GeoTesting Express Laboratory Testing Field Testing Qualifications Contact Us

Lab Services: Rock testing

Lab Services: Rock testing

Back to Search

Test Method Title

Standard Test Method for Unconfined Compressive Strength of Intact Rock Core Specimens **ASTM has discontinued this method, the industry-accepted standard test method is now ASTM D7012C

Reference Number

ASTM D2938



Test Property

Unconfined Compressive Strength

Description of Test

A rock core sample is cut to length and the ends are machined flat. The specimen is placed in a loading frame and, if required, heated to the desired test temperature. Axial load is continuously increased on the specimen until peak load and failure are obtained. Unconfined compressive strength of rock is used in many design formulas and is sometimes used as an index property to select the appropriate excavation technique.

Preferred Test Sample Size

Number of Test Specimens

Enough samples to represent a valid average of the type of rock under consideration

Test Specimen Size

Right circular cylinder, with diameter of at least 1 7/8 in and a length to diameter ratio of 2 to 2.5:1


Compression testing, compressive strength, loading tests, rock

For more information, contact GeoTesting Express:







New York