Friday, 9 March 2018

Air-entrained concrete And Their Advantages

Air Entrained Concrete

                                                                                   Air en-trained concrete is made by mixing a small quantity of air en-trained agent or using air en-trained cement. These air entraining agents produces of non coalescing air bubbles. These air bubbles acts as flexible ball bearings and modifies the properties of plastic concrete (such as workability , segregation , bleeding and finishing quality.

It also modifies the properties hardened concrete (such as resistance to frost action and permeability).The commonly used air entraining agents are natural wood resin, animal and vegetable fats and oil (such as tallow, olive oil e.t.c), various wetting agents (such as alkali salts, animal and vegetable fatty acids etc) . 

This concrete is particularly suitable for places where there is a greater chance of frost attack.

Advantages of Air Entrained Concrete

                       The air entrained concrete has the following advantages
1)Its resistance to freezing and thawing is more
2)Its workability is better than ordinary concrete.
3)It has more resistance to chemical attack.
4)The tendency of bleeding and segregation is less
5)It reduces the cement content ,sand content and thereby the cost of work.
6)The heat of hydration is less
7)Its unit weight is less than the ordinary concrete.
8)The alkali-aggregate reaction is less.