Bond slip monitoring between steel and concrete using multi modal piezoelectric sensor an experimental and deep learning approach

Abstract

The inspection of the structural integrity of reinforced concrete structures is crucial due to wide urbanization and growth in infrastructure systems from the last few decades to ensure the safety and serviceability of infrastructure. The interfacial bond behavior between steel and concrete governs load transmission, structural stability of civil infrastructure, and overall building performance. A weaker bond can lead to defects in the structure due to various forces such as tension, compression, and shear, posing safety issues and raising maintenance expenses. The zone of contact and mechanical interaction between aggregates and cement paste is influenced by aggregate size, shape, and texture, grade of cement, workability etc. Traditional bond strength prediction approaches frequently depend on empirical formulae and analytical formulations, and code based recommendation, which restrict the representation of complicated interactions between different material properties and onset of bond degradation properties Piezo impedance based structural health monitoring (SHM) has gained much popularity as compared to other methods for adequately assessing and continuously monitoring bond strength in real time due to its high sensitivity, durability, and non-invasiveness. The conventional method of incorporating piezoelectric sensors into these applications has mainly employed direct bonded piezo configurations i.e., surface-bonded piezo configurations are frequently used, but they have several disadvantages, such as low electromechanical performance in the case of complex systems and vulnerability to temperature and mechanical stress. Moreover, the ribbed surface of RC bar generate complex stress distributions leads to poor signal attenuation. newlineThis study explores the interfacial bond strength monitoring of using piezoelectric sensors for the electro mechanical impedance technique. Firstly, it addresses the problems associated with the surface attachment of piezoelectric (PZT) sensors at the concrete-steel transition zone.