Permeability is defined as the property that governs the rate of flow of a fluid into a porous solid. If concrete is impermeable, corrosive agents cannot penetrate and attack it. Concrete basically has two types of pores, which determine permeability. These are capillary pores (with a diameter varying between 0.01 to 10 micron) in the cement paste which coats the aggregates and larger micro voids, between 1 mm to 10 mm, which are caused by faulty compaction of fresh concrete. When voids are interconnected because of their larger number and size a continuous link is formed, which makes the concrete permeable.
Factored Affecting Permeability of Concrete
1. W/C ratio:
2. Curing :
3. The use of Admixtures :
4. Other Factors :