Existing Reinforced Concrete Bridges Research Articles

Effect of interface treatment on the flexural performance of existing RC bridge beams strengthened with UHPC

As one of the most innovative cement-based materials, ultra-high performance concrete (UHPC), with excellent durability and mechanical properties, has been widely used in strengthening existing bridges. In this study, in-situ four-point bending tests were carried out to investigate the flexural behavior of precast reinforced concrete (RC) hollow slab beams in service for 15 years strengthened with UHPC. Among them, three hollow slab beams were strengthened with UHPC, and the interface treatment was chiseling, planting rebars, and a combination of chiseling and planting rebars, respectively. The remaining one without any strengthening treatment was used as the control specimen. To evaluate the enhancement effect of different interface treatments on UHPC-strengthened beams, the cracking load, ultimate load, crack development and failure modes of UHPC-strengthened beams were analyzed. Results indicated that the stiffness, deflection capacity and flexural capacity of UHPC-strengthened beams was significantly improved. Meanwhile, the stiffness of UHPC-strengthened beams in the pre-damage stage was increased by 49%–94%, when compared with the unstrengthened beam. Correspondingly, the ultimate flexural capacity was increased by 29%–38%. The interface chiseling treatment was more favorable to enhance the deformation capacity of UHPC-strengthened beams. The interface planting rebar treatment was more favorable to enhancing the ductility of UHPC-strengthened beams. The crack development was effectively suppressed by the interface chiseling and planting rebars together. This contributes to a higher load capacity reserve for UHPC-strengthened beams. The bearing capacity under serviceability limit state of the UHPC-strengthened beams was increased by 1.25, 2, and 2.5 times through the interface treatments of chiseling, planting rebars, and a combination of both, respectively.

On the structural behaviour of existing RC bridges subjected to corrosion effects: Numerical insight

The evaluation of the structural behaviour of existing reinforced concrete (RC) bridges represents one of the most current structural engineering research topics due to their strategic importance, especially if they are subjected to corrosion effects which can lead to a significant reduction of load-bearing capacity of the main structural elements (e.g., the piers). In the last decades, different types of numerical approaches have been proposed for the evaluation of the structural behaviour of these strategic infrastructures, especially after the recent collapses that have affected this type of structures during last years. In this paper, the structural behaviour of an existing RC bridge subjected to corrosion effects due to carbonation is analysed by means of an efficient procedure based on the implementation of a Finite Element Model (FEM) where the main structural elements are implemented using only Timoshenko beam elements. The safety level of the bridge has been evaluated considering different load conditions (e.g. traffic load, seismic action, etc.) calculated according to the Italian Design Code (NTC2018). Finally, a retrofitting intervention is proposed in order to guarantee and adequate safety level of the bridge under the considered different load combinations.

Physical interpretation of machine learning-based recognition of defects for the risk management of existing bridge heritage

The challenge of the research work presented in the paper is to combine the growing interest in monitoring the health condition of existing bridge heritage through systematic and periodic visual inspections with automated recognition of typical bridge defects, which can greatly facilitate the assessment of defect evolution over time. The study focused on the automated identification of defects in existing Reinforced Concrete (RC) bridges exploiting different Deep Learning (DL) approaches and techniques to interpret the obtained predictions. Ensuring the safety of infrastructures is typically a technical and economic issue. Still, in the case of the engineering infrastructure heritage, there are existing bridges and viaducts with a high historical, cultural, and symbolic value. For them, accurate knowledge and characterization of possible degradation processes become particularly important in order to define intervention strategies that combine safety and conservation requirements. With the aim to develop systematic and non-invasive investigation protocols for continuous and effective control of defects and their evolution, a database of existing RC bridge defect images was collected, and the most recurrent defect typologies were classified by domain experts. Some existing Convolutional Neural Networks (CNNs) algorithms were applied to the dataset for automatically recognizing all defects, but the specific novel contribution of the research work is the interpretation of the obtained results in a form that is humanly explainable and directly implementable in new tools for bridge inspections. To interpret the results, Class Activation Maps (CAMs) approaches were employed within available eXplainable Artificial Intelligence (XAI) techniques, which allow to observe the activation zones and nearly perfectly highlight the type of specific defect in a given image. The obtained results, besides suggesting which network works better than others and if the specific defect is effectively recognized, have been evaluated through a quasi-quantitative procedure that compared a qualitative assessment of the CNNs models reliability with two novel indexes representing new explaining metrics of the obtained results. In the end, the outcomes of the proposed study were observed also in a real-life case study. The proposed discussion opens new scenarios in the application of these techniques for supporting road management companies and public organizations in the evaluation of the road networks health state.

