ASTM C138 / C138M

This test method covers determination of the density of freshly mixed concrete and gives formulas for calculating the unit weight, yield or relative yield, cement content, and air content of the concrete. Yield is defined as the volume of concrete produced from a mixture of known quantities of the component materials. The test method shall use the following apparatuses: balance or scale; tamping rod, which is a round straight steel rod having the tamping end rounded to a hemispherical tip; internal vibrator which may have rigid of flexible shafts, preferably powered by electric motors; measure, which is a cylindrical container made of steel or other suitable metal specified herein; strike-off plate; mallet; and scoop of a size large enough so each amount of concrete obtained from the sampling receptacle is representative and small enough so it is not spilled during placement in the measure.

This abstract is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.

1. Scope

1.1 This test method covers determination of the density (see Note 1) of freshly mixed concrete and gives formulas for calculating the yield, cement content, and air content of the concrete. Yield is defined as the volume of concrete produced from a mixture of known quantities of the component materials.

1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. 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.

Note 1—Unit weight was the previous terminology used to describe the property determined by this test method, which is mass per unit volume.

1.3 The text of this test method references notes and footnotes that provide explanatory information. These notes and footnotes (excluding those in tables) shall not be considered as requirements of this test method.

2. Referenced Documents

ASTM Standards
C143/C143M Test Method for Slump of Hydraulic-Cement Concrete
C150 Specification for Portland Cement
C172 Practice for Sampling Freshly Mixed Concrete
C173/C173M Test Method for Air Content of Freshly Mixed Concrete by the Volumetric Method
C188 Test Method for Density of Hydraulic Cement
C231 Test Method for Air Content of Freshly Mixed Concrete by the Pressure Method
C29/C29M Test Method for Bulk Density (Unit Weight) and Voids in Aggregate
C31/C31M Practice for Making and Curing Concrete Test Specimens in the Field

Index Terms

air content; cement content; concrete; relative yield; unit weight; yield; Air content--concrete; Cement content (of concrete); Concrete; Density--concrete; Gravimetric determination; Unit weight; Weight--concrete/aggregates; Yield ICS Number Code 91.100.30 (Concrete and concrete products)

Citing ASTM Standards

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