CBR Testing

We carry these out all over the UK.  We can attend at short notice and you always get your reports the same day.

The California Bearing Ratio (CBR) test is an empirical measure of soil strength.  It is most often used on subgrade for road design and construction to determine the thicknesses of materials to be used.  The stronger the material being tested, the higher the CBR value, which can lead to thinner layers of material being used, which in turn can reduce construction cost.

Not sure which test or method you need?  Click here

“What a CBR test can’t tell you is soil bearing capacity, shear strength or suitability of material for use as a crane base or piling mat.  For these parameters it would be best to conduct plate bearing testing.”

 

CBR Testing using the Plate Bearing Test

With its direct measure of the material in-situ, its quick method and the prompt availability of test results, testing for CBR on-site by the plate bearing method is often the preferred approach.

The test is carried out using the same equipment and process as the plate bearing test and is particularly suited to testing when:

  • the material to be tested is granular in nature

  • additional parameters are required to be measured such as stress under the plate in kN/m2 with corresponding plate settlement.

  • There is construction plant available to act as a reaction load for the test

InSitu CBR Testing using the Standard Method

InSitu CBR testing is the definitive method of determining the CBR value of materials on-site.  The equipment is attached to our vehicles and is self-sufficient, needing no construction plant to be provided to act as a reaction load.

It is quick to carry out and CBR values can be provided immediately after testing.  It is particularly suited to testing when:-

  • The material to be tested is free of particles over 20mm

  • There is no construction plant available to act as reaction load or no room to place it

  • Tests are required at depth in small excavated trial holes