Spliced Girders A Producer’s Perspective by Chad Saunders Chief Engineer Bayshore Concrete Products presented at the Virginia Concrete Conference Richmond, Virginia March 11, 2005

Bayshore Concrete Products Cape Charles, VA 90 acre casting facility on Cape Charles Harbor and Chesapeake Bay

The shape. How did we get here? PCEF Prestressed Concrete Committee for Economic Fabrication A committee established by FHWA for economic fabrication of prestressed/precast concrete Consists of Mid Atlantic states

PCEF Cross Section Variability 6” 7” 8” Different web thicknesses = diff. soffit

PCEF Cross Section Variability 58” 59” 60” 12” wider top flange = same side form with blockout removed

Form modification

VDOT PCBT 32” bottom flange width 7” thick bottom flange 7” web 47” top flange width DESIGNATION DEPTH AREA CENTROID TO BOTTOM MOMENT OF INERTIA WEIGHT (150 PCF)   (IN) (IN2) X 103 (IN4) LBS/LF PCBT-29 29 634.7 14.66 66.8 661 PCBT-37 37 690.7 18.43 126.0 720 PCBT-45 45 746.7 22.23 207.3 778 PCBT-53 53 802.7 26.06 312.4 836 PCBT-61 61 858.7 29.92 443.1 899 PCBT-69 69 914.7 33.79 601.3 953 PCBT-77 77 970.7 37.67 788.7 1011 PCBT-85 85 1026.7 41.57 1007.2 1070 PCBT-93 93 1082.7 45.48 1258.5 1128

Rte 123 over the Occoquan River Fairfax and Prince William Counties VDOT’s first PCBT spliced girder bridge

Close proximity to I-95 and Route 1 = detour = high traffic Location Close proximity to I-95 and Route 1 = detour = high traffic

Affluent neighborhood = pressure for aesthetic design Town of Occoquan Affluent neighborhood = pressure for aesthetic design

Who’s Who Owner – VDOT Designer – Moffatt & Nichol General Contractor – Archer Western Erection Engineer – McNary Bergeron Precast – Bayshore Concrete Products PT Hardware - VSL

Approach Girders (4 spans) Erection plan Approach Girders (4 spans) End Span Haunch Drop In Haunch End Span

Bridge Cross Section At Haunch Piers Other piers

Concrete Concrete – 28 day: 8000 psi Concrete - release: 5800 psi Low permeability Release strength cylinders matched cured

Approach Girders 4 span unit Pieces: 58 total beams Type: PCBT-77 Length: 144 ft Weight: 73 tons Strand: 0.6” LRS Cast two per pour Cross section

Approach Girder Casting setup Gravity abutment to withstand prestress force Conventionally prestressed with draped strands

Maturity meter testing Research for more accurate prediction and control of camber by VA Tech

Forms and casting Side forms with fall protection rail Placing concrete with Tuckerbuilt

Storage 300 ton twin gantry crane in background

Spliced Girders End span Haunch Drop-In Pieces: 28 total beams Length: 127 ft Weight: 88 tons Haunch Length: 98.5 ft Weight: 77 tons Drop-In Pieces: 14 total beams Length: 137 ft Weight: 87 tons

Special form needs End span and Drop-In Haunch Approach 34” soffit (4) sections of end block form (end span only) Extra 2” angle full length of side forms to create 6” thick top flange Haunch Complete form system including soffit and side forms Approach Standard PCBT-77

Erection Sequence Temporary support Erect haunch segment then end span segment Back span = 185 ft Erect drop-in segment Main span = 225 ft

Erection Sequence Make closures and begin PT Remove strong backs Cast deck and complete PT

End Span and Drop In cross sections Type: Modified PCBT-77 Depth: 79” Strand: 0.6” LRS Variations: 6” thick top flange 9” wide web for PT tendons = 34” wide bottom flange & 49” wide top flange Cast two per pour End Span and Drop-In End Block at End Span

End Span end condition PT ducts: (3) 4” OD for 0.6” LRS Extremely congested area due to bursting reinforcement

End Span and Drop-In connection at splice with haunch Very congested area due to splice plates with welded rebar and projecting rebar

Casting setup Ducts in place Setting ducts

End block Up close near anchorage Horizontal reinforcement

End block Termination of end block Pre-assembly of end cages

Splice End Top splice plates Bottom plates and projecting bars

Haunch Type: Modified PCBT-77 Depth: varies from 79” to 12’-6” Strand: 0.6” LRS Variations: 6” thick top flange 9” wide web for PT tendons = 34” wide bottom flange & 49” wide top flange Cast one per pour

Haunch NTS nts Challenges: 12’-6” depth at midpoint = extreme height full length Most strands located in top flange Location of the PT tendons makes concrete placement and consolidation difficult = addition of pour windows Extra setup required for storing and handling of variable depth side forms and beams

Bed setup

Pulling strand

Stressing

Rebar and PT tendons

How did he tie the bars in the top flange?

Forms

Grout vents Top Splice Plate

Look at the view from up here. Pouring with buckets

First casting is a success Girder bracing

Shipping All beams to be shipped by barge starting early April 2005

Erection Phase I – setting beams from the existing bridge

Erection Phase II – setting beams from the phase I bridge

Lessons learned Producer - Seek possible use of SCC concrete for heavily congested area Contractor - Get “construction engineer” involved early to ensure means and methods are established (i.e. temporary bracing embedments, special lifting requirements, strong back design, etc.) Engineer - Require complete shop drawings from PT supplier DOT – consider having a notch in back span girder(s) designed and included in plans to ensure maximum flexibility in construction sequence

Rte 33 over the Pamunkey River West Point and New Kent County What’s Next?

Location

Town of West Point

Who’s Who Owner – VDOT Designer – Parsons Brinckerhoff General Contractor – Tidewater Skanska Precast – Bayshore Concrete Products

Concrete Concrete – 28 day: 8000 psi Concrete - release: 6000 psi Low permeability Lightweight: 115 pcf (concrete) 125 pcf (total)

Approach Girders 3 span unit Pieces: 21 total beams Type: Modified PCBT-93 Variations: 9” thick bottom flange 8” wide web = 33” wide bottom flange & 60” wide top flange Depth = 95.5” Length: 137 ft Strand: 0.5” LRS Cast two per pour Cross section

Spliced Girders End span Haunch Drop-In Pieces: 42 total beams Length: 159 ft Haunch Pieces: 28 total beams Length: 80 ft Drop-In

Haunch Type: Modified PCBT-93 Depth: varies from 95.5” to 10’-5 1/2” Strand: 0.6” LRS Variations: 8” wide web for PT tendons = 33” wide bottom flange & 60” wide top flange Cast one per pour

Haunch Challenges: Pros: 10’-5 ½” depth at midpoint = setup remains at 12’-6” to avoid costly rework = extreme height full length Others same as previous project. Pros: Not having to set up a new stressing frame Booster Form – utilize existing forms Haunch

Special form needs End span and Drop-In Haunch Approach 33” soffit (2) sections of end block form (end span only) – different from Occoquan because same quantity of end span and drop-in 16” riser for PCBT-77 form Haunch Booster form (bolts on to bottom of standard form) Approach 16” riser for PCBT-77 form (same as above)

Questions?

Thank You Please feel free to come visit our plant OR call if we can be of assistance in any way Contact: Joe Rose 757-331-2300 jrose@bcpcorp.com

Bayshore Concrete Products Cape Charles, VA 90 acre casting facility on Cape Charles Harbor and Chesapeake Bay