S1 When the use of nonagitating transportation equipment is approved by the purchaser, the concrete shall be manufactured in a central mix plant. S2 The proportions of the concrete shall be approved by the purchaser, and the following limitations shall apply: It is not the intention of ASTM C 94/C 94M to require the use of nonagitating equipment when the mixing is accomplished in a central-mix plant. It is the intention of ASTM C 94/C 94M to require the purchaser's approval to use non-agitating equipment as a delivery vehicle. The question to be answered is if the purchaser will allow the concrete to be hauled by nonagitating equipment, or if agitating equipment will be required or permitted.