ASTM C94/C94M-21, Specification for Ready Mixed Concrete, includes a revision related to the time limit to discharge concrete; the time limit of 1 ½ hours to discharge has been removed. This revision indicates that the time limit can be stated by the purchaser at the time concrete is ordered. If the limit is not stated by the purchaser, the producer should establish a time limit. The revision was proposed because delivery time can vary on projects depending on distance or placement methods. Additionally, there may be some mixtures in some conditions where the previous default time limit was not appropriate without using special means or could cause excessive addition of water. Another part of the revision requires the established time limit to be stated on the delivery ticket.
For more information, contact Colin Lobo at clobo@nrmca.org.
National Ready Mixed Concrete Association