The above link is a brief pdf presentation relating to laboratory testing of backfill materials using the penetrometer method. Many practitioners are relating to CBR% values which generally provide measurement of bearing ratio only and can be confused with surface modulus. The idea of this presentation is to provide graphic representation of compacted layer values and how they are measured, as surface modulus is by no means a measurement of compaction alone, unless applied to each individual lift and tested accordingly.
It is possible to have a respectable surface modulus CBR% value, but where greater depth has not been compacted in layers using the correct specified method it is likely that performance will be compromised at some time in the future (not necessarily short term) and we hope this presentation will provide a clearer understanding of application.
For animated Power Point slide show of this please email firstname.lastname@example.org