ASTM C138
Full Name
ASTM C138 – Standard Test Method for Density (Unit Weight), Yield, and Air Content (Gravimetric) of Concrete
Scope
ASTM C138 outlines procedures to determine the following properties of freshly mixed concrete:
- Density (unit weight): the mass of concrete per unit volume, typically expressed in pounds per cubic foot (lb/ft³) or kilograms per cubic meter (kg/m³).
- Yield: the volume of concrete produced from a known mass of ingredients, usually expressed in cubic yards (yd³) or cubic meters (m³).
- Air content (gravimetric): the percentage of air voids in the concrete, calculated by comparing the actual density of the concrete to its theoretical maximum density.
The scope of ASTM C138 includes:
- Materials: freshly mixed concrete from various types of construction projects.
- Test methods:
- Density: determined by measuring the mass and volume of a representative sample of concrete.
- Yield: calculated from the mass of the concrete ingredients and the density of the freshly mixed concrete.
- Air content: calculated using the gravimetric method, which involves comparing the actual mass of the concrete to its theoretical mass if it contained no air voids.
- Applications:
- Quality control of concrete production to ensure consistency and compliance with specifications.
- Verification of concrete mix designs to ensure they meet desired properties.
- Troubleshooting problems with concrete performance or placement.
By following ASTM C138, the construction industry can maintain consistency and reliability in concrete testing, ensuring the quality and performance of concrete structures.
ASTM C138 Accredited Laboratory
Applied Testing & Geosciences, LLC is accredited for performing tests using the ASTM C138 standard.
Our laboratory offers precise and reliable ASTM C138 testing services to ensure the quality and performance of your concrete. Our experienced technicians utilize modern equipment and follow strict quality control procedures to deliver accurate results.
By understanding the density, yield, and air content of your concrete, you can optimize your concrete mixtures and construction processes. Contact us today to learn more about our testing capabilities and how we can support your concrete projects.
Resources
Keywords
density; unit weight; yield; air content; concrete; gravimetric; tamping rod; calibration; measure