NEXT beams and Accelerated Bridge Construction (ABC) NEXT beams and Accelerated Bridge Construction (ABC) Outline: 1. Background/Overview to NEXT Beams 2. Considerations for Bridge Applications 3. Accelerated Bridge Construction (ABC) 4. NEXT Beam Projects Background/Overview to NEXT Beams Background/Overview to NEXT Beams

• Precast/Prestressed Concrete Institute (PCI) Northeast Region • Created bridge technical committee consisting of various PCI Producer Members, Owners/State DOTs, local Consultants, and PCI Northeast Region • The Northeast Extreme Tee (NEXT) beam is a variation to the traditional double-tee stemmed beams and is a precast/prestressed concrete section. • 2010 PCI Journal article “Development of the Northeast Extreme Tee (NEXT) beam for Accelerated Bridge Construction by Michael Culmo and Rita Seraderian • http://www.pcine.org/cfcs/cmsIT/baseComponents/fileManagerProxy.cfc?method=GetFi le&fileID=108C69E6-EF30-AEED-96BF506C3412967E Background/Overview to NEXT Beams

• Highlights • Short to medium span ranges • Section depths vary from 24 to 36 inches • Top flange width varies from 8 to 12 ft. • Single form allows for variation in beam depths and widths by using fillers and/or adjustable side rails • Distance between stems can accommodate utilities • 4” top flange thickness acts as a stay-in-place form (eliminating deck forming) • Variable top flange width allows for variable bridge widths to match/fit any combination of roadway number of lanes and shoulder widths • Speed of construction (by eliminating field work) • Top flange can be thickened to 8” and can act as the structural slab for the bridge • Ease of fabrication by using straight prestressing strands NEXT F Beam Section (PCI Bridge Design Manual)

Refer to PCI Bridge Design Manual for beam section properties NEXT D Beam Section (PCI Bridge Design Manual)

Refer to PCI Bridge Design Manual for beam section properties Preliminary Design Aids (PCI Bridge Design Manual) Design Criteria used to satisfy AASHTO LRFD Specs: • f’ci up to 6.8 ksi • f’c up to 8.0 ksi • Allowable tension at release = 0.24sqrt(f’ci) • 0.6” diameter 270 ksi low- relaxation strands • Refer to section 6.5.2 in PCI’s BDM for complete listing of design criteria Considerations for Bridge Applications Considerations for Bridge Applications

• Design criteria • Time • Functional requirements • Safety for both construction workers • Geometrics and public • Roadway typical section, alignment, & • Durability/Service-Life profile • Bridge Characteristics • Clearances • Length • skew • Typical section/width • Hydraulics • Depth • Access • Number of spans/substructure units • Right-of-Way • Material(s) type (superstructure & • Utilities substructure) • Environmental • Geotechnical/foundations • Cost • Aesthetics • Initial • Seismic • Life-cycle • Road-user Considerations for Bridge Applications

• Constructability • Project Delivery Methods • Maintenance • Traditional • Inspection • Design-Bid-Build • Type of bridge projects • Alternative • New • Design Build • Public-Private Partnership (P3) • Widening • CM/GC • Replacement • A+B • Retrofit • Accelerated Bridge Construction • Funding (ABC) Cost-Plus-Time (A+B) Innovative Contracting Method • A+B Bidding • The nature of Accelerated Bridge Construction projects is that a reduction in project time is desirable. The selection of the low bid can take into account the time component of the project. There are two common methods of addressing this in the bidding phase of the project. • A+B bidding is a method that assigns a value to the base bid price (the “A” component) and a value to a time component (The “B” component). The low bid is determined the sum of these two components. • The "A" component is the dollar bid for the contract work items. • The "B" component is the time to complete the project or a portion of the project converted to dollars, usually by using road user cost models that compute the “cost” of road user delays. Accelerated Bridge Construction (ABC)

