Published on: 30 June, 2022

Short notes on :


SLUMP TEST:- slump cone test is done to determine the workability of concrete or how much the concrete is fluid or plastic . This test is suitable for high workability mix.


  1. fill the slump cone in 3 equal layers , with the concrete mix and each layer is tamped 25 times by tamping rod.
  2. Now the slump cone is raised vertically but slowly and allowed the concrete to subside. This subsidence is referred as slump of concrete.

    Value- 100mm to 190mm {workable concrete}


COMPACTING FACTOR TEST:- This test is useful for concrete mix of very low workability and when concrete is to be compacted by vibration.

COMPACTING FACTOR = wt. of partially compacted concrete / wt. of fully compacted concrete


  1. firstly the concrete mix is dumped in to the upper hopper [ top dia. = 25.4 cm; bottom dia. = 12.7 cm; height = 27.9 cm]. the trap door i.e. bottom dia. Portion is opened and the concrete falls into the lower hopper.
  2. Lower hopper [ top dia. = 22.9 cm; bottom dia. = 12.7 cm; height = 22.9 cm ]. The concrete mix gets placed in the lower hopper and the trap door of lower hopper is opened again to collect the concrete mix in cylinder.
  3. Cylinder [ dia.= 15.2 cm; height = 30.5 cm ]. The concrete is collected in cylinder and it is leveled and finished and then wt. of cylinder + concrete is noted down as partially compacted concrete.
  4. Then the cylinder is cleared an filled a new sample of concrete mix and then compact it by vibrator and note down the wt. of cylinder + concrete as fully compacted concrete.


CRUSHING TEST:- It is a relative measure of resistance of an aggregate to crushing under gradually applied compressive load. Crushing value of aggregate is restricted to 30% as per IRC.

IMPACT TEST:- It is a measure of resistance of an aggregate to sudden impact or shock i.e. it is done to measure the toughness of an aggregate. Impact value should not normally exceed 40% as per IRC.

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