EXPANDING THE USE OF PRECAST CONCRETE IN TEXAS BRIDGES Graham Bettis, P.E. TxDOT Bridge Division Construction & Maintenance
Just the Facts Total Number of On-System Bridges (Excluding Culverts): 21,686 Total Number with Prestressed Concrete Superstructures: 11,037 (that s 51%) About 90% of New Bridges Built with Prestressed Concrete Superstructures 92% in FY 2013 2
Standard I-Beam Construction 3
Standard U-Beam and Deck Panel Construction 4
Precast Concrete - How Do We Love Thee? Owner s Perspective Inexpensive Fast Durable Redundant Contractor s Perspective Fast $$$* * Sometimes difficult for Primes to let go of cast-in-place. 5
Concrete Production in Texas Cement Lots of Limestone 10 Cement Producers Coarse Aggregate River Rock Limestone Fine Aggregate River Beds (Sand) Manufactured Sand (Limestone) Fly Ash Coal Plants in Texas 6
Precast Concrete Fabricators Major Prestressed 7
Precast Concrete Fabricators Minor Prestressed 8
Precast Concrete Fabricators Nonstressed 9
Average Bridge Costs FY 2013 Structural Steel* Plate Girders: $126/SF Trapezoidal Tubs: $153/SF Prestressed Concrete Tx Girders (Bulb Tees): $65/SF U54 Beams: $52/SF * Must take into account that almost all steel spans are long and continuous, raising the construction cost significantly. But still 10
Durability Extremely Low Permeability Fly Ash Steel Form Finish Produced in Controlled Environment Self-Consolidating Concrete Low Water-to-Cement Ratio Moist Curing QC/QA Repair and Rejection Plant vs. Job Site 11
Curing 12
Permeability 13
Not All Concrete Cracks 14
Conventional Concrete Deterioration 15
Conventional Concrete Deterioration 16
Conventional Concrete Deterioration 17
Conventional Concrete Deterioration 18
Conventional Concrete Deterioration 19
Structural Steel Deterioration 20
Structural Steel Deterioration 21
Structural Steel Deterioration 22
High Performance Concrete Item 421: Hydraulic Cement Concrete 8 Mix Design Options HPC = Design Options 1 through 5 In Reality, HPC = Design Option 1 Replace 25% of Cement with Class F Fly Ash Applies to All Precast Concrete 23
Precast Concrete Current, Widespread Usage 24
Standard Precast Items Railing Traffic Barrier Decked Slab Beams Prestressed Piling Bent Cap for Round Columns Bent Cap for Steel Piling Spread Boxes X-Beams End Treatments Manholes & Inlets Tx Girders (Bulb Tees) U-Beams Slab Beams I-Beams Prestressed Deck Panels Sheet Piling Culverts Reinforced Concrete Pipes Box Beams 25
Prestressed Piling 26
Prestressed Piling 27
Standard I-Girder Shapes 28
I-Girders 29
What We re Doing Now Tx Girders 30
Decked Slab Beams 31
Decked Slab Beams 32
U-Beams 33
Precast Deck Panels 34
Precast Deck Panels 35
Precast Deck Panels with PMDF 36
Precast Deck Panels to Joints 37
Precast Overhang Deck Panels with Pockets 38
Precast Overhang Deck Panels with Channel 39
Precast Overhang Deck Panels with Channel 40
Full Depth Panels 41
Full Depth Panels 42
Full Depth Panels 43
MSE Panels 44
Existing Concepts Desire for Expanded Use 45
Precast Bent Caps 46
Precast Bent Caps 47
Precast Bent Caps 48
Precast Bent Caps 49
Precast Abutments 50
Precast Abutments 51
Precast Segmental 52
New Concepts Current Implementation 53
Long Spans - Existing 54
Long Spans Trending Upwards 55
Long Spans Existing Bridge Construction 56
Spliced Precast Girders Uniform Cross Section (Non- Haunched): 225 240 Haunched: 325 Curved Tubs: 240 260 57
Spliced Precast Girders 58
Haunched Section 59
Spliced Precast Girders 60
Spliced Precast Girders with Haunch 61
Spliced Precast Girders with Haunch 62
Post-Tension Anchorage Zones 63
Post-Tension Anchorage Zones 64
Post-Tension Anchorage Zones 65
Post-Tension Anchorage Zones 66
Cylinder Piling 67
Cylinder Piling 68
Cylinder Piling 69
Innovation and Unique Applications 70
Curved Precast Concrete Tubs 71
Curved Precast Concrete Tubs 72
Curved Precast Concrete Tubs 73
Spliced Concrete Tubs 74
Prestressed Concrete Bent Caps 75
Unique Precast Applications West 7 th Street Arch 76
Unique Precast Applications West 7 th Street Arch 77
Graham Bettis, P.E. TxDOT Bridge Division - Field Operations Section Construction & Maintenance Group graham.bettis@txdot.gov Office: 512-416-2526 Mobile: 512-658-1231