Influence of Silica Fume on Diffusivity in Cement-Based Materials II. Multi-Scale Modeling of Concrete Diffusivity

Published

July 1, 2000

Author(s)

Dale P. Bentz

Abstract

Based on a set of multi-scale computer models, an equation is developed for predicting the chloride ion diffusivity of concrete as a function of water-to-cement (w/c) ratio, silica fume addition, degree of hydration, and aggregate volume fraction. Silica fume influences concrete diffusivity in several ways: 1) densifying the microstructure of the interfacial transition zone (ITZ) regions, 2) reducing the overall (bulk and ITZ) capillary porosity for a fixed degree of cement hydration, and 3) producing a pozzolanic C-S-H gel with a relative diffusivity about 25 times less than that of the C-S-H gel produced from conventional cement hydration. According to the equation and in agreement with results from the literature, silica fume is most efficient for reducing diffusivity in lower w/c ratio concretes (w/c

Citation

Cement and Concrete Research

Volume

30

Issue

No. 7

Pub Type

Journals

Download Paper

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Keywords

building technology, concrete, diffusion, hydration, modeling, silica fume

Citation

Bentz, D. (2000), Influence of Silica Fume on Diffusivity in Cement-Based Materials II. Multi-Scale Modeling of Concrete Diffusivity, Cement and Concrete Research, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=860225 (Accessed October 17, 2025)