compaction control of saprolitic soils

[Groundegr]

Does any one have experience with compaction control of saprolitic soils? I am particularly interetested in comparisons with oven drying versus other methods (air drying, speedy moisture etc)and the impact of each on the measured moisture content (i.e. optimum)and max dry density. Thanks

 

[Ron]

Rehydrating clayey soils in the lab can be a bit tricky. I would not dry the soils completely before running moisture-density relationship tests.

As for determining field moisture content, I would do a correlation between oven-dried and Speedy, then adjust accordingly when using the Speedy in the field. You might also consider checking a dessication moisture content (drying to constant weight in a dessicator, rather than an oven). Oven drying, particularly at required standard temperatures, can be a bit misleading in some clayey materials.

As for the field, you might consider some lime treatment of the soil. If you do so, make sure the lab tests reflect this as well.

 

[Tatsu]

I managed to use Speedy to measure water content for residual soil. I had a good correlation between Speedy and Oven Dry. I did not use Nuclear Density Meter, because the correlation between NDM and Oven Dry was not good at all.

I guess you can use any mean as far as it correlates to Oven Dry well for compaction control, in case that specification is based on data from Oven Dry. I used fry pan too, since I found good agreement with Oven Dry.