Practice of technical mineralogy: phase-forming processes in a monolith on the base of fly ash

Chervonny A. D., Chukanov N. V., Pekov I.V.

Zapiski RMO (Proceedings of the Russian Mineralogical Society). 2015. V. 144. N 4. P. 13-25

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Language: Russian


Processes proceeding during the long-time (up to 20 years) curing of the SCAS-A-monolith (cement material obtained on the base of fly ash) have been investigated using powder X-ray diffraction, IR spectroscopy and X-ray spectrum analyses. The phase composition of the initial SCAS-A-monolith and the processes of its transformation (the formation of calcium hydrosilicates, carbonates and secondary sulphates) are analogous to the mineral composition and the processes of low-temperature alteration of calcic xenoliths from igneous rocks. The participation of melilite in formation of the binder in a cement material is demonstrated for the first time. Factors preventing the crystallization of ettringite-type phases, which cause sulphate corrosion of concrete, have been determined on the base of SCAS-A-monolith comparison with its natural analogues.

Key words: synthetic calcium aluminosilicate, metasomatism, xenoliths, larnite, ettringite, sulfate corrosion.