Materials

Use Class H (HPC) concrete for girder elements:
  • Precast Elements:
    • Minimum fci'
      = 4.0 ksi, Maximum fci'
      = 6.0 ksi
    • Minimum fc'
      = 5.0 ksi, Maximum fc'
      = 10.0 ksi
  • Cast in Place Elements:
    • Maximum fc'
      = 6.0 ksi
Use Class S concrete for cast in place deck. Use Class S (HPC) if de-icing chemicals are routinely used at the site:
  • Maximum fc'
    = 4.0 ksi
Use prestressing strand with specified tensile strength,
fpu
 of 270 ksi.
  • Use 0.6 in low-relaxation strands for pretensioning strands.
  • Use 0.6 in low-relaxation strands for post-tensioning tendons.
Provide post tension system in accordance with Item 426, “Post-Tensioning” of the
Texas Department of Transportation Standard Specifications for Construction and Maintenance of Highways, Streets, and Bridges, with the following exceptions
:
  • Non-Severe Corrosive Environments:
    • Galvanized or plastic duct can be used
    • Meet requirements for Protection Level 1B.
    • Do not use tape-sealed connections.
  • Severe Corrosive Environments:
    • Use plastic duct only
    • Meet requirements for Protection Level 2
All stressed tendons in the finished structure must be grouted. All permanent tendons that are stressed at the precast yard must be grouted prior to transport.