Soil compaction below optimum moisture
Soil compaction below optimum moisture
(OP)
I am working on a project where I have to compact my soil to 95% of a modified proctor within a moisture range of + or - 1.5%. In my case this works out to 5% to 8%. I am having trouble increasing the moisture percentage to above 5%. Besides having to perform more work to achieve compaction, what is the harm of achieving compaction this far below the optimum moisture %.





RE: Soil compaction below optimum moisture
RE: Soil compaction below optimum moisture
RE: Soil compaction below optimum moisture
"Soils close to the optimum water content require less compactive effort to achieve the required relative compaction"
In other words, achieving optimum moisture content should be considered a tool to assist the effort of compaction.
If you are achieving 95 to 103 percent compaction I would say you've met your requirements, irregardless of how your moisture content percentage is reading.
Also you mentioned lots of rocks. Be careful in sandy/rocky soils with the large cobbles (6 to 8 inches plus). Many specifications call for the screening out of such rocks because it is difficult to really compact around them (they create litte void spaces, especially when in contact with eachother).
Anyway, sandy soil is usually the best material as a sub base, as opposed to say clay, which can swell or consolodate with added moisture or load respectively.
Good luck, and thank you for your efforts in that part of the world.
RE: Soil compaction below optimum moisture
RE: Soil compaction below optimum moisture
RE: Soil compaction below optimum moisture
RE: Soil compaction below optimum moisture