Slump test is undertaken to evaluate the functionality of fresh concrete as well as verify the water ratio and the consistency of concrete from batch to batch.
The instruments which are used in slump test comprise of a mould shaped like the frustum of a cone having the following dimensions :-
Bottom Diameter : 200 mm
Top Diameter : 100 mm
Height : 300 mm
Tamping rod of steel should contain diameter of 16 mm, 600 mm long and rounded at one end.
The following methods are used to work out slump :-
nternally and externally cleanse the inner surface of mould without applying any grease or oil.
Fill the mould with concrete in 4 layers.
Tamp each later with 25 strokes of the rod to get rid of bubbles and voids.
Allocate the strokes consistently over the whole cross-section of the mould.
The rod should infiltrate each bottom-line layer.
By applying a trowel, eliminate surplus concrete after the top layer.
Take away mould gradually and vertically.
The concrete will slump or slide.
Calculate the slump height in mm.
To maintain normal functionality, the slump should not be over 50 mm.
Cleanse the slump cone.
To get more detailed information, go through the following video tutorial.