2010年7月4日星期日

To determine initial setting time

-Steps:
  1. A cement paste of standard consistency is prepared using water content determined earlier
  2. A needle of 1mm2 cross sectional area is fixed to appratus and released
  3. Check penetration
  4. When needle penetrate to 5mm from bottom , initial set have taken place
  5. Initial set is the time elaspsed since water has added to cement
  6. Minimum of 45 minutes for OPC

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