Determination of percolation threshold in cement composites with expanded graphite by impedance spectroscopy

Pichór, Waldemar; Frąc, Maksymilian; Radecka, M.

doi:10.1016/j.cemconcomp.2021.104328

Cited by 27 publications

(14 citation statements)

References 62 publications

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“…10 6 –10 7 Ω cm [37,38] . On the other hand, with the increasing moisture content, cement composites become electrically conductive due to the ionic conduction phenomena depending strongly on the movement of ions in the interconnected pore network of hardened matrix [27,39] . Moreover, the scenario becomes even more complicated with the addition of conductive functional fillers – the electrical behavior of cement composites is then driven by a variety of conduction mechanisms, i. e., ionic, tunneling and contact conduction [16] .…”

Section: Resultsmentioning

confidence: 99%

“…Moreover, the scenario becomes even more complicated with the addition of conductive functional fillers – the electrical behavior of cement composites is then driven by a variety of conduction mechanisms, i. e., ionic, tunneling and contact conduction [16] . In this perspective, Electrochemical Impedance Spectroscopy has emerged as a powerful tool allowing to distinguish between the conduction paths within concrete microstructure and to specify their contribution to the general electrical response of cement composites [27] …”

Section: Resultsmentioning

confidence: 99%

“…Therefore, the tremendous increase of the C 2 capacitance with high rGO dosage is associated as well with the decreasing distance between its nanosheets. Nevertheless, in this case one can expect that the capacitance C 2 will start to decrease again with higher rGO loadings allowing the contact conduction and therefore precluding further storage of electric charge [27] …”

Section: Resultsmentioning

confidence: 99%

“…Initially, EIS was mainly used to monitor the corrosion of concrete reinforcement, on‐going hydration and microstructure of cement composites, carbonation processes and chloride migration [26] . More recently, EIS has emerged also as a powerful technique for the investigation of cement composites incorporating conductive additives allowing to gain detailed insight into the conduction mechanism and the quality of the functional filler dispersion [27,28] . Nevertheless, the high complexity of concrete microstructure as well as the lack of clear guidelines and well‐established universal equivalent circuit for the fitting procedure makes it extremely challenging to fully interpret the results of impedance studies of cement composites.…”

Section: Introductionmentioning

confidence: 99%

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Controlling the Formation of Electroactive Graphene‐Based Cementitious Composites: Towards Structural Health Monitoring of Civil Structures

Safuta,

Ciesielski,

Samorì

2023

Chemistry A European J

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The development of composites combining multiple components each one imparting a specific function to the ensemble is highly sought after for disruptive applications in chemistry and materials science, with a particular importance for the realization of smart structures. Here we report on the development of an unprecedented multifunctional cementitious composite incorporating reduced graphene oxide (rGO). By design, this material features enhanced electrical properties while retaining the excellent cement’s hydration and microstructure.The multiscale investigation on the physico‐chemical properties of the dispersion allowed to establish an efficient preparation protocol for rGO aqueous dispersion as well as rGO‐based cementitious composites using a commercial poly(carboxylate ether)‐based superplasticizer. Conduction mechanisms within the matrix of rGO containing mortars were unraveled by electrochemical impedance spectroscopy revealing conductive paths originating from bulk cement matrix and rGO nanosheets in composites with rGO loadings as low as 0.075wt.%. For this rGO loading, we observed the reduction of the resistivity of bulk cement mortar layers from 18.3MΩ cm to 2.8MΩ cm. Moreover, the addition of 0.2wt.% of rGO resulted in the formation of rGO conductive paths with resistivity of 51.1kΩ cm. These findings represent a major step forward towards the application of graphene in structural health monitoring of concrete structures.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Controlling the Formation of Electroactive Graphene‐Based Cementitious Composites: Towards Structural Health Monitoring of Civil Structures

Safuta,

Ciesielski,

Samorì

2023

Chemistry A European J

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“…The bulk conductivity of the system is thus governed by the electronic conduction through the contacting fibres (i.e., ohmic conduction), and the quantum tunnelling between adjacent fibres (i.e., the non-ohmic conduction) (Sun et al, 1998;Xu et al, 2010Xu et al, , 2011Pichór et al, 2022). Strictly speaking, the classic percolation law can only be applied under the following two principles, where the percolation threshold is solely dependent on the conductive filler to use (Zallen, 1998):…”

Section: Electrical Propertiesmentioning

confidence: 99%

Effect of fibre loading on the microstructural, electrical, and mechanical properties of carbon fibre incorporated smart cement-based composites

et al. 2022

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Carbon fibre incorporated smart cement-based composite has great potential for the multifunctional health monitoring of concrete structures. This paper presents the microstructural, electrical, and mechanical properties of smart cement-based composites incorporating chopped carbon fibres from low dosages at 0–0.1% by volume (vol%) with detailed intervals, to high dosages up to 2.4 vol%. In comparison to a plain mortar, smart cement-based composites at all fibre contents had higher flexural strength. A 95% improvement in flexural strength was obtained at a fibre content of 0.3 vol%, whereas compressive strength increased up to a fibre content of 1.0 vol%, with the highest improvement, 105%, at 0.2 vol%. The bulk conductivity of smart cement-based composites underwent a double percolation process where the percolation zone of the fibres was identified at fibre contents of 0–0.1 vol% and the percolation zone of the capillary pores resided at fibre contents of 2.1–2.4 vol% indicating an extremely low durability. This study presents the laboratory characterization on smart cement-based composites where the fundamentals of the transitional behaviours of the mechanical properties and the percolation in electrical property through fibre loading were studied, which is a necessary step prior to the assessment of the self-sensing performance. The impact of this study will enable the physical properties of carbon fibre incorporated smart cement-based composites to be optimized through the design and manufacturing process. This will lead to robust performance and superior in-situ multi-functional health monitoring of concrete structures.

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Influence of additives on strength enhancement and greenhouse gas emissions of pre-cast lime-based construction products

O’Flaherty,

Khalaf,

Starinieri

2023

Low-carbon Mater. Green Constr.

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Strength properties of laboratory scale lime-based samples enhanced with additives such as nanomaterials (nanofibrillated cellulose, nanosilica, nanoclay, expanded graphite), hemp & glass fibres, hemp shiv and polyvinyl acetate (PVAc) are determined. Samples were cured for 26 days in air at 20˚C / 60% RH after casting before being oven dried for a further two days at 50˚C (28 days total). Results show that the nanomaterials on their own had a mixed effect on the strength although nSiO2 as a solo additive performed exceptionally well. The combination of fibres in conjunction with PVAc also greatly enhanced the strength due to increased bond between the fibres and the matrix. In addition, Greenhouse Gas emissions (GHG, kgCO2eq) of an arbitrary block was determined for all composites and compared to the GHG of a commonly used lightweight aerated concrete block. Comparison of the normalised compressive strengths to the different loading conditions as outlined in BS EN 8103 shows that a more widespread use of pre-cast lime composites is possible and without unduly increasing GHG emissions.

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Determination of percolation threshold in cement composites with expanded graphite by impedance spectroscopy

Cited by 27 publications

References 62 publications

Controlling the Formation of Electroactive Graphene‐Based Cementitious Composites: Towards Structural Health Monitoring of Civil Structures

Controlling the Formation of Electroactive Graphene‐Based Cementitious Composites: Towards Structural Health Monitoring of Civil Structures

Effect of fibre loading on the microstructural, electrical, and mechanical properties of carbon fibre incorporated smart cement-based composites

Influence of additives on strength enhancement and greenhouse gas emissions of pre-cast lime-based construction products

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