To: Kohner Materials Customers

RE: Concrete in Cold Weather Conditions

When the cold seasons approach, and arrive to our service areas, we do not recommend the placing of concrete unless you follow the guidelines that are in ACI (American Concrete Institute) 306, cold weather concrete practices. ACI 306 states that cold weather concreting exists when the air temperature has fallen or is expected to fall below 40 degrees F during the protection period of the concrete. Concrete can be placed and reach it’s potential for desired strength and durability as long as it is produced, placed, and protected during the cold temperatures. The practices that you will have to use will vary dependent on the ambient temperature.

ACI 306 states that in dry conditions it is critical to maintain a concrete temperature for at least the first 72 hours or until the concrete reaches 500 psi. During this time you will need to protect the concrete with blankets, heating devises, or other insulating options.

In wet conditions ACI states that it is critical to maintain concrete temperatures for at least 7 days, or until the concrete reaches 3500 psi by using the same types of protection.

KOHNER MATERIALS COMPANIES WILL NOT BE RESPONSIBLE FOR CONCRETE FAILURES DUE TO IMPROPER COLD WEATHER PLACING PRACTICES, IMPROPER MIX DESIGN SELECTION, AND THE LACK OF PROTECTING, CURING, OR SEALING OF THE CONCRETE.

If you have any questions or concerns please contact one of our Ready Mix plants and we will assist you with your questions.

Sincerely,
Kohner Companies