CHLORIDE TRANSFERENCE NUMBERS IN MIGRATION EXPERIMENTS: NOMENCLATURE AND APPLICATIONS

摘要

Migration experiments have the advantage to shorten the testing time and enable the rapid determination of the concrete's resistance to chloride ingress. However, many aspects of the test remain without basic explanations. In the present paper, consideration is given to transference numbers of chlorides during a steady-state migration experiment. According to their own definition, the calculation of chloride transference numbers can be done from current circulating through the specimen and from the flux of chlorides resulting from this circulation. Thus, transference numbers can be calculated in several ways that depend on the fluxes and currents considered: The total amount of chlorides having passed to the anolyte or remaining in the catholyte can be used for calculating an averaged flux and current. However, the flux and current recorded during two consecutive samplings can also be used, and the differential chloride transference number corresponding to a discrete period of time can be calculated as well. Therefore, it is necessary to properly define the conditions for the calculation of transference numbers. In this theoretical paper, a nomenclature for transference numbers is proposed, according to which, transference numbers can be: anodic or cathodic, differential or accumulative, maximum or residual.