Dynamic sensing properties of a multifunctional cement composite with carbon black for traffic monitoring

The growing concern in monitoring civil infrastructures, combined with recent technological advances in sensing and information technology led to a concept known as 'smart infrastructures'. Recently, nanotechnology has been contributing with the development of innovative and multifunctional building materials. For example, cementitious composites with specific conductive composition allow the detection of mechanical stresses and may be used not only to build infrastructures but to monitor them as well. In this paper, a stress-sensitive cement composite integrating a conductive carbon black filler (CB) is investigated for traffic monitoring purposes, relying on piezoresistivity. The sensitivity of the composite was evaluated in specific specimens by performing traffic-like loading experiments, at temperatures between 15 C and 45 C. Experiments showed linear and reversible piezoresistive responses with average gauge factors registered between 40 and 50 and demonstrated that such composites may act as stress-sensitive materials for traffic monitoring, such as traffic flow, vehicular speed and weigh-in-motion measurements.