Reinforced concrete columns strengthened with angles and battens subjected to eccentric load

Numerical Investigation on Load-carrying Capacity of High-strength Concrete-encased Steel Angle Columns

“…Thus, unlike the existing models (Calderon et al 2009;Montuori and Piluso 2009;Nagaprasad et al 2009;Badalamenti et al 2010), in which the full leg b s of steel angles was assumed to exert the confining pressure in whole analysis steps, the proposed model assumed that only the effective leg b s;eff exerts the confining pressure after local buckling of steel angles (Fig. 6).…”

“…It is noted that when battens are used for transverse reinforcement, the center-to-center spacing s t can be substituted by an effective spacing in the calculation of k 2 (Montuori and Piluso 2009;Nagaprasad et al 2009). Thus, the clear spacing s c ¼ s t À h t (h t = height of a batten) was used as the effective spacing.…”

“…(2) Steel angles provide good confinement to concrete core (Calderon et al 2009;Montuori and Piluso 2009;Nagaprasad et al 2009;Badalamenti et al 2010;Kim et al 2014Kim et al , 2017Eom et al 2014;Hwang et al 2015Hwang et al , 2016, but the effect of local buckling on the confinement should be also considered. Thus, unlike the existing models (Calderon et al 2009;Montuori and Piluso 2009;Nagaprasad et al 2009;Badalamenti et al 2010), in which the full leg b s of steel angles was assumed to exert the confining pressure in whole analysis steps, the proposed model assumed that only the effective leg b s;eff exerts the confining pressure after local buckling of steel angles (Fig.…”

“…Since the distribution of confining pressure in CES-A sections is similar to that of rectangular tied RC sections, existing concrete confinement models can be used, regarding steel angles and transverse reinforcement as longitudinal bars and transverse bars, respectively (Montuori and Piluso 2009;Nagaprasad et al 2009). In the present study, the compressive stress-strain relationship of concrete was characterized by the confinement model of Saatcioglu and Razvi (Saatcioglu and Razvi 1992;Razvi and Saatcioglu 1999) (Fig.…”

“…Structural steel angles for columns have been widely studied and used in various ways: (1) to externally strengthen existing RC columns with batten plates (i.e., steel jacketing for reconstruction or seismic retrofitting) (Critek 2001;Zheng and Ji 2008a, b;Montuori and Piluso 2009;Nagaprasad et al 2009;Calderon et al 2009;Badalamenti et al 2010;Garzon-Roca et al 2011a, b, 2012Campione 2012a, b;Khalifa and Al-Tersawy 2014;Tarabia and Albakry 2014;Cavaleri et al 2016); (2) to replace wideflange members with the built-up members connected by battens (Hashemi and Jafari 2004); (3) to reduce laborious fieldwork of composite columns by prefabrication (Kim et al 2011;Eom et al 2014;Hwang et al 2015Hwang et al , 2016; and/ or (4) to improve structural capacity and cost efficiency of composite columns by maximizing the contribution of highstrength steel (Kim et al , 2017. According to the primary purpose, steel angles could be either encased in concrete or exposed, and could transmit column loads or not (providing confinement only).…”