ASTM C78

Full Name

ASTM C78 – Standard Test Method for Flexural Strength of Concrete (Using Simple Beam with Third-Point Loading)

Scope

ASTM C78 covers the determination of the flexural strength of concrete specimens using a simple beam subjected to a third-point loading configuration.

The scope includes:

• Purpose: to determine the flexural strength, also known as modulus of rupture (MOR), of concrete specimens.
• Specimen types:
  • Beams prepared and cured in accordance with ASTM C31 (Standard Practice for Making and Curing Concrete Test Specimens in the Field).
  • Beams prepared and cured in accordance with ASTM C42 (Standard Test Method for Obtaining and Testing Drilled Cores and Sawed Beams of Concrete).
  • Beams prepared and cured in accordance with ASTM C192 (Standard Practice for Making and Curing Concrete Test Specimens in the Laboratory).
• Test method: applying a load at the third points of a simply supported beam until failure occurs.
• Calculations: determining the flexural strength (MOR) based on the maximum load applied and the dimensions of the specimen.
• Applications: primarily used for testing concrete intended for use in slabs and pavements.

ASTM C78 does not cover:

• Alternative test methods for flexural strength (e.g., center-point loading).
• Testing of specimens with other shapes or sizes than those specified in the standard.

The significance of ASTM C78 lies in its ability to provide a standardized method for assessing the flexural strength of concrete, which is a crucial property for many concrete applications. By following this standard, consistent and reliable results can be obtained, contributing to the quality control and performance evaluation of concrete structures.

ASTM C78 Accredited Laboratory

Applied Testing & Geosciences, LLC is accredited for performing tests using the ASTM C78 standard.

Contact us for more information.

Resources

• ASTM International Website: ASTM C78

Keywords

flexural strength; concrete; modulus of rupture; third-point loading; beam; testing; simple beam; specimen preparation; curing; calculation; results