Monday, November 28, 2011

CT 202 Changes-November 2011

You may have already noticed but Caltrans has posted a new version of CT 202-Method of Tests for Sieve Analysis of Fine and Coarse Aggregates as of November.  Luckily there isn't much change this time.  In fact, the main test method has not changed at all except for some very minor formatting updates.  The noticeable changes to the test method are in Appendix A: Sieve Analysis of Aggregate from Extracted Bituminous Mixtures and are as follows:

  • You no longer need to use a washing solution containing denatured alcohol.  The test method now only requires distilled, deionized, or good-quality tap water as the washing solution.
  • The notes about “sudsing” previously in the materials section of the test method are moved from the materials section to the procedure section.
  • For samples extracted using CT 382, washing of the entire sample is no longer required.  You can now grade the material as if it was a normal sieve analysis (ex. base rock) and only wash the fine aggregate portion.
  • When you add the sample to the wash vessel, you no longer need to add exactly 1000mL of washing solution.  Now you will add “enough water to cover sample”.
  • The test procedure now adds the wetting agent to the wash vessel before shaking.  Previously, although the wetting agent was mentioned in the materials section, the wetting agent was not actually mentioned in the test procedure and as a result was not used.

   That's all! The new test method can be found on the Caltrans website and here.

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