Investigation of interface response of reinforced concrete columns retrofitted with composites

Interfacial stresses in reinforced concrete cantilever members strengthened with fibre-reinforced polymer laminates

“…Many studies on FRP-strengthened flexural members have demonstrated that both their strength and stiffness increase significantly after strengthening. However, the strengthening effectiveness and mechanical behaviour of the strengthened beam or slab are greatly affected by the interfacial bond performance (Achillopoulou et al, 2016; Gao et al, 2007; Kim et al, 2015; Sayin and Manisali, 2010; Tounsi and Benyoucef, 2007; Xie et al, 2017). When the interfacial principal stress exceeds the bond strength of the FRP/concrete interface, premature brittle debonding failure may occur unless reliable additional anchoring measures (Oller et al, 2011; Smith and Teng, 2002; Teng and Chen, 2008; Zhou et al, 2017a, 2017b) are provided.…”

Experimental Investigation on Interfacial Defect Criticality of FRP-Confined Concrete Columns

“…However, most of the studies focus on the FRP bonded flexural members, and few results on the defect criticality of FRP confined concrete columns are reported [21,22,23,24]. Notably, defects in FRP bonded concrete beams can propagate rapidly into a plate end interfacial debonding and intermediate flexural crack induced interfacial debonding, which results in global failure of the structure, while defects in FRP confined columns can influence the confinement effectiveness of FRP and result in weakening of confined structures [25,26,27]. Due to defects in FRP confined concrete column, the shear stress cannot transfer effectively from FRP to concrete at localized defect region, and confinement effectiveness can be affected by stress redistribution [25].…”