Seismic vulnerability assessment of reinforced concrete bridge piers exposed to chloride-induced corrosion

Existing reinforced concrete (RC) bridge piers located near the sea are vulnerable to corrosion phenomena that might negatively affect the load-bearing capacity of the overall bridge, especially under seismic loading. It is of primary importance to assess the seismic vulnerability of existing RC bridge piers under different corrosion scenarios, in order to quantify the reduction of the seismic structural safety induced by these frequent material degradation phenomena. This contribution deals with an experimental-numerical procedure for the seismic vulnerability assessment of corroded bridge piers. The procedure is illustrated in the context of the Zappulla multi-span viaduct (Sicily, Italy), whose RC piers are experiencing chloride-induced corrosion. A comprehensive quality control is conducted, including carbonation tests, corrosion potential mapping and extraction of corroded steel bars for tensile tests, in conjunction with SonReb tests and concrete coring. The test results are critically interpreted to calibrate a numerical fiber-hinge model of the bridge pier, through which numerical seismic analysis is performed under two different corrosion scenarios. It has been found that the seismic safety margin of pier structures is reduced of up to 20-40% by taking into account a mass loss in percentage of the steel bars equal to 20-30%, as suggested by experimental findings.

Critical issues in safety assessment of existing reinforced concrete bridges by means of nonlinear analysis

In the last decade, the Italian bridge heritage, mostly made of ordinary or pre-stressed Reinforced Concrete (RC) elements, has increasingly shown signs of ageing, testified by the recent collapses as consequences of concurrent lack of maintenance, degradation of materials, increase in vehicular traffic and exceptional actions (e.g. due to landslides and floods). The recent Italian “Guidelines for classification and risk management of existing bridges” confirm the large interest at policy-making level for accurately assessing ordinary and ultimate performances of existing bridges, through a multi-level approach. As for the numerical simulations, to date Non-Linear Analysis (NLA) methods have been proposed in the literature only for designing new RC bridges. Among the others, EuroCode 2 (EC2) proposes a specific method for simulating the structural performance of new RC bridges, based on a specific safety-format (SF), where the mean values are the representative strengths for materials. In this paper, the application of the EC2 method, proposed for new RC bridges, is critically reviewed in order to examine its applicability to existing RC bridges. The use of the representative strengths is discussed, in relation to the current knowledge level achieved before the structural assessment. Estimation of modelling uncertainty is proposed to define some acceptance criteria for the specific numerical solution strategy to be used, following the most recent international research outputs. Finally, the relationship between the predictions provided by nonlinear analysis and those obtained by linear methodologies involving different levels of modelling detail is comparatively investigated with reference to a specific case study.

Quantification of multi-hazard risk of existing RC bridges in Barak Valley region, India

The ability to assess and evaluate the condition of existing bridges adequately and accurately is a critical aspect of bridge maintenance and management, which involves condition assessments. Multiple hazards can affect existing bridges, making them vulnerable or risky, and any decision support concerning their management requires special attention. A rational and systematic framework for making practical decisions about the hazards present in a region and the appropriate level of risk is presented in this paper. An analytical hierarchy process (AHP) framework is proposed to rank hazards in hierarchical order based on a region's characteristics and a suitable analysis range, which provides the degree of risk that could jeopardise bridges. The proposed method can assist decision makers in selecting appropriate strategies for improving existing bridges. As a result, bridge inspection costs can be significantly reduced, maintenance and repair funds can be more effectively allocated and the safety, mobility, longevity and reliability of highway transportation assets can be improved. The approach was used in a case study of existing reinforced concrete (RC) bridges in the Barak Valley region in Assam, India. Such an approach is novel to the Indian subcontinent.

