31 1.00 IRI/Year -0.29 -0.09 0.24 -0.19 -0.09 1.00 Rutting/Year -0.23 -0.22 -0.17 -0.04 -0.52 0.51 1.00 Friction/Year -0.42 -0.47 -0.32 -0.08 -0.47 -0.12 0.14 1.00
12.5 mm
AC AV VMA 0.075 mm 4.75 mm IRI/Year Rutting/Year Friction/YearAC 1.00AV -0.01 1.00VMA 0.25 0.63 1.000.075 mm 0.10 0.28 0.15 1.004.75 mm -0.15 0.20 0.27 -0.09 1.00 IRI/Year -0.12 -0.06 0.04 0.05 0.08 1.00 Rutting/Year 0.20 -0.25 -0.01 -0.06 -0.18 0.09 1.00 Friction/Year -0.01 -0.04 0.11 -0.40 0.26 -0.30 0.20 1.00
19 mm
• SMALL RANGE OF PERFORMANCE
• SMALL RANGE OF MIX PROPERTIES
SUMMARYSUMMARY• Performance and material
property data for 85 SMA projects– 1300 lane miles– Up to 10 years service life– Primarily 19 and 12.5 mm SMA mixes
• Excellent performance:– Rutting: 0.04 inches/year (avg)– Roughness (IRI): 3.2 in/mile-year
(avg)– Friction (FN): 1.3/year (avg)
SUMMARYSUMMARY
• Inconclusive correlations between performance and mix properties– Too little variation/deterioration of
performance– Too little variation in mix properties
Many of the Maryland SMA sectionsMany of the Maryland SMA sectionslook better today than when firstlook better today than when first
opened to traffic!opened to traffic!
SMA looks good...
…Let’s use it!