Soil Testing Instruments

The CBR test is used for determining the relative bearing ratio and expansion characteristics under known surcharge weights of base, sub-base and sub grade soils for the design of roads, pavements and runways. Tests can be conducted on all types of soils including sand, gravel and washed stone (passing through 20 mm IS Sieve). The CBR test is used extensively in selection of materials and control of sub grades. The procedure consists of loading soil with a circular piston, 50 mm dia face and maintaining a penetration rate of 1.25 mm/min. The load is noted and the results of test on natural or recompacted soils, in soaked and unsoaked conditions, can be compared with standard test results.
Meets: - IS: 9669 - 1980 IS: 2720 (Part 16) - 1979