Seismic Performance of Hybrid SMA/Steel Reinforced Hollow Section Concrete Bridge Piers

2021 ◽  
Author(s):  
Tadesse Gemeda Wakjira ◽  
M. Shahria Alam ◽  
Usama Ebead
Keyword(s):  
Plastic Hinge ◽  
Residual Deformation ◽  
Steel Reinforcement ◽  
Bridge Piers ◽  
Partial Replacement ◽  
Concrete Bridge ◽  
Hollow Section ◽  
Conventional Steel ◽  
Damage States ◽  
Hinge Zone

Abstract Concrete bridge piers reinforced with conventional steel bars experience large permanent (residual) deformation that may lead to uneconomical repair or demotion of bridges due to their non-functionality post strong seismic event. Thus, sufficiently ductile materials are required to reinforce concrete bridge piers in the plastic hinge zone in order to limit their permanent damage and deformation post-earthquake event. Previous studies showed that partial replacement of conventional steel reinforcement bars with superelastic shape memory alloy (SMA) bars in the plastic hinge zone of concrete bridge piers has the capacity to limit the residual deformation owing to the superior self-centering properties of SMA bars. In this study, the efficacy of hybrid SMA/steel reinforcement for hollow section concrete bridge piers under combined reverse cyclic and constant axial loading is numerically investigated for the first time. The responses of the piers were evaluated in terms of different performance indices including hysteretic characteristics, residual deformation, energy dissipation capacity, and self-centering capacity. A sensitivity analysis was used to explore the main effects of key design parameters and their interactions on each performance index at four damage states, namely, complete, extensive, moderate, and slight damage states. The results of this study demonstrate the effectiveness of hybrid SMA/steel reinforcement for enhancing the seismic behavior of hollow section concrete bridge piers.

Seismic Performance of Concrete Bridge Piers Reinforced with Hybrid Shape Memory Alloy (SMA) and Steel Bars

2019 ◽  
Vol 14 (01) ◽  
pp. 2050001
Author(s):  
Jize Mao ◽  
Daoguang Jia ◽  
Zailin Yang ◽  
Nailiang Xiang
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Seismic Performance ◽  
Residual Deformation ◽  
Steel Reinforcement ◽  
Bridge Piers ◽  
Dissipated Energy ◽  
Concrete Bridge ◽  
Loss Of Function ◽  
Hybrid Reinforcement

Lack of corrosion resistance and post-earthquake resilience will inevitably result in a considerable loss of function for concrete bridge piers with conventional steel reinforcement. As an alternative to steel reinforcement, shape memory alloy (SMA)-based reinforcing bars are emerging for improving the seismic performance of concrete bridge piers. This paper presents an assessment of concrete bridge piers with different reinforcement alternatives, namely steel reinforcement, steel-SMA hybrid reinforcement and SMA reinforcement. The bridge piers with different reinforcements are designed having a same lateral resistance, or in other words, the flexural capacities of plastic hinges are designed equal. Based on this, numerical studies are conducted to investigate the relative performance of different bridge piers under seismic loadings. Seismic responses in terms of the maximum drift, residual drift as well as dissipated energy are obtained and compared. The results show that all the three cases with different reinforcements exhibit similar maximum drifts for different earthquake magnitudes. The SMA-reinforced bridge pier has the smallest post-earthquake residual displacement and dissipated energy, whereas the steel-reinforced pier shows the opposite responses. The steel-SMA hybrid reinforcement can achieve a reasonable balance between the residual deformation and energy dissipation.

Seismic performance of a bridge pier reinforced with titanium alloy bars

2021 ◽  
Author(s):  
Mahesh Acharya ◽  
Mustafa Mashal ◽  
Jared Cantrell
Keyword(s):  
Titanium Alloy ◽  
Cyclic Loading ◽  
Seismic Performance ◽  
Large Scale ◽  
Plastic Hinge ◽  
Bridge Pier ◽  
Bridge Piers ◽  
Structural Performance ◽  
Concrete Bridge ◽  
Hinge Zone

<p>The research in this paper focuses on the use of Titanium Alloy Bars (TiABs) in concrete bridge piers located in high seismic zones. The paper discusses a new bridge pier system that incorporates both seismic resiliency and durability concepts. A large-scale bridge pier, reinforced with TiABs and spiral, is tested under quasi-static cyclic loading protocol. The results are compared against a benchmark cast-in-place pier with normal rebars and spiral under the same loading protocol. Based on the testing results, the use of TiABs in concrete piers would reduce rebar congestion up to 50%, provide adequate ductility, and would result in reduced residual displacement following an earthquake. The pier reinforced with TiABs reached higher drift ratios compared to cast-in-place pier. Furthermore, smaller flexural cracks that are likely to appear in the plastic hinge zone during moderate earthquakes are not a major concern for structural performance and durability of bridge piers reinforced with TiABs.</p>

scholarly journals Cyclic performance of exterior R.C beam-column strengthened with different thicknesses of CFRP sheets

