Abstract
The sequence of microstructural changes occurring at the wet paste-aggregate interface is documented at an age as early as 5 min using the environmental scanning electron microscope (ESEM). Unlike other microscopic techniques, the ESEM allows pastes of normal water: cement ratio to be observed at early ages without reducing the paste to a powder. Evolution of the paste-aggregate microstructure is followed up to an age of 24 h. The region adjacent to the aggregate surface contains a phase with a morphology referred to as a “sheaf of wheat” morphology. The same interfacial region in a 10-day-old specimen has a microstructure similar to the interfacial transition zone (ITZ) reported in the literature. Variations of the “sheaf of wheat” morphology due to original water-to-cement ratio, mixing energy, incorporation of silica fume, and drying are documented. As revealed by energy dispersive x-ray analysis (EDS), the microstructure contains significant amounts of calcium and silica. These results indicate that the observed morphology is likely to be a calcium silicate hydrate (C-S-H) product that is a precursor to type I C-S-H. A description of the evolution of the observed microstructural features is presented. The “sheaf of wheat” morphology appears to be a general precursor to morphologies commonly seen in mature pastes.
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References
B. D. Barnes, S. Diamond, and W.L. Dolch, Cem. Conc. Res. 8, 233 (1978).
B. D. Barnes, S. Diamond, and W.L. Dolch, J. Am. Ceram. Soc. 62 (1,2), 21 (1978).
K. L. Scrivener and P. L. Pratt, in A Preliminary Study of the Microstructure of the Cement/Sand Bond in Mortars (8th Int. Congress on the Chemistry of Cement, Rio de Janiero 3, Abla Grafica e Editora, Rio de Janiero, Brazil, 1986), p. 466.
K. L. Scrivener and E. M. Gartner, in Bonding in Cementitious Composites, edited by S. Mindess and S. P. Shah (Mater. Res. Soc. Symp. Proc. 114, Pittsburgh, PA, 1988), pp. 77–88.
J. P. Ollivier and M. Massat, in Microstructure of the Paste-Aggregate Interface, Including the Influence of Mineral Additions, edited by M.W. Grutzeck and S.L. Sarkar (Advances in Cement and Concrete, American Society of Civil Engineers, New York, 1994), p. 175.
J. A. Larbi and J. M. J.M. Bijen, Cem. Conc. Res. 20, 461 (1990).
P.J. M. Monteiro, J.C. Maso, and J. P. Ollivier, Cem. Conc. Res. 15, 953 (1985).
P.J. M. Monteiro and C. P. Ostertag, Cem. Conc. Res. 19, 987 (1989).
J. Grandet and J. P. Ollivier, in Proceedings of the 7th International Congress on Chemistry of Cement, Paris, Vol. III (Editions Septima, Paris, 1980), pp. VII-85.
S. Diamond, S. Mindess, and J. Lovell, in On the Spacing Between Aggregate Grains in Concrete and the Dimensions of the Aureole de Transition (Liasons de Ciment Mater. Assoc. Proceedings of RILEM Colloq., Toulouse, France, 1982), p. c-42.
H.M. Jennings, B. J. Dalgleish, and P. L. Pratt, J. Am. Ceram. Soc. 64, 567 (1981).
A. Grudemo, in The Chemistry of Cements, edited by H. F. W. Taylor (Academic Press, New York, 1964), p. 371.
A. Grudemo, C.B.I. Proc. 26, 1–103 (1955).
T.D. Ciach, J. E. Gillot, E. G. Swenson, and P. J. Sereda, Cem. Concr. Res. 1, 13–25 (1971).
H.M. Jennings and P. L. Pratt, J. Mater. Sci. 15, 250–253 (1980).
T.N. Tiegs, M. Sc. Thesis, University of Illinois, Urbana-Champaign, IL (1975).
B.J. Dalgleish, P. L. Pratt, and R. I. Moss, Cem. Concr. Res. 10, 665–676 (1980).
B. Marchese, J. Am. Ceram. Soc. 61, 349–355 (1978).
S. Goto, M. Daimon, G. Hosaka, and R. Kondo, J. Am. Ceram. Soc. 59, 281 (1976).
L. Ben-Dor and D. Perez, J. Mater. Sci. 11, 239–245 (1976).
M.S. Stucke and A. J. Majumdar, Cem. Concr. Res. 7, 711–718 (1977).
S. Diamond, in Cement Paste Microstructure: An Overview at Several Levels (Conf. Proc. on Hydraulic Cement Pastes: Their Structure and Properties, Cement and Concrete Association, Slough, UK, 1976), p. 2.
R.B. Williamson, J. Cryst. Growth 3 (4), 787 (1968).
S. Goto, M. Daimon, G. Hosaka, and R. Kondo, ibid. 59, 281–285 (1976).
A.I. Rashed and R. B. Williamson, J. Mater. Res. 6, 2004 (1991).
A.I. Rashed and R. B. Williamson, J. Mater. Res. 6, 2474 (1991).
R.B. Williamson and R. S. Markiewicz, Report R68-57, Dept. of Civil Engineering, M.I.T., Cambridge, Massachusetts (1968).
H.E. Buckley, Crystal Growth (John Wiley, New York, 1951), p. 500.
Z.-Q. Wu and J. F. Young, J. Am. Ceram. Soc. 67, 48 (1984).
M.E. Tardos, J. Skalny, and R. S. Kalyoncu, J. Am. Ceram. Soc. 59, 344 (1976).
J. F. Young, H-S. Tong, and R. L. Berger, J. Am. Ceram. Soc. 60 (5–6), 193 (1977).
P.A. Slegers and P.G. Rouxhet, Cem. Conc. Res. 7, 31 (1977).
N.L. Thomas and D. D. Double, Cem. Conc. Res. 11, (5/6), 675 (1981).
D. Bonen, J. Am. Ceram. Soc. 77 (1), 193 (1994).
D. Bonen and S. Diamond, in Application of Image Analysis to a Comparison of Ball Mill and High Pressure Roller Mill Ground Cement (Proc. 13th Int. Conference on Cement Microscopy, Tampa, FL, International Cement Microscopy Association, Duncanville, TX, 1991), p. 101.
J. B. Ings, P. W. Brown, and G. Frohnsdorff, Cem. Conc. Res. 13(6), 843 (1983).
R. Sierra, Ph.D. Thesis, University of Rennes, Feb. 1974.
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Zampini, D., Shah, S.P. & Jennings, H.M. Early age microstructure of the paste-aggregate interface and its evolution. Journal of Materials Research 13, 1888–1898 (1998). https://doi.org/10.1557/JMR.1998.0268
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DOI: https://doi.org/10.1557/JMR.1998.0268