Objective

For determination of relative quantity of mixing water that will bleed from a sample of freshly mixed concrete. 

Reference Standard

IS : 9103-1999 – Method of sampling and analysis of concrete.

Equipment & Apparatus

• Cylindrical measure
• Tamping Bar
• Pipette
• Graduated Jar

Procedure

1. The container is filled with concrete up to a height of 250±3 mm. It is filled approximately 50 mm deep and each layer is compacted by hand. The minimum numbers of strokes are 60 strokes per layer. The top surface of the concrete is leveled. The mass is recorded.
2. The specimen is kept at a temperature of 27±2⁰C. The container is kept on a level surface free from vibration and covered with a lid.
3. Water accumulated at the top is drawn off by means of a pipette, at 10 min intervals during the first 40 min and at 30 min interval subsequently till bleeding water.
4. The water is transferred to graduated jar and accumulated quantity of water is recorded after each transfer. 

Calculation

Accumulated bleeding water expressed as a percentage of the net mixing water is calculated as follows.

Where,

V_w=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

Reports

The result is expressed in percentage. 

Safety & Precautions

• To wear hand gloves, safety shoes & apron at the time of test.
• Carefully handle the glass jars during the test time.
• Equipment should be cleaned thoroughly before testing & after testing.
• Petroleum jelly should be applied to the mould.