DETERMINATION OF BLEEDING OF FRESH CONCRETE PREPARED WITH ADMIXTURE
TEST STANDARD: IS 9103:1999, Reaffirmed 2008
OBJECTIVE: To determine the bleeding of fresh concrete by determining the relative quantity of mixing water that will bleed from a sample of freshly mixed concrete
APPARATUS: Concrete batch mixer, weighing balance, cement OPC 43 or 53 grade, Coarse aggregates conforming to IS 383 & fine aggregates conforming to Zone II of IS 383, Measuring cylinder of 10 litre capacity having diameter of 250mm and height of 280mm, tamping rod of 16mm diameter, 600mm long rounded at one end, pipette, measuring cylinder 100ml
PROCEDURE: The concrete mix shall be prepared both with and without admixture, the latter being treated as the reference or control concrete mixture. The proportioning of concrete mix shall be done in such a way so as to achieve the following parameters:
a) The cement content of the mix shall be 307±3 kg/cum
b) The concrete mix shall have a slump of 50±10 mm
After finalisation of control concrete mix by preparing trial mix batches and achieving the required parameters, concrete The container shall be filled with concrete as soon as practicable after mixing to a height of 250±3 mm. The concrete shall be filled into the measure in layers approximately 50 mm deep and each layer shall be compacted by hand. When compacting by hand, tamping with the tamping bar shall be distributed in a uniform manner over the cross-section of the measure. The number of strokes per layer required to produce the specified condition will vary according to the type of concrete, but in no case shall the concrete be subjected to less than 60 strokes per layer for the 10 litre capacity cylinder. Then, the top surface of the concrete shall be levelled to a reasonably smooth surface by a minimum amount of towelling.
The test specimen shall be kept at a temperature of 27±2°C. Immediately after trowelling the surface of test specimens the time as well as the mass, of the cylinder and its contents shall be recorded. The container shall be kept on a level surface free from vibration and covered with a lid. Water accumulated at the top shall be drawn off by means of a pipette, at 10 min intervals during the first 40 min and at 30 min intervals subsequently till bleeding ceases. To facilitate collection of bleeding water, the specimen may be tilted by placing a 50mm block under one side of the measure
during collection of water. The water shall be transferred to graduated jar and accumulated quantity of water shall be recorded after each transfer.
Accumulated bleeding water expressed as a percentage of the net mixing water shall be calculated as follows:
Bleeding water percentage = [Vw / (w/W) x s] x 100
Vw = total mass of the bleeding water, kg
w = net mass of water in the batch, kg
W = total mass of the batch, kg
s = the mass of sample, kg
- Determination of compressive strength of Concrete Cubes
- Compacting Factor Test of concrete IS 1199 : 1959
- Compressive strength of Concrete Core specimen IS 516-1959
- Slump test of fresh concrete
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