A revision to ASTM C94/C94M, Specification for Ready Mixed Concrete, was approved for batching accuracy of water. The revision requires water to be batched to an accuracy of ±1.5% of the target batch water. This was changed from batch water should be accurate to ±1% of total mixing water and the total mixing water should be within ±3% of mixing water required by the mix design. The revision permits an easier verification of accuracy to the batchman during the batching process. The revision will be reflected in version C94/C94M-21a. This requirement is consistent with the NRMCA plant certification checklist. Devices for measuring batch water by weight or volume should be verified to achieve this accuracy. C94 does not have an accuracy requirement for water added through the truck water system. NRMCA’s plant certification checklist does have a requirement for these devices.
For more information contact Colin Lobo at clobo@nrmca.org.
National Ready Mixed Concrete Association