Carbon nanofiber embedded cement composites: Properties and promises as sensor – A review

Dinesh, A.; Abirami, B.; Moulica, G.

doi:10.1016/j.matpr.2020.10.526

Cited by 11 publications

(1 citation statement)

References 30 publications

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“…When comparing CNT and CNF, a smaller fractional change in resistance has been observed when comparing 0.6 wt% of CNF and CNT under identical loading conditions [ 28 ]. Thus, the exact values associated with the percolation threshold are unknown, with significant factors associated with the size and length of the CNF, the cementitious matrix used (cement paste or mortar), the water-to-cement ratio and the superplasticizer content used in the mixing [ 9 , 29 ]. To facilitate substrate dispersion in the hydrophilic cement paste, we propose using CaO as a substrate for the growth of CNF, resulting in an amphiphilic composite.…”

Section: Introductionmentioning

confidence: 99%

Carbon Nanofibers Grown in CaO for Self-Sensing in Mortar

et al. 2022

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Intelligent cementitious materials integrated with carbon nanofibers (CNFs) have the potential to be used as sensors in structural health monitoring (SHM). The difficulty in dispersing CNFs in cement-based matrices, however, limits the sensitivity to deformation (gauge factor) and strength. Here, we synthesise CNF by chemical vapour deposition on the surface of calcium oxide (CaO) and, for the first time, investigate this amphiphilic carbon nanomaterial for self-sensing in mortar. SEM, TEM, TGA, Raman and VSM were used to characterise the produced CNF@CaO. In addition, the electrical resistivity of the mortar, containing different concentrations of CNF with and without CaO, was measured using the four-point probe method. Furthermore, the piezoresistive response of the composite was quantified by means of compressive loading. The synthesised CNF was 5–10 μm long with an average diameter of ~160 nm, containing magnetic nanoparticles inside. Thermal decomposition of the CNF@CaO compound indicated that 26% of the material was composed of CNF; after CaO removal, 84% of the material was composed of CNF. The electrical resistivity of the material drops sharply at concentrations of 2% by weight of CNF and this drop is even more pronounced for samples with 1.2% by weight of washed CaO. This indicates a better dispersion of the material when the CaO is removed. The sensitivity to deformation of the sample with 1.2% by weight of CNF@CaO was quantified as a gauge factor (GF) of 1552, while all other samples showed a GF below 100. Its FCR amplitude can vary inversely up to 8% by means of cyclic compressive loading. The method proposed in this study provides versatility for the fabrication of carbon nanofibers on a tailored substrate to promote self-sensing in cementitious materials.

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Section: Introductionmentioning

confidence: 99%