Measurement of porosity as a predictor of the durability performance of concrete with and without condensed silica fume

The objective of this article is to investigate the use of porosity as a predictor of the properties of concrete that control its durability. In particular concretes containing silica fume (SF) have been investigated. Four different mixes were made, two containing SF and two control mixes without SF. The mixes were tested using three different curing conditions and three different test ages. The porosity was measured with helium intrusion, mercury intrusion and by calculation from weight loss observations. A wide range of durability related properties were measured and the results correlated with the porosities. It is concluded that the porosity is an excellent predictor for the transport properties but less good for actual corrosion rates. It is also indicated that models developed for concretes without SF should be used with great caution for SF concretes.