Performance-based design for improving impact resistance of RC bridge piers with CFRP grid-reinforced ECC

This study explores the performance-based design of a composite material named carbon fiber reinforced polymer (CFRP) grid-reinforced engineering cementitious composite (ECC) to improve the impact resistance of reinforced concrete (RC) bridge piers. The finite element (FE) model of a benchmark bridge with its pier strengthened with CFRP grid-reinforced ECC is built in LS-DYNA, whereas a medium truck model is employed to impose the impact loading. The accuracy of the FE model is verified against (1) experimental results of a scaled column colliding with a moving truck and (2) the pier damage observed after a real-world bridge-truck collision accident. Subsequently, numerous FE analyses are conducted to (1) identify the accumulation of shear damage under the sequence of engine-cargo impacts, (2) pinpoint flexural damage at different column heights, and (3) derive closed-form expressions to quantify the shear/flexural demand parameters under different truck loads, and the associated intact and residual capacity models provided by the composite pier. These demand/capacity parameters are further utilized to compute shear and flexural-based damage indexes to quantify distinct damage modes and damage states by developing a series of limit state models. To this end, a complete performance-based collision design workflow is devised to strengthen the existing RC bridge piers using the CFRP grid-reinforced ECC composite material. Two case studies are further carried out to verify the effectiveness of the proposed design framework, which provides a sound reference for both researchers and practitioners to employ the CFRP-ECC composite material as a viable retrofit measure to enhance the impact resilience of RC bridge piers.

Safety assessment of existing RC bridge piers subjected to vehicle impact

Impact accidents between bridges and vehicles have great randomness, and the threat of various vehicles to bridge structures is also different. In this case, the vehicle impact shall be regarded as a risk event from the perspective of economic and safety requirements, but current studies mainly focus on the deterministic analysis of bridges subjected to vehicle impact. For this reason, this work aims to establish a probability-based safety assessment method for existing reinforced concrete (RC) bridge piers against potential vehicle impact based on the reliability theory. Firstly, a simplified approach is developed for the preliminary impact hazard analysis of RC piers using the probability method, in which the vehicle type and impact probability are considered. Then, the shear and flexural responses of RC piers under vehicle impact are numerically investigated, and the corresponding limit state functions are determined. Furthermore, a procedure to assess the safety level of RC piers is proposed, including preliminary hazard analysis, reliability analysis, and safety evaluation. Finally, a case example of a bridge pier against vehicle impact is given to demonstrate the proposed safety assessment procedure. This method could provide a reference and basis for the anti-impact decision-making of bridge structures in their service period.

Life-Cycle Assessment of Deteriorating RC Bridges Using Artificial Neural Networks

Life-cycle structural assessment of existing bridges under aging and deterioration processes is of paramount importance for authorities managing road networks. In fact, in most developed countries many bridges and infrastructure facilities are approaching 50 years of lifetime or are even older, and a significant percentage of them are prone to be rated as structurally deficient. In this context, a quick and reliable estimation of the bridge condition is needed for the prioritization of maintenance and repair interventions and the optimal allocation of resources over large bridge stocks. In the last decades, computerized bridge management systems (BMSs) emerged worldwide to support decision makers in the definition of operational management policies. BMSs often incorporate soft computing tools, such as artificial neural networks (ANNs), which can provide reliable bridge assessments over time under uncertainty on the basis of limited data stored in bridge databases. This paper proposes an approach to the life-cycle assessment of deteriorating reinforced concrete (RC) bridges based on ANNs. Two-layer ANNs are formulated and trained for this purpose. The proposed approach is preliminarily applied to a time-variant structural capacity assessment of a RC bridge deck cross-section under chloride-induced corrosion to compare the results obtained with both full and limited input datasets. Finally, the methodology is applied to the prediction over time of the condition state of a group of existing RC bridges based on the information stored in the US National Bridge Inventory.

