What is CBR Describe the Procedure of CBR Test

This article is about California Bearing Ratio (CBR) the definition, scope and procedure of CBR test have been explained step by steps in simple words.


Take a sample 18 to 20 Kg and divide into three equal portions for each mould take 6Kg(min) than replace the sample (same proctor procedure) than clamp the mould and take weight with collar and insert the spacer disk and place a filter paper on the top of the disk.

Mix each of the sample with water according to the optimum moisture and compact the mould with 10,30,and 65 blows per layer in five equal layers and take the sample for moisture content from the mixing tray of sample.

Remove the spacer disk and place a filter paper on base plate clamp the perforated base plate than attach a collar and take the weight of mould with specimen than place the surcharge weights and dial indicator on the sample and immerse the sample in water for 96 hours,

After 96 hours calculate the swelling and after draining the water set the sample in CBR crushing machine and apply the load and record the penetration and calculate the CBR value at specified compaction.


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