Field CBR Test Apparatus

The California Bearing Ratio (CBR) field test measures the relative strength of in–situ soils and some base course materials for use in pavement design. The field test procedure uses a loading jack to force a piston into the soil at the test site and comparing the piston load to the depth of penetration. The jack is loaded against dead weights or a heavy piece of equipment such as a loaded dump truck.


CBR Field Test Set
Model: BR-12
CBR Penetration Pistons

CBR Penetration Pistons

Starting at $116.00
Models: BRA-30, BRA-31
Field CBR Loading Jack
Model: BR-2
Connector Set for CBR Test
Model: BRA-33
CBR Surcharge Masses

CBR Surcharge Masses

Starting at $162.00
Models: BRA-40, BRA-41, BRA-42
2,000lbf Load Ring
Model: HM-425
5,000lbf Load Ring
Model: HM-427
CBR Field Equipment

Field CBR apparatus are ordered individually for tests performed according to ASTM or Army Corps of Engineers (C.O.E.) test methods. Additional surcharge masses may be needed to simulate large pavement loads. Components are available individually or as a set with either a two-speed or three-speed jack that conforms to ASTM and C.O.E.

  • CBR Field Test Sets include the two-speed or three-speed field CBR Loading Jack with swivel base, along with Load Rings and Dial Gauges, Penetration Piston with Connector and Extension Sets, Surcharge Weights, Surcharge Plate, Support Bridge, and Dial Indicator.
  • Field CBR Loading Jacks come in two models, a two-Speed CBR Loading Jack and three-Speed CBR Loading Jack, each with 10,000lbf (45kN) capacity and swivel base.
  • Penetration Piston for CBR Test penetrates the soil under load during testing. Piston load is compared to the depth of penetration in determining CBR values.
  • Piston Extension Set for Field CBR Test ensures proper positioning of penetration piston for application of load.
  • Connector Set for CBR Test is required for the connection of multiple Extension Rods and Penetration Piston in CBR testing.
  • Field Surcharge Plate and Masses with annular or slotted openings simulate loads from base course or pavement.
  • Dial Support Bridge for CBR Test positions mechanical dial indicator for accurate penetration measurements. Meets ASTM and COE standards.
  • 2,000lbf Load Ring accurately measures applied loads. Includes dial indicator with 0.0001in resolution and calibration chart.
  • 5,000lbf Load Ring for accurate measurement of applied loads. Comes with a 0.0001in a resolution dial indicator and calibration chart.

For more information on Field CBR Test Apparatus, here are our related blogs: