Similar International Standards
ASTM D7012-23ASTM International, USA
HighCurrent
Standard Test Methods for Compressive Strength and Elastic Moduli of Intact Rock Core Specimens under Varying States of Stress and Temperatures
Method C of this standard specifically covers the determination of unconfined compressive strength of intact rock core.
ISRM Suggested Methods (2007)International Society for Rock Mechanics (ISRM), International
HighCurrent
The Complete ISRM Suggested Methods for Rock Characterization, Testing and Monitoring: 1974-2006 (Part 1, Method 2)
Provides a globally recognized procedure for determining the uniaxial compressive strength of rock materials.
EN 1926:2006European Committee for Standardization (CEN), Europe
HighCurrent
Natural stone test methods - Determination of uniaxial compressive strength
Specifies the method for determining the uniaxial compressive strength, primarily focused on natural stone for construction.
ASTM D2938-14ASTM International, USA
HighWithdrawn
Standard Test Method for Unconfined Compressive Strength of Intact Rock Core Specimens
Was the dedicated ASTM standard for this specific test before being consolidated into the more comprehensive D7012.
Key Differences
≠The recommended length-to-diameter (L/D) ratio in IS 9143 is 2.0 to 2.5, whereas the ISRM Suggested Methods recommend a slightly higher ratio of 2.5 to 3.0.
≠IS 9143 specifies a loading rate designed to cause failure in 5 to 15 minutes, while ASTM D7012 mandates a more precise, constant stress rate of 0.5 to 1.0 MPa/s.
≠IS 9143 requires testing a minimum of 3 specimens, whereas ASTM D7012 requires a minimum of 5 specimens to obtain a representative average strength.
≠The tolerance for end perpendicularity to the specimen axis is stricter in ASTM D7012 (0.001 radians or ~0.06°) compared to IS 9143 (0.1° or ~0.0017 radians).
Key Similarities
≈All standards are based on the fundamental principle of applying a continuously increasing, uniaxial compressive load to a prepared cylindrical or prismatic rock specimen until it fails.
≈The core calculation for strength is identical across all standards: Unconfined Compressive Strength (UCS) equals the maximum load at failure divided by the initial cross-sectional area of the specimen.
≈All referenced standards require the use of a spherically seated block in the loading apparatus to ensure uniform application of load and to compensate for any minor non-parallelism of the specimen ends.
≈The standards mandate similar specimen preparation requirements, including precise cutting, lathing, and grinding to achieve smooth, flat, and parallel end surfaces.
≈All standards require reporting the mode of failure (e.g., shear, splitting, conical) and the condition of the specimen (e.g., saturated, as-received moisture content).