Best Practices Guide

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Best Practices Guide

• DRAFT
• Soliciting Comments for 30 Days
• As lab testing moves forward
• Changes in limits may be fine tuned
• As field work moves forward
• Construction procedures will be amended
• Casting sequence may be changed

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Goals

• Tools for Engineers and Contractors
• Design Aides (hard copy and web based)
• Durable Bridge Decks and Other Structures
• Reduced Life-Cycle Cost
• Longer Span Options with High Strength Concrete

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Structural / Material Designer Structural / Material Designer Structural / Material Designer
Element Type_________ Yes No
Reinforced? Yes No
Exposed to freezing or thawing? Yes No
Exposed to salt or seawater Yes No
Saturated Yes No
Tidal Zone Yes No
Fc at 28 days ___________
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Structural / Materials Designer Structural / Materials Designer Structural / Materials Designer
Reactive Aggregate HR MR NR HR MR NR
Early age fc______at_____days Yes No
Acceleration or deceleration zone Yes No
Contact to studded tires or chains Yes No
Exposed to SO4 Yes No
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Design Factors affecting Cracking

• Major
• Restraint

• Moderate
• Continuous spans
• Girder Size
• Girder type
• Deck Thickness
• Alignment of rebars

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Material Factors Affecting Cracking

• Major
• Heat of Hydration
• Cement Content/Type
• Aggregate Type
• Modulus of Elasticity
• Creep Coefficient

• Moderate
• Coefficient of Thermal Expansion
• Paste Volume
• W/cm ratio
• Deck Thickness
• Silica Fume

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Construction Factors Affecting Cracking

• Major
• Weather
• Time of Casting

• Moderate
• Curing period
• Curing measures
• Finishing procedures

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QC/QA before casting

• Planning, time scheduling, assignments
• Material selection and maintaining quality
• Inspection of batch plant and trucks
• Qualification of employees (certification)
• Mixture designs to optimize only needed properties

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QC/QA during casting

• Planning, time scheduling, assignments
• Timely transport and delivery
• Fresh concrete testing
• Qualification of employees (certification)
• Verification of mixture design
• Continuous casting
• Minimize Finishing
• Curing measures immediately following placement

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QC/QA after casting

• Planning, time scheduling, assignments
• Maintenance of curing measures
• Hardened concrete testing
• Qualification of employees (certification)
• Monitor in-situ strength gain (maturity)
• Periodic evaluation for repair, rehab, or
  replacement.

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Review and Comments

• Provide comments by mid June
• Second Draft will come out on the web in late
  June
• www.engr.psu.edu/ce/I-99hpc