California Bearing Ratio
Overview
Road
A road is a thoroughfare, route, or way on land between two places, which typically has been paved or otherwise improved to allow travel by some conveyance, including a horse, cart, or motor vehicle. Roads consist of one, or sometimes two, roadways each with one or more lanes and also any...
subgrade
Subgrade
In transport engineering, subgrade is the native material underneath a constructed road, pavement or railway track. It is also called formation level.The term can also refer to imported material that has been used to build an embankment....
s and basecourses. It was developed by the California Department of Transportation
California Department of Transportation
The California Department of Transportation is a government department in the U.S. state of California. Its mission is to improve mobility across the state. It manages the state highway system and is actively involved with public transportation systems throughout the state...
before World War II.
The test is performed by measuring the pressure
Pressure
Pressure is the force per unit area applied in a direction perpendicular to the surface of an object. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure.- Definition :...
required to penetrate a soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...
sample with a plunger of standard area. The measured pressure is then divided by the pressure required to achieve an equal penetration on a standard crushed rock material.
