Which of the following does not correspond to the recommendations of IRC: 37-2018, for pavement thickness determination by California Bearing Ratio (CBR) method?
1
The top 50 cm of subgrade should be compacted minimum 97% of maximum Proctor compaction test density.
2
CBR tests are to be conducted in-situ in field
3
For the design of the subgrade soil sample should be compacted at Optimum moisture content to proctor density.
4
At least 3 samples should be tested on each type of soil at the same density and moisture content.