Standard proctor test
Standard proctor test
(OP)
Is there any significant difference between 90% vs. 95% proctor compaction?
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RE: Standard proctor test
That's the difference between loose and fairly dense. I've never seen anything below 95% spec'd. 98% is typical for dam embankments.
RE: Standard proctor test
f-d
¡papá gordo ain't no madre flaca!
RE: Standard proctor test
cost, strength, permeability, compactive effort, potential for settlement?
RE: Standard proctor test
RE: Standard proctor test
RE: Standard proctor test
The variation in MDD which is achieved using either the 2.5kg (standard) or 4.5kg (modified) will be dependant upon the soil type, however, as a rule of thumb, in the UK cohesive soils generally have a MDD suing the 2.5kg rammer close to 95% of the MDD for the 4.5 kg rammer. With alluvial silts and sands, the numbers can be very similar as there is a paucity of clay fines, and the materials in it self very spherical (like compacting marbles).
As to the difference between 90% and 95%, then the easiest way to get a handle on this is to draw out the graph of the moisture content/dry density relationship, then add the horizontal lines equivalent to 95% and 90% of the MDD. In addition to this, add in the air void lines. The range of materials which can meet the 90% requirement as opposed to the 95% is obviously much larger, has a significantly larger range in moistures and also much higher air void contents. Risk is as follows:
1. the increase in moisture permissible between 95% and 90% will reduce the bearing capacity/shear strength for cohesive soils and will increase the long-term settlement (self-weight, creep and consolidation) of the fill;
2. the increase in air void content permissible by increasing the range of densities from 95% to 90% will make the fill more susceptible to collapse and inundation settlement.
Therefore the difference is a 'potential' reduction in end-performance, reduction in bearing capacity, increase in settlement etc... In addition to this, if the material is cohesive, and is placed wetter than the 95% limit to the 90% limit, the trafficability of the fill will be greatly reduced and you will run the risk of the fill being unsuitable for placement. Again, based on experience with soils in the UK, fill placed above the moisture equivalent to 95% MDD will have a CBR of less than 2.5%, the lower permissible limit for engineered fill (in the UK according to the SHW and IAN 73 [HD 25])
RE: Standard proctor test
Good answer iandig.
Note: The OP said "Standard" in the title.
RE: Standard proctor test
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RE: Standard proctor test
RE: Standard proctor test
RE: Standard proctor test