10+ Important Points regarding mixing of Fresh Concrete

Mixing of concrete is a very important step as the final finish quality depends on it. Effective use of vibrator and screed depends only on how good or bad the mixing quality of the fresh concrete is. In this regard here are some important points and tips which every civil engineer must know in order to get a very excellent and outstanding concrete mix.

source: http://www.condell-ltd.com/Page.aspx?catid=120

ADDING 4 LITERS OF WATER TO 1 CUBIC METER OF FRESHLY MIXED CONCRETE WILL:

Increase slump about 25 mm.
Decrease compressive strength about 1.5 to 2 N/mm2.
Increase shrinkage potential about 10%.

IF TEMPERATURE OF FRESHLY MIXED CONCRETE IS INCREASED BY 1 DEGREE CELSIUS:

Add about 4 litres of water per cubic meter maintains equal slump.
Air content decreases about 1%.
Compressive strength decreases about 1.0 to 1.5 N/mm2.

IF THE AIR CONTENT OF FRESHLY MIXED CONCRETE:

Increases 1% then compressive strength decreases about 0.5%.
Decreases 1% then yield will decrease about 0.03 cubic meter per 1 cubic meter.
Decreases 1% then slump decreases about 12.5mm.
Decreases 1% then durability decreases about 10%.