Effect of Air on the Hydraulic Conductivity of Concrete

The effect of air on the hydraulic conductivity or permeability of concrete has been discussed in the literature for many years. Although the effect of air may affect the rate of water flow significantly, this effect is very seldom accounted for in routine testing and evaluation of permeability of concrete. Since concrete is being used now to an increasing extent for large offshore structures in deep ocean waters, a better and more reliable basis for testing and evaluating concrete permeability is greatly needed.

This is the background for a research program where the effect of varying testing conditions are being studied. In the present paper some preliminary results on the effect of air in the test system are reported. A few results of the effect of evaporation from the output side of the concrete also are included. Testing and evaluation of permeability are discussed, and a new approach for testing is outlined briefly.