What are the drawbacks of California bearing test.?
We know that CBR TEST is a test used for evaluating the stability of soil subgrade and other flexible pavements. The thickness of the pavement is determined based on this test. In this post, we are going to describe some drawbacks about the CBR test or California bearing test.
The first drawback or disadvantage is it does not consider whether the road is multi-lane single carriageway or dual carriageway.
The second disadvantage of the CBR test is it does not fully take into account the effect of heavier loads and their frequency in the wheel load spectrum.
The design curve only gives the value for the total thickness of pavement for different traffic intensity and CBR values of subgrade. These curves do not specify the thickness of subbase, base and surfacing separately which are needed to evolve most economic design pavement.
It permits the equivalency factor of up to 2 for bituminous constructions to equate the thickness of bound base to that conventional water bound macadam.
This is the main drawbacks of cbr test..
Read more: Different methods of road construction.