Effect of Surface Roughness, Type and Size of Model Aggregates on the Bond Strength of Aggregate/Mortar Interface
Tóm tắt
The paper reports on a two-stage study of the interface between three types of model cylindrical aggregates (sandstone, limestone and granite) and two types of mortar matrix (plain and 20% Silica Fume mortar). In the first stage, the surface roughness (R
a) of the aggregates and the interfacial bond strength using push-out specimens have been experimentally determined. In the second, aggregate push-out geometry has been modelled using two different approaches. In the first approach, the surface roughness is ignored and the cylindrical aggregates are assumed to have an ideally smooth surface with a constant radius, r
0 over the aggregate length, L. In the second approach, the surface roughness of the aggregates is included so that the radius, r varies along the length of the cored rock aggregate. Hence, the influence of the surface roughness of the aggregates on the interfacial bond strength is obtained. It is found that the surface roughness plays a significant role in determining the interfacial bond strength, in particular of smaller size aggregates. The effect, however, diminishes as the aggregate size increases, regardless of the aggregate and mortar type.
Tài liệu tham khảo
S. Caliskan, B.L. Karihaloo, and B.I.G. Barr, Magazine of Conc. Research 54, 449 (2002).
W.A. Tasong, C.J. Lynsdale, and J.C. Cripps, Cement and Conc. Research 28, 1453 (1998).
D.M. Tan, E.K. Tschegg, H. Rotter, and H.O.K. Kirchner, Acta Metall. Materials 4, 3701 (1995).
A.M. Neville, Properties of Concrete, 4th edition (Longman, London, 1995), p. 844.
L. Struble, J. Skalny, and S. Mindess, Cement and Conc. Research 10, 277 (1980).
S. Caliskan, B.L. Karihaloo, and B.I.G. Barr, Magazine of Conc. Research 54, 463 (2002).
S. Chatterji and A.D. Jensen, in Interfaces in Cementitious Composites, edited by J.C. Maso (E & FN Spon, London, 1992), p. 3.
P.J.F. Wright, Magazine of Conc. Research, 151 (Nov. 1955).
R.D. Britton, Surface Roughness Effects in Gears (PhD Thesis, School of Engineering, Cardiff University, Cardiff, 1998), p. 220.
M.J. Patching, The Effect of Surface on the Micro-Elastohydrodynamic Lubrication and Scuffing Performance of Aerospace Gear Tooth Contacts (PhD Thesis, School of Engineering, Cardiff University, Cardiff, 1994), p. 259.
T.R. Thomas, Rough Surfaces (Imperial College Press, London, 1999), p. 278.
British Standards Institution, Method for the Assessment of Surface Texture (BS 1134: Part 1, London, 1972).
K.F. Riley, M.P. Hobson, and S.J. Bence, Mathematical Methods for Physics and Engineering: A Comprehensive Guide (Cambridge University Press, Cambridge, 1998), p. 1008.
H. Stang, Z. Li, and S.P. Shah, Journal ASCE, Eng. Mechanics 116, 2136 (1990).
K. Mitsui, Z. Li, D.A. Lange, and S.P. Shah, in Interfaces in Cementitious Composites, edited by J.C. Maso (E & FN Spon, London, 1992), p. 119.
H.K. Versteeg and W. Malalasekera, An Introduction to Computational Fluid Dynamics, The finite Volume Method (Longman Group Ltd., 1995), p. 275.
S.V. Fletcher, Computational Techniques for Fluid Dynamics Volume 1: Fundamental and General Techniques, 2nd edition (Springer-Verlag, Berlin, 1991), p. 401.
S. Caliskan, Cement and Conc. Composites Journal 25, 557 (2003).