ASTM C227

1.1 This test method covers the determination of the susceptibility of cement-aggregate combinations to expansive reactions involving hydroxyl ions associated with the alkalies (sodium and potassium) by measurement of the increase (or decrease) in length of mortar bars containing the combination during storage under prescribed conditions of test.

1.2 Alkalies participating in the expansive reactions usually are derived from the cement; under some circumstances they may be derived from other constituents of the concrete or from external sources. Two types of alkali reactivity of aggregates are recognized: (1) an alkali-silica reaction involving certain siliceous rocks, minerals, and natural or artificial glasses and (2) an alkali-carbonate reaction involving dolomite in certain calcitic dolomites and dolomitic limestones (see Standard C 294). The method is not recommended as a means to detect the latter reaction because expansions produced in the mortar-bar test by the alkali-carbonate reaction (see Test Method C 586) are generally much less than those produced by the alkali-silica reaction for combinations having equally harmful effects in service.

1.3 The values stated in SI units are to be regarded as standard. The non-SI values, shown in parentheses, are for informational purposes only.

1.4 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.

2. Referenced Documents

ASTM Standards
C109/C109M Test Method for Compressive Strength of Hydraulic Cement Mortars (Using 2-in. or [50-mm] Cube Specimens)
C1437 Test Method for Determining Flow of Hydraulic Cement Mortar
C289 Test Method for Potential Alkali-Silica Reactivity of Aggregates (Chemical Method)
C294 Standard Descriptive Nomenclature for Constituents of Concrete Aggregates
C295 Guide for Petrographic Examination of Aggregates for Concrete
C305 Practice for Mechanical Mixing of Hydraulic Cement Pastes and Mortars of Plastic Consistency
C33 Specification for Concrete Aggregates
C490 Practice for Use of Apparatus for the Determination of Length Change of Hardened Cement Paste, Mortar, and Concrete,
C511 Specification for Moist Cabinets, Moist Rooms, and Water Storage Tanks Used in Testing of Hydraulic Cements and Concretes,
C586 Test Method for Potential Alkali Reactivity of Carbonate Rocks for Concrete Aggregates (Rock Cylinder Method)
C856 Practice for Petrographic Examination of Hardened Concrete
E11 Specification for Wire Cloth and Sieves for Testing Purposes

Index Terms

aggregate; alkali-silica reaction; cement; length change; mortar; ICS Number Code 91.100.10 (Cement. Gypsum. Lime. Mortar)

Citing ASTM Standards

[Back to Top]