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FAA Airport Pavement Technology Program. National Airport Pavement Test Facility, FAA William J. Hughes Technical Center, Atlantic City, New Jersey, U.S.A. New PCC Test Items Pavement Thickness Design Software www.airporttech.tc.faa.gov. New Concrete Mix Design.
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FAA Airport PavementTechnology Program • National Airport Pavement Test Facility, FAA William J. Hughes Technical Center, Atlantic City, New Jersey, U.S.A. • New PCC Test Items • Pavement Thickness Design Software • www.airporttech.tc.faa.gov 1
New Concrete Mix Design • 5.2 MPa (750 psi) or lower flexural strength to maximize thickness and minimize tendency for corner cracking due to curl (minimum 4.1 MPa (600 psi)). • Final mix has 50 percent cement replacement with flyash. 2
Single Test Slab Placement • Gain experience with high volume flyash mix placement and finishing. • Measure curling of cured slab. • Further refine instrument installation from that done in previous test strip. • Monitor procedures for test item curing and early age behavior. • Develop field curing methods. 3
Placing Test Slab Finished Slab 4
Field Curing of Slab, Beams and Cylinders • Soaker hoses • Burlap • Plastic • Automatic timer for water • Wet cure for 28 days 5
Results from Test Slab • Experience in placing the high flyash concrete mix. • Instrumentation installation procedures satisfactory. • Low heat of hydration with fairly uniform temperature profile during first 24 hours. • Curling minimal during 28-day cure. • Curling significant after removal of burlap and during drying period. 8
Remaining Plans for CC2 • Continue monitoring test slab behavior. • Place three concrete test items on 8 CBR subgrade. • One on grade (concrete placed by 1/30/04). • One on aggregate subbase (concrete placed by 1/30/04). • One on econocrete subbase (concrete placed by 3/12/04). • Subgrade and support placement complete. • Instrumentation complete and installed. 9
CC2 Test Objectives • Compare life and performance for 4-wheel and 6-wheel traffic. • Compare life and performance for three different support conditions. • Obtain data on SCI versus repetitions to failure. • Compare interior and edge stresses. • Measure shrinking/warping. 10
Tilling Subgrade Rolling Subgrade 11
Placing Test Item Slabs in a Checker-Board Pattern 13
Installing Strain Gages at Slab Center Strain Gages Installed at Slab Edge 14
Pavement Software Products Ö Ö Ö Ö Ö Ö Ö *All checked programs available on www.airporttech.tc.faa.gov 15