Slump Test

The Slump Test is done to make sure a concrete mix is workable. The measured slump must be within a set range, or tolerance, from the target slump.

Tools:

  • Standard Slump Cone (100mm top diameter x 200 mm bottom diameter x 300 mm high)
  • Small Scoop
  • Bullet-nosed rod (600 mm long x 16 mm diameter)
  • Rule
  • Slump Plate (500 mm x 500 mm)

Methods:

  • Clean the cylinder mould and coat the inside lightly with form oil. Then place on a clean, level and firm surface, (i.e.), the steel plate.
  • Collect a sample.
  • Fill the ½ the volume of the mould with concrete then compact by rodding 25 times. Cylinders may also be compacted by vibrating using a vibrating table.
  • Fill the cone to overflowing and rod 25 times into the top of the first layer, then top up the module till overflowing.
  • Level off the top with steel float and clean any concrete from around the mould.
  • Cap, clearly tag the cylinder and put it in a cool dry place to set for at least 24 hours.
  • After the mould is removed the cylinder is sent to the laboratory where it is cured and crushed to test the compressive strength.