The CBR test (California Bearing Ratio test) is a very common Geotechnical Engineering laboratory and field test used to evaluate the strength of subgrade soil and base materials, especially for road and pavement design. Purpose • To determine the bearing capacity of soil • To help in designing thickness of pavement layers • To assess suitability of soil for road construction Applications of CBR Test 1. Design of flexible pavements (roads, highways) 2. Determination of subgrade soil strength 3. Design of base and sub-base layers thickness 4. Airfield and runway pavement design 5. Evaluation of load-bearing capacity of soil 6. Comparison of different soil types for construction suitability 7. Quality control during road construction 8. Assessment of compaction effectiveness 9. Selection of suitable fill material for embankments 10. Design of rural and low-volume roads 11. Determining soaked and unsoaked soil conditions performance 12. Checking stability of pavement structure under traffic loads