Influence of Nano-Anatase TiO2 Additions on Cement Hydration: Experiments and Modeling
Amal R. Jayapalan*, Bo Yeon Lee, Kimberly E. Kurtis
Georgia Institute of Technology
The performance and properties of cement-based materials can potentially be altered by the addition of nano-sized inclusions. In this study, the effect of chemically non-reactive anatase titanium dioxide (TiO2) nanoparticles on early age hydration of cement was investigated. First, the effects of different percentage addition rates of TiO2 to Portland cement on early age behavior were examined using isothermal calorimetry and measurements of chemical shrinkage. Based upon the accelerations in hydration observed in TiO2-Portland cements, additional experiments were performed with tricalcium silicate (C3S) to determine if the influence of the TiO2 could be adequately described by the a kinetic model relying upon boundary nucleation theory. Comparison between the experimental results and modeling showed that the increase in addition rates of TiO2 accelerates the rate of cement hydration and heterogeneous nucleation effect was found to be dominant compared to dilution effect. The result of the boundary nucleation model reinforces the concept of the heterogeneous nucleation effect, and demonstrates that the surface area provided by nano-TiO2 particles increases the rate of hydration reaction.
* Presenter