Calculation of tortuosity factor for the model based in concrete resistivity

Author(s): C. Andrade, R. D’Andrea and N. Rebolledo
Paper category: conference
Book title: Microstructural-related Durability of Cementitious Composites
Editor(s): Guang Ye, K. van Breugel, Wei Sun and Changwen Miao
Print ISBN: 978-2-35158-129-2
e-ISBN: 978-2-35158-123-0
Publisher: RILEM Publications SARL
Publication year: 2009
Pages: 99 - 107
Total Pages: 9
Language: English

Abstract: Service life is in general modelled been the diffusion coefficient the rate controlling parameter. In recent years as an alternative, a model based in the use of the electrical resistivity of the concrete has been proposed and justified by some of the authors. This model has several advantages among which are the possibility to calculate the resistivity from the mix proportions of the concrete. This calculation is feasible using a modification of Archie’s law which relates the concrete porosity to the resistivity but a factor is needed that represents the “tortuosity” or pore connectivity. In present paper it is calculated in two manners: 1) through inverse analysis by fitting a potential expression to the relation between porosity and resistivity of a set of concretes and 2) by trying to understand better what the tortuosity factor represents in the equation and obtaining it from the “slope” of the MIP pore size distribution and from the w/c ratio through the relation of this last one to the pore threshold.

Online publication: 2012-05-16
Publication Type: full_text
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