Title: Variability of 4 x 8 in. Cylinder Tests
Author(s): Rachel J. Detwiler, Wendy Thomas, Thorlief Stangebye, and Michael Urahn
Publication: Concrete International
Appears on pages(s): 57-61
Keywords: compression tests; compressive strength; cylinders; variation; statistical analysis
ACI 318-08 allows the testing of two 6 x 12 in. (150 x 300 mm) cylinders or three 4 x 8 in. (100 x 200 mm) cylinders for compressive strength acceptance testing of concrete. During 2006 and 2007, compressive strength test data for both cylinder sizes was collected at a single testing laboratory. The data represent a wide range of field conditions and a consistent set of laboratory conditions. Thus, these data can provide a useful basis for comparing the precision of tests using the two cylinder sizes and for determining whether there is a need to test three replicate 4 x 8 in. (100 x 200 mm) cylinders.