Basically there are 3 aspects • Goals & Initiatives associated with ABC • Considerations • Technologies Accelerated Bridge Construction (ABC) Goals & Initiatives • Minimize traffic disruptions and/or road closures during bridge construction • Reduce user delay-related costs • Improve work-zone safety • Improve bridge construction quality and/or durability • Minimize disruption to environmentally sensitive areas • Promote standardization • Take advantage of site accessibility and/or existing right-of-ways • Reduce construction time • Accelerate the overall project • Utilize accelerated bridge construction techniques Accelerated Bridge Construction (ABC) Considerations • Planning, Design, & Construction • High traffic volumes • Site Selection • Right-of-way • Contracting/Procurement • Environmental /Delivery Methods • Time • Construction equipment • Cost and/or means-and- methods • Construction quality • Standardization • Safety • Construction • Mobility Impacts Specifications and • Availability of Prefabrication Bridge Materials Elements • Bridge • ABC Technologies Program/Management Accelerated Bridge Construction Technologies

• source: FHWA Every Day Counts Initiative from USDOT/FHA Accelerated Bridge Construction Manual (Publication No. HIF-12-013) Self Propelled Modular Trailer (SPMT)

Photo provided by: Sarens Group ABC Resources/Websites Highways for LIFE (LIFE is an acronym for Long-lasting, Innovative, Fast construction, Efficient, and safe, all characteristics of the ideal highway or bridge construction project) www.fhwa.dot.gov/publications/publicroads/10janfeb/01.cfm www.slideinbridgeconstruction.com/ FHWA Center for Accelerating Innovation http://www.fhwa.dot.gov/innovation/ Every Day Counts (EDC) www.fhwa.dot.gov/innovation/everydaycounts/ Second Strategic Highway Research Program (SHRP2) www.fhwa.dot.gov/goshrp2/ FHWA’s ABC www.fhwa.dot.gov/bridge/abc/index.cfm Slide In Bridge Construction www.fhwa.dot.gov/construction/sibc/ Florida International University-Accelerated Bridge Construction University Transportation Center https://abc-utc.fiu.edu/ ALDOT Dothan Bridge Project www.dothanbridge.com/ NEXT Beam Projects NEXT Beam Projects Northeast PCI Region • 20 Projects are listed on PCI’s Northeast Regions website http://www.pcine.org/index.cfm/pr ojects/next-beam

• MassDOT, NYSDOT, and PENNDOT have standards for NEXT beams NEXT Beam Case Study webinar • Rita L. Seraderian, P.E., FPCI, LEED by Rita L. Seraderian AP Florida International University Executive Director Accelerated Bridge Construction Precast/Prestressed Concrete University Transportation Center Institute Northeast 116 Radcliffe Road (ABC-UTC) Belmont, MA 02478 February 15, 2018 617-484-0506 or 888-700-5670 https://abc-utc.fiu.edu/mc- events/northeast-extreme-tee-next- beam-with-rochester-vt-case- study/?mc_id=341 The first NEXT Beam bridge Route 103 over the York River (York, Maine)

• PCI Journal Winter 2013 article by Lauren S. • Six alternatives considered during preliminary Gardner and Steven M. Hodgdon design • “The first NEXT beam bridge” • Right-of-way limits • 7-span bridge • Profile requirements • 510 ft. length, max. span = 80 ft. • Environmental impacts • Span configurations • 36” NEXT F beams • Cost • Shallow superstructure to maintain existing • Ease and duration of construction navigational clearances • Dual-design superstructures carried into bids • Increased roadway width • NEBT • Historic and environmentally sensitive site; • NEXT beams • 4 of the 5 contractors bid the project using NEXT accelerated bridge construction critical beams • Project cost savings by reducing erection and construction time Georgia Department of Transportation (GDOT) GDOT NEXT beam projects Project Name NEXT Beam Span Project Type Construction 0007171, SR 97 over Big NEXT F, 36”, 10’-9¼” 70’-0” Bridge 2016 Slough, Decatur County Replacement

0007181, SR 64 over Ten NEXT F, 32”, 9’-3¼” 60’-0” Bridge 2017 Mile Creek, Lanier County Replacement

