A blended binder system (10 % portland cement, 45 % fly ash, and 45 % slag) is characterized as part of a broader study of its long-term effectiveness in stabilizing treated salt waste at the Savannah River Site. The binder system is reproduced in the laboratory using a simulated salt solution, and the hydrated phases are identified and quantified out through one year of hydration. The phases are identified through the use of thermogravimetric analysis and X-ray diffraction. Supporting information is obtained from scanning electron microscopy and pore solution analysis by inductively coupled plasma optical spectroscopy. The evidence suggests that the phases being formed are the types one would expect, given the starting materials. Moreover, even though the salt solution adds considerable sulfate to the system, there is no evidence of excess sulfate bearing phases indicative of expansive sulfate attack. Furthermore, the data out to one year of hydration suggests that the phases observed are stable.
Citation: NIST Interagency/Internal Report (NISTIR) - 7947Report Number:
NIST Pub Series: NIST Interagency/Internal Report (NISTIR)
Pub Type: NIST Pubs
cementitious materials, grout, microscopy, saltstone