This work describes a method to determine the diffusion coefficients of dissolved gases in saturated cement-based materials in order to study the effects of degradation on the transport properties. The method is based on a through-diffusion methodology and allows simultaneous determination of diffusivi-ties of two dissolved gases diffusing in opposite directions. A cement plug is mounted between two water reservoirs pressurized by two different gases at equal pressure (∼1 MPa) to avoid advection. The changes in the dissolved gas concentration (at the opposite sides) are measured indirectly via gaseous phases which are in equilibrium with aqueous phases according to Henry's law. Additionally, a simple 1-D diffusive transport model is developed to interpret the experimental data. Experiments were performed on intact and carbonated cement (CEM I) paste samples with a gas com-bination: He and Xe. The results showed that the proposed method is providing reliable results within a reasonable experimental time and is useful to study the effects of degradation on the transport properties of cementitious materials. Carbonation resulted in a lower diffusivity.
|Title of host publication||Concrete Repair, Rehabilitation and Retrofitting IV|
|Place of Publication||London, United Kingdom|
|State||Published - Jan 2016|
|Event||ICCRRR 2015 - International Conference on Concrete Repair, Rehabilitation and Retrofitting - MFPA Leipzig, Leipzig|
Duration: 5 Oct 2015 → 7 Oct 2015
|Conference||ICCRRR 2015 - International Conference on Concrete Repair, Rehabilitation and Retrofitting|
|Period||2015-10-05 → 2015-10-07|