Wyniki wyszukiwania - BazTech

Ograniczanie wyników

1 Materials Science Poland

1 2007

Znaleziono wyników: 1

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Influence of modification of SiO2 on the formation of calcium silicate hydrate

Baltakys K., Jauberthie R., Siauciunas R., Kaminskas R.

Materials Science Poland

2007

Vol. 25, No. 3

663--670

Interactions of Ca(OH)2 with various modifications of SiO2: amorphous (Hi-Sil, TSD) or crystalline (quartz) silica were established. The molar ratio of primary mixtures CaO/SiO2 was 0.5. The samples were cured in a vapour chamber (20 oC, 100% humidity) for 7 and 28 days. The products were characterized by X-ray diffraction, thermogravimetry, differential scanning calorimetry, Fourier-transform infrared and scanning electron microscopy analysis. SiO2 modification used had a decisive influence on the processes of formation of calcium silicate hydrates. In the mixture with amorphous SiO2, Ca(OH)2 reacted completely during 7 days of synthesis, while large quantity of Ca(OH)2 remained unreacted even after 28 days when quartz was used. It was found that in the Ca(OH)2-amorphous SiO2-H2O system, after a 28-day exposure, the surface of SiO2 globules was totally covered with well-crystalline C-S-H(I) plates. Moreover, in the samples with quartz, only the gaps between quartz crystals were filled with C-S-H(I).