220 likes | 361 Views
NCAT WMA Research 2007. Andrea Kvasnak. WMA Field Projects. Chattanooga, TN Silverthorne, CO Birmingham, AL Nashville, TN Rock Hill, SC. Chattanooga. Two site visits Both using Astec Green System Visit 1: Parking lots at Astec Plant Visit 2: North Terrace Road . Chattanooga Site 1.
E N D
NCAT WMA Research 2007 Andrea Kvasnak 1
WMA Field Projects • Chattanooga, TN • Silverthorne, CO • Birmingham, AL • Nashville, TN • Rock Hill, SC 2
Chattanooga • Two site visits • Both using Astec Green System • Visit 1: • Parking lots at Astec Plant • Visit 2: • North Terrace Road 3
Chattanooga Site 1 • Foamed Asphalt • Moisture added was 0.1% by wt of total mix • Compaction Temperatures • 245°F for Virgin • 265°F for RAP • Haul, place and compact using normal procedures 4
Placement of Foamed Asphalt at Astec Plant • 30% RAP base placed first • Some issues with poor base support • Material was workable • Reduced odor 5
Placement of Virgin Mix • Outside bay doors • Target compaction temperature of 245°F • Compaction was same • Some issues with handwork 6
Placement of 30% RAP Surface • Atop 30% base course • Compacted at lower temperature than target • No issues with compacting 7
Chattanooga Site 1: Laboratory Testing • Mobile lab compacted specimens at location • Moisture Susceptibility • 30% RAP base and virgin surface > 0.9 TSR • 30% RAP surface ~ 0.58 TSR • Asphalt Pavement Analyzer • RAP mixes performed better than virgin • Hamburg Wheel Tracking Device • Stripping inflection points < 10,000 • RAP mixes passed, virgin did not 8
Chattanooga TN Site 2 • Astec Double Barrel Green • 2” overlay • 50% RAP • Place at 270°F 9
Chattanooga Site 2:Laboratory Testing • Moisture Susceptibility • Average TSR of 0.8 • Asphalt Pavement Analyzer • Average rut depths < 4 mm • Hamburg Wheel Tracking Device • Ruts < 5 mm • Stripping inflection < 10,000 10
Silverthorne, CO • Three WMA technologies • Advera WMA • Sasobit • Evotherm DAT • Night time paving • Mountain terrain with heavy truck traffic 11
Birmingham, AL • Evotherm DAT • State Rd 79 • Night time paving • WMA and HMA produced and placed • WMA: 15% RAP • HMA: 10% RAP and 5% shingles • Originally considered RAS for both 12
Birmingham, AL cont. • PG 67-22 binder • HMA and WMA placed in the same lane • About 2050 tons of each mix • 1.5 nights of paving for each mix • Test strips (500 tons) and full paving stretch 13
Birmingham, AL:Laboratory Testing • Moisture susceptibility • 3 out of 4 nights passed (2nd WMA 0.7) • APA • APA: WMA > 5 mm, HMA > 3 mm • IDT creep compliance • Not completed • Dynamic modulus • Not completed 14
Shingles • ALDOT and others interested in trying shingles • Concern: Temperature not high enough to get shingle binder activated • Looking into doing some at the NCAT test track • Specimens will be compacted on site 15
Nashville, TN • SR 46 in Nashville • 4 WMA Technologies and 2 controls • Astec Green System • Advera WMA • Evotherm DAT • Sasobit • 3 Plants • 2 different aggregate sources • Furthest haul 45-60 minutes 16
Nashville, TN cont • PG 70-22 • Marshall mix 17
Nashville, TN Field Information • Astec Green System • 775 tons • Compaction: 230°F • Density: 91.6% • Advera WMA • 1150 tons • Compaction: 235°F • Density: 92.7% 18
Nashville, TNField Information Cont. • Evotherm DAT • 750 tons • Compaction: 230°F-250°F • Density: 91% • Sasobit • 705 tons • Compaction: 245°F • Density: 91.7% 19
Nashville, TN:Laboratory Testing • Moisture Susceptibility • All failed except Astec Green (0.83) • APA • Average rut depths for all less than 8mm • Hamburg • Not completed • IDT Creep Compliance • Not completed • Dynamic Modulus • Not completed 20
Rock Hill, SC • 4 mixes • Fractionated RAP • 30% RAP Intermediate and Surface • 50% RAP Intermediate and Surface • PG 64-22 • Testing has not been initiated 21
Questions? 22