0007180, SR 171 over Little NEXT F, 36”, 9’-9¼” 80’-0” Bridge 2017 Ohoopee River, Johnson Replacement County 0007161, SR 32 over Little NEXT F, 32”, 10’-9¼” 55’-0” Bridge 2017 Satilla River O/F, Brantley Replacement County GDOT NEXT beam project SR 97 over Big Slough, Decatur County

4-spans (70-70-70-70 ft.) 36” NEXT F-beams Photos and shop drawings provided by FORTERRA (Pelham, AL) Alabama NEXT beam project • Bridge Replacement on Dunlap Drive over Pinto Pass (Mobile, AL) • Design by ALDOT Bridge Bureau • 60 ft. single span • 28” NEXT D beams

Google maps Baldwin County Highway Department (BCHD) Baldwin County, AL BRIDGE RETROFITS • The following bridges are under consideration as potentiation retrofits • CR65 Bridge over Turkey Branch • 2 spans at 34-34 ft. • Doc McDuffie Road Bridge over Wolf Creek • 3 spans at 34-34-34 ft. • Both bridges have high truck traffic • No existing approach/end slabs • Roadway approach pavement is rutted and depressed • Existing bridges were constructed around 2005 using reinforced concrete channel beams that have deterioration of the longitudinal joint in between the reinforced concrete channel beams and have damage to the edges of the channel beam top flanges BCHD Bridge Retrofits Project Goal 1. Replace the superstructure and Re-use the Existing Substructures/Bents 2. Consider accelerated construction techniques/solutions 3. Address long-term serviceability and bridge maintenance 4. Maintain existing right-of-way Retrofit Options to Replace the Existing Superstructure • Conventional AASHTO Type I girders with a cast-in-place deck and modified roadway profile and regrading at approaches (would require roadway profile to be raised approx. 1.4 ft. including regrading of approaches with possible bank stabilization and possible ROW impacts) • Double Tee/NEXT beams with 8-inch top flange and UHPC joints (would match roadway profile and eliminate roadway improvements and maintain existing ROW) Bridge Retrofits Retrofit Considerations o Structure Depth o Existing o 21.5” (21” channel beams + 0.5” bearing) o AASHTO Type I girders w/ CIP Deck o 38” (2’-4” girder + 7” CIP deck + 1.5” haunch + 1.5” bearing) o Modified Double Tee/NEXT beams o 22” (21” beam + 1” bearing) o Minimize or eliminate roadway improvements and avoid Right-of-Way Impacts o AASHTO Type I girders w/ CIP deck would require existing roadway profile to be raised approx. 1.4 ft. including regrading with possible bank stabilization o Modified Double Tee/NEXT beams match the existing structure depth and eliminates roadway improvements and maintains existing ROW o Re-use Existing Substructures/Bents o Construction Cost o Construction Duration/schedule UHPC Resources

▪ UHPC is an advanced cementitious composite material whose mechanical and durability properties far surpass those of conventional concrete ▪ UHPC has compressive strengths above 21.7 ksi, pre-and post-cracking tensile strengths above 0.72 ksi, & enhanced durability via their discontinuous pore structure ▪ FHWA has been engaged in research on the optimal uses of UHPC in the highway bridge infrastructure since 2001 • Ultra-High Performance Concrete: A State-of-the-Art Report for the Bridge Community • https://www.fhwa.dot.gov/publications/research/infrastructure/structures/hpc/13060/13060.pdf • FHWA-HRT-14-084 (Design and Construction of Field-Cast UHPC Connections) and FHWA-HRT-11-038 (Ultra- High Performance Concrete) • FHWA-HRT-14-090 (Bond Behavior of Reinforcing Steel in Ultra-High Performance Concrete) • Benjamin Graybeal’s (FHWA) presentation at 61st Annual AL Transportation Conference on “Ultra-High Performance Concrete and its Use for Accelerated Bridge Construction” BCHD Bridge Retrofits Bridge Typical Sections Modified Double Tee/NEXT Beam (H = 1’-9”)

