Ultra-High-Performance Concrete for the Alabama Transportation Industry

Details

• Creators:
  Osibodu, Segun J. ; Coleman, Daniel M. ; Schindler, Anton K.
• Corporate Creators:
  Auburn University. Highway Research Center
• Corporate Contributors:
  Alabama. Department of Transportation
• Subject/TRT Terms:
  • Testing
  • Flexural strength
  • Steel fibers
  • Proportion
  • Ultra high performance concrete
  • Transportation
  • Cast in place structures
  • Tensile strength
  • Laboratory tests
  • Direct-tension testing
  More +
• Publication/ Report Number:
  931-069
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States ; Alabama
• Corporate Publisher:
  Auburn University. Highway Research Center
• Abstract:
  Ultra-high-performance concrete (UHPC) offers exceptional compressive strength, sustained post-cracking tensile capacity, and inherent durability that makes it well suited for transportation applications such as closure pours, deck overlays, and precast element connections. The objective of this study was to develop, characterize, and field-validate non-proprietary UHPC using Alabama materials that satisfies Federal Highway Administration (FHWA) structural requirements for cast-in-place applications at a significantly lower cost when compared to proprietary UHPC. During the laboratory-testing phase, UHPC mixtures were produced using a planetary high-shear mixer to systematically evaluate five constituent variables: steel fiber dosage (0% to 2.0% by volume), fine aggregate gradation, cementitious blend type (binary versus ternary), silica fume content (9% to 15% of total binder), and water-to-binder ratio (0.18 to 0.22). Each mixture was evaluated in compression, flexure per ASTM C1609, and direct tension per AASHTO T 397 at 28 and 91 days, with select mixtures further tested for freeze-thaw durability through 300 cycles. A refined testing protocol for AASHTO T 397 was developed that improved the direct-tension test success rate from 44% to 75% using a 220-kip universal testing machine with wedge grips. A forward analysis was also performed to establish equivalent flexural stress acceptance criteria corresponding to the FHWA tensile stress requirements. During the field-testing phase, three production trials were performed where two cubic yards of UHPC were produced in a ready mixed concrete plant. During each full-scale trial the mixing and loading sequence was progressively adjusted to eliminate cement balling during mixing. The non-proprietary UHPC, proportioned with standard AASHTO M 6 river sand, Type IL cement, slag cement, 9% silica fume, and 1.5% steel fibers by volume, exceeded the FHWA minimum post-cracking tensile strength of 750 psi at an estimated material cost of $640 to $760 per cubic yard, representing less than 40% of the cost of proprietary alternatives. All mixtures tested were inherently freeze-thaw resistant without air entrainment, and field-produced UHPC achieved tensile performance comparable to laboratory specimens, confirming the viability of full-scale production. A draft ALDOT special provision with performance-based acceptance criteria was developed from these findings. This work provides ALDOT with the technical basis and specification framework needed to implement non-proprietary UHPC using materials already available within the Alabama concrete industry.
• Format:
  PDF
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/93186/dot_93186_DS1.pdf
• File Type:
  [PDF - 9.65 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:49f9cf91fd4e8ac4a95174fef4821ac3151b88ff2898aca11499d0211043260d2bde3a4729069bcaff4d0b6066f4f6a45eee8175cdf978a3710392a5f8f4a4f2