In-situ California bearing ratio

The in-situ California bearing ratio (CBR) test is typically used for road, runways or car park pavement design to assess the strength of the sub-grade. The test involves driving a cylindrical plunger of a defined area into the soil at a uniform rate. This requires the use of a reaction load, (for example, a four wheel drive vehicle or mechanical excavator), to provide the force. Alternatively a profile of equivalent in-situ CBR can be measured using the dynamic cone penetrometer (DCP).