California bearing ratio( CBR)

California bearing ratio

Introduction

The California bearing ratio (CBR) is a penetration test for evaluation of the mechanical strength of natural ground, subgrades and base courses beneath new carriageway construction. It was developed by the California Department of Transportation before 2nd World War

Significance and Use

The CBR rating was developed for measuring the load-bearing capacity of soils used for building roads. The CBR can also be used for measuring the load-bearing capacity of unimproved airstrips or for soils under paved airstrips. The harder the surface, the higher the CBR rating.

CBR Test at site (ASTM D4429)

CBR Test in Laboratory( ASTM D1883)

Nasir Abbasi