Ultra-High-PerformanceConcrete
Parviz Soroushian
Email: parvizsoroushian@engineer.com
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Concrete:
TheMostWidelyUsedConstructionMaterial
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Dams Canals
Pipes
Offshore Platforms Bridges
Buildings Nuclear Power Plants Highway & Airfield Pavements Hazardous Waste Containment
Tunnels Protective Structures/Shelters
Water Tanks
Ultra-High-PerformanceConcrete:KeyAttributes
• Distinctly high compressive strength (>20 ksi, 140 MPa), tensile strength (>2.6 ksi, 18 MPa), ductility, toughness, blast and fire resistance, impermeability and durability.
• Some key features include high packing density of particulate matter, very low water/cementitious ratio, and effective use of discrete fibers.
3 Compressive Stress-Strain Behavior
Ultra-High-PeformanceConcreteVs. Normal-andHigh-StrengthConcrete
Typical Performance Characteristics of Normal-Strength Concrete (NSC), HighStrength Concrete (HSC), and Ultra-High-Performance Concrete (UHPC)
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StructuralEfficiencyBenefits
(quantifiedforexistingUHPCs)
Conventional Design
UHPC Design
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DurabilityBenefits
(quantifiedforexistingUHPCs)
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ApplicationsBeyondConcrete-BasedInfrastructure (benefitsquantifiedfor
existingUHPCs)
Structural Frame: Steel Replacement
Abrasion-Resistant, Low-Cost Dies for Production of Metal & Polymer Parts
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ExistingUHPCMixDesigns
• High Packing Density
• Removal of coarse aggregate
• Use of specially graded fine aggregates
• Optional use of relatively inert powder
• Use of fine pozzolans (silica fume)
• Low Water/Binder Ratio
• Use of Advanced Superplasticizers
• Effective Use of Fibers
• High-Temperature Curing
Typical Mix Designs of Normal-Strength Concrete (NSC), High-Strength Concrete (HSC), and Ultra-HighPerformance Concrete (UHPC)
8 NSC HSC UHPC Max. Aggregate Size, mm 25 15 0.5 Aggregate/Binder Ratio 5.5 3.5 0.5 Water/Binder Ratio 0.55 0.35 0.15 Packing Density 0.65 0.7 0.8 Fiber Volume Fraction, % 0 0 2
DrawbacksofExistingUHPCs
• Excess Cementitious Contents
• High Heat of Hydration
• Large (Autogenous) Shrinkage (correlated with temperature rise)
• Restrained (thermal/autogenous)
Shrinkage Cracking
• Large Creep Deformations
• Need for Thermal Curing
• Specialty Aggregates
• Excess Mixing Time/Effort
• Cost
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Temperature Gradient
Large, Temp.-Dependent Autogenous shrinkage
Restrained Shrinkage Cracking
FutureNeeds&Benefits
• Future Needs: Develop mix design and production methods for reliable and costeffective construction of UHPC infrastructure systems using commonly available materials and equipment.
• Key Benefit: Enable effective use of UHPC towards enhancement of the safety, structural efficiency, durability, sustainability, and initial and life-cycle economy of concrete-based infrastructure systems.
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