Значение и использование

Measurement of length change permits assessment of the potential for volumetric expansion or contraction of mortar or concrete due to various causes other than applied force or temperature change. This test method is particularly useful for comparative evaluation of this potential in different hydraulic-cement mortar or concrete mixtures.

This test method provides useful information for experimental purposes or for products that require testing under nonstandard mixing, placing, handling, or curing conditions, such as high product workability or different demolding times. Standard conditions are described in 5.4.1.

If conditions for mixing, curing, sampling, and storage other than specified in this test method are required, they shall be reported but are not to be considered as standard conditions of this test method. Nonstandard conditions and the reasons for departure from standard conditions shall be reported clearly and prominently with comparator values.

Область применения DESIG: C 157/C 157M 08 ^TITLE: Standard Test Method for Length Change of Hardened Hydraulic-Cement Mortar and Concrete ^SIGNUSE:

Measurement of length change permits assessment of the potential for volumetric expansion or contraction of mortar or concrete due to various causes other than applied force or temperature change. This test method is particularly useful for comparative evaluation of this potential in different hydraulic-cement mortar or concrete mixtures.

This test method provides useful information for experimental purposes or for products that require testing under nonstandard mixing, placing, handling, or curing conditions, such as high product workability or different demolding times. Standard conditions are described in 5.4.1.

If conditions for mixing, curing, sampling, and storage other than specified in this test method are required, they shall be reported but are not to be considered as standard conditions of this test method. Nonstandard conditions and the reasons for departure from standard conditions shall be reported clearly and prominently with comparator values.

^SCOPE:

1.1 This test method covers the determination of the length changes that are produced by causes other than externally applied forces and temperature changes in hardened hydraulic-cement mortar and concrete specimens made in the laboratory and exposed to controlled conditions of temperature and moisture.

1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. An exception is with regard to sieve sizes and nominal size of aggregate, in which the SI values are the standard as stated in Specification E 11. Within the text, the SI units are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.

1.3 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. ^REFERENCE:

ASTM Standards:

C 125 Terminology Relating to Concrete and Concrete Aggregates

C 143/C 143M Test Method for Slump of Hydraulic-Cement Concrete

C 172 Practice for Sampling Freshly Mixed Concrete

C 192/C 192M Practice for Making and Curing Concrete Test Specimens in the Laboratory

C 305 Practice for Mechanical Mixing of Hydraulic Cement Pastes and Mortars of Plastic Consistency

C 490 Practice for Use of Apparatus for the Determination of Length Change of Hardened Cement Paste, Mortar, and Concrete

C 511 Specification for Mixing Rooms, Moist Cabinets, Moist Rooms, and Water Storage Tanks Used in the Testing of Hydraulic Cements and Concretes

C 596 Test Method for Drying Shrinkage of Mortar Containing Hydraulic Cement

C 1347 Practice for Preparation and Dissolution of Uranium Materials for Analysis

E 11 Specification for Wire Cloth and Sieves for Testing Purposes

E 337 Test Method for Measuring Humidity with a Psychrometer (the Measurement of Wet- and Dry-Bulb Temperatures)

^KEYWORDS: length change; mortar concrete ^INDEX TERMS: Cement mortars; Change in length; Hardened concrete; Hydraulic cement concrete; Volumetric measurement--cement/concrete ^STATUS: Dn Cn Sn Nn Mn ^APPROVAL: 20081001 ^PAGES: 7 ^COMMITTEE: C09 ^SUBCOMMITTEE: 6800 ^BOS: 04.02 ^ORGINFO: DOD ^ACTION: STD_REVISION ^MISCPUB: ^PDESIG: C0157 ^PYEAR: 2008 ^CLASS: Test Method