In-situ wireless monitoring of fiber reinforced cementitious composite bridge piers

High-performance fiber reinforced cementitious composites (HPFRCC) are a cement-based material in which a relatively low volume fraction of short fibers (steel, polymeric or carbon) are included in a cement matrix to produce a material that strain hardens under tension. Exhibiting high damage tolerance and tensile strain capacity on the order of 1 to 3%, HPFRCC materials can be used to reduce transverse steel reinforcement and associated reinforcement bar congestion in shear-dominated structural components designed for seismic loadings. To monitor the long-term performance of critical structural components within civil structures, low-cost monitoring technologies are necessary. In this study, a wireless structural monitoring system is proposed for in-situ monitoring of HPFRCC structural components subjected to reversed cyclic loading. A low-cost wireless sensing unit designed to collect data with high precision is adopted to monitor the response of an HPFRCC bridge pier column instrumented with a dense array of linear voltage displacement transducers (LVDTs), strain gages and accelerometers. The wireless sensing unit platform is shown to be capable of recording the response of a structural system with accuracies comparable to those of a laboratory data acquisition system employing traditional coaxial cables.