Validation of Micromechanical Model for Prediction of ITZ Thickness of High-Strength Concrete Containing Secondary Cementitious Materials

Abstract:

The mechanical properties of a cementitious composite are strongly affected by interfacial transition zone (ITZ) between the matrix and the aggregates, mainly by its strength and thickness. A micromechanical model based on Mori-Tanaka scheme coupled with an estimation of deviatoric stress in ITZ was developed for evaluation of the effect of selected secondary cementitious materials (SCMs – silica fume, fly ash and metakaolin) on the properties of ITZ in high-strength concrete (HSC). The model was validated by means of comparison of predicted ITZ thickness with direct ITZ thickness measurements performed by a combination of scanning electron microscopy and grid nanoindentation. Very good agreement between the theoretical and experimental results was reached, therefore the developed micromechanical model can be used for further research and optimization of HSC containing SCMs. Silica fume was determined to be the most efficient supplementary cementitious material from the point of view of ITZ thickness reduction.

• Periodical: Materials Science Forum (Volume 995)
• Pages: 143-148
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.995.143
• Online since: June 2020
• Authors: Petr Bily*, Václav Nežerka, Vladimír Hrbek, Josef Fladr
• Keywords: High-Strength Concrete, ITZ Thickness, Micromechanical Model, Secondary Cementitious Material

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