Geotechnical Engineering Laboratory Experiment: California Bearing Ratio (CBR) Test
Aim: To determine the California Bearing Ratio (CBR) value of a soil sample.
Apparatus: CBR mould with base plate, Loading machine, Standard plunger (50 mm dia), Proving ring/load cell, Dial gauge, Surcharge weights, Soaking tank, Balance and oven.
Theory: The CBR test evaluates the strength of subgrade soil for pavement design. CBR (%) = (Test Load / Standard Load) × 100
Standard load: 1370 kg at 2.5 mm, 2055 kg at 5.0 mm
Calculation:
CBR (%) = (Test Load / Standard Load) × 100
Student's Signature:
Instructor's Signature:
Aim: To determine the California Bearing Ratio (CBR) value of a soil sample.
Apparatus: CBR mould with base plate, Loading machine, Standard plunger (50 mm dia), Proving ring/load cell, Dial gauge, Surcharge weights, Soaking tank, Balance and oven.
Theory: The CBR test evaluates the strength of subgrade soil for pavement design. CBR (%) = (Test Load / Standard Load) × 100
Standard load: 1370 kg at 2.5 mm, 2055 kg at 5.0 mm
Observation Table:
Penetration (mm) | Load (kg) | Standard Load (kg) | CBR (%) |
0.5 | |||
1.0 | |||
1.5 | |||
2.0 | |||
2.5 | |||
4.0 | |||
5.0 | |||
7.5 | |||
10.0 | |||
12.5 |
Calculation:
CBR (%) = (Test Load / Standard Load) × 100
Result:
The CBR value of the given soil sample = %Student's Signature:
Instructor's Signature:
