Investigations into the role of activated carbon in a moisture-blocking cement formulation

Physical deterioration is a natural consequence of moisture attack in finished concrete. Moisture is retained in open voids in prepared cement during mixing and hydration stages. Further atmospheric moisture uptake occurs following dehydration under use conditions in polymer-containing cement formulations, since polymers act as conduits for moisture ingress. The initial attribute of added strength from the polymer in improved cement formulations is thus nullified. Customary solution to the moisture problem has centered around improving moisture resistance by significant reduction of inherent macro defects. A more complete method of moisture blocking by the reaction of activated carbon with a vinyl polymer included in the cement formulation is described here. The moisture blocking action is due to the mitigation of open voids by the occlusion of a carbon-vinyl additive, essentially resulting in filled voids or no voids in the prepared cement, producing a durable finished concrete product. Supporting evidence for the above by thermal, polarization, X-ray and SEM are reported in this paper. This revised version was published online in July 2006 with corrections to the Cover Date.