An electron optical examination of zoning in blastfurnace slag hydrates: Part I. Slag cement pastes at early ages

1989 ◽  
Vol 2 (8) ◽  
pp. 171-179 ◽  
Author(s):  
A. P. Barker
Keyword(s):  
Slag Cement ◽  
Cement Pastes ◽  
Blastfurnace Slag ◽  
Optical Examination

Microstructure and Microchemistry of Slag Cement Pastes

1986 ◽  
Vol 85 ◽  
Author(s):  
A. M. Harrisson ◽  
N. B. Winter ◽  
H. F. W. Taylor
Keyword(s):  
Portland Cement ◽  
Bound Water ◽  
Compositional Variation ◽  
Slag Cement ◽  
Cement Pastes ◽  
Blastfurnace Slag ◽  
The Individual ◽  
Bound Water Content ◽  
Water Contents

ABSTRACTPastes of a portland cement (60%) blended with a granulated blastfurnace slag (40%) were examined, principally by SEM with EDX analysis. Reaction rims around slag particles and relicts of fully reacted slag particles had compositions compatible with mixtures, in varying proportions, of C-S-H having Si/Ca -0.62 and a phase of the hydrotalcite family having Al/Mg -0.38. Calculations taking into account relevant densities and water contents indicated that replacement of the slag by its in situ hydration products entails little or no change in the numbers of Mg and 0 atoms per unit volume, but that substantial proportions of the Ca, Si and Al are released and an equivalent amount of H gained. In other respects, the microstructures qualitatively resembled those of pure portland cement pastes of similar ages, but less CH was formed and the C-S-H not formed in situ from the slag had a Si/Ca ratio of 0.56, higher than that of 0.50 to 0.53 found in the absence of slag. None of the individual phases in the slag cement pastes showed significant compositional variation with time in the 28 day to 14 month period studied. The relative amounts of Ca, Si and Al expelled from the slag are such that, in order to form C-S-H and AFm phase, more Ca is required. It is obtained partly at the expense of CH formation, and partly through increase in the Si/Ca ratio of the C-S-H formed from the clinker phases. Mass balance, volume composition and bound water content were calculated for the 14 month old paste and compared with corresponding results for the pure portland cement.

Microstructure and Microchemistry of Slag Cement Pastes

1986 ◽  
Vol 86 ◽  
Author(s):  
A. M. Harrisson ◽  
N. B. Winter ◽  
H. F. W. Taylor
Keyword(s):  
Portland Cement ◽  
Bound Water ◽  
Compositional Variation ◽  
Slag Cement ◽  
Cement Pastes ◽  
Blastfurnace Slag ◽  
The Individual ◽  
Bound Water Content ◽  
Water Contents

ABSTRACTPastes of a portland cement (60%) blended with a granulated blastfurnace slag (40%) were examined, principally by SEM with EDX analysis. Reaction rims around slag particles and relicts of fully reacted slag particles had compositions compatible with mixtures, in varying proportions, of C-S-H having Si/Ca -0.62 and a phase of the hydrotalcite family having Al/Mg -0.38. Calculations taking into account relevant densities and water contents. indicated that replacement of the slag by its in situ hydration products entails little or no change in the numbers of Mg and O atoms per unit volume, but that substantial proportions of the Ca, Si and Al are released and an equivalent amount of H gained. In other respects, the microstructures qualitatively resembled those of pure portland cement pastes of similar ages, but less CH was formed and the C-S-H not formed in situ from the slag had a Si/Ca ratio of 0.56, higher than that of 0.50 to 0.53 found in the absence of slag. None of the individual phases in the slag cement pastes showed significant compositional variation with time in the 28 day to 14 month period studied. The relative amounts of Ca, Si and Al expelled from the slag are such that, in order to form C-S-H and AFm phase, more Ca is required. It is obtained partly at the expense of CH formation, and partly through increase in the Si/Ca ratio of the C-S-H formed from the clinker phases. Mass balance, volume composition and bound water content were calculated for the 14 month old paste and compared with corresponding results for the pure portland cement.

Hardened slag-cement pastes of various porosities. II. Water and nitrogen adsorption

2007 ◽  
Vol 25 (11) ◽  
pp. 835-847 ◽  
Author(s):  
Raouf Sh. Mikhail ◽  
Salah A. Abo-El-Enein ◽  
Mohamed Abd-El-Khalik
Keyword(s):  
Nitrogen Adsorption ◽  
Slag Cement ◽  
Cement Pastes
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