Area = 1151 sq. in. Unit weight = 1199 plf (150 pcf) Unit weight = 1079 plf (135 pcf) Unit weights do not include Cast-in Diaphragm/end block Re-Use Existing Substructures/Bents existing 21-inch precast channel beams: Beam area = 475 in^2 9-existing beams Total beam area = (9)x(475 in^2) = 4275 in^2 Using 150 pcf unit wt. concrete Total precast channel beams self wt. = (4275 in^2)x(150 pcf)/144 = 4453 plf Bridge Superstructure Superstructure Weight (plf) Existing Channel Beams 4453 Proposed AASHTO Type I beams + 7-inch deck (5 4413 Double Tee/NEXT beam (21-96): beams) Beam area = 1151 in^2 Proposed NEXT F beams (4 beams) using 135 pcf 4316 4-beams Proposed AASHTO Type I beams + 7.5-inch deck (4 4338 Total beam area = (4)x(1151 in^2) = 4604 in^2 beams) Using 150 pcf unit wt. concrete Total NEXT beams self wt. = (4604 in^2)x(150 pcf)/144 = 4796 plf (1.08% increase in self weight compared to existing channel beams) Using 135 pcf unit wt. concrete Total NEXT beams self wt. = (4604 in^2)x(135 pcf)/144 = 4316 plf (slightly less than the existing precast channel beams BCHD Bridge Retrofits Construction Schedule • AASHTO Type I girders w/ CIP Deck • NEXT D beams with UHPC

Construction Duration, Construction Duration, Activity Description weeks Activity Description weeks 1 miscellaneous-mobilization 3 1 miscellaneous-mobilization 3 2 remove existing channel beams 2 2 remove existing channel beams 2 3 erect AASHTO Type I girders 1 3 erect NEXT D beams 1 4 form diaphrams & pour 2 4 form & pour UHPC joints 1.5 5 form overhang 1 5 form & pour bridge barrier 2 6 install SIP metal deck forms 1 place precast end slabs & pour UHPC 6 0.5 7 place rebar 1 joints 8 pour deck 1 subtotal (weeks) = 10 9 form & pour bridge barrier 2 10 form & pour end slabs 1 11 remove forms 1 12 approach roadway embankment 1 13 approach roadway asphalt 1 subtotal (weeks) = 18 Construction Costs

• Not only is the construction duration a lot For programming/budgeting using $150- less using the precast double tee/NEXT 175/sq. ft. beams with UHPC connections but the initial construction cost appears to also • CR65 be less due to time and cost savings with • 2238 sq. ft. > 340k to 395k eliminating forming and placing • Doc McDuffie reinforcing in both the end diaphragms and deck overhangs. • 3460 sq. ft. > 520k to 605k • The AASHTO Type I girders with a cast-in- place deck retrofit option was eliminated • CEI costs also reduced as a result of the as it would have required the existing accelerated construction and reduction in roadway profile to be raised adding cost schedule and possibly creating additional Right-of- Way impacts. Bridge Retrofits-End Slabs

Other Considerations • Connection to bents • Transverse joints at bents • Precast End Slabs/Approach slabs • Existing bridges do not have end slabs • Rutting • Bumps at approaches • High truck traffic • Section dimension/layout • Accommodate roadway transverse cross-slope • Option to fabricate full-width precast end slabs with variable depth BCHD Bridge Retrofits Construction Sequence Existing Bridge BCHD Bridge Retrofits Construction Sequence

Step 1: remove existing superstructure BCHD Bridge Retrofits Construction Sequence Step 2: erect NEXT beams BCHD Bridge Retrofits Construction Sequence Step 3: pour UHPC joints BCHD Bridge Retrofits Construction Sequence

Step 4: pour barriers Life-Cycle Cost Analysis A COST COMPARISON BETWEEN A PRESTRESSED CONCRETE I-BEAM BRIDGE AND A PAINTED STEEL (A572) ROLLED I-BEAM BRIDGE IN THE STATE OF OHIO

