Testing Compressive Strength of High Strength Gypsum used in ASTM C617 by way of ASTM C109

[TTPJC]

I work in a concrete material testing lab and we have to test 2 inch cubes of high strength gypsum as proof tests for C617

ASTM C617 in Section 5 (materials) 5.1.3 says to test the compressive strength of 2 inch cubes in accordance with C109. Does anyone know whether a flow test needs to be done for high strength gypsum, since it isn't mortar? Or do I just skip down to 10.4 Molding the Specimens? I have to comply with the C617 testing of high strength gypsum capping material every 3 months, or every new batch. If anyone out there uses C617 to test high strength gypsum paste for the purpose of capping cylinders or cores in a material lab, any additional information would be appreciated. My general understanding is that I just need to establish tests that show water/cement ratios along with a few time increments to prove that it reaches the 5,000 psi or cylinder strengh, whichever is greater requirement.

 

[Ron]

Use only the parts of C109 that apply to the actual test. Flow is not a consideration for your application so I would ignore that. C109 gets specified as a testing method in quite a few ASTM standards, even though its primary purpose is for portland cement.