Effects of temperature rising inhibitor on nucleation and growth process of ettringite

Nucleation and growth of ettringite in solution with and without temperature rising inhibitor (TRI) were investigated. Electrical conductivity, X-ray diffraction, scanning electron microcopy, optical microcopy and Fourier transform infrared were used to analyze the mechanism of effects of TRI on nucleation and growth of ettringite. Based on classical nucleation theory, the results show that TRI has little influence on the crystal-solution interfacial energy. In contrast, the inhibition of TRI on ettringite crystal growth rate of ettringite is observed from the initial slopes of conductivity curves. In-situ observation, SEM, XRD and FT-IR measurements seemed to prove that TRI containing large amount of hydroxyl will adsorb on surface of different surfaces of ettringite, resulting in the reduced growth rate and small crystal size. The decreased shrinkage strain of cement pastes can be attributed to the delayed ettringite when TRI is added into systems.