Kelly Ball Penetration Test: –
Its a test performed to find out workability of fresh concrete. It is also called as ball penetration test. It is an alternative for slump cone test. It is easy to perform and not so complex test. The workability is decided by the depth of the penetration of metal hemisphere which will penetrate under its own weight into the fresh concrete. The Metal ball has 152 mm diameter and 13.6 kg weight. J. W. Kelly (Professor, University of California) had devised the plan of the Kelly ball test apparatus. If large coarse aggregates are used then this test might fail.
Kelly Ball Test Apparatus: – It has a handle, a hemisphere, graduated scale and a frame to support all this things.
- Take sufficient amount of concrete in a container. Depth of the container should be minimum 200mm.
- Level the concrete. Keep the apparatus on concrete. Its should be minimum 230mm far from surface. Frame of the Kelly ball appratus must touch the bottom of container.
- Now Slowly release the ball and let it penetrate in concrete.
- Note down the reading on scale. Repeat this for 6 times to average the workability
Workability is average of min 3 repeat tests