Assessment of multi-hazards affecting service life of existing reinforced concrete (RC) bridges of Barak valley region, Assam, India

ABSTRACT The probabilistic approach for estimating deterioration of existing RC bridges due to multiple hazards becomes an important subject for the bridge management system. In the present study, a multi-hazard approach as well as investigation proposed to assess how service life of the bridges affected due to the amalgamation of the physical deterioration (aging) along with earthquake hazards. In this approach, the Weibull distribution is found suitable and employed for determining deterioration in terms of hazard function ha(t) of the bridges due to aging. Conversely, the northeast (NE) region of India is highly tectonically active and prone to earthquakes of higher magnitude (Mw>8). Considering the high seismicity in the study region, respective active faults and their corresponding maximum PGA values are taken into account to evaluate the earthquake hazard of the region in a site specific manner. By applying this proposed approach, significant site specific in-depth ideas and facts about their service life span could be evaluated considering the condition of existing bridges for satisfactory performance that would be helpful in taking rational decisions for the bridge management system (BMS) in terms of safety, rehabilitation, repair and inspection strategies of the bridges available in the study region for sustainable growth.

Comparative assessment of seismic collapse risk for non-ductile and ductile bridges: a case study in China

Risk assessment plays an important role in quantifying earthquake loss and has been widely used in the field of seismic engineering. However, current studies of the risk assessment rarely consider the different failure modes of piers (i.e., flexure failure, flexure-shear failure and shear failure), which will lead to an excessive estimation for the seismic performance and collapse safety of the reinforced concrete girder bridges. This paper focuses on studying the seismic behavior of bridges considering different failure modes and comparing the seismic collapse risk of the bridges with and without ductile detailing. The numerical analysis is performed in an open source finite element (FE) software framework, Open Sees. Nonlinear shear springs are introduced into the FE models of reinforced concrete (RC) columns to accommodate the shear and flexural-shear effect of the bridges. The accuracy of the FE models is validated by using the existing results of static cyclic-loading experiments. Case studies are conducted for two categories of the girder bridges, which are designed based on new and old seismic design criteria in China, respectively. The collapse fragility curves are developed by using the incremental dynamic analysis method, which considers the uncertainties of the ground-motion characteristics and the structural material parameters. Based on the seismic hazard curve of a designated region, a comparative assessment of the seismic collapse risk is performed regarding mean annual collapse rate for the non-ductile and ductile bridges. The main results of the paper are: (1) The FE model with the nonlinear shear spring provides an acceptably accurate solution for simulating the initial stiffness, shear failure point, strength degradation slope and residual shear strength of the RC columns; (2) The structural collapse safety is shown to be related not only to the collapse probability of the bridges but also to the occurring probability of the ground motion intensity exceeding a given threshold; (3) The mean annual collapse rate of the ductile girder bridges is significantly smaller than that of the non-ductile girder bridges. The results can be used as a reference to implement specific policies for appraising and mitigating the seismic risk of existing RC bridges.

Finite Element Analysis of Reinforced Concrete Bridge Piers Including a Flexure-Shear Interaction Model

This paper discusses the seismic behavior of reinforced concrete (RC) bridge structures, focusing on the shear–flexure interaction phenomena. The assessment of reinforced concrete bridges under seismic action needs the ability to model the effective non-linear response in order to identify the relevant failure modes of the structure. Existing RC bridges have been conceived according to old engineering practices and codes, lacking the implementation of capacity design principles, and therefore can exhibit premature shear failures with a reduction of available strength and ductility. In particular, recent studies have shown that the shear strength can decrease with the increase of flexural damage after the development of plastic hinges and, in some cases, this can cause unexpected shear failures in the plastic branch with a consequent reduction of ductility. The aim of the research is to implement those phenomena in a finite-element analysis. The proposed model consists of a flexure fiber element coupled with a shear and a rotational slip spring. The model has been implemented in the OpenSEES framework and calibrated against experimental data, showing a good ability to capture the overall response.

