Identification of bond behavior between FRP/steel bars and self-compacting concrete using piezoceramic transducers based on wavelet energy analysis

Abstract

The civil infrastructures constructed using self-compacting concrete (SCC) reinforced with fiber-reinforced polymer (FRP) bars are advocated for engineering applications due to corrosion resistance and environmental-friendly performance. The bond behavior between FRP reinforcement and SCC is a significant factor affecting the serviceability and failure mechanism of this composite structure. However, it is hard to identify the damage mechanism and failure mode of the interface bond using the traditional test methods. Therefore, an effective monitoring method of interface damage using piezoceramic transducers is proposed in this paper. A series of pull-out tests were performed, and the test variables involved concrete materials and reinforcing bar types. A lead zirconate titanate (PZT) patch transducer acting as an actuator was bonded on the outer surface of reinforcing bars, and a piezoceramic smart aggregate transducer acting as a sensor was embedded in the SCC. A wavelet energy ratio index (WERI) is proposed to identify the damage mechanism of interface between reinforcing bars and SCC. The experimental test results reveal that the damage mechanism and failure mode of the bond between different reinforcing bars and concrete materials can be identified effectively and the peak of bond stress can be captured accurately by using WERI values.

Experimental and theoretical study of bond behaviour between FRP bar and high-volume fly ash-self-compacting concrete

“…Also, the test results are used to discuss the influence of those parameters on the bond strength, failure mechanism and bond-slip relationship of FRP reinforced HVFA-SCC specimens. The results of interface damage can be verified by the test results of piezoelectric ceramic sensors given in Reference [22]. Considering the influence of filling performance of HVFA-SCC on bond properties, the theoretical models of bond strength and development length of GFRP reinforced HVFA-SCC are proposed.…”

“…3c. The piezoelectric signals were recorded synchronously in the pull-out test and the piezoelectric test results had been discussed in detail in Reference [22]. In this paper, the piezoelectric test results are used to verify the results of interface damage.…”

“…As reported in the literature [22], an active sensing technology using a pair of Smart Aggregates (SA) is adopted to identify the failure mechanism of steel/FRP reinforced concrete in pull-out process. It is found that the failure of steel reinforced HVFA-SCC specimen depends on the mechanical interlocking damage, and the failure of FRP reinforced HVFA-SCC is mainly the chemical adhesion and friction damage.…”

Detecting of the Crack and Leakage in the Joint of Precast Concrete Segmental Bridge Using Piezoceramic Based Smart Aggregate

“…The WPEI defined by Equations (1)–(3) has been applied to signal processing in SHM of various structures, such as concrete structures [ 64 , 65 ], steel structures [ 66 , 67 ], composite structures [ 68 , 69 ] among others [ 70 , 71 ]. The received energy by SA can be calculated with WPEI in this experiment.…”

Mechanical properties and environmental performance of seawater sea-sand self-compacting Concrete

“…Sea-sand generally contains a small content of shell fragments, but they are relatively pure calcium. High content of chloride ions in these materials will corrode rebar, but this difficulty can be completely avoided by adopting fiber reinforced polymer (FRP) and, where necessary, stainless steel (Liu et al, 2020; Zhou et al, 2020). Fly ash is an industrial by-product.…”