Civil Engineering - Concrete Technology - Discussion

If air entrained in cement then concrete is losses it's strength upto 10-15 %.

Air entrainment in concrete reduces bleeding and segregation, increasing workability.

A concrete using an air-entrained cement exhibits the following characteristics:

*Has more resistance to weathering:* This is a primary benefit. The entrained air voids provide space for water to expand upon freezing, reducing internal pressure and damage from freeze-thaw cycles.
*Is more plastic and workable:* The air bubbles act as a sort of lubricant, improving the workability of the fresh concrete.
*Is free from segregation and bleeding:* The air bubbles help to hold the mix together, reducing the tendency for the aggregates to separate (segregation) and for water to rise to the surface (bleeding).

However, it's important to note that air entrainment typically *has a strength of less than 10% to 15%* compared to non-air-entrained concrete.
The introduction of air voids reduces the overall density of the concrete, which can slightly decrease its compressive strength.

Therefore, the most accurate answer considering all the options is **all the above**.

The correct answer is E. I too agree.

It should be E.

It should be E but in Arora also option C is given.

Option E is correct.

Yes, I also think All are correct.

Yes, all the above correct.

If air entrained cement is used then the water-cement ratio also increases which causes segregation and bleeding in concrete. So option C is correct.