For determination of consistency of concrete where the nominal maximum size of aggregate does not exceed 38 mm using slump test apparatus.
IS : 1199 – 1959 – Method of sampling and analysis of concrete.
Equipment & Apparatus
The internal surface of the mould is thoroughly cleaned by grease/oil and freed from superfluous moisture before commencing the test.
The mould is placed on a smooth, horizontally leveled rigid and non-absorbent surface such as a plate.
The mould is filled by concrete in four layers, each approximately one-quarter of height of the mould and each layer is tamp with 25 strokes by tamping rod of dia 16mm &length 600mm with pointed end in a uniform manner.
After tamping the top layer, the concrete is struck off level with a trowel and any mortar leaked out between the mould and base plate is to be cleaned away.
The mould is removed from the concrete immediately by raising it slowly and carefully in a vertical direction.
The slump is measured immediately by determining the difference between the height of the mould and that of the highest point of specimen.
The slump measured is to be reported in terms of millimeters.
Safety & Precautions
Use hand gloves & shoes while testing.
Equipment should be cleaned thoroughly before testing & after testing.
Use apron & goggles at the time of testing.
The apparatus should remain free from vibrations during the test.