Studies of Fractal Aspects of Cement

J.A. Janika, W. Kurdowskib, R. Podsiadłyc and J. Samsethd aH. Niewodniczański Institute of Nuclear Physics, Radzikowskiego 152, 31-342 Kraków, Poland bMining Academy, Mickiewicza 30, 30-059 Kraków, Poland cFaculty of Chemistry of the Jagiellonian University, Ingardena 3, 30-060 Kraków, Poland dInstitutt for energiteknikk, 2007 Kjeller, Norway

Received: May 22, 1996; in final form: October 22, 1996

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Small angle neutron scattering can be used to reveal the fractal nature of matter. The problems of fractal aspects of the structure of cement are related to those of fractal aspects of silica aerogels. Natural cement, when mixed with water, transforms after a series of chemical reactions (in a large part) into an amorphous phase called C-S-H. It is believed that the cationic sublattice composed of CaO6 octahedrons constitutes the C-S-H structural basis, to which the SiO4 tetrahedral chains are attached. It is a layer structure in which the cation sublattice determines the way of SiO4 condensation. It is natural to expect that in this way one may obtain a really amorphous substance, since some tetrahedrons may be lacking, which leads to defects. We present here the results of a small angle neutron scattering and X-ray diffraction study of several samples with the pure C-S-H phase for which during the process of chemical synthesis various ratios of molar contents of CaO and SiO2 were used (various C/S ratios). We obtained a gradual change of fractal characteristics with the change of C/S ratio.

DOI: 10.12693/APhysPolA.90.1179 PACS numbers: 61.12.Ex, 82.70.Gg