Cement-based materials that exhibit piezoresistivity with sufficient magnitude and reversibility contain electrically conductive fibers. The phenomenon allows the materials to sense their own strain. The fibers are preferably discontinuous. Carbon fibers (15 mm diameter) are most effective. Steel fibers (8 mm diameter) are less effective. Carbon filaments (0.1 mm diameter) are ineffective. The piezoresistive behavior, mechanism and materials are reviewed, including cement-based materials with continuous and discontinuous fibers.

Piezoresistive Cement-Based Materials for Strain Sensing

Damage detection of CFRP laminates using electrical resistance measurement and neural network

Smart concretes and structures are intelligent systems that have properties different from normal concrete, such as self-sensing and self-healing properties, or have the ability to react upon an ex

Smart concretes and structures: A review:

Self-sensing of flexural strain and damage in carbon fiber polymer-matrix composite by electrical resistance measurement

Damage in carbon fiber-reinforced concrete, monitored by both electrical resistance measurement and acoustic emission analysis

Carbon fiber glass fiber reinforced plastic (CFGFRP) is used in concrete structures as a reinforcement material. Appropriate materials design indicates that CFGFRP should be a hybrid of a conductive material with a small ultimate elongation value and an insulating material with a large ultimate elongation value. In the present study, we evaluated three types of carbon fiber tows used in CFGFRP composites. We observed a very clear and significant change in electrical resistance at the transition point where carbon fiber tows fractured, and found that this point could be easily controlled through the use of carbon fibers with different ultimate elongation values. The electrical resistance characteristics of CFGFRP-reinforced concrete change along with changing loads. Furthermore, a permanent residual electrical resistance could be observed after the removal of load, and its change was dependent on the maximum load applied. The information on the fracture position was obtained by the arrangement of the CFGFRP composites. Monitoring changes in electrical resistance during and after loading is thus a promising method for anticipating the fracture of CFGFRP-reinforced concrete.

https://iopscience.iop.org/article/10.1088/0964-1726/4/1A/007/pdf

N. Muto

Papers

Materials design for self-diagnosis of fracture in CFGFRP composite reinforcement