S1 In the event that concrete tested in accordance with the requirements of Section 17 fails to meet the strength requirements of this specification, the manufacturer of the readymixed concrete and the purchaser shall confer to determine whether agreement can be reached as to what adjustment, if any, shall be made. S2 If an agreement on a mutually satisfactory adjustment cannot be reached by the manufacturer and the purchaser, a decision shall be made by a panel of three qualified engineers, one of whom shall be designated by the purchaser, one by the manufacturer, and the third chosen by these two members of the panel. S3 The question of responsibility for the cost of such arbitration shall be determined by the panel. S4 Its decision shall be binding, except as modified by a court decision.