Reader, Heriot-Watt University, Edinburgh,
This paper presents data from a test program investigating water and ionic movement in the cover region of reinforced concrete under a cyclic wetting and drying regime. Experiments were conducted over an eighteen month period on slabs containing OPC and OPC with partial replacement with PFA and GGBS, with samples being exposed to water and chloride solution. Water and ionic ingress through the cover zone was monitored by means of small conductivity probes embedded within the surface of 50-mm concrete specimens. The conductivity profiles obtained from the experimental program highlight the influence of repeated absorption on water and ionic ingress, hydration, pozzolanic activity and chloride binding. A simple electrical model was used to explain the influence of pore fluid and microstructure on conductivity. Traditional methods of examination were also employed to corroborate conductivity data and included cumulative volumetric gain, coring for carbonation and chloride ingress, and drillings for chloride concentration profiles.
Paper ID: CCA10312J