Correlating lab compaction effort with construction plant effort

[mollymawk]

Hi
Does anyone have any useful info, links or references giving guidance on the correlation between laboratory compaction curves (standard & heavy) -vs- construction method specifications for a selection of construction plant/passes/layers etc?

I'm assuming there is a nice table out there that gives a range of axle masses, no. of passes, layer thickness etc. and listing that they correlate with either the standard or modified Proctor test, or BS test.

For example, for a silty clay a BomagXYZ, at 8 passes on 200mm layers correlates with the compactive energy of the Modified Procter test. I made this up, but this is what I'm looking for for a range of plant and soil types.

Thank you.

 

[Focht3]

Molly -

I'm afraid that any such table would be virtually useless, since too many factors affect the relationship between the lab and field compaction efforts. A better method would be to develop correlations for each specific site and soil - that what the good earthwork contractors do on every job. And you can develop your own localized table based on the local soils, equipment, etc.

Good luck -



Please see FAQ731-376 for great suggestions on how to make the best use of Eng-Tips Fora.

 

[roadspecialist]

focht3 is right there are too many factors that affect the relationship between field and labo compaction effort. it would be a good practice to have "trial sections" conducted to gauge the compaction efficiency of available equipment.

 

[iandig]

I have read the comments from Focht3 and roadspecialist, and do agree with everything they have put,however there is a publication which does look at this very subject.
The book is called "Compaction of soils and Granular Materials: A Review of the research performed at the Transport Research Laboratory" carried out by A W Parsons during his time at the TRL in the UK. The books ISBN is 0 11 551091 5, and is printed by the HMSO. The book, as the title suggests, is a publication containing all the reseach work done by TRL, including compaction trials and test methods and is a very good point of reference, howver much of the compaction plant used during the trials is now out of date. If you can get hold of this book, it can provide a great deal of guidance on the subject, as well as looking at how the selection of plant can be directly influenced by differenct types of material.

 

[pba]

In the UK 'Manual of contract documents for highway works - Specification for highway works' contains information similar to that requested in series 600. The process is called 'method compaction'. Performance compaction is the alternative solution under which the earthworks contractor undertakes to provide a compacted fill which achieves a specified parameter - i.e. 95% dry density.

Method compaction is risky for engineered fills due to the variability of the materials as aluded to in previous responses