The oldest, most widely used test for determining workability. This test is used to determine the
workability of fresh concrete, which would normally be undertaken at the point of delivery to ensure the
concrete, is of adequate consistency for placement. The test is applicable to concrete of medium
workability.
The device is a hollow cone-shaped mould. The mold is filled in three layers of each volume. Each layer
is rodded with a 16mm steel rod 25 times. The mould is then lifted away and the change in the height of
the concrete is measured against the mould. The slump test is a measure of the resistance of concrete to
flow under it own weight.
GENERAL DESCRIPTION AND SPECIFICATION:
The apparatus comprise of a slump cone with handles made of mild steel sheet, a chrome plated steel
tamping rod of 16 mm diameter X 600 mm long, rounded off at one end, with a scale marked on it and a
steel base plate with a carrying handle.
The mould for the test specimen will be in the form of frustum of a cone having the following internal
dimensions as follows.
• Dimensions Cm
• Bottom diameter 20
• Top diameter 10
• Height 30
The Cone is constructed of metal of at least 1.6 mm thickness and the top and bottom are open and at
right angles to the axis of the cone. The mould have a smooth internal surface and provided with suitable
foot pieces to a base plate and also handles to facilitate lifting it from the moulded concrete test specimen
in a vertical direction as required by the test. The base plate is provided with cleats & swivel handle.
