The effect of conditioning to a predetermined weight loss on the permeability of concrete

The durability properties of concrete can be assessed via gas permeability tests. The moisture content of the concrete plays a major role in its permeability to gas, and the conditioning stage of any gas permeability test aims to minimise and standardise the amount of moisture present in the concrete via oven drying, usually at a temperature of 105 °C. However, this is known in some circumstances to take a considerably longer period of time in comparison to the permeability testing itself. This study examines whether a relationship exists between the moisture content of a specimen and its permeability by investigating the permeability of concrete specimens dried by varying amounts. It was found that a simple relationship of the form y = ax^b could be established for both normal and high strength concrete subjected to pressure decay-time permeability testing.