Issue 42

A. Khitab et alii, Frattura ed Integrità Strutturale, 42 (2017) 238-248; DOI: 10.3221/IGF-ESIS.42.26 239 Fracture toughness and failure mechanism of high performance concrete incorporating carbon nanotubes Anwar Khitab, Sajjad Ahmad Mirpur University of Science and Technology, Mirpur AJK, Pakistan Chairman.ce@must.edu.pk , http://orcid.org/0000-0001-2345-6789 Sajjad.ce@must.edu.pk, http://orcid.org/0000-0002-1139-8726 Rao Arsalan Khushnood, Syed Ali Rizwan National University of Sciences and Technology, Islamabad, Pakistan arsalan.khushnood@nice.nust.edu.pk, http://orcid.org/0000-0002-9532-4096 syedalirizwan@hotmail.com , http://orcid.org/0000-0001-2345-6789 Giuseppe Andrea Ferro, Luciana Restuccia Politecnico di Torino, Turin, Italy ferro@polito.it, http://orcid.org/0000-0002-2345-6790 luciana.restuccia@polito.it, http://orcid.org/0000-0001-2345-6789 Mustajab Ali, Imran Mehmood Mirpur University of Science and Technology, Mirpur AJK, Pakistan mustajab .ce@ must .edu.pk , http://orcid.org/0000-0001-2345-67989 imran.mehmood@must.edu.pk , http://orcid.org/0000-0001-2345-6789 A BSTRACT . Cement and concrete composites are inherently brittle and exhibit very less tensile/flexural strength capacity as compared to their compressive strength. Use of thoroughly dispersed carbon nanotubes in the concrete matrix is one of the possible solution for enhancing mechanical properties in tension/flexure. In the present research work, small fractions of multiwall carbon nanotube (MWCNTs) i.e. 0.05 and 0.10 wt% of cement have been integrated into the cement concrete to study their effect on the mechanical properties of the resultant concrete mixtures. The enhanced performance of the whole mix lies on a single point that MWCNTs must be thoroughly disperse in the mixture. Hence, special arrangement through usage of high energy sonication along with amended acrylic based polymer (performing as a surfactant) was made to have a uniform dispersion of MWCNTs in the concrete mix. The testing of concrete samples includes i.e., flexure, splitting tensile and compressive strengths after 3, 7, 28 and 56 days of curing. After having comparison with the control mix cured for 28 days, it was observed that the addition of 0.05 wt% MWCNTs increased the splitting Citation: Khitab, A., Ahmad, S., Khushnood, R.A., Rizwan, S.A., Ferro, G.A., Restuccia, L., Ali, M., Mehmood, I., Fracture toughness and failure mechanism of high performance concrete incorporating carbon nanotubes, Frattura ed Integrità Strutturale, 42 (2017) 238-248. Received: 25.06.2017 Accepted: 25.07.2017 Published: 01.10.2017 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.