Self similarity of the spherical C-S-H particle in cement paste

Abstract

Cement paste with low water/cement ratio of 0.3 was observed using AFM. It is found that C-S-H has self similarity trait from scanning scale 20 μm×20 μm down to 300 nm×300 nm, and the feature of C-S-H at large scale is very similar to those smaller scales. It can be concluded that C-S-H is composed with some fundamental spherical globule, the fundamental globules agglomerate into bigger ones, moreover the bigger ones agglomerate into even bigger one. A C-S-H globule fractal model was put forward to describe the self similarity of the C-S-H globule, which can be used to reveal how the C-S-H globule contacts with each other.

Keywords

self-similar / C-S-H / cement paste / fundamental unite / granular / pattern

References

[1] Mandelbrot B. How Long Is the Coast of Britain? Statistical Self-Similarity and Fractional Dimension[J]. Science, 1967, 156(5): 636-638.

[2] Richardson I. G. The Calcium Silicate Hydrates[J]. Cement and concrete Research, 2008, 38(1): 137-158.

[3] Taylor H. F. W. Nano Scale Microstructure of C-S-H: Current Status[J]. Adv. Cem. Mater., 1993, 1: 38-46.

[4] Allen A. J., Thomas J. J., Jennings H. M. Composition and Density of Nano Scale Calcium Silicate Hydrate in Cement[J]. Nat. Materi., 2007, 6(2): 311-316.

[5] Jennings H. M. Colloid Model of C-S-H and Implications to the Problem of Creep and Shrinkage[J]. Concrete Science and Engineering, 2004, 37: 59-70.

[6] Jennings H. M., Thomas J. J., Gevrenov J. S., . A Multi-technique Investigation of the Nanoporosity of Cement Paste[J]. Cem. Concr. Res., 2007, 37: 329-336.

[7] Franz-Josef U.L.M. The Nanogranular Nature of C-S-H[J]. J. Mech. Phys. Solids, 2007, 55(1): 64-90.

[8] Liu X., Wang P., Chen H., . Application of Atomic Force Microscope in Study of Hydration Products in Early Hardening Stage of Cement Clinker Minerals[J]. J. Chin. Ceram. Soc., 2004, 32(3): 327-333.

[9] Paramita Mondal, Surendra P Sharh, Laurence Marks. Characterization of Cementitious Materials at Nano Scale with a Focus on Mechanical Properties[A]. NSF Workshop on Nanomodification of Cementitious Materials, Florida, 2006: 38–44

[10] André N. The Structure and Stoichiometry of C-S-H[J]. Cem. Concr. Res., 2004, 34: 1521-1528.

[11] Bonen D. The Nano Scale Microstructure of the Cement Paste and Its Porosity[C]. The 2nd International RILEM Symposium on Advances in Concrete through Science and Engineering. RILEM, 2006: 23–27

[12] Richardson I. G. The Nature of the Hydration Products in Hardened Cement Pastes[J]. Cem. Concr. Compo., 2000, 22: 97-133.

[13] Shen W., Xiao L., Ma W., . Investigation on Nano-scale Microstructure of C-S-H with Atomic Force Microscopy[J]. Jounal of the Chinese Ceramic Society, 2008, 36(4): 487-493.