Hybrid testing for evaluation of seismic performance of highway bridge with pier made of HyFRC

The present research is focused on Hybrid testing of a highway Reinforced Concrete (RC) bridge, wherein fibres available in India were used to improve the seismic performance of bridge pier. In order to arrive at best possible fibre proportions to be used, prisms made of conventional concrete and Hybrid Fibre Reinforced Concrete (HyFRC) were first tested to account for variability in fibre proportions. Two types of steel and polypropylene fibres available in India were used, where prisms made of HyFRC exhibited enhancement in energy dissipation capacity. HyFRC was used by previous researchers to investigate their performance in isolated structural elements, but no such research papers are found, wherein structural elements made of HyFRC were investigated using Hybrid testing. Scaled bridge piers of an existing RC bridge designed for most active seismic zones in India and made of conventional concrete as well as HyFRC were considered as experimental elements in the hybrid testing under the action of recorded earthquake excitation of different intensities. After completion of the hybrid testing, cyclic tests were carried out to find the ultimate capacity of these test specimens. Pier specimens made of HyFRC outperformed specimens made of conventional concrete in terms of all the seismic performance parameters, such as improved damage tolerance, enhanced energy-dissipation capacity, higher stiffness at any drift ratio, improved load-carrying capacity and ductility. Detailed strain measurements in concrete and reinforcing bars revealed the merits of HyFRC over conventional concrete as measured strain values were appreciably lesser at any load level.

Application of J-BMS to Performance Evaluation and Remaining Life Prediction of an Existing RC Bridge

This paper describes a method of performance evaluation and remaining life prediction for an aged reinforced concrete (RC) T-girder bridge by J-BMS RC version via close visual inspection data, and also verifies the assessment results obtained as outputs from the Bridge Rating Expert System (RC-BREX) which is a subsystem of the J-BMS, to evaluate the effectiveness of the system. The Bridge Management System (J-BMS) that was previously developed by the authors, and which is capable of forecasting the deterioration process of existing bridge members, was applied to evaluate the safety indices (soundness score) and remaining life of the target bridge based on these test results. Using these methods, the remaining life of an aged RC-T girder bridge (SK-bridge) can be quantitatively estimated by applying the bridge rating expert (BREX) system, which is a subsystem of the J-BMS RC version that incorporates with the field inspection data. In this study, close visual inspection was carried out on the aged bridge by professional visual inspectors, during which all variations of the inspection results were evaluated using a five-step questionnaire. As a result, it was found that the soundness score (safety index) and remaining life predictions were influenced by the learning (supervised) data selection. Additionally, the predicted remaining lives were verified through concrete core tests extracted from main girders and deck slabs.

Life-cycle reliability assessment of reinforced concrete bridges under multiple hazards

This paper proposes a novel probabilistic methodology for estimating the life-cycle reliability of existing reinforced concrete (RC) bridges under multiple hazards. The life-cycle reliability of an RC bridge pier under seismic and airborne chloride hazards is compared to that of a bridge girder under traffic and airborne chloride hazards. When conducting a life-cycle reliability assessment of existing RC bridges, observational data from inspections can provide the corrosion level in reinforcement steel. Random variables related with the prediction of time-variant steel weight loss can be updated based on the inspection results using Sequential Monte Carlo Simulation (SMCS). This paper presents a novel procedure for identifying the hazards that most threaten the structural safety of existing RC bridges, as well as the structural components with the lowest reliability when these bridges are exposed to multiple hazards. The proposed approach, using inspection results associated with steel weight loss, provides a rational reliability assessment framework that allows comparison between the life-cycle reliabilities of bridge components under multiple hazards, helping the prioritisation of maintenance actions. The effect of the number of inspection locations on the updated reliability is considered by incorporating the spatial steel corrosion distribution. An illustrative example is provided of applying the proposed life-cyle reliability assessment to a hypothetical RC bridge under multiple hazards.

Seismic Fragility Analysis of Multispan Reinforced Concrete Bridges Using Mainshock-Aftershock Sequences

Although the knowledge and technology of performance-based earthquake engineering have rapidly advanced in the past several decades, current seismic design codes simply ignore the effect of aftershocks on the performance of structures. Thus, the present paper investigated the effect of aftershocks on seismic responses of multispan reinforced concrete (RC) bridges using the fragility-based numerical approach. For that purpose, a continuous girder RC bridge class containing 8 bridges was selected based on the statistical analysis of the existing RC bridges in China. 75 recorded mainshock-aftershock seismic sequences from 10 well-known earthquakes were selected in this study. In order to account for the uncertainty of modeling parameters, uniform design method was applied as the sampling method for generating the samples for fragility analysis. Fragility curves were then developed using nonlinear time-history analysis in terms of the peak curvature of pier column and displacement of bearings. Finally, the system fragility curves were derived by implementing Monte Carlo simulation on multinormal distribution of two components. From the results of this investigation, it was found that, for the RC continuous bridges, the influence of aftershocks can be harmful to both bridge components and system, which increases both the component fragility of the displacement of bearings and seismic curvature of pier sections and system fragility.

