Smart Cement Behavior with Aggregates, Silicate, Clay, Carbon Dioxide and Real-Time Monitoring Characterized Using Vipulanandan Models

Chemo-thermo-piezoresistive smart cement is a highly sensing binder that was recently developed to be used in multiple infrastructure applications in new constructions and also integrated into in-service infrastructures for real-time monitoring. In this study, the effects of up to 75% aggregates (representing concrete), 0.3% silicate, 5% clay (inorganic contamination) and 3% carbon dioxide (CO2) on the curing and compressive piezoresistive behavior of the smart cement with less and 0.1% well dispersed carbon fibers was investigated. Also, the effect of temperature on the smart cement with silicate additive was investigated. A new material characterization method has been developed and was used to identify the critical electrical property of the smart cement with aggregates and other additives and the electrical resistivity was identified as the critical property to monitor. Hence a two-probe method was developed to monitor the resistivity changes in the cement. The piezoresistive axial strain at peak stress for the concrete with smart cement was over hundred percent which is 336 times (33,600%) higher compared to the concrete failure strain of 0.3%. The effects of silicate, clay and carbon dioxide on the initial resistivity (quality of mixing), temperature and compressive piezoresistivity have been quantified using Vipulanandan Models. It is important to monitor the real material property changes in the field and not just the temperature which is not a material property. A new approach has been developed to wirelessly transfer the two probes monitoring of the changes in resistivity of smart cement, smart concrete, regular cement and concrete to the phone and computers.