NASA Road 1 over I-45: High Performance Concrete Mix Designs

Class "F" Bent Cap Concrete

• 7 Sacks Per Yard with 20% replacement of cement with Class F Fly Ash
• Crushed Granite Coarse Aggregate (1 ½ inch maximum size aggregate)
• 0.37 Water to Cement Ratio
• Used High Range Water Reducer
• Test batches were made and strength gain curves were developed
  (To predict when beams could be set on the new caps)
  • 4000 psi - One Day Strength
  • 5100 psi - Three Day Strength
  • 5500 psi - Seven Day Strength
  • 5500 to 6500 - 9 Day Strengths from Material Test Reports from cap test cylinders
  • 7400 psi - Twenty Eight Day Strength

Class "S" Concrete Wearing Surface and Shear Key Concrete

• 6.5 Sacks Per Yard with 30% replacement of cement with Class F Fly Ash
• Crushed Granite Coarse Aggregate (1 ½ inch maximum size aggregate)
• 0.41 Water to Cement Ratio
• Used Mid range Water Reducer/Retarder
• Test batches were made and strength gain curves were developed
  (To predict when equipment could be put on the bridge to pour the rail)
  • 3600 psi - One Day Strength
  • 5800 psi - Three Day Strength
  • 6300 psi - Five Day Strength
  • 4900 Average 7 Day Strengths from Material Test Reports from actual deck test cylinders