David Tomley University of Dayton May, 1994

42 CREDITS

Governing Agency: The Ohio Department of Transportation Bridge Bureau (Columbus, Ohio)

Societies: The Prescast/Prestressed Concrete Institute (Dayton, Ohio)

Construction Marketing: Bethlehem Steel Corporation (Bethlehem, PA)

Design Consultants: Janssen & Spaans Engineering, Inc. (Indianapolis, IN) T.Y. Lin International (Phoenix, AZ) Korda/Nemeth Engineering, Inc. (Columbus, OH) Hazelet & Erdal Engineering, Inc. (Cincinnati, OH)

Fabricators: Phoenix Steel, Inc. (Eau Claire, WI) Hartwig Manufacturing Corp. (Wausau, WI)

Precasters: ESSROC Materials, Inc. (Melbourne, KY) Prestress Services (Decatur, IN)

Contractors: Kokosing Construction Company, Inc. (Columbus, OH) S.E. Johnson Companies, Inc. (Maumee, OH)

Developer of the Inorganic Zinc AMERON PCS Division (Chicago, IL) primers and Manufacturers & Suppliers of the Epoxy Urethane mid and top coats to the Bridge Industry: 43 Project Tasks

• Optimize designs for both structures according to the American Association of State Highway and Transportation Officials Bridge Design Specifications Fifteenth Edition, 1992 and the Ohio Department of Transportations Bridge Design Manual, 1993. • Provide details for 2 to 4 Precasters, Fabricators, Contractors for actual pricing (i.e. labor plus material costs). • Compile above prices along with unit prices from ODOT's Summary of Contracts Awarded for Calendar Year 1992. • Economic Analysis for selection.

44 Lauver Road Bridge over Stillwater River

45 PRESTRESSED CONCRETE DESIGN

• Optimal spans are 3 at 90 ft. The equal span arrangement provided the pracaster with only one I-Beam detail. The controlling moment for maximum positive moment is in the end span. Use of a span ratio of 0.8-1.0-0.8 (85-104-85) would result in a reduction of the maximum positive moment of 10%; however the savings in section is insignificant compared to the benefits of precasting even span arrangements.

46 ROLLED STEEL DESIGN

• A steel I-Beam optimization program was analyzed by the Construction Marketing Department of Bethlehem Steel Corporation. The cost indexes for the seven schemes analyzed ranged from 1.00 (being the optimum) to 1.16. The A588 weathering steel (90-90-90 ft. spans) had the lowest cost index of 1.00. The painted A572 steel (90-90-90 ft. spans) had a cost index of 1.11. This indicates that the price per pound of structural steel for the painted A572 beams was 11% higher than the most optimum scheme

47 AVERAGE CONTRACTOR ESTIMATES (Rolled Steel)

Superstructure Estimated Quantities (Rolled Steel I-Beam Bridge) UNIT ITEM DESCRIPTION QUANTITY UNIT PRICE COST 509 Epoxy Coated Reinforcing Steel, Grade 60 51,503 Lbs. 0.40 20,601 511 Class S Concrete, Superstructure 238 Cu. Yd. 267.00 63,546 Special Sealing of Concrete Surfaces 675 Sq. Yd. 6.50 4,388 ** 513 Structural Steel, A572-50 AISC Category I 217,548 Lbs. 0.57 124,002 * 513 Structural Steel, A588-50 AISC Category I 217,548 Lbs. 0.56 121,827 513 Welded Stud Shear Connector, 5"x7/8" 2,148 Each 1.50 3,222 Special Painting of New Steel, System IZEU 217,548 Lbs. 0.15 32,632 516 Structural Expansion Joint Including 2" Elastomeric 60 Lin. Ft. 145.40 8,724 Compression Seal 516 Elastomeric Bearing With Internal Laminates and 8 Each 497.00 3,976 Load Plate (Neoprene) (14"x18"x1" Bearing With 15"x24"x1 1/2" Load Plate) 516 Elastomeric Bearing With Internal Laminates and 8 Each 447.00 3,576 Load Plate (Neoprene) (10"x12"x2 3/4" Bearing With 11"x13"x1 1/2" Load Plate) 517 Concrete Parapet (BR-1) 542 Lin. Ft. 46.00 24,932

