2.9.2. Test Procedure

Try these first

1. 1.

   What does CBR stand for?

   Hint

   Think about what this test measures.

2. 2.

   What is the purpose of soaking a soil sample before the CBR test?

   Hint

   Recall the effect of water on soil strength.

3. 3.

   What does the CBR test measure?

   • A. Shear strength of soil
   • B. Load-bearing capacity of soil
   • C. Soil moisture content

   Hint

   Focus on what kind of capacity it evaluates.

4. 4.

   True or False: The soaking of soil samples may increase their strength.

   • True
   • False

   Hint

   Think about how water interacts with soil.

5. 5.

   Analyze a CBR test result of a sandy soil which shows a CBR of 10%. Discuss the implications for road construction.

   Hint

   Consider the implications on structural needs based on traffic type.

6. 6.

   Assuming a specific subgrade has a CBR value of 20%, calculate the required pavement thickness if a standard design suggests 300 mm for a CBR of 10%.

   Hint

   Think about structural requirements and how they change with CBR values.