The hydration of tricalcium silicate in the presence of colloidal silica
Tóm tắt
Reactions of colloidal silica fumes with calcium hydroxide or hydrating tricalcium silicate (C3S) have been studied using calorimetry, chemical analyses, and scanning electron microscopy. Silica fume reacts immediately with calcium hydroxide forming a colloidal calcium silicate hydrate (C-S-H) similar to that formed by the hydration of C3S. When excess silica is present it reacts with C-S-H already formed to produce a new, highly polymerized C-S-H, having a very low C/S ratio (1.0). Silica fume accelerates the hydration of C3S, reduces the amount of calcium hydroxide formed by reacting with it, and slightly lowers the C-S-H ratio of the C-S-H formed by hydration. When large amounts of silica fume are present the formation of calcium hydroxide may be entirely suppressed and a highly polymerized C-S-H is formed. Silica fume is considered a good model for reactive pozzolans used in concrete.
Tài liệu tham khảo
J. A. Nelson andJ. F. Young,Cem. Concr. Res.7 (1977) 227.
H. N. Stein andJ. M. Stevels,J. Appl. Chem.14 (1964) 338.
W. Kurdowski andW. Nocum-Wezelik,Cem. Concr. Res.13 (1983) 341.
A. Traettegerg,Cemento75 (1978) 364.
H. Asgeorsson andG. Gudmundsson,Cem. Concr. Res.9 (1979) 249.
P.-C. Aitcin, P. Pinsonneault andG. Rau, in “Effects of Flyash Incorporation in Cement and Concrete”, edited by S. Diamond (Materials Research Society, University Park, PA, 1981) p. 316.
L. Hjorth, in “Nordic Concrete Research”, Publ. 1 (Nordic Concrete Federation, Oslo, Norway, 1982) p. 9.1; also in “Characterization and Performance Prediction of Cement and Concrete”, edited by J. F. Young (The Engineering Foundation, New York, 1982) p. 165.
E. J. Sellevold, D. H. Bager, E. K. Jenson andT. Knucksen, in “Condensed Silica Fume in Concrete”, edited by O. E. Gjørv and K. J. Løland. Report BML 82.610. (Cement and Concrete Research Institute, Trondheim Institute of Technology, Trondheim, Norway, 1982) p. 19.
J. H. Baache, paper presented at 2nd International Conference on Superplasticizers in Concrete, Aalborg Portland, Aalborg, Denmark, 1981.
S. Chatterji, N. Thaulow andP. Christensen,Cem. Concr. Res.12 (1982) 781.
A. D. Buck andJ. P. Burkes, Proceedings of the 3rd International Conference on Cement Microscopy, Houston, TX, March, 1981 (International Cement Microscopy Association, Duncanville, TX) p. 279.
F. M. Gragg andJ. Skalny,Cem. Concr. Res.2 (1972) 745.
K. Mohan andH. F. W. Taylor, in “Effects of Flyash Incorporation in Cement and Concrete”, edited by S. Diamond (Materials Research Society, University Park, PA, 1981) p. 54.
F. D. Tamas, A. K. Sarkar andD. M. Roy, in “Hydraulic Cement Pastes: Their Structure and Properties” (Cement and Concrete Association, Slough, UK, 1976) pp. 55.
J. Hriljac, Z.-Q. Wu andJ. F. Young,Cem. Concr. Res.13 (1983) 877.
Z.-Q. Wu andJ. F. Young,J. Amer. Ceram. Soc.67 (1984) 48.
Z.-Q. Wu, J. Hriljac, C.-L. Hwang andJ. F. Young,ibid.66 (1983) C-86.
I. Jawed andJ. Skalny, in “Effects of Fly-Ash Incorporation in Cement and Concrete”, edited by S. Diamond (Materials Research Society, University Park, PA, 1981) p. 60.
S. Chatterji,Cem. Concr. Res.10 (1980) 783.
A. Ghose andP. L. Pratt, in “Effects of Flyash Incorporation in Cement and Concrete”, edited by S. Diamond (Materials Research Society, University Park, PA, 1981) p. 82.
W. Lukas,Mater. Constr. (Paris)9 (1977) 331.
D. L. Rayment,Cem. Concr. Res.12 (1982) 133.