A critical review of carbon nanomaterials applied in cementitious composites-A focus on mechanical properties and dispersion techniques

This paper provides a current overarching review of several commonly used carbon nanomaterials applied within cementitious composites. It reviews the typical weight percentages used within mixes from several researchers in the field and assesses the application of these nano materials on the mechanical properties. Mechanical properties covered include compressive strength, flexural strength and tensile strength as well as elastic modulus. It was clear from this extensive but initial review that the dispersion methods and techniques used during mixing not only influenced the mechanical properties but also influenced the percentages of nanomaterials used in the mixes. This leads to a further review of dispersion methods and dispersion measurement techniques in order to gain insight into the best approach to take. The effect of dispersion methods on the quantities of nanomaterials used in mixes raised an interesting, last review on pricing comparisons (2020) and the development of a cost-to-weight ratio to better evaluate and compare between options from a cost perspective. Recommendations from this extensive review include; low percentage of graphene oxide provides better improvement compared with other carbon nanomaterials; Use of superplasticiser in mixes such as ADVA 210 to better aid dispersion; use of ultrasonication for a short cycle to improve dispersion; and finally, a mixed mode approach to the measurement of dispersion in mixes which includes scanning electron microscope (SEM) + ultraviolet- visible spectroscopy (UV-Vis) testing at solution phase + Mechanical properties after 28 days. (c) 2021 THE AUTHORS. Published by Elsevier BV on behalf of Faculty of Engineering, Alexandria University. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/ 4.0/).

Automated summary

This paper provides a comprehensive review of commonly used carbon nanomaterials in cementitious composites, focusing on their effects on mechanical properties. The study finds that dispersion methods and techniques significantly influence both the mechanical properties and the percentage of nanomaterials in the mixes. Recommendations include the use of low percentages of graphene oxide for improvement, the use of superplasticisers and ultrasonication for better dispersion, and a mixed mode approach to measuring dispersion.