Electrical percolation threshold of cementitious composites possessing self-sensing functionality incorporating different carbon-based materials

Abstract

An experimental study was carried out to understand the electrical percolation thresholds of different carbon-based nano-and micro-scale materials in cementitious composites. Multi-walled carbon nanotubes (CNTs), graphene nanoplatelets (GNPs) and carbon black (CB) were selected as the nano-scale materials, while 6 and 12 mm long carbon fibers (CF6 and CF12) were used as the micro-scale carbon-based materials. After determining the percolation thresholds of different electrical conductive materials, mechanical properties and piezoresistive properties of specimens produced with the abovementioned conductive materials at percolation threshold were investigated under uniaxial compressive loading. Results demonstrate that regardless of initial curing age, the percolation thresholds of CNT, GNP, CB and CFs in ECC mortar specimens were around 0.55%, 2.00%, 2.00% and 1.00%, respectively. Including different carbon-based conductive materials did not harm compressive strength results; on the contrary, it improved overall values. All cementitious composites produced with carbon-based materials, with the exception of the control mixtures, exhibited piezoresistive behavior under compression, which is crucial for sensing capability. It is believed that incorporating the sensing attribute into cementitious composites will enhance benefits for sustainable civil infrastructures.

Mechanical and Self-Sensing Properties of Multiwalled Carbon Nanotube-Reinforced ECCs

“…Engineered cementitious composites (ECCs) are fiberreinforced cementitious composites with excellent tensile ductility and good durability under harsh environment [11][12][13][14][15][16][17][18][19]. e research found that incorporating conductive filler into ECCs could make it self-sensing [18][19][20][21][22][23]. Lin et al found that adding a small dosage of carbon black (CB) into the ECC system could enhance matrix tensile strength and achieve selfsensing ability [20].…”

“…Lin et al found that adding a small dosage of carbon black (CB) into the ECC system could enhance matrix tensile strength and achieve selfsensing ability [20]. Al-Dahawi et al [21] found the percolation threshold of multiwalled carbon nanotubes, graphene nanoplatelets, carbon black, and carbon fiber in ECCs was around 0.55%, 2.00%, 2.00%, and 1.00%, respectively. ese carbonbased materials improved compressive strength and selfsensing ability under both compressive and flexural tests [22].…”

Electromechanical Response of High-Performance Fiber-Reinforced Cementitious Composites Containing Milled Glass Fibers under Tension

“…Furthermore, cement-based composites containing short carbon fibers have produced much higher gauge factors (up to 700) under compressive, tensile, and flexural loads [ 25 ]. Cement-based composites containing nanomaterials, e.g., carbon nanotubes and carbon nanofibers, have also demonstrated a high self-strain or -damage sensing capacity [ 4 , 14 , 15 , 19 , 20 , 21 , 22 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ], even though achieving a uniform distribution of nanomaterials within cement-based composites remains quite challenging [ 33 ]. The distribution of nanomaterials could be enhanced by using surfactants, sonicators, and/or mechanical mixing procedures [ 10 , 12 , 15 , 22 , 27 , 30 , 34 , 35 , 36 ].…”

Effect of curing age on the self-sensing behavior of carbon-based engineered cementitious composites (ECC) under monotonic flexural loading scenario

“…Water to cementitious materials (PC + FA) ratio (W/CM) and fly ash to Portland cement ratio (FA/PC) were kept constants as 0.27 and 1.2, respectively during the preparation of mixtures. The dosage of CF as it was reported by Al-Dahawi et al [10]. This dosage was 1.00% by volume of mixture.…”