What is the required diameter for a tamping rod used on cylinders with a diameter of 6 inches or greater?

The required diameter for a tamping rod used on cylinders with a diameter of 6 inches or greater is 5/8 inch with a tolerance of +/- 1/16 inch. This specification ensures that the tamping rod is substantial enough to effectively consolidate concrete mixes in cylinders of this size while allowing enough weight for proper tamping without causing damage to the cylinder itself.

Using a rod that is too thin may not provide sufficient mass for effective compaction, while a rod that is too thick could cause unintended variations in the density of the concrete due to over-compaction. Therefore, the 5/8 inch diameter meets the standard for achieving optimum results during the testing process.