Title:
Concrete Q & A: Number of 4 x 8 in. Cylinders Required for a Test Result
Author(s):
Publication:
Concrete International
Volume:
31
Issue:
11
Appears on pages(s):
76
Keywords:
DOI:
Date:
11/1/2009
Abstract:
We’re building a multistory reinforced concrete frame building and using 4 x 8 in. (100 x 200 mm) cylinders for acceptance testing at 28 days. The engineer of record says we need to average three cylinders for a test result instead of the two cylinders per test we were planning on. What is the standard number of cylinders that comprises a valid test? And if it is three, when did the requirement change from two to three cylinders?