Smyrna Times

Heat Concrete In Cold Weather

Concrete can be poured in cold weather on Kent County farms provided certain precautions are followed to insure high quality construction, says County Agent George K. Vapaa.

If temperatures are below 40 degrees Fahrenheit, the sand, gravel and water should be heated before mixing-but in no case heated hotter than can be tolerated by the human hand. The concrete should be poured immediately after mixing, before it cools off. Avoid pouring on frozen earth.

As soon as the concrete is poured it should be protected against loss of heat. Covers of canvas, straw or hay are often used for this purpose. Manure, salt, sugar or other chemicals should not be placed immediately on new concrete.

Protection should be continuous for 4 or 5 days at a temperature of 50 degrees or higher.

Calcium chloride may be added to the mix to speed up the setting but it should not be relied on to prevent freezing of concrete.

When used it should be added to the mixing water at the rate of not more than two pounds per bag of cement. This chemical has little effect on the strength of the concrete.

High-early strength cement may also be used instead of ordinary Portland Cement. High-early concrete requires only a fourth of the time to set as needed by regular concrete.