Highly Reactive β‐Dicalcium Silicate: III, Hydration Behavior at 40–80°C

The effect of curing temperature (40°, 60°, 80°C) on the hydration behavior of β‐dicalcium silicate (β‐C 2 S) was investigated. The β‐C 2 S was obtained by decomposition of hillebrandite, Ca 2 (SiO 3 )(OH) 2 , at 600°C, has a specific surface area of about 7 m 2 /g, and is in the form of fibrous crystals. The dependence of the hydration reaction on temperature continues until the reaction is completed. The hydration is completed in 1 day at 80°C and in 14 days at 14°C. The hydration mechanism is different above and below 60°C, but at a given temperature, the reaction mechanism and the silicate anion structures of C‐S‐H do not change significantly from the initial to the late stages of the reaction. High curing temperature and long curing times after completion of reaction promote silicate polymerization. The Ca/Si ratio of C‐S‐H shows high values, being almost 2.0 above 60°C and 1.95 below 40°C.