Measurement and simulation of dendritic growth of ice in cement paste

We re-examine experiments by Helmuth (1962) from which he concluded that ice grows in the pores of cement paste under heat-flow control, and that the internal temperature rises to the melting point given by the Gibbs-Thomson equation. We find that his conclusions are correct, but the growth rates he reports are misleading. Using experimental and computational methods, we show that the ice grows in the form of dendrites, which allows a constant growth rate under heat-flow control. A modification of the experimental procedure permits accurate measurement of the growth rate of ice in the pores.