The Unsoaked California Bearing Ratio (CBR) Test measures the load-supporting capacity of soil in its natural moisture state or at a specific compacted density. It is the standard parameter used to design pavements and shallow foundations for regions with low water tables or controlled drainage environments.
Core Objectives
- Measure soil shear strength in its immediate natural state
- Design road and infrastructure foundations for normal conditions
- Evaluate material suitability without saturation delays
Pavement Design
- Determines thickness for dry/arid subgrade layers
- Benchmarks bearing performance for internal warehouse slabs
- Informs immediate ground improvement requirements
Structural Safety
- Provides accurate parameters for non-saturated design scenarios
- Prevents settlement under static and dynamic structural loads
- Optimizes material usage based on actual soil strength
Key Metrics
- Load vs. Penetration data for 2.5mm and 5.0mm depth
- Direct comparison with standard crushed stone values
- Correlation with soil classification and density tests
The Unsoaked CBR test is significantly faster than the soaked version as it bypasses the 96-hour immersion period. Soil is compacted in a standard mold and immediately subjected to penetration by a 50mm diameter plunger at a rate of 1.25 mm/min.
This test is particularly useful for Quality Assurance during construction, as it provides immediate feedback on whether the compacted fill meets the engineer's design requirements. Our team ensures that every sample is prepared to match the site's field density and moisture, giving you results you can trust for immediate construction decisions.
Our Laboratory Procedure
- 1 Compaction of soil at specified moisture and density
- 2 Precision plunger penetration via digital loading frame
- 3 Real-time data recording of pressure and depth increments
- 4 Rapid turnaround reporting with engineering design advice