Total Structures Over 20 Foot Span $289,599 (A572) * Alternate Bid Item $254,792 (A588) ** Includes all fabricating, transportation and erection costs (field splices & welding intermediate crossframes) 48 AVERAGE CONTRACTOR ESTIMATES (Prestressed)

Superstructure Estimated Quantities (Prestressed Concrete I-Beam Bridge) UNIT ITEM DESCRIPTION QUANTITY UNIT PRICE COST 509 Epoxy Coated Reinforcing Steel, Grade 60 56,306 Lbs. 0.40 22,522 511 Class S Concrete, Superstructure 254 Cu. Yd. 260.00 66,040 Special Sealing of Concrete Surfaces 655 Sq. Yd. 6.50 4,258 * 515 Prestressed Concrete Bridge Member (91'-0" length) 12 Each 7404.00 88,848 (AASHTO-PCI Type IV I-Beam) 516 Structural Expansion Joint Including 2" Elastomeric 60 Lin. Ft. 145.00 8,700 Compression Seal 516 Elastomeric Bearing With Internal Laminates and 16 Each 447.00 7,152 Load Plate (Neoprene) (12"x16"x1" Bearing With 13"x17"x1 1/2" Load Plate) 516 Elastomeric Bearing With Internal Laminates and 8 Each 372.00 2,976 Load Plate (Neoprene) (12"x14"x2 1/2" Bearing With 13"x15"x1 1/2" Load Plate) 517 Concrete Parapet (BR-1) 542 Lin. Ft. 46.00 24,932

Total Structures Over 20 Foot Span $225,428

* Includes all precasting, transportation and erection costs 49 MAINTENANCE COSTS (Prestressed)

AASHTO Type IV Prestressed Concrete I-Beams Life span 60 years interest rate 7 % initial cost $225,428 Concrete deck overlay 20 years @ $36,000 deck replacement 40 years @ $216,150 annual maintenance $ 4000 per year n = 0 20 40 60

i = 7%

annual $4,000

$36,000 $216,150 $225,428

(EUAC) = 4,000 + 225,428(0.07123) + 36,000(0.2584)(0.07123) + 216,150(0.0668)(0.07123) = $21,748/year 50 MAINTENANCE COSTS (Rolled Steel- Painted)

A572 Painted Steel Rolled I-Beams Life span 60 years interest rate 7 % initial cost $289,599 Concrete deck overlay 20 years @ $36,000 deck replacement 40 years @ $216,150 Repaint (IZEU) 20 years @ $32,650 annual maintenance $ 4000 per year n = 0 20 40 60

i = 7%

annual $4,000

$36,000 $216,150 $289,599 $32,650 $32,650 (EUAC) = 4,000 + 289,599(0.07123) + 68,650(0.2584)(0.07123) + 248,800(0.0668)(0.07123) = $27,076/year 51 MAINTENANCE COSTS (Rolled Steel- Weathering)

A588 Weathering Steel Rolled I-Beams Life span 60 years interest rate 7 % initial cost $254,792 Concrete deck overlay 20 years @ $36,000 deck replacement 40 years @ $216,150 annual maintenance $ 4000 per year n = 0 20 40 60

i = 7%

annual $4,000

$36,000 $216,150 $254,792

(EUAC) = 4,000 + 254,792(0.07123) + 36,000(0.2584)(0.07123) + 216,150(0.0668)(0.07123) = $23,840/year 52 ECONOMIC ANALYSIS

• The method used is the Equivalent Uniform Annual Cost (EUAC). This particular economic analysis converts every present and future cost into an equivalent uniform annual cost from which the cheaper alternative is chosen. Refer to textbook "Principles of Engineering Economy" Eighth Edition 1990 by Grant/Ireson/Leavenworth for interest tables.

