full-depth reclamation pavement rehabilitation method existing asphalt, cabc and a pre-determined...
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Full-Depth Reclamation
Pavement Rehabilitation Method • existing asphalt, CABC and a pre-determined
depth of the subgrade soils are uniformly pulverized and blended
• Chemical additive (cement) and water are added, material is mixed and compacted
• “Reclaimed” material acts as a new base material for the placement of a new asphalt course
Full-Depth Reclamation
• Referenced by NCDOT Section 541
• Flexible Pavement Reclamation Using Portland Cement - on NCDOT Geotechnical Engineering Unit website
• www.ncdot.org/doh/preconstruct/highway/ geotech/supportserv/geopavement/• Then choose “FDRwithcement.pdf”
Full-Depth Reclamation
Recently Performed for 2 S&ME Projects
• Trinity Industrial Park Roadways (documented with photos herein)
• Forsyth Technical Community College Greene Hall Parking Lot
Trinity Industrial Park Roadway Prior to Improvement –
Subjected to Relatively Heavy Truck Traffic Volume
Full-Depth Reclamation
• Asphalt pavement had moderate to severe distress with cracking, potholes, and rutting
• 14 cores encountered 1.25“ to 3.25“ asphalt and 2.25” to 9.75” of aggregate base course
• Borings encountered variably compacted, high plasticity clay fill to depths of 2 to 4.5 feet
Trinity Industrial Park Roadway Prior to Improvement –
Subjected to Relatively Heavy Truck Traffic Volume
Full-Depth ReclamationTrinity Industrial Park Roadways
• Obtained bulk sample of asphalt, base course, soils and performed LABORATORY MIX DESIGN
• Mix design for cement contents of 3%, 6% and 9% by weight
• Performed standard Proctor test for each cement content
• Compressive strength specimen were molded at each cement content – compressive strength testing performed
• A target compressive strength between 300 and 400 psi is recommended by research and industry literature for the reclaimed materials
• Laboratory test results indicated a compressive strength of 350 psi for approx. 6.5% cement by weight
Full-Depth Reclamation
Trinity Industrial Park Roadways
• New pavement section – 4 inches asphalt / 12 inches of reclaimed material was recommended as option to conventional remove/replace
• Full-Depth Reclamation was bid as well as conventional remove/replace pavement construction
• Full-Depth Reclamation was lowest cost
Trinity Industrial Park Roadways
Cement placed on existing asphalt
Trinity Industrial Park Roadways
Materials Pulverized & Mixed - 12 inches deep
Trinity Industrial Park Roadways
After Dry Mixing
Trinity Industrial Park Roadways
Adding Water & Mixing Again
Trinity Industrial Park Roadways
Adding Water & Mixing Again
Trinity Industrial Park Roadways
• Reclaimed material was compacted and then proofrolled prior to placement of new asphalt
• Reclaimed material was stable during proofroll evaluation
• No undercutting was necessary prior to, during, or after FDR was performed
Trinity Industrial Park Roadways
Trinity Industrial Park Roadways