Issue 41

H. Šimonová et alii, Frattura ed Integrità Strutturale, 41 (2017) 211-219; DOI: 10.3221/IGF-ESIS.41.29 211 Focused on Crack Tip Fields Modelling of interfacial transition zone effect on resistance to crack propagation in fine-grained cement-based composites H. Šimonová, M. Vyhlídal, B. Kucharczyková, P. Bayer, Z. Keršner Brno University of Technology, Faculty of Civil Engineering, Veveří 331/95, 602 00 Brno, Czech Republic simonova.h@vutbr.cz , http://orcid.org/0000-0003-1537-6388 Michal.Vyhlidal@vutbr.cz Barbara. Kucarczykova@vutbr.cz , http://orcid.org/0000-0002-7123-5099 bayer.p@fce.vutbr.cz kersner.z@fce.vutbr.cz , http://orcid.org/0000-0003-4724-6166 L. Malíková, J. Klusák Institute of Physics of Materials, Academy of Sciences of the Czech Republic, v. v. i., Žižkova 22, 602 00 Brno, Czech Republic malikova.l@fce.vutbr.cz , http://orcid.org/0000-0001-5868-5717 klusak@ipm.cz A BSTRACT . In this paper, the attention is paid to investigation of the importance of the interfacial transition zone (ITZ) in selected fine-grained cement-based composites for the global fracture behaviour. This is a region of cement paste around the aggregate particles which specific features could have significant impact on the final behaviour of cement composites with a crack tip nearby this interface under applied tension. The aim of this work is to show the basic interface microstructure by scanning electron microscopy (SEM) done by MIRA3 TESCAN and to analyse the behaviour of such composite by numerical modelling. Numerical studies assume two different ITZ thicknesses taken from SEM analysis. A simplified cracked geometry (consisting of three phases – matrix, ITZ, and aggregate) is modelled by means of the finite element method with a crack terminating at the matrix–ITZ interface. ITZ’s modulus of elasticity is taken from generalized self-consistent scheme . A few conclusions are discussed based on comparison of the average values of the opening stress ahead of the crack tip with their critical values. The analyses dealing with the effect of ITZ’s properties on the stress distribution should contribute to better description of toughening mechanisms in silicate-based composites. K EYWORDS . Fine-grained concrete; Interfacial transition zone; Scanning electron microscopy; Three-point bending fracture test; Effective fracture toughness. Citation: Šimonová, H., Vyhlídal, M., Kucharczyková, B., Bayer, P., Keršner, Z., Malíková, L., Klusák, J., Modelling of interfacial transition zone effect on resistance to crack propagation in fine-grained cement- based composites, Frattura ed Integrità Strutturale, 41 (2017) 211-219. Received: 28.02.2017 Accepted: 15.04.2017 Published: 01.07.2017 Copyright: © 2017 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.