BLEEDING TEST OF CONCRETE
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- IS: 9103 - 1999
APPARATUS REQUIRED
FOR THE TEST:-
- Round-ended Tamping Rod of 16 mm diameter and 600 mm length
- Pipette used to draw off the bleed water from specimen
- Weighing Scale
- Graduated Jar of 100 cm³ capacity
- A cylindrical container of 250 mm inside diameter, 280 mm inside height & 0.001 m³ (approx.) capacity.
Apparatus for Bleeding Test of Concrete |
Sampling:-
The sample of freshly mixed concrete shall be obtained
according to IS: 1199
PROCEDURE OF
THE TEST:-
- At first, take sufficient quantity of freshly mixed concrete of known water content.
- Then fill the cylindrical container with concrete as soon as practicable after mixing to a height of 247 mm to 253 mm. The concrete shall be filled into the measure in 5 layer approximately 50 mm deep and each layer shall be compacted by hand.
- When compacting by hand, tamping with the tamping rod shall be distributed in a uniform manner over cross section of measure.
- The no. of strokes per layer required to produce the specified condition will vary according to the type of concrete but it must be minimum 60 strokes per layer.
- Place the specimen at a temperature of 25 °C to 29 °C.
- After compacting the final layer, top surface should be level & smooth by troweling.
- Immediately after troweling the surface of test specimen, note down the time as well as the mass, of the cylinder and its content.
- Keep the container on a leveled surface which should be free from vibration & covered with a lid to prevent evaporation of bleed water.
- Draw off the water accumulated at the top surface of concrete using a pipette for every 10 minutes. Collect the water in graduated jar. This should be done for 1st 40 minutes and after this continuously for every 30 minutes until bleeding stop.
10.To facilitate
collection of bleeding water, the specimen may be tilled by placing a 50 mm
block under one side of the measure during the collection of water.
11.Transfer the
water into graduated jar and note down the accumulated quantity of water after
each transfer.
CALCULATIONS:-
Accumulated bleeding water is expressed as
percentage of the net mixing water and it is calculated by the formula given
below:
Where,
Vw
= Total mass of the bleeding water in kg,
w =
Net mass of water in the batch in kg,
W =
Total mass of the batch in kg,
S =
The mass of sample in kg.