LimsPulse
Construction materials testing

California Bearing Ratio (CBR) Test Apparatus

A load frame that pushes a 50 mm plunger into a compacted soil specimen at 1.25 mm/min and compares the load needed with that for a standard crushed stone. The ratio (CBR) is used to design road and pavement thickness.

  • Road and highway construction
  • Geotechnical testing
  • Airports and railways
  • Construction materials testing
  • Academic labs
Illustration of California Bearing Ratio (CBR) Test Apparatus
PREVENTIVE MAINTENANCE

Maintenance checklist

Each use

  • Clean plunger, mould and surcharge weights
  • Check dial gauges move freely and return to zero

Monthly

  • Lubricate the screw jack and gearbox as the manual states
  • Inspect the proving ring for knocks or damage

Annual

  • Load ring (or load cell) calibration traceable to national standards
  • Penetration rate verification
  • Dial gauge calibration
  • Mould and plunger dimension check
SAFETY

Safety precautions

Before you work on the CBR apparatus
  • Keep hands away from the plunger and moving platen.
  • Lift moulds and soaking specimens with care; a soaked CBR mould is heavy.
  • Never overload the proving ring.
  • Check electrical earthing of the motorised frame.
In LimsPulse · Calibration Management

Keep every CBR apparatus in control: usage logs, calibration and maintenance schedules, and automatic blocking of overdue instruments.

See how