Ultra-High-Performance Fiber-Reinforced Concrete Jacket for the Repair and the Seismic Retrofitting of Italian and Chinese Rc Bridges

Lavorato, Davide; Bergami, Alessandro Vittorio; Nuti, Camillo; Briseghella, Bruno; Xue, Junqing; Tarantino, Angelo Marcello; Marano, Giuseppe Carlo; Santini, Silvia

doi:10.7712/120117.5556.18147

Cited by 21 publications

(14 citation statements)

References 14 publications

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“…Once the structure of a continuous girder bridge is damaged under a strong earthquake, the pier, as a ductile member, is most likely to be damaged. Therefore, it is usually necessary to strengthen the pier column after the earthquake [4][5][6][7][8]. When the pier damage is serious, it will also cause the structure collapse and cannot wait for the pier column reinforcement.…”

Section: Introductionmentioning

confidence: 99%

Research on Longitudinal Collapse Mode and Control of the Continuous Bridge under Strong Seismic Excitations

Zong

Yang

et al. 2020

Applied Sciences

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Bridge collapse events are common in major earthquakes around the world, among which continuous girder bridges are the most involved. In order to explore the collapse mechanism of a continuous girder bridge in an earthquake, the collapse mode of a two-span continuous girder bridge specimen which had been studied by the shaking table test was analyzed. Then, on the basis of the conventional plate rubber bearing system, the collapse control strategies which were high damping rubber bearing, fluid viscous damper, lock-up clutch control methods were discussed. It is found that high damping rubber bearing can delay the collapse time but the collapse mode remains the same; lock-up clutch has the best displacement control effect for the superstructure, but its energy consumption performance is not as good as that of a fluid viscous damper; high damping rubber bearing is quite suitable for protecting the substructure under short-period ground motion to avoid the bridge collapse caused by the failure of piers; fluid viscous damper and lock-up clutch are suitable for protecting the superstructure under long ground seismic motion to avoid the bridge non-use resulted from girder lowering; three collapse control methods can improve the anti-collapse ability of the bridge specimen, although no matter which control method is used, the bridge specimen may still collapse under strong earthquakes, but the target of postponing collapse time can be realized by means of various effective control methods.

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Section: Introductionmentioning

confidence: 99%

Research on Longitudinal Collapse Mode and Control of the Continuous Bridge under Strong Seismic Excitations

Zong

Yang

et al. 2020

Applied Sciences

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“…In seismic regions such as Italy, the evaluation of the capacity and fragility of structural and infrastructural systems subjected to seismic events [1][2][3][4][5][6][7][8][9], and implementing proper survey programs to monitor the evolution of their capabilities [10,11] are important for preventing severe seismic damage being observed in recent seismic events [12] by means of retrofitting interventions [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31].…”

Section: Introductionmentioning

confidence: 99%

“…This resulting solution was effective, but the column core was entirely removed to ensure adequate proper work space, and the use of steel segment rebar with the same size and mechanical characteristics of the existing rebar may not guarantee plasticization in the plastic hinge only-away from the original anchorages of the rebar-because the strength of the new steel segments may be statistically higher than that of the original rebar. Lavorato and colleagues [24,31] simplified Cheng et al's dog-bone solution and locally substituted the rebar with turned rebar segments connected by a butt head and lateral welding chords along a steel coupler. This strong connection system ensured plastic dissipation in the plastic hinge region only and the protection of the existing rebar (anchorages and existing undamaged rebar part outside the plastic hinge).…”

Section: Introductionmentioning

confidence: 99%

“…(2) the cleaning of the residual concrete from the rebar surface; (3) shaping the surface of the concrete core to improve the interlock between existing and new concrete parts; (4) substitution of the damaged longitudinal rebar parts with new shaped rebar segments, tested successfully by Lavorato et al [31]; and (5) constructing a concrete jacket by means of high-performance fiber reinforced concrete (HPFRC) with steel or polymer fibers to restore the removed concrete parts and to ensure seismic retrofitting (column shear strength and ductility improvements).…”

