The California Bearing Ratio test is a procedure commonly used to do what?

The California Bearing Ratio (CBR) test is primarily utilized to assess the strength of subgrade soil, which is crucial for determining its load-bearing capabilities. In this test, a standardized piston is pressed into the soil at a slow rate, and the pressure required to achieve a specific penetration depth is measured. The results are expressed as a ratio of the soil’s strength compared to a standard, typically crushed rock. This test is significant in pavement design as it helps engineers select suitable materials and construction methods, ensuring the stability and durability of roadways and airfields.

While quantifying particle sizes, qualifying density achieved, and quantifying Reclaimed Asphalt Pavement (RAP) are also important aspects in civil engineering and materials testing, they are not the primary function of the CBR test. The focus of this test is distinctly on evaluating the strength characteristics of the soil rather than these other parameters.