Effect of different size of joint enlargement on seismic behavior of gravity load designed RC beam‐column connections

Abstract

Summary Effect of different size of planer joint enlargement as a noninvasive and practical strategy for seismic retrofit of gravity load designed external reinforced concrete beam‐column connections was experimentally investigated. The joint region was enlarged using steel angles that are mounted using prestressed cross‐ties. Reverse cyclic load tests on five half‐scale control and retrofitted external RC beam‐column connections were conducted. Three different size of planer joint enlargement being 180, 140, and 90 mm were considered for retrofitted specimens. The performance of the retrofitted specimens is compared with that of the control gravity load designed beam‐column connections, in terms of load–displacement hysteresis curve, energy dissipation and ductility capacities, and global strength and stiffness degradation behavior. The experimental results showed that increasing the size of planer joint enlargement significantly enhances the seismic capacity of the retrofitted connections, in terms of strength, stiffness, energy dissipation, and ductility capacity and also planer joint enlargement can relocate beam plastic hinges to outside the joint panel.

Seismic Retrofitting of Nonseismically Detailed Exterior Reinforced Concrete Beam-Column Joint by Active Confinement Using Shape Memory Alloy Wires

“…Realizing the severity of the problem, researchers in the past few decades have developed several retrofitting techniques for BCJs, most common of them include joint enlargement by providing either haunches (Pampanin et al 2006;Shafaei et al 2016;Shafaei and Nezami 2019) or shape modification of the joint core (Chaimahawan and Pimanmas 2008;Pimanmas and Chaimahawan 2010;Tsonos 2010) by casting in-situ concrete or jacketing: either using fibre reinforced polymer (FRP) wraps (Ghobarah et al 1996;Seible et al 1997;Mosallam 2000;Antonopoulos and Triantafillou 2003;Corte et al 2005), steel plates (Chai et al 1991;Priestley et al 1994;Fardis 2009), ultra-high performance hybrid fibre reinforced concrete (UHP-HFRC) (Sharma and Bansal 2019), ferrocement (Li et al 2013) or textile-based reinforced mortars (Al-Salloum et al 2011). Most recently, a technique of providing prestressed diagonal reinforcement in the joint core panel alone (Suhail et al 2015(Suhail et al , 2021aYurdakul et al 2018) has also been investigated.…”

Shear Strength Model for Reinforced Concrete Corner Joints Based on Soft Computing Techniques

“…Beam-column joints made from reinforced concrete (RC) have attracted considerable attention in the last few decades [1][2][3][4][5][6][7][8][9][10] because of the di culty in predicting their behavior. Although extensive e ort has been put forward to studying various conventional RC joints, a reliable prediction method for the beam-column corner joints is rare.…”

Shear Strength Prediction Model for RC Exterior Joints Using Gene Expression Programming

“…The failures of reinforced concrete structures during earthquakes seem to mostly occur at the connections of main structural elements. This is due to the complexity of the forces generated during the cyclic loadings at the joints of the supporting members [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 ]. In this respect, the shear failure of the beam–column joints was noted as the principal cause of the collapse of RC frame buildings in recent earthquakes.…”