Research On The Piezoresistivity Of Composites Containing Nano-sized Carbon Black And Its Appilication

A thin film of carbon black reinforced epoxy-matrix composite attached to a steelbar is used to sense its strain. Results under tension show that the fractional change inelectrical resistance of the composite varies monotonically with bar strain. In the elasticregime, the fractional change in resistance increases linearly upon loading and decreaseslinearly upon unloading. When the bar yielding, the fractional change in resistanceincreases sharply with strain. A mathematical relation between the fractional change inresistance and strain is derived.Compared with normal cement composites, cement-matrix composites containingnano-sized carbon black/silica fume have superior compressive strength, flexural strengthand impact strength, and most important pressure-sensitive behaviour. Presently, both themechanical properties and piezoresistivity were studied through experiments, andmechanism is discussed.Base on the above two parts, the electromechanical behaviour of a frame joint wasstudied, and the curve between loads, resistance and strain obtained.