Cyclic behaviors of reinforced concrete beam-column joints with debonded reinforcements and beam failure: experiment and
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Cyclic behaviors of reinforced concrete beam‑column joints with debonded reinforcements and beam failure: experiment and analysis J. H. Wang1 Received: 23 April 2020 / Accepted: 2 October 2020 © Springer Nature B.V. 2020
Abstract It was experimentally validated that partially debonded high-strength longitudinal reinforcement can provide strong self-centering capacity to minimize residual deformation, and greatly mitigate seismic damage of column. To continuously investigate the influence of partially debonded longitudinal rebars (PDLR) of column and beam on seismic behaviors of beam-column joint assembly, three interior and three exterior joint specimens were fabricated to subject to cyclic lateral loading. It was showed experimentally that joint specimens with PDLRs in both beams and columns had slighter seismic damages, smaller stiffness and energy dissipating ratios, better ductility compared with joint specimens without PDLRs in the beams. Furthermore, the lateral load of joint specimens without PDLRs in the beams decreased from lateral drift of about 4.0%–5.0% due to much crushing and spalling of concrete in the compressive zones of the beams. Whereas, joint specimens with PDLRs in the beams had continuously increased lateral load until lateral drift up of 10.0%. An analytical approach was derived to evaluate the lateral behavior of beam-column joint assembly which can considering joint deformation and steel bond slip. The proposed approach can reasonably predict the lateral behaviors of joint specimens with or without PDLRs. Analytical results indicate that approximately 70% of total deformation of joint specimens with PDLRs in both beams and columns is contributed by slippage deformation of the beams, whereas, that contribution ratio of the other joint assembly specimens is only 30%. Keywords Cyclic behaviors · Residual deformation · Analysis · Beam-column joint · Partially debonded longitudinal rebar List of symbols Ast Total area of tensile steel rebar Asc Total area of compressive steel rebar Asi Total area of longitudinal reinforcement layer i * J. H. Wang [email protected] 1
Guangdong Provincial Key Laboratory of Durability for Marine Civil Engineering, College of Civil and Transportation Engineering, Shenzhen University, Shenzhen 518000, Guangdong Province, China
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Vol.:(0123456789)
Bulletin of Earthquake Engineering
BI Beam reinforcement index (= ρb × fyb)/fc) B1, B2 Resultant carried by compressive concrete of beam section b Width of cross-section bj Effective width of joint bb Width of beam section bc Width of column section C1, C2 Resultant carried by compressive concrete of column section db Diameter of reinforcing bar Es Young’s modulus of steel Esi Young’s modulus of longitudinal reinforcement layer i e Eccentricity En Dissipated energy at each lateral loading cycle fc Measured concrete compression strength of cylinder according to material test fy Yield stress of steel fyb Yield stress of beam reinforcement fyj Yield stress of joint transverse reinforcement
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