Stabilised Proctor testing
Stabilised Proctor testing
(OP)
I'm carrying out stabilization on subbase materials by usung 3% of cement.I have made a modified Proctor by using same percentage of cement.The values of the Maximum dry density(MDD) obtained were found lower compared to the modified Proctor without cement.According to my experience I could expect the one with cement to be more than the one without cement.Ihave repeated the testing several times but the results remain same.The procedure used was as follows:6kg of subbase materials were weighed less 3% of 6kg(to take the place of cement)=5820grams of subbase materials and then 3% of cement(180grames)were added to the subbase material making a total of 6kg as before and the Proctor testing was conducted as mormal.Iam I wright or I should add the 3%percent cement directly to the 6kg of subbase materials without reduction?Please assist!





RE: Stabilised Proctor testing
It seems that you are looking only at desity to provide resistance to deformation rather than the effect of the cement in producing a modified material. On the other hand the low cement content may not be seen as providing sufficient strength but acting as a filler to improve density, which then translates into better strength and deformation characteristics. I have added cement as afiller to sand asphalt bituminous mix and have tested them both after 24 hours and after 7 days and have noted that the Marshall stability increased considerably.
Cement content is normally expressed as percent by weight of dry soil.
For your material I would add a percent or two more and derive the benefit of a stronger material. However cracking is another issue.
Hope this discussion helps some what
RE: Stabilised Proctor testing
In my experience the addition of lime or cement to soil always results in a decrease in density. The best way to determine if the soil/lime/cement mixture is being propertly mixed and compacted is to watch the operation from begining to end. Once the material has been mixed and compacted, let it set for a few hours to over night, then test it with a footing probe or pocket penetrometer. If the proceedure has been completed correctly, then the soil will be very hard, PP=4.5+ tsf and footing probe indent of less than 1 inch.
If someone else just must see a density test, i.e. the owner or building inspector, run the test and approve the compaction based on "...density, strength, and observations..."