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© 2008 NPCA
 
MC Magazine Archive

A Summary of Precautions during Hot Weather

Decrease concrete temperature:

  • Cool the cement
  • Cool the water
  • Cool the aggregate

Increase initial set time:

  • Use a set-retarding admixture
  • Use ASTM C 150 Type II cement or ASTM C 595 Type IP or Type IS blended cements, all of which are slower-setting cements

Maintain slump:

  • Use water reducers
  • A good aggregate gradation will decrease water demand
Protect from sudden decreases in air temperature:
  • Keep indoors as long as practical
  • Maintain a moist curing environment

Protect from the wind:

  • Set up windbreakers
  • Maintain a moist curing environment
Prevent cracking:
  • Add fiber reinforcement
  • Use admixtures to increase bleeding (also to prevent loss of surface moisture)
  • Maintain a moist curing environment

Maintain entrained air content:

  • Increase dosage per the manufacturer’s recommendations
  • Check with the admixture supplier for your brand’s performance under high temperatures

 
 
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