Experimental Cyclic Behavior of Precast Hybrid Beam-Column Connections with Welded Components

Abstract

Post-earthquake observations revealed that seismic performance of beam-column connections in precast concrete structures affect the overall response extensively. Seismic design of precast reinforced concrete structures requires improved beamcolumn connections to transfer reversed load effects between structural elements. In Turkey, hybrid beam-column connections with welded components have been applied extensively in precast concrete industry for decades. Beam bottom longitudinal rebars are welded to beam end plates while top longitudinal rebars are placed to designated gaps in joint panels before casting of topping concrete in this type of connections. The paper presents the major findings of an experimental test programme including one monolithic and five precast hybrid half scale specimens representing interior beam-column connections of a moment frame of high ductility level. The required welding area between beam bottom longitudinal rebars and beam-end plates were calculated based on welding coefficients considered as a test parameter. It is observed that the maximum strain developed in the beam bottom flexural reinforcement plays an important role in the overall behavior of the connections. Two additional specimens which include unbonded lengths on the longitudinal rebars to reduce that strain demands were also tested. Strength, stiffness and energy dissipation characteristics of test specimens were investigated with respect to test variables. Seismic performances of test specimens were evaluated by obtaining damage indices.

Seismic performance evaluation of a precast concrete structure with deformation-based limit criterions

“…In the draft version of TBEC [24], nonlinear analysis procedures were considered in deformation-based design of precast concrete structures. Performance limits for moment-resisting precast beam-column connections were determined according to ASCE/SEI 41 [5] considering experimental observations on MAB3 specimens tested by Girgin et al [6]. Performance limit states, and the corresponding drift ratios for precast connection tests are summarized in Table 2.…”

“…Damage pattern and lateral cyclic response of a precast beam-column connection is shown in Fig. Lateral load-drift ratio response for SP3-R specimen [6] Performance-based seismic evaluation of structures has gained attention for two decades to estimate the seismic risk in a realistic manner. Magliulo et al [7] performed nonlinear static and dynamic analyses on existing precast concrete structures considering all seismic components.…”

Behavior of Precast Reinforced Concrete Beam-Column External Connections Under Cyclic Loading

“…The results proved that the industrial type and residential type joint connections could be classified as low and medium ductility type connections, respectively. Similarly, Girgin et al [22] presented a similar beam-column connection using steel plates, which were welded to the lower beam reinforcement. The results showed that while increasing the embedded upper reinforcement of beam, the relative energy dissipation ratio was raised.…”

A Review of Seismic Response of Precast Structures

“…new connection for precast concrete frames (reprinted from[55], Copyright Elsevier, 2013) Girgin et al[56] investigated the seismic performance of hybrid beam-to-column connections that employed welded components. As can be seen fromFig.…”

“…hybrid beam-to-column connection (reprinted from[56], Copyright Girgin, Sadik Can, Misir, Ibrahim Serkan, Kahraman, Serap, 2017)…”