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Nor Shore Inc.

Cold Weather Concrete

Cold Weather Concreting Plain facts and Common Sense

Concrete can be placed safely throughout the winter months if the concrete mixture and its temperature are adapted to the construction procedure and the ambient weather conditions.

How to work with concrete in cold weather

When winter arrives, we need to take certain precautions to protect against some of the potential problems of placing concrete in cold weather-specifically, when the temperature drops below 4 degrees C.


Commonsense tips for concreting in cold weather:

  1. Discuss with your ready-mix producer the possibilities of using hot water, heating the aggregates, increasing the cement content, or adding an accelerating admixture.
  2. Order air entrainment if the concrete is exposed to freeze-thaw conditions during or after construction.
  3. Plan ahead. Have insulation and heaters ready, and inform your ready-mix producer of what concrete temperature you'll need for your project.
  4. Don't place concrete on a frozen subgrade; thaw the subgrade with steam or protect it with insulation.
  5. Add 5 litres of water per cubic metre of concrete to increase set time up to one-half hour; adding 10 litres can increase set time up to an hour.
  6. Provide triple insulation thickness at the corners and edges of walls and slabs.
  7. Protect fresh concrete against the disruptive effects of freezing until the concrete attains a compressive strength of about 3.5 mpa. Concrete gains very little strength at low temperatures.
  8. Don't expose concrete surfaces to a sudden temperature drop; gradually reduce the insulation or enclosure temperature to control concrete cooling (no more than a 10 degree C drop in 24 hours).
  9. Avoid using unvented heaters; carbon dioxide from the heaters can cause soft, dusting floors.
  10. Keep heaters attended at all times; they are a fire hazard when burning and are of no value when out of fuel.
  11. It is good practice in cold weather to leave forms in place as long as possible. Even within heated enclosures, forms serve to distribute heat more evenly and help prevent drying and local overheating.


Concrete that has been frozen just once at an early age can be restored to nearly normal strength by providing favorable curing conditions. Such concrete, however, is not as resistant to weathering, nor is it as watertight as concrete that has not been frozen. If concrete is frozen and kept frozen at about -10 degrees C, it will gain strength slowly. Below that temperature, cement hydration or concrete strength gain ceases.


For more information regarding cold-weather concreting, please contact your Nor-Shore sales representative.


Nor-Shore Ready Mix is committed to providing the best possible service to our customers. For more information about concrete or concrete materials, please contact your Nor-Shore sales representative.

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