Concrete Testing
Concrete Testing
(OP)
ASTM C31, Section 7.2 specifically states that concrete used in the air content test shall not be used in fabricating test specimens.
No mention is made concerning the re-use of the concrete that was used in the slump test to fabricate the compression test cylinders.
Comments?
No mention is made concerning the re-use of the concrete that was used in the slump test to fabricate the compression test cylinders.
Comments?





RE: Concrete Testing
When I was a student doing my practical in concrete technology I asked the same question about reusing the sample from the slump test to make cubes. I was told that it was not good practice and not to consider it in the future.
RE: Concrete Testing
The air content test is a destructive test. By adding the water you change the characteristics of the concrete.
Best practices would be to not reuse the slump concrete. I have used it when the contractor comes to me and asks "Can we get another set of cylinders for an early break?"
RE: Concrete Testing
This being said, the intent of the procedure is to remove as much error as possable between operators. reusing any portion of the test sample introduces error that can't be quantified and therefore can't be removed.