Characterization of smart brass fiber reinforced concrete under various loading conditions

Abstract

Self-sensing smart cementitious materials can enable development of load carrying structural systems with an intrinsic condition monitoring system. This paper discusses extensive experimental tests conducted on the brass fiber reinforced concrete composites that incorporates coarse aggregates. First, compressive and split tensile tests were conducted to assess strain sensitivity of the developed smart concrete. In addition, notch bending tests were performed to evaluate ability of the developed concrete in crack or damage sensing. Furthermore, the influence of different parameters such as loading rate, cyclic loading, electrode type, current type, and specimen age on the compressive strain sensitivity of smart concrete was assessed. The governing mechanisms for the self-sensing during the split tensile test and notched bending tests were described. Results indicate that the developed smart concrete with low-cost brass fibers exhibits high compressive strain sensitivity both under monotonic and cyclic loading conditions. The gage factor under compressive loading ranged from 20 to 54 at different loading rates. In addition, a gage factor of 3 was observed under tensile loading. Smart concrete also revealed a very strong correlation between the crack length and change in the electrical resistivity during notched bending tests. These findings suggest that the developed smart concrete can be used as a loading bearing multifunctional material that can sense its own damage and strain.