NRC-4012

STANDARDS: ASTM D5873

This lightweight and portable impact hammer is used for rock classification tests. Includes rubbing stone for surface preparation.
The hammer is similar to a device used for many years for strength classification tests of mass concrete.

Cylindrical cores, usually NW size, are held in a horizontal position and the hammer mechanism impacted against the core to obtain rebound readings. A series of readings is taken along the length of the core to get the average rebound number.

The core rock specimen normally NX Ø54,7 mm is held on a special cradle in horizontal position and the hammer tests the same in all its length to obtain average of the readings.

The Rock Cradle is used to hold cores (EX Ø21,46 mm and NX Ø54,74 mm) in place during rock classification test procedures. The cradle incorporates a guide for positioning the hammer to allow for a series of readings along the length of the core.

Rock cradle and Calibration Anvil should be ordered separately.