Resistance Changes during Compression of Carbon Fiber Cement Composites

Abstract

The incorporation of a small volume of carbon fibers into a concrete mixture produces a strong and durable concrete and at the same time lends the product a smart material property. This intrinsic capability can be tapped by using simple electrical resistance techniques. There is the potential for these techniques to be used as nondestructive testing methods to assess the integrity of the composite. The results of some fundamental investigations on the bulk electrical properties of carbon fiber cement composites under compressive loading are presented. Well-defined patterns are exhibited in the electrical resistance behavior which can be correlated with the stress-strain behavior. The resistance behavior was evaluated for various fiber volume contents for both mature and early-age specimens. The response under cyclic compressive loading was studied. The effect of taking measurements both parallel and perpendicular to the axis of loading was also investigated.