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.
PROCEDURE:-
- fill the slump cone in 3 equal layers , with the concrete mix and each layer is tamped 25 times by tamping rod.
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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
PROCEDURE:-
- 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.
- 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.
- 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.
- 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.