Properties of concrete in the cover zone: water penetration, sorptivity and ionic ingress

The work described in this paper forms part of a wider research programme being undertaken on water and ionic movement within the cover region of structural concrete. In-situ monitoring techniques described previously were used to measure the depth of penetration of water, cumulative volume gain and sorptivity of concrete samples containing different types of aggregate. The effects of dissolved ions (chlorides) in the invading water were also monitored. As a direct result of the monitoring techniques employed in the testing programme, it is possible to present many of the results in considerably more detail than has previously been the case. Possibilities for evaluating the electrical properties of concrete in the cover zone, and at rebar level, are also discussed. In addition, a method of estimating chloride concentration within the pore water is suggested.