AASHTO M 157 2006 Edition, January 1, 2006
Standard Specification for Ready-Mixed Concrete
This specification covers ready-mixed concrete manufactured and delivered to a purchaser in a freshly mixed and unhardened state as hereinafter specified. Requirements for quality of concrete shall be either as hereinafter specified or as specified by the purchaser. In any case where the requirements of the purchaser differ from those in this specification, the purchaser's specification shall govern. This specification does not cover the placement, consolidation, curing, or protection of the concrete after delivery to the purchaser.
The values stated in SI units are the preferred standard. The values given in parentheses are for information only.
As used throughout this specification the manufacturer shall be the contractor, subcontractor, supplier, or producer who furnishes the ready-mixed concrete. The purchaser shall be the specifying agency and designated representatives thereof. The engineer shall be interpreted to mean the designated representative of the specifying agency.