Cement-based controlled electrical resistivity materials

Abstract

Low-cost controlled electrical resistivity materials based on Portland cement and exhibiting low values of the relative dielectric constant have been attained. The materials are cement paste containing short electrically-conducting fibers. With steel fibers (0.1 vol.%), the resistivity and relative dielectric constant (10 kHz) are 8 ¥ 10 4 W◊cm and 20, respectively. With carbon fibers (1.0 vol.%) and silica fume, these quantities are 8 ¥ 10 2 W◊cm and 49, respectively.

Piezoresistive Cement-Based Materials for Strain Sensing

“…Steel fibers are even more conductive than carbon fibers. Short steel fibers are used in cement-based materials to enhance the tensile, flexural and shear properties (Chen and Chung, 1996c;Alavizadeh-Farhang and Silfwerbrand, 2000;Bayasi and Kaiser, 2001;Lotfy, 2001;Nataraja et al, 2001;Teutsch, 2001) and the abrasion resistance (Febrillet et al, 2000), decrease the drying shrinkage (Sun et al, 2001), increase the effectiveness for electromagnetic interference (EMI) shielding (Wen and Chung, 2002) and provide controlled electrical resistivity (Wen and Chung, 2001b). Moreover, stainless steel fibers of diameter 60 mm render piezoresistivity to a cement-based material, as shown under compression, though the phenomenon is noisy in that the resistivity does not vary smoothly with the strain (Chen and Chung, 1996b).…”

Electrically Conductive Dense and Porous Alumina with In‐Situ‐Synthesized Nanoscale Carbon Networks

“…Moreover, dense electrically conductive ceramics have found use as anti-static floor tiles in applications as diverse as call centers, server rooms, flight towers, and electronic manufacturing centers. [2] In contrast, porous electrically conductive ceramics have attracted much renewed interest for the development of high-performance radiative heaters. [3,4] Such porous materials also show great potential for applications in filters for the aeration of liquids, [5] ceramic foam heaters, and exhaust traps for automotive cold start applications, [3] as well as for the combustion of diesel soot and the non-catalytic oxidation of noxious gases.…”

Optimization of Graphene Nanoplatelets Dispersion and Its Performance in Cement Mortars

“…Nevertheless, these sensors and strain gages inherently have poor durability and stability in defective electrical conductivity and usually require expensive external facilities [ 4 , 5 ]. Recently, many researchers have reported that pressure-sensitive function can be achieved by adding conductive filler in cement-based materials, which provides an alternative to monitoring the health of concrete structures [ 6 , 7 ].…”