P-209 Modified Proctor Test Result Help
P-209 Modified Proctor Test Result Help
(OP)
I have recently received the modified proctor lab results for P-209 crushed aggregate base we plan on using as a base for a new taxiway. The sample was collected at the quarry and taken to a construction materials lab for testing. The lab result indicated an uncorrected maximum dry density of 148.5 pcf at an optimum water content of 4.1%. After correcting for the oversized fraction, the oversize corrected density was 151.6 pcf and the oversize corrected moisture was 5.2% (the percent retained on the 3/4" sieve was 28%). The problem - I expected to see a dry density around 148 pcf (4.0% moisture) which is where P-209 from this quarry typically falls. With the corrections added, there is NO WAY to get 100% compaction at that moisture per the specifications given. After approximating the zero air voids curve on the moisture-density curve, the uncorrected moisture-density curve looks good. However, when you apply the correction factor, it is way right of the zero air voids curve which, I assume with little knowledge of the subject, is not possible.
Could someone help me with this??? I am very concerned that something is not right and I do not know the right questions to ask. I have attached the results I received.
Could someone help me with this??? I am very concerned that something is not right and I do not know the right questions to ask. I have attached the results I received.





RE: P-209 Modified Proctor Test Result Help
Looking at that lab report with cook-book text for reporting. Why not ask the writer if that sample was first carried around in the truck for a day or two, if somehow it was then "returned to the lab". How'd it get there to begin with to have to be "returned"? The tech may have returned, but that sample only made the trip to the lab once.
RE: P-209 Modified Proctor Test Result Help