Concrete-encased composite structure is a type of structure that takes the advantages of both steel and concrete materials, showing improved strength, ductility, and fire resistance compared to traditional reinforced concrete structures. The interface between concrete and steel profiles governs the interaction between these two materials under loading, however, debonding damage between these two materials may lead to severe degradation of the load transferring capacity which will affect the structural performance significantly. In this paper, the electro-mechanical impedance (EMI) technique using piezoceramic transducers was experimentally investigated to detect the bond-slip occurrence of the concrete-encased composite structure. The root-mean-square deviation is used to quantify the variations of the impedance signatures due to the presence of the bond-slip damage. In order to verify the validity of the proposed method, finite element model analysis was performed to simulate the behavior of concrete-steel debonding based on a 3D finite element concrete-steel bond model. The computed impedance signatures from the numerical results are compared with the results obtained from the experimental study, and both the numerical and experimental studies verify the proposed EMI method to detect bond slip of a concrete-encased composite structure.

https://iopscience.iop.org/article/10.1088/0964-1726/25/9/095003/pdf

Bond-slip detection of concrete-encased composite structure using electro-mechanical impedance technique

Concrete-encased composite structure exhibits improved strength, ductility and fire resistance compared to traditional reinforced concrete, by incorporating the advantages of both steel and concrete materials. A major drawback of this type of structure is the bond slip introduced between steel and concrete, which directly reduces the load capacity of the structure. In this paper, an active sensing approach using shear waves to provide monitoring and early warning of the development of bond slip in the concrete-encased composite structure is proposed. A specimen of concrete-encased composite structure was investigated. In this active sensing approach, shear mode smart aggregates (SAs) embedded in the concrete act as actuators and generate desired shear stress waves. Distributed piezoceramic transducers installed in the cavities of steel plates act as sensors and detect the wave response from shear mode SAs. Bond slip acts as a form of stress relief and attenuates the wave propagation energy. Experimental results from the time domain analysis clearly indicate that the amplitudes of received signal by lead zirconate titanate sensors decreased when bond slip occurred. In addition, a wavelet packet-based analysis was developed to compute the received signal energy values, which can be used to determine the initiation and development of bond slip in concrete-encased composite structure. In order to establish the validity of the proposed method, a 3D finite element analysis of the concrete–steel bond model is further performed with the aid of the commercial finite element package, Abaqus, and the numerical results are compared with the results obtained in experimental study.

https://iopscience.iop.org/article/10.1088/0964-1726/24/12/125026/pdf

Bond slip detection of concrete-encased composite structure using shear wave based active sensing approach

The evolution of composite flooring systems: applications, testing, modelling and eurocode design approaches

New composite beams having cold-formed steel joists and concrete slab

Experimental study on perfobond strip connector in steel–concrete joints of hybrid bridges

https://scholarsmine.mst.edu/cgi/viewcontent.cgi?article=1973&context=isccss

Finite element analysis of new composite floors having cold-formed steel and concrete slab

Local bond–slip behavior between cold-formed metal and concrete

/pdf/behavior-of-composite-beams-with-cold-formed-steel-joists-4bql2shrmj.pdf

Yazdan Majdi

Papers

New composite beams having cold-formed steel joists and concrete slab

Finite element analysis of new composite floors having cold-formed steel and concrete slab

Local bond–slip behavior between cold-formed metal and concrete

Behavior of Composite Beams with Cold-formed Steel Joists and Concrete Slab

Underpinning Historic Structures at Grand Central Station, New York