Reaching the compaction value on field more than 100% for subbase and base

[Ale_Hideki]

Hello guys, I need to conduct a work on field and the requirement for compaction of subbase and base is more than 100%. So we are gonna conduct compaction tests on field and we have two questions. First, what is best value to use of maximum dry density (MDD) and optimum moisture (OP), because we have two values for these materials. One of them, I have a MDD of 1.912 and OP of 11.84%, and the other value is MDD 1.999 and OP of 7.7%.
The second question is about what kind of equipment I have to use for reaching the compaction value more than 100%? Well, in this work, the area of compaction is 3m x 3m and a depth of 2 m. We are intending to use the rammer and the hand roller for this work. What can I do if we don't reach this value? I will have to pass more times this hand roller, or if the material is dry, moisten the material?

Thank you!

 

[Ron]

Use the value of the lab test (moisture density relationship) that best fits the materials encountered in the field. Your optimum moisture contents are significantly different which implies that you have a range of materials. You might also have some mixing of those materials so you might have to do more lab testing for moisture density relationships. My rule of thumb is that if your compaction as determined in the field is more than about 103 to 105 percent of the lab density you are probably comparing the wrong material and need to revise your lab testing.

If your specification calls for greater than 100% compaction, it is a poor specification. That can be a difficult requirement to meet.

The methods you are describing for compaction are not likely to achieve the compaction you require. It would be helpful if you would provide a description of the material that you are compacting....it is clean sand? Does it have clay fines? Does it have silt fines? Give the classification of the material.


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