A1.2.1 These tests and requirements are used to evaluate loading and operating procedures; verify the accuracy of proportioning and indicating systems; and determine if mixing uniformity has been degraded by excessive wear or by accumulations of hardened concrete, or both (Note A1.1).

Note A1.1: The method of loading the batching-mixing unit, proper maintenance, and other factors may have an effect on the ability of the unit to produce uniformly mixed concrete. For this reason, the use of this test method not only measures the efficiency of the mixer, but also the combined effect of the method of loading and operating the unit.

A1.2.2 This annex provides additional procedures and cautions that are necessary in the application of existing test methods and practices when used to determine the uniformity of freshly mixed concrete.

This specification covers concrete made by volumetric batching and continuous mixing. Requirements for quality of concrete shall be either as hereinafter specified or as specified by the purchaser. When the requirements of the purchaser differ from this specification, the purchaser's specification shall govern. This specification does not cover the placement, consolidation, finishing, curing, or protection of the concrete after delivery to the purchaser. Tests and criteria for batching accuracy and mixing efficiency are specified herein. Materials such as cement, aggregates, water, ground granulated blast-furnace slag, air-entraining admixtures, and chemical admixtures shall conform to the requirements covered in this specification. The material shall be subjected to the following test methods: compression test specimens; compression tests; yield; unit weight; air content; slump; and temperature.

1.1 This specification covers concrete made from materials continuously batched by volume, mixed in a continuous mixer, and delivered to the 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. When the requirements of the purchaser differ from this specification, the purchaser's specification shall govern. This specification does not cover the placement, consolidation, finishing, curing, or protection of the concrete after delivery to the purchaser. Tests and criteria for batching accuracy and mixing efficiency are specified herein.

1.2 As used throughout this specification the producer manufactures ready-mixed concrete and the purchaser buys ready-mixed concrete.

1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.

Note 1: Sieve size is identified by its standard designation in Specification E11. The alternative designation given in parentheses is for information only and does not represent a different standard sieve size. Specification E11 cites the following with respect to SI units versus inch-pound units as standard. “The values stated in SI units shall be considered standard for the dimensions of the sieve cloth openings and the wire diameters used in the sieve cloth. The values stated in inch-pound units shall be considered standard with regard to the sieve frames, pans, and covers”.

1.4 If required results obtained from another standard are not reported in the same system of units as used by this standard, it is permitted to convert those results using the conversion factors found in the SI Quick Reference Guide.2

1.5 This specification refers to notes and footnotes that provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of this specification.

1.6 This standard does not purport to address all the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. (Warning—Fresh hydraulic cementitious mixtures are caustic and may cause chemical burns to skin and tissue upon prolonged use.3)

1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.