Permeability
Summary
Permeability - measures the ease with which fluids infiltrate concrete.
Technical Information
Low permeability is very important for the durability of concrete as it limits the ability of water to enter the cement, reducing the risk of:
- Chemical attack; chloride and sulphate leaching reduced, limiting the probability of the steel rusting or delayed ettringite formation.
- Physical attacks; with less water travelling around the concrete there is a diminished chance of freeze-thaw attack.
The permeability of the concrete can be measured by an oxygen permeability test which measures how much oxygen can pass through the concrete at a fixed pressure in a certain amount of time.
The results from this test can then be used to calculate how permeable the concrete is to water. Power trowelling the surface of a concrete slab will significantly reduce its permeability.
Permeability is closely related to porosity.
Related Definitions
Water to Cement Ratio , Air Entrainment , Effective Depth (d) , Ground Granulated Blast Furnace Slag (GGBFS) , Steel Fibre ReinforcementResources
The Concrete Society: Technical Report 31; Permeability testing of site concrete.Please share this definition:
