a b s t r a c t Keywords: 3CaO·3Al 2 O 3 ·CaSO 4 (D) Clinkerization (E) Belite sulfoaluminate cem... more a b s t r a c t Keywords: 3CaO·3Al 2 O 3 ·CaSO 4 (D) Clinkerization (E) Belite sulfoaluminate cement (D) Hydration (A) Quantitative mineralogical phase analysis (B)
High belite cements may be an alternative to reduce CO 2 emissions. Although CO 2 emissions may b... more High belite cements may be an alternative to reduce CO 2 emissions. Although CO 2 emissions may be depleted up to 10%, unfortunately, the hydration reactivity of belite phases is slow which leads to low mechanical strengths at early ages. In order to enhance their hydraulic reactivity, the activation of these cements by doping with alkaline oxides has been proposed. Here, we have synthesised a laboratory belite clinker without activation (47 wt.% of β-C 2 S and 19 wt.% of α H ′-C 2 S) and two alkaline oxide activated clinkers (one with 13 wt.% of β-C 2 S, 24 wt.% of α H ′-C 2 S and 19 wt.% of α-C 2 S; and the second with 12 wt.% of β-C 2 S, 42wt.% of α H ′-C 2 S and 5wt.% of α-C 2 S). We have also developed a methodology to analyse quantitatively the phase evolution of cement pastes and we have applied it to these high belite cements. Rietveld quantitative phase analysis of synchrotron X-ray powder diffraction data, together with chemical constraints, is used to determine the phase development up to 1 year of hydration in the belite cement pastes. β-C 2 S almost does not react during the first 3 months, meanwhile α H ′-C 2 S reacts on average more than 50% in the same period. Moreover, the degree of reaction of α-C 2 S is slightly larger (on average about 70% after three months) than that of α H ′-C 2 S. Full phase analyses are reported and discussed including the time evolution of amorphous phases and free water.
Aclaremos ante todo que no vamos robar un mes del año para quedarnos con 11 meses. El "Ladrón de ... more Aclaremos ante todo que no vamos robar un mes del año para quedarnos con 11 meses. El "Ladrón de Julios" no es más que el nombre que se le da a un circuito electrónico que me ha llamado mucho la atención. Tanto, que me puse a construir uno (lectura de 4 minutos) Llevo algún tiempo desempolvando mis conocimientos de electrónica y lo cierto es que no paro de llevarme sorpresas. Una de ellas fue darme cuenta de que lo que yo consideraba útiles conocimientos, resulta que se han convertido en obsoletos conocimientos. Más que obsoletos casi diría que están "obsolestísimos".
a b s t r a c t Keywords: 3CaO·3Al 2 O 3 ·CaSO 4 (D) Clinkerization (E) Belite sulfoaluminate cem... more a b s t r a c t Keywords: 3CaO·3Al 2 O 3 ·CaSO 4 (D) Clinkerization (E) Belite sulfoaluminate cement (D) Hydration (A) Quantitative mineralogical phase analysis (B)
High belite cements may be an alternative to reduce CO 2 emissions. Although CO 2 emissions may b... more High belite cements may be an alternative to reduce CO 2 emissions. Although CO 2 emissions may be depleted up to 10%, unfortunately, the hydration reactivity of belite phases is slow which leads to low mechanical strengths at early ages. In order to enhance their hydraulic reactivity, the activation of these cements by doping with alkaline oxides has been proposed. Here, we have synthesised a laboratory belite clinker without activation (47 wt.% of β-C 2 S and 19 wt.% of α H ′-C 2 S) and two alkaline oxide activated clinkers (one with 13 wt.% of β-C 2 S, 24 wt.% of α H ′-C 2 S and 19 wt.% of α-C 2 S; and the second with 12 wt.% of β-C 2 S, 42wt.% of α H ′-C 2 S and 5wt.% of α-C 2 S). We have also developed a methodology to analyse quantitatively the phase evolution of cement pastes and we have applied it to these high belite cements. Rietveld quantitative phase analysis of synchrotron X-ray powder diffraction data, together with chemical constraints, is used to determine the phase development up to 1 year of hydration in the belite cement pastes. β-C 2 S almost does not react during the first 3 months, meanwhile α H ′-C 2 S reacts on average more than 50% in the same period. Moreover, the degree of reaction of α-C 2 S is slightly larger (on average about 70% after three months) than that of α H ′-C 2 S. Full phase analyses are reported and discussed including the time evolution of amorphous phases and free water.
Aclaremos ante todo que no vamos robar un mes del año para quedarnos con 11 meses. El "Ladrón de ... more Aclaremos ante todo que no vamos robar un mes del año para quedarnos con 11 meses. El "Ladrón de Julios" no es más que el nombre que se le da a un circuito electrónico que me ha llamado mucho la atención. Tanto, que me puse a construir uno (lectura de 4 minutos) Llevo algún tiempo desempolvando mis conocimientos de electrónica y lo cierto es que no paro de llevarme sorpresas. Una de ellas fue darme cuenta de que lo que yo consideraba útiles conocimientos, resulta que se han convertido en obsoletos conocimientos. Más que obsoletos casi diría que están "obsolestísimos".
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