Recent Advances in Properties and Applications of Carbon Fiber-Reinforced Smart Cement-Based Composites

Abstract

Under the strategies of low-carbon and environmental protection, promoting green technology innovation to achieve carbon neutrality in the construction field has become a universal goal. As the building material with the highest consumption, concrete has gradually begun to transform into a multi-functional and intelligent product. Therefore, the research on carbon fiber-reinforced cement-based composites (CFRCs) is of relative interest. It mainly uses carbon fibers (CFs) with high elasticity, strength, and conductivity to disperse evenly into the concrete as a functional filler, to achieve the intelligent integration of concrete structures and function innovatively. Furthermore, the electrical conductivity of CFRC is not only related to the content of CFs and environmental factors but also largely depends on the uniform dispersion and the interfacial bonding strength of CFs in cement paste. This work systematically presents a review of the current research status of the enhancement and modification mechanism of CFRC and the evaluation methods of CF dispersion. Moreover, it further discusses the improvement effects of different strengthening mechanisms on the mechanical properties, durability, and smart properties (thermoelectric effect, electrothermal effect, strain-sensitive effect) of CFRC, as well as the application feasibility of CFRC in structural real-time health monitoring, thermal energy harvesting, intelligent deformation adjustment, and other fields. Furthermore, this paper summarizes the problems and challenges faced in the efficient and large-scale applications of CFRCs in civil engineering structures, and accordingly promotes some proposals for future research.

Research on the dispersion of carbon fiber and recycled carbon fiber in cement-based materials: a review

“…Currently, the evaluation methods can be usually classified into two categories: direct methods and indirect methods (Gao et al, 2017;Zhu et al, 2021;Hao et al, 2023). Direct methods involve analyzing the individualization of carbon fiber or the formation of fiber clusters, while indirect methods rely on assessing the macroscopic properties that reflect the degree of fiber dispersion.…”

“…This phenomenon introduces an excessive number of weak interfacial regions, seriously compromising the mechanical properties of the matrix, and thereby limiting the extent of research and application in the field of CFCC (Wang et al, 2014;Li et al, 2019b). Therefore, investigating the dispersion of carbon fiber serves as a fundamental step in the subsequent research on CFCC (Zhu et al, 2021;Hao et al, 2023). It is of utmost importance to explore effective methods for carbon fiber dispersion and accurately evaluate the degree of fiber dispersion.…”

“…Although there have been reviews on the evaluation methods for the dispersion of synthetic fibers in cement-based materials, some of these methods may not be directly applicable to carbon fiber due to its unique properties. Additionally, there is a notable absence of evaluation methods based on electrical properties, creating a gap in establishing an effective validation system for these methods (Cao et al, 2018;Hao et al, 2023). Therefore, conducting a comprehensive retrospective analysis of the dispersion of carbon fiber in cement-based materials becomes imperative.…”

Mechanical and Durability Investigation of Composite Mortar with Carbon Microfibers (CMF)

“…The existing literature predominantly explores cement-based matrices (such as cement pastes or mortars) and small-sized samples [26][27][28]. Nevertheless, the behavior of concrete smart composites and medium-to high-scale elements, together with the investigation of the tailored setup and implementation, remains largely unexplored territory, but are essential for real application of this technology [9,29,30]. Challenges associated with scaling this technology include ensuring the proper dispersion of fillers to achieve a homogeneous material, addressing potential adverse effects of coarse aggregates on strain sensitivity, and optimizing the type and placement of electrodes in large structures [31][32][33].…”

Capacitive self tension sensing properties of steel beam: electrode configuration and stress regime

“…Although capacitance-based self-detection is less studied in the literature compared to resistance-based selfsensing, it is more likely to be widely used because it does not require any additive. Resistance-based self-sensing mechanism is based on the principle that the conductivity of the structure changes as a result of the deformation of the sufficiently conductive material with stresses, which requires conductive fillers to make the base material sufficiently conductive (Li and Ou 2009, Makul 2020, Taheri et al 2022, Li et al 2022b, Dinesh et al 2023, Elseady et al 2023, Hao et al 2023, Kim and Kim 2023, Qi et al 2023, Chung 2023a. For this reason, capacitance-based measurements provide the possibility of application in both existing and new structures (Ozturk and Chung 2021, Chung 2023b).…”