53 CONCLUSIONS

• The AASHTO Type IV Prestressed • Therefore, based on the (EUAC) Concrete I-Beams had the lowest economic analysis , the AASHTO annual cost of $21,748/yr. T Type IV Prestressed Concrete I- • The A572 Painted Structural Steel Beams is the optimal design Rolled I-Beams had an annual cost choice for this particular study. of $27,076/yr. The savings by selecting the AASHTO Type IV Prestressed • For comparison the A588 Concrete I-Beams over the life Weathering Steel Rolled I-Beams span of the structure would amount had an annual cost of $23,840/yr. to $319,680.

54 Spliced-girders PCI Fast Team for SGD John Baker, Chairman Gordon Nagle Reid Castrodale Joe Nagle John Dick Chuck Prussack Joe Golden Joe Roche Jon Grafton Don Theobald Mark Holloran David Tomley Howard Knapp Mark Zirbel Andrew Maybee Objective of PCI Fast Team

• Review Previous Solutions and Successes • Producers Limitations • Standardization • Identify Optimum Applications • Develop Recommended Standard Practices Objective of NCHRP 12-57

Extending Span Ranges of Precast, Prestressed Concrete Girders Objective: To develop recommended load and resistance factor design (LRFD) procedures, standard details, and design examples for achieving longer spans using precast, prestressed concrete bridge girders. PCI’s BDM Ch. 11 “Extending Spans”

Principal Author: Dr. Maher Tadros Focuses on: • Guidelines • Examples • Details • Recommendations Status: Blue Ribbon Panel Review Applications of Spliced-Girder Technology Single Span Limitations

• Single Spans with Multiple Segments • Single or Multi- Stage PT Conventional Design Improvements

• Conventional Simple Span Design with Longitudinal PT Aesthetics

• Variable Depth and Non-Prismatic Sections New Replacement Options

• Precast Arches Rehabilitation

• Rehabilitation of Existing Steel Superstructures Longer Spans

• Multiple Spans with Drop-In Girders New & Special Opportunities

Virginia DOT: • Route 123 Bridge over Occoquan River Opportunities Spliced-Girder Provides Increased Financial Benefit

• Having more than one material option results in a direct benefit to the Owner (Win-Win) • Why should precast spliced-girder design be considered for rehabilitation of deficient bridge superstructures? More choices = better $$ Spliced-Girder Design Spliced-Girder Bridge Design Activities

• Material Properties • Grouting Specifications • Time Dependent • AASHTO LFD/LRFD Spec. Analysis Check • Construction • Stresses Sequence/Steps • Moment • Staged Post-Tensioning • Shear • Model Codes (CEB-FIP, • Deflections & Losses ACI, or LRFD) • Perform a Critical Stress • Initial and Final Design Check and Factor of • Consider deck Safety Check for Precast replacement analysis Beam Lateral Stability • Reinforcing and Detailing Connections and Temp. Bents • Cast-in-place • Drop-in connection • Specify temporary splice connections (strongbacks) bents/falsework supports Time Dependent Analysis Time Dependent Loss Models

• ACI-209 • CEB-FIP • AASHTO LRFD Time Dependent Materials • Concrete material • f’c = Concrete properties vary with Compressive Strength time, and various models • fr = Modulus of Rupture have been developed by different code developing • E = Modulus of Elasticity organizations to predict (Tangent) this behavior. • S = Shrinkage Strain • N = Creep Coefficient = Ratio of creep strain to instantaneous strain Time Dependent Modeling

• Construction Stages • Prestress Losses over time Lateral Beam Stability

• AASHTO LRFD Art. 5.5.4.3 “Buckling of precast members during handling, transportation, and erection shall be investigated.” Lifting Transportation + Impact Superelevation Lateral Beam Stability

• Factor of Safety (1.5 - 2.5) • Ways to increase beam stability: • move lifting points inward • increase beam section (Iy) • increase E and f’c • add top strand