CALIFORNIA BEARING RATIO TEST (FIELD TYPE)

AS PER IS: 2720 (Part - XXXI) 1969.

Introduction:

• In recent years it has become important to know C.B.R. Values in situ.
• It is useful in determining the load carrying capacity in the field when in-place density and water contents are such that the degree of saturation is 80% or greater, when material is cohesion less and coarse grained, such that it is not affected by changes in water contents and when the material has been in-place for considerable time.
• The loading is effected by means of a mechanical load frame which can be fixed to the underside of a truck.

General Description and Specifications:

• Mechanical screw loading jack:  10000 kg capacity with U-bracket and swivel head.
• Penetration piston: 50mm dia. threaded at the upper end.
• Extension rods: consisting of 2 lengths 5 cm, 2 lengths 10 cm, 1 length 30 cm, 1 length 50 cm and 1 length 100 cm, used as spacers between the proving ring and penetration piston. The lengths are machined from steel tubing.
• Connector set: It has eight connectors for coupling the penetration piston and proving ring assembly either directly or through extension pieces. Dial gauge support of seamless pipe construction. It stands 30cm high and 45cm wide at the base.
• Provided with a quick release screw type clamp capable of sliding and locking anywhere along 2 meter length of the bridge.
• Annular metal weight: 5 kg, 250 mm dia with 53 mm dia central hole,
• Slotted metal weight: 5 kg, 215 mm to 250 mm dia with 53 mm dia slot, 2 Nos.
• Slotted metal weights: 10 kg, 215 mm to 250 mm dia with 53 dia slot, 2 Nos.
• Dial gauge: 0.01 mm x 25mm.
• High sensitivity Proving Ring 5000 kg capacity with calibration chart and carrying case.