1905.3.3 Test records and trial mixtures.
BC § 1905.3.3
Field strength test records or trial mixtures used to determine f 'cr shall not be more than 24 months old measured from the date of batching, provided the materials are the same as those proposed for use and the concrete producer provides a written statement confirming the materials are the same as those proposed for use. Exceptions: 1. Coarse aggregates may be acquired from an alternative source provided the nominal maximum size and the volume of coarse aggregate used remain unchanged.
2.Fine aggregates may be acquired from an alternative source provided the volume of fine aggregate used remains unchanged.