2022 ◽  
Vol 961 (1) ◽  
pp. 012069
Author(s):  
Mustafa Kareem Hamzah ◽  
Raizal Saifulnaz M. Rashid ◽  
Farzad Hejazi
Keyword(s):  
Compressive Strength ◽  
Plastic Hinge ◽  
Cost Effective ◽  
Cyclic Performance ◽  
Concrete Compressive Strength ◽  
Cfrp Sheets ◽  
Panel Zone ◽  
External Strengthening ◽  
Damage States ◽  
Hinge Zone

Abstract The recent ground motion results indicated that the RC buildings are required to be retrofitted by different strengthening techniques. Nowadays, the external strengthening gain interest since its easy, cost effective and not required redesign of buildings. The CFRP sheets are suitable solution and utilized by a number of researchers. However, the numerical cyclic performance of connection strengthened with different thicknesses of CFRP need to be well investigated. This study assessed the performance of RC exterior beam column connection strengthened with CFRP sheets First, two grades of concrete are utilized to be control specimens, normal concrete compressive strength (C20) and high concrete compressive strength (C50) then, the specimens are retrofitted with different thicknesses (1.2, 2.4, 3.6mm) of CFRP sheets. The stresses and damage states showed the importance of connection retrofitting. The CFRP shift the plastic hinge zone away from the panel zone. Furthermore, the results demonstrated that by increase of CFRP thickness the connection resistance will be improved. The comparison between the hysteresis curves demonstrated that the yield and ultimate loading were enhanced for strengthened connection for both concrete grades and the incremental in thicknesses also increase them. The outputs also exhibited that the stiffness and ductility has increased for retrofitted specimens indicating that the CFRP comprehensively overcome the applied cyclic loading and the beam column connection is able to resist such type of loading.

scholarly journals Behaviour of ductile hollow reinforced concrete columns

1983 ◽  
Vol 16 (4) ◽  
pp. 273-290 ◽  
Author(s):  
J. B. Mander ◽  
M. J. N. Priestley ◽  
R. Park
Keyword(s):  
Reinforced Concrete ◽  
Axial Load ◽  
Plastic Hinge ◽  
Concrete Columns ◽  
Bridge Piers ◽  
Reinforced Concrete Bridge ◽  
Hinge Zone ◽  
Lateral Displacements ◽  
Transverse Steel ◽  
Constant Axial Load

An experimental investigation into the seismic performance of ductile hollow reinforced concrete bridge piers is described. Four 3.2 m high specimens, 750 mm square with 120 mm thick walls containing 60 longitudinal steel bars and different arrangements of confining steel in the plastic hinge zone were subjected to a constant axial load and cyclic lateral displacements. An assessment of the effect of axial load and the amount of transverse steel on the rotational capacity of the plastic hinge is made. The specimens performed satisfactorily at member ductilities between 6 and 8 without 
any significant degradation of strength under cyclic loading.

Seismic evaluation and retrofit with steel jackets of reinforced concrete bridge piers detailed with lap-splices

2000 ◽  
Vol 27 (1) ◽  
pp. 1-16 ◽  
Author(s):  
Xavier Daudey ◽  
André Filiatrault
Keyword(s):  
Reinforced Concrete ◽  
Seismic Behavior ◽  
Plastic Hinge ◽  
Bridge Piers ◽  
Concrete Bridge ◽  
Eastern Canada ◽  
Bond Slip ◽  
Lap Splices ◽  
Reinforced Concrete Bridge ◽  
Recent Earthquakes

Recent earthquakes around the world have confirmed the poor seismic behavior of reinforced concrete bridge piers incorporating typical pre-1971 reinforcement details. Since the 1971 San Fernando earthquake in California, procedures to evaluate accurately the flexural and shear behavior of reinforced concrete bridge piers, as well as retrofit techniques to address economically the most common deficiencies, have been elaborated. In eastern Canada, the majority of reinforced concrete bridge structures incorporate piers with similar reinforcement details as those that suffered severe damage, or collapse, during recent earthquakes in California and Japan. Very little research, however, has been conducted on the seismic behavior of these structures, which often exhibit complex cross-sectional geometries and lap-splices in the plastic hinge region. This paper presents a contribution towards a better understanding of the seismic behavior and retrofit of reinforced concrete bridge piers in eastern Canada through quasi-static tests performed on five 1/3.65-scale pier models of an existing bridge structure in the Montreal region. The first specimen was tested in its existing conditions, while the four others were retrofitted with steel jackets. The geometry of the jacket, the size of the gap at the base of the pier, and the properties of the fill material between the jacket and the original cross section were investigated in these last four tests. A numerical model, considering the bond-slip between the concrete and the longitudinal reinforcement, is proposed to simulate the experimental results. Key words: bond-slip, bridge piers, ductility, hysteresis loops, lap-splices, seismic retrofit, steel jackets.

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