Section: Introductionmentioning

confidence: 99%

“…The rebar substitution was performed as outlined by Lavorato and colleagues [24,31], and because this process is simple, it is effective, rapid, and adaptable to each specific intervention, allowing cost savings.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Severely Damaged Reinforced Concrete Circular Columns Repaired by Turned Steel Rebar and High-Performance Concrete Jacketing with Steel or Polymer Fibers

et al. 2018

Self Cite

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A new strategy that repairs severely damaged reinforced concrete (RC) columns after an earthquake is proposed as a simpler and quicker solution with respect to the strategies currently available in the literature. The external concrete parts are removed from the column surface along the whole plastic hinge region to uncover the steel reinforcement. The transverse steel is cut away, and each longitudinal rebar is locally substituted by steel rebar segments connected by welding connections to the original undamaged rebar pieces outside the intervention zone. The new rebar segments have a reduced diameter achieved by turning to ensure plastic deformation only in the plastic hinge, protecting the original rebar and the welding connections. The connection is specifically designed to be effective and simple, and is directly realized on column reinforcement. Finally, the removed concrete is restored by a jacket built with high-performance concrete with steel or polymer fibers. The use of concrete with high volume fraction of polymer fibers to repair the column is investigated for the first time in this paper. This concrete was characterized by compression and flexural tests in the laboratory and its mechanical characteristics were compared with those of the concrete with steel fibers, which are being increasingly used in construction. The repair strategy was applied to two RC columns (1:6 scaled bridge piers), tested by asymmetric cyclic tests. The results show that the column strength, stiffness, and ductility were restored, and the energy dissipation capacity improved. The experimental evidence was investigated by fiber models in OpenSees.

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Mechanical properties and constitutive model of the buckling restraint rebar under compression loads

Jia

Zhao

Bai

et al. 2023

Structural Concrete

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Buckling of the longitudinal rebar is one of the main forms of plastic hinge failure in reinforced concrete (RC) columns after an earthquake. This rebar buckling significantly impacts the seismic bearing capacity and energy dissipation capacity. To restrain the development of longitudinal rebar buckling behavior and delay the degradation of lateral strength in RC columns, this paper developed a new type of buckling restraint rebar (BRR) consisting of three components: longitudinal rebar, a restraint sleeve, and foam material. First, the BRR mechanical properties under compression and tension‐compression cyclic loading were obtained through quasi‐static loading tests. Then, the BRR compression and tension‐compression cyclic loading processes were numerically simulated based on ABAQUS finite element software. The simulated results were compared with the test results. Finally, a stress–strain constitutive model for this new BRR was proposed based on this study. Results showed that the restraint sleeve could significantly enhance the lateral stiffness and the bearing capacity of longitudinal reinforcement after yielding. The compressive performance of BRR was mainly affected by the length and wall thickness of the sleeve. The cyclic performance was mainly affected by the length of the sleeve and the clearance between the sleeve and the reinforcement. The BRR constitutive model proposed in this paper can accurately reflect the influence of restraint sleeves on the stiffness of longitudinal reinforcement after yielding.

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Ultra-High-Performance Fiber-Reinforced Concrete Jacket for the Repair and the Seismic Retrofitting of Italian and Chinese Rc Bridges

Abstract: Abstract. The seismic behavior of Chinese RC (Reinforced Concrete)

Cited by 21 publications

References 14 publications

Research on Longitudinal Collapse Mode and Control of the Continuous Bridge under Strong Seismic Excitations

Research on Longitudinal Collapse Mode and Control of the Continuous Bridge under Strong Seismic Excitations

Severely Damaged Reinforced Concrete Circular Columns Repaired by Turned Steel Rebar and High-Performance Concrete Jacketing with Steel or Polymer Fibers

Mechanical properties and constitutive model of the buckling restraint rebar under compression loads

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