ASTM-C494 › Standard Specification for Chemical Admixtures for Concrete
The following bibliographic material is provided to assist you with your purchasing decision:
Scope
1.1 This specification covers materials for use as chemical admixtures to be added to hydraulic-cement concrete mixtures in the field for the purpose or purposes indicated for the seven types as follows:
1.1.1 Type A--Water-reducing admixtures,
1.1.2 Type B--Retarding admixtures,
1.1.3 Type C--Accelerating admixtures,
1.1.4 Type D--Water-reducing and retarding admixtures,
1.1.5 Type E--Water-reducing and accelerating admixtures,
1.1.6 Type F--Water-reducing, high range admixtures, and
1.1.7 Type G--Water-reducing, high range, and retarding admixtures.
1.2 This specification stipulates tests of an admixture with suitable concreting materials as described in 11.1 - 11.3 or with cement, pozzolan, aggregates, and an air-entraining admixture proposed for specific work (11.4). Unless specified otherwise by the purchaser, the tests shall be made using concreting materials as described in 11.1 - 11.3.
Note 1--It is recommended that, whenever practicable, tests be made using the cement, pozzolan, aggregates, air-entraining admixture, and the mixture proportions, batching sequence, and other physical conditions proposed for the specific work (11.4) because the specific effects produced by chemical admixtures may vary with the properties and proportions of the other ingredients of the concrete. For instance, Types F and G admixtures may exhibit much higher water reduction in concrete mixtures having higher cement factors than that listed in 12.1.
Mixtures having a high range water reduction generally display a higher rate of slump loss. When high-range admixtures are used to impart increased workability (6 to 8-in. slump [150 to 200-mm]), the effect may be of limited duration, reverting to the original slump in 30 to 60 min depending on factors normally affecting rate of slump loss. The use of chemical admixtures to produce high-slump (flowing) concrete is covered by Specification C 1017.
Note 2--The purchaser should ensure that the admixture supplied for use in the work is equivalent in composition to the admixture subjected to test under this specification (see Section 6, Uniformity and Equivalence).
Note 3--Admixtures that contain relatively large amounts of chloride may accelerate corrosion of prestressing steel. Compliance with the requirements of this specification does not constitute assurance of acceptibility of the admixture for use in prestressed concrete.
1.3 This specification provides for three levels of testing.
1.3.1 Level 1--During the initial approval stage, proof of compliance with the performance requirements defined in Table 1 demonstrates that the admixture meets the requirements of this specification. Uniformity and equivalence tests of Section 6 shall be carried out to provide results against which later comparisons can be made.
1.3.2 Level 2--Limited retesting is described in , and . Proof of compliance with the requirements of demonstrates continued conformity of the admixture with the requirements of the specification.
1.3.3 Level 3--For acceptance of a lot or for measuring uniformity within or between lots, when specified by the purchaser, the uniformity and equivalence tests of Section 6 shall be used.
1.4 The values stated in either inch-pound or SI units shall be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system must be used independently of the other, without combining values in any way.
1.5 The text of this standard references notes and footnotes which provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the standard.
1.6 The following precautionary caveat pertains only to the test method sections, Sections 11-18 of this Specification: This standard does not purport to address all of 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.
Keywords
accelerating; chemical admixtures; concrete; physical requirements; retarding; testing; water reducing
To find similar documents by ASTM Volume:
04.02 (Concrete and Aggregates)
To find similar documents by classification:
91.100.30 (Concrete and concrete products Including admixtures)
This document comes with our free Notification Service, good for the life of the document.
This document is available in either Paper or PDF format.
Customers who bought this document also bought:
IPC-A-610Acceptability of Electronic Assemblies (Hardcopy format)
IPC-A-600
Acceptability of Printed Boards
ASTM-A240
Standard Specification for Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip for Pressure Vessels and for General Applications
Document Number
ASTM-C0494_C0494M-24
Revision Level
2024 EDITION
Status
Current
Modification Type
Revision
Publication Date
Aug. 6, 2024
Document Type
Specification
Page Count
15 pages
Committee Number
C09.23