Field Experience with Acid Modified Asphaltin Arizona
Glendale
Terminals
Artesia and
Lovington
Refineries
Albuquerque
Terminal
Artesia
Terminal
Holly Asphalt Company“Who are those guys?”
outside asphalt
Once Upon a Time…
There was Holly Asphalt Company dba Navajo Western Asphalt Company mostly PG 70-10 to fixed HMA plants in S. AZ
occasional ADOT project (86 deg PG spread)
ADOT PG strategy changes in 1999 PG 70-16 and PG 76-10 become PG 76-16
use of 110 deg PAV aging
Created significant technical challenge!
The Technical Challenge (1999)
Figure out PG 76-16 for ADOT market Most obvious choice is PMA but…
not enough heat, people, time, or tanks
competition with “modification by process”
need something effective, easy, economical, perform
Research Approach literature review
networking thru industry contacts
develop/test hypothesis thru lab study try polyphosphoric acid
Effect of PPA on PG
-30
-20
-10
0
10
20
30
40
50
60
70
80
A A+1% B B+1% C C+1%
PG
Cro
ssove
r T
em
p,
C
Stability of PPA Modification
0
1000
2000
3000
4000
5000
6000
7000
0 10 20 30
Time in Bucket Heater, days @ 165 C
Vis
cosi
ty @
60 C
, Pois
e
B
B+1%
Effect of PPA on TSR
0
20
40
60
80
100
C C+1% PPA C+ 0.75%
Lime
C+1% PPA +
0.75%lime
TSR
, %
Bullhead City Aggregate, ADOT/SP 19 mm
Effect of PPA on Rutting Susceptibility
0
2
4
6
8
10
12
14
16
C C+1% PPA C+1% PPA +
0.75%lime
Rut
Depth
(50 C
), m
m
Salt River Aggregate, MAG 3/4-inch
Proposed to ADOT (2000)
A.H.B.L. 2002 - 2003
King, et al. AAPT paper PPA failures in OK, KS
problems with amine antistrips
Ho, et al. TRB paper PPA effect temporary
“washed away bywater?”
“pollute groundwater?” Somewhere inNebraska
Facts in 2003 About PPA Use in Arizona and New Mexico
5 yrs experience with AMA
We heard of no epidemic of distress
No onerous effect on construction
Mitigating factors to consider? prevalent use of OGFC (NM) and AR-ACFC (AZ)
dry/moderate climate
mandated use of lime on DOT systems
no amine antistrips
Projects seemed okay, but…
Somewherein Arizona…
do AMAprojects turn out looking likethis???
October 2003 Performance Review in Arizona
7 projects using AMA PG 76-16
2001 thru 2003 construction
roads in good shape,
contractors got paid,
roads smooth and
quiet, didn’t wash away
SR 68
BH City
US 93
Wikieup
US 60
Surprise
SR 85
Buckeye
US 60
@ Thomas Rd
US 60
Florence Jct.
IH-10
@ GRIR
PSR = f(Ride)
SR 68, Bullhead City, PSR = 4.36, RD 0.03, PC 0
PG 76-16, 2001
PSR = 4.13
IH-10 @ GRIR, PSR = 4.03, RD 0.10, PC 2.9
PG 76-16, 2001
PSR = 4.09
US 93, S of Wikieup, PSR = 4.60, RD 0.05, PC 1.2
PG 76-16, 2001
PSR = 4.33
US 60, Surprise, PSR = 4.07, RD 0.12, PC 0.6
PG 76-16, 2002
PSR = 3.85
SR 85, Buckeye, PSR = 3.79, RD 0.16, PC 3.5
PG 76-16, 2003 (rated before this?)
PSR = 3.80
US 60 @ Thomas Rd (no AR-ACFC yet)
October 2003
US 60 @ Thomas Rd, PSR = 4.24, RD 0.08, PC 0
PG 76-16, 2003
February 2004
Road didn’twash away!
PSR = 2.68
Road still didn’twash away!(No ACFC)
US 60, Florence Jct, PSR = 4.16, RD 0.09, PC 2.0
PG 76-16, 2003
PSR = 4.26
QC Data (G*/sin d) 2005 - YTD
PG 76-16, Glendale Terminal
0.00
0.40
0.80
1.20
1.60
Lot No.
10 20 30 40
QC Data (G*/sin d) 2005 - YTD
PG 70-10, Glendale Terminal
0.00
0.40
0.80
1.20
1.60
Lot No.
100 200 300 400 500
QC Data 2005 - YTD
Ease of manufacture Consistency Constructability Performance
G*/sin d, kPa Grade Avg SD n TonsPG 70-10 1.180 0.055 533 752,000PG 76-16 1.176 0.046 47 50,000
Summary
AMA implemented based on specification environment in AZ circa 2000
Up to 8 years performance history in AZ
No epidemic of (or undue) distress
2009 condition similar to 2003 condition
Comparatively easy to manufacture
variability similar to unmodified binders