WMA TWG December NCAT WMA Research 2007 Andrea Kvasnak
WMA TWG December WMA Field Projects Chattanooga, TN Silverthorne, CO Birmingham, AL Nashville, TN Rock Hill, SC
WMA TWG December Chattanooga Two site visits Both using Astec Green System Visit 1: –Parking lots at Astec Plant Visit 2: –North Terrace Road
WMA TWG December 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
WMA TWG December Placement of Foamed Asphalt at Astec Plant 30% RAP base placed first Some issues with poor base support Material was workable Reduced odor
WMA TWG December Placement of Virgin Mix Outside bay doors Target compaction temperature of 245°F Compaction was same Some issues with handwork
WMA TWG December Placement of 30% RAP Surface Atop 30% base course Compacted at lower temperature than target No issues with compacting
WMA TWG December 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
WMA TWG December Chattanooga TN Site 2 Astec Double Barrel Green 2” overlay 50% RAP Place at 270°F
WMA TWG December 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
WMA TWG December Silverthorne, CO Three WMA technologies –Advera WMA –Sasobit –Evotherm DAT Night time paving Mountain terrain with heavy truck traffic
WMA TWG December 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
WMA TWG December Birmingham, AL cont. PG 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
WMA TWG December Birmingham, AL: Laboratory Testing Moisture susceptibility –3 out of 4 nights passed (2 nd WMA 0.7) APA –APA: WMA > 5 mm, HMA > 3 mm IDT creep compliance –Not completed Dynamic modulus –Not completed
WMA TWG December 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
WMA TWG December 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 minutes
WMA TWG December Nashville, TN cont PG Marshall mix
WMA TWG December 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%
WMA TWG December Nashville, TN Field Information Cont. Evotherm DAT –750 tons –Compaction: 230°F-250°F –Density: 91% Sasobit –705 tons –Compaction: 245°F –Density: 91.7%
WMA TWG December 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
WMA TWG December Rock Hill, SC 4 mixes –Fractionated RAP –30% RAP Intermediate and Surface –50% RAP Intermediate and Surface PG Testing has not been initiated
WMA TWG December Questions?