The California Bearing Ratio (CBR) test is to provide an indication of pavement formation competency together with validating the installed compaction of pavement/hard standing sub-base layers.
The CBR is the ratio of the bearing load that penetrates a material to a specific depth compared with the load giving the same penetration into crushed stone. The test measures neither Stiffness Modulus nor Shear Strength directly but gives a combined measure of both. Penetration is measured by applying the bearing load on the sample using a standard plunger of diameter 50mm at the rate of 1.25mm/min.
The CBR is expressed as a percentage of the actual load causing the penetrations of 2.5mm or 5.0mm to the standard loads on crushed stone.
All reports are electronic so site records can be emailed to ensure rapid delivery of results.