New insights into the effects of sugar on the hydration and microstructure of cement pastes

The effects of adding sugar to cement paste on hydration and microstructure were observed. While 1% sugar delayed hydration as expected, the delay period was shortened by increased curing temperature. When samples containing sugar began to react, hydration progressed very quickly and the degree of hydration soon surpassed that of control samples. Sugar addition increased the surface area and altered the pore size distribution, as measured by nitrogen, of cement pastes. Results indicate that sugar not only alters the rate of cement paste hydration, but the microstructure of calcium-silicate-hydrate (C-S-H) as well.