Compaction testing report
Compaction testing report
(OP)
The attached report shows results of compaction testing on 75 mm minus crushed rock material with 38% oversize.
The Modified Proctor value is 2270 kg/m3 at 7.7% MC. The required compaction was 95%.
Could anyone tell me if this report is legitimate based on ASTM standards.
The Modified Proctor value is 2270 kg/m3 at 7.7% MC. The required compaction was 95%.
Could anyone tell me if this report is legitimate based on ASTM standards.





RE: Compaction testing report
RE: Compaction testing report
RE: Compaction testing report
I suggest you get a copy of the appropriate standard (ASTM D6938) for in-place density testing of soil and soil-aggregate mixtures using the nuclear method to see if the reporting requirements have been met.
One would have to observe the testing to determine if the field test methods employed complied with ASTM requirements.
On the surface, the report looks ok from a results reporting standpoint.
RE: Compaction testing report
Field densities are in the 2150-2200 kg/m3 range and still make 95% or higher relative compaction.
RE: Compaction testing report
If you can justify the coefficient, then use it. If not, document why you can't justify it and the figure out how you want to develop a maximum dry density using some other test method besides D1557, the Modified Proctor.
I would also suggest that you read two publications:
"CONTROL OF EARTH-ROCK MIXTURES: HOW TO DEVELOP AND USE DENSITY INTERFERENCE COEFFICIENTS AND OPTIMUM WATER CONTENT FACTORS"
US Army Corps of Engineers Instruction Report GL-92-1, Written by Victor H. Torrey, III.
and
"A Rapid Method of Construction Control For Embankments of Cohesive Soil" by Jack W. Hilf
US Bureau of Reclamation Engineering Monograph No. 26
RE: Compaction testing report
The question is - is it allowed to submit a compaction testing report as it is shown?
Does it make any sense to have that correction down option in the ASTM standard?
In order to calculate relative compaction using this method, you have to correct down every field density test result and compare it with an uncorrected Proctor value. And you have to do all calculations by hand using a calculator in the field. Of course nobody would do it this way. A technician would enter a corrected up Proctor value, do the test, get the actual density and relative compaction form the nuclear gauge, then, in the office, correct every field density down and put in the report.
RE: Compaction testing report
The report should not any corrections that are applied and should include both the corrected and uncorrected values.
RE: Compaction testing report
RE: Compaction testing report
This is a convoluted process. It appears that your testing laboratory has at least jumped through the ASTM hoops for correcting things. In my opinion, the only deficiency in the report, assuming all corrections have been applied properly, is that the report does not lay out all the assumptions and corrections that have been made.
My $0.02
RE: Compaction testing report
RE: Compaction testing report
DBasement, you do not correct the field densities, you write them down and report them, ASTM also requires you to estimate OS rock percentage by digging up each test location - then estimate it either visually by volume or in the lab by weight.
It seems like it is not a very important issue - wrong reporting, as soon as we know that compaction is good, but it always starts with small things like that. It is clear to me that there are lots of professionals who don't understand the methodology and very often don't care.
RE: Compaction testing report
I never heard of correcting down a field dry density, its always correcting the proctor dry density to count for the over size. your field value is your value unless you want to correct for the moisture content.
Its very hard to get good reading when you have more than 30% OS because of the segregation of the material and more practical solution is to use control strip instead.
RE: Compaction testing report
ICC Master Special Inspector, Structural Masonry, Reinforced Concrete, Soils, Structural Bolted Joints, Structural Welding, AWS CWI D1.1
RE: Compaction testing report
RE: Compaction testing report
Good luck.
RE: Compaction testing report
"1.4 If the test specimen contains more than 5 % by mass of
oversize fraction (coarse fraction) and the material will not be
included in the test, corrections must be made to the unit
weight and water content of the test specimen or to the
appropriate field in place density test specimen using Practice
D 4718."