Evaluation of Mechanical and Microstructural Properties of Mortar Reinforced with Carbon Nanotubes at Elevated Temperatures
Abstract
An experimental study was performed to analyze the effect of multi-walled carbon nanotubes (MWCNT’s) on preheated and post heated mechanical properties of cement mortar. Cement was replaced with 0.125%, 0.25%, 0.375%, and 0.5% MWCNT’s and mortar cubes were then subjected to 25oC, 400oC, and 800oC after 90 days of curing to determine the residual compressive strength. Microstructural analysis was performed on pre-heated and post-heated samples to identify changes in hydration products and decomposition phases by using scanning electron microscopy (SEM). Mortar samples heated at 400oC showed slight changes in microstructure but became more evident at 800oC. Tests performed on pre-heated samples show that the addition of 0.125% in cement as an optimum dosage can increase mortar strength up to 53.4% due to the bridging effect of CNT’s which improve load distribution, however higher dosages of CNT’s lead to a decrease in strength as compared to optimum mix. It has been determined that higher dosages of CNT’s (0.375% and 0.5%) enhanced relative compressive strength of mortar up to 26.3% and 66.9% respectively at 400oC. Similarly, the addition of 0.375% and 0.5% CNT’s improved residual compressive strength by 23.64% and 61.4% respectively at 800oC due to reduction in the size of cracks and formation of compact and stable microstructure as observed from SEM images. Besides, an increase in the dosage of CNT’s provide sufficient resistance against spalling and reduction in mass of mortar at elevated temperatures.
Copyright (c) 2021 Pakistan Journal of Engineering and Technology
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
COPYRIGHT POLICY
UOL journals follow an open-access publishing policy and full text of all articles is available free, immediately upon acceptance. Articles are published and distributed under the terms of the CC BY-SA 4.0 International License. Thus, work submitted to UOL Journals implies that it is original, unpublished work of the authors; neither published previously nor accepted/under consideration for publication elsewhere.
Authors will be responsible for any information written/informed/reported in the submitted manuscript. Although we do not require authors to submit the data collection documents and coded sheets used to do quantitative or qualitative analysis, we may request it at any time during the publication process, including after the article has been published. It is author's responsibility to obtain signed permission from the copyright holder to use and reproduce text, illustrations, tables, etc., published previously in other journals, electronic or print media.
Conflict of interest statements will be published at the end of the article. If no conflict of interest exists, the following sentence will be used: "The authors declare no conflict of interest." Authors are required to disclose any sponsorship or funding received from any institution relating to their research. The editor(s) will determine what disclosures, if any, should be available to the readers.
Authors are not permitted to post the work on any website/blog/forum/board or at any other place, by any means, from the time such work is submitted to UOL journals until the final decision on the paper has been given to them. In case a paper is accepted for publication, the authors may not post the work in its entirety on any website/blog/forum/board or at any other place, by any means, till the paper is published in UOL Journals.
The authors may, however, post the title, authors’ names and their affiliations and abstract, with the following statement on the first page of the paper - "The manuscript has been accepted for publication in UOL Journals". After publication of the article, it may be posted anywhere with full journal citation included.
All articles published in UOL journals are open-access articles, published and distributed under the terms of the Creative Commons Attribution-ShareAlike 4.0 International License which permits remixing, transformation, or building upon the material, provided the original work is appropriately cited mentioning the authors and the publisher, as well as the produced work is distributed under the same license as the original.
In the future, UOL may reproduce printed copies of articles in any form. Without prejudice to the terms of the license given below, we retain the right to reproduce author's articles in this way.
Brief Summary Of The License Agreement
By submitting your research article(s) to UOL Journal(s), you agree to Creative Commons Attribution-ShareAlike 4.0 International License which states that:
Anyone is free:
o To copy and redistribute the material in any medium or format
o To remix, transform, or build upon the material for any purpose, even commercially
Provided:
o The author and the publisher have been appropriately credited
o The link to license is provided
o Indicated if any changes were made
o The material produced is distributed under the same license as the original
