Design and characterization of self-sensing steel fiber reinforced concrete

The purpose of this communication is to develop a self-sensing cement composite capable of detecting stress variation in concrete by monitoring its electrical property. The relationship between the electrical properties, i.e. electrical resistance of steel fiber reinforced concrete, and stress under loading as part of self-sensing study is presented in here. Amorphous metallic fibers (AMF) with two different lengths i.e. 10 mm and 30 mm are used as concrete reinforcement at a content of 40 kg/m(3). A water to cement ratio of 0.39 was adopted for the mix proportions. Natural fine and coarse siliceous aggregates were used for this research. Superplasticizer was used to achieve the target of workability. The two-probe method is used for measuring electrical properties on cylinder specimens with diameter 100 mm and height 200 mm. The influence of different parameters such as fiber length, frequency of power input, maximum stress and variation of potential input on the sensitivity of the sensing are investigated. The results indicate that the electrical resistance of the concrete decreases reversibly during loading and increases reversibly during unloading. Good sensitivity obtained for the mix using 30 mm AMF length indicates that the addition of this type of fiber into concrete can be suitable to produce a self-sensing cement composite.