precast prestressed concrete pavement convention... · title: precast prestressed concrete pavement...

Precast Prestressed Concrete PavementPrecast Prestressed Concrete Pavement

2009 PTI Technical Conference and Exhibition 2009 PTI Technical Conference and Exhibition May 3May 3--5, 20095, 2009

Portland, OregonPortland, Oregon

David K. Merritt, P.E.David K. Merritt, P.E.www.PrecastPavement.com

2009 PTI Technical Conference Precast Prestressed Concrete Pavement David K. Merritt, P.E.

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Overview

BackgroundBenefitsBenefitsBenefitsFHWA Demonstration ProjectsFHWA Demonstration ProjectsFHWA Demonstration ProjectsUpcoming Projects & Potential Future Upcoming Projects & Potential Future Upcoming Projects & Potential Future ApplicationsApplicationsApplications



PPCP Background

2000: FHWA Feasibility Study (University of Texas at Austin) 2002: FHWA Pilot Project in Georgetown, TX 2004: FHWA Demonstration Project in El Monte, California2006: FHWA Demonstration Project in Sikeston, Missouri2006: FHWA Demonstration Project in Sheldon, Iowa2009: FHWA Demonstration Projects in Bear, DE and Fairfax, VACurrently: FHWA providing design and construction support for additional Demonstration Projects



What is PPCP?

Precast Prestressed Concrete Pavement• “Standardized” full-depth precast panels• Keyed panel joints for vertical alignment during

assembly• Constructed over a prepared base (HMA, LCB,

Aggregate Base, etc.)



What is PPCP?

• 2-way prestressing• Combination of pretensioning/post-tensioning• 2-way post-tensioning• Bonded/grouted P-T system

Precast Prestressed Concrete Pavement



Typical PPCP Panel

Continuous Shear Key

Ducts for Post-tensioning

Pretensioning Strands



Typical PPCP Panel Layout

Prepared Base (HMA or LCB)

Base or Existing pavement

Joint Panel Base Panel(Multiple)

C.S. PanelBase Panel(Multiple)

Joint Panel

Polyethylene SheetDuct Holes

Traffic Flow




2” AC Leveling Course

Post-tensioning Post-tensioning




2” AC Leveling Course



Overview

BackgroundBackgroundBackgroundBenefitsFHWA Demonstration ProjectsFHWA Demonstration ProjectsFHWA Demonstration ProjectsUpcoming Projects & Potential Future Upcoming Projects & Potential Future Upcoming Projects & Potential Future ApplicationsApplicationsApplications



Why?

New techniques are needed for Expedited Pavement ConstructionNighttime or weekend construction



Why Precast Concrete?

Expedited construction technique for the commercial building and bridge industriesDurable, High-Performance solution



Benefits

Expedited Construction• Overnight or weekend “invisible” construction • Reduced user delay costs• Reduced disruption to local businesses• Reduced traffic control costs

Small Placements in Remote Areas• Does not require a local concrete plant• Does not require specialized equipment

Extended Construction Season



Benefits

Controlled Fabrication Conditions• Improved Durability and Performance

(consistent mix and mixture flexibility, adequate curing, adequate air entrainment, etc.)



Why Prestressed Precast Concrete?

Benefits

Why Not?

• Reduces/eliminates slab cracking (maintenance)• Reduced number of joints (maintenance/smoothness)• Reduced Slab Thickness (8” vs. 12”)

– Material savings– Allows for replacement of pavement in-kind

• Proven Long-Term Performance– 6” CIP post-tensioned pavement constructed in 1985 (near

West, Texas)– Virtually no maintenance in 22 years



Benefits

Why Prestressed Precast Concrete?• Ability to span voids/unsound support layers

• Move expansion joint further away from abutment (bridge approach slabs)

Approach Slab

AbutmentEmbankment



Overview

BackgroundBackgroundBackgroundBenefitsBenefitsBenefitsFHWA Demonstration ProjectsUpcoming Projects & Potential Future Upcoming Projects & Potential Future Upcoming Projects & Potential Future ApplicationsApplicationsApplications



Texas Demonstration Project (2002)2,300 ft of Interstate 35 frontage road pavement just north of Georgetown, Texas.Surface preparation: 2” HMA leveling course and single layer of polyethyleneFull-width (36 ft x 10 ft) AND Partial-width (16 ft + 20 ft x 10 m) panels8” thick 339 panels total Prestressing• Pretensioning: 6-0.5” strands/panel• Post-Tensioning: monostrand (0.6”) grouted tendons, 24” o.c.



California Demonstration Project (2004)

Widening of Interstate 10 near El Monte, CANight constructionPrecast Panel Dimensions: 37 ft x 8 ft x 10”- 13.1”248 ft total project length (2 post-tensioned sections @ 124 ft)Panels installed over lean concrete basePrestress• Transverse Pretensioning: six 0.5” strands • Longitudinal (grouted) Post-tensioning: 0.6” strands @ 36” o.c. • Epoxy-coated (fine grit impregnated) strand for post-tensioning



Missouri Demonstration Project (2006)Replacement of 40+ yr. old Interstate JRCP1,010 ft total length (4 sections @ 250 ft)• 2 lanes plus shoulders: 38 ft wide• Pavement crown incorporated into panels

Installed over permeable asphalt-stabilized basePrecast Panels: 10 ft x 38 ft x Variable thickness101 panels totalPrestress• Transverse Pretensioning: eight 0.5” strands • Longitudinal (grouted) Post-tensioning: 0.6” strands @ 24” o.c. • End-Stressing for post-tensioning



Iowa Demonstration Project (2006)Precast Prestressed Bridge Approach Slabs• 77 ft at either end of a skewed bridge (16 panels)• Tied to an integral bridge abutment

2-way Post-Tensioning (no pretensioning)Partial-width panels (lane-by-lane construction)Installed over crushed limestone basePrecast Panels: 14 ft x 20 ft x 12 inPost-Tensioning (Longitudinal and Transverse)• 0.6” strands @ 24” o.c.• Grouted Tendons



Iowa Demonstration Project



Other Projects:Red Dog Mine, Alaska (2002)



Overview

BackgroundBackgroundBackgroundBenefitsBenefitsBenefitsFHWA Demonstration ProjectsFHWA Demonstration ProjectsFHWA Demonstration ProjectsUpcoming Projects & Potential Future Applications



Upcoming Projects

I-5/Hwy 14 Interchange – Sylmar/Los Angeles, CA (Aug. 2009)• Ramp• Nighttime construction

Rte. 896 – Bear/Wilmington, DE (May 2009)• Arterial turn lanes• Nighttime construction

I-66 – Fairfax, VA (Summer/Fall 2009)• Interstate main lanes• Nighttime construction



Potential Future Applications

Potential FHWA Demonstration Projects1) Weigh-in-Motion Installations2) Intersections3) Unbonded Overlays4) Temporary Pavement/Crossovers5) Thinner pavement sections beneath bridgesOthers……FHWA is providing design and construction support for demonstration projects.



precast prestressed concrete pavement convention... · title: precast prestressed concrete pavement...

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