Typical values may be around 30 – 50 IV for sub base materials, and up to 70 or more for base-course layers on highways.

As with the Clegg, exceeding the scale of 100 IV is not advised as this may damage the internal instrumentation.

The new 4.5 kg (9.9 lb) impact tester from Geotechnics has been designed to mirror the effectiveness and relevance of more common brand impact testers such as Clegg.

This means that unlike cut-rate imitation testers that come from Europe , the Geotechnics Impact Tester can be used under existing standards and regulations. The Geotechnics and Clegg Impact Testers both comply to ASTM D-5874-95.

The Geotechnics Impact Tester can infer a CBR value (%) by using a simple formula. From a design perspective this can prove to be useful in setting targets for contractors to achieve.

Clegg Impact Values are now common place around the world in compaction specifications.

For more information and Impact Tester sales, contact Geotechnics