Tuesday, July 19, 2011

CT 216 Changes-June 2011

Caltrans has released a new version of CT 216: Relative Compaction of Untreated and Treated Soils and Aggregates.  The basic test method has remained the same but there were a few additional notes added and a few minor changes that will help to clarify the test method.  The changes worth mentioning can be found below:

·         It no longer specifies miscellaneous equipment in the apparatus section
·         In the test method of Laboratory Compacted samples, it now specifies that if there is less than 10% retained on the ¾”, you should divide the passing the ¾” into 5 test specimens of equal weight (within ± 1 g) in the prep stage.  Previously it did not specify the amount of specimens at this point in the process and did not specify the tolerance for variance in weight between the samples. 
·         It now notes that after compaction, when reading the graduated tamper shaft, if the graduation is not level with the top of the mold, you should read the next highest graduation.
·         It now notes that some materials may require different moisture content variations besides 2% but that if another increment is used it should be used throughout the test. 
·         It now notes that excessive moisture on the base plate denotes a failed test point and what to do if this happens. 
·         Relative compaction is now recorded as the nearest whole number, not to the nearest 0.1% as was previously specified.
·         It now specifies that the corrected density on the plot is denoted as a dot with a circle labeled “Adjusted Density”
The June 2011 version of CT 216 can be found on the Caltrans website and at: CT 216 June 2011

Happy reading and good luck!

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