A systematic method from influence line identification todamage detection: Application to RC bridges

Ordinary reinforced concrete (RC) and prestressed concrete bridges are two popular and typical types of short- and medium-span bridges that accounts for the vast majority of all existing bridges. The cost of maintaining, repairing or replacing degraded existing RC bridges is immense. Detecting the abnormality of RC bridges at an early stage and taking the protective measures in advance are effective ways to improve maintenance practices and reduce the maintenance cost. This study proposes a systematic method from influence line (IL) identification to damage detection with applications to RC bridges. An IL identification method which integrates the cubic B-spline function with Tikhonov regularization is first proposed based on the vehicle information and the corresponding moving vehicle induced bridge response time history. Subsequently, IL change is defined as a damage index for bridge damage detection, and information fusion technique that synthesizes ILs of multiple locations/sensors is used to improve the efficiency and accuracy of damage localization. Finally, the feasibility of the proposed systematic method is verified through experimental tests on a three-span continuous RC beam. The comparison suggests that the identified ILs can well match with the baseline ILs, and it demonstrates that the proposed IL identification method has a high accuracy and a great potential in engineering applications. Results in this case indicate that deflection ILs are superior than strain ILs for damage detection of RC beams, and the performance of damage localization can be significantly improved with the information fusion of multiple ILs.

Fatigue behavior of naturally corroded plain reinforcing bars

Segments of corroded plain reinforcing bars were firstly extracted from an aged reinforced concrete (RC) pole after its breaking. The testing specimens were then taken from these segments. The cause for corrosion of the specimens was analyzed, and the corrosion degree of the specimens was measured before testing. Tensile loading tests were performed with 3 non-corroded specimens to obtain the mechanical properties of the plain reinforcing bars prior to any corrosion. Axial tensile fatigue tests were conducted with 34 corroded specimens to investigate the fatigue behavior of the naturally corroded plain reinforcing bars. Corrosion of the specimens was initiated by the carbonation of concrete. Two corrosion levels and five stress ranges were considered. Fatigue test results showed that the median fatigue life of lightly and medium corroded plain reinforcing bars was reduced by 48 and 75% respectively under the same stress range of 240MPa by compared with that of non-corroded plain reinforcing bars. Based on the test results, the fatigue Src-N curves of the lightly and medium corroded specimens were presented by using least square method. Then, the predicted fatigue lives and fatigue strengths of naturally corroded plain reinforcing bars were suggested and compared with those of other related literature. The fatigue strength with 50% guarantee rate of lightly and medium corroded plain reinforcing bars is reduced by 18 and 28% respectively under a fatigue loading with cycles of 2 million by compared with that of non-corroded plain reinforcing bars. The fatigue fracture mechanism of the corroded specimens was interpreted by using Scanning Electron Microscope (SEM) images. Further, the pit depth was measured, and the relationship between the relative maximum pit depth and fatigue life of the corroded specimens was explored. It was found that one or more crucially localized pits of a specimen leading to the reduction of fatigue strength had an important influence on its fatigue life. A linear relationship between the relative maximum pit depth and the relative fatigue life of the corroded specimens was observed under three given stress ranges. This study provides a necessary basis for the determination of the remaining fatigue life of aged existing RC bridges.

Probabilistic seismic performance assessment of an existing RC bridge with portal-frame piers designed for gravity loads only

Abstract The present analytical work illustrates a thorough assessment of the seismic performance of an existing reinforced concrete (RC) bridge with framed piers designed for gravity loads only. The seismic response is investigated through advanced, comprehensive and efficient dynamic non-linear analyses. The evaluation of the seismic performance for ductile and fragile components has been carried out with simplified yet reliable formulations, either based on codes or experimentally derived, partially validated with numerical simulations. The effects of far-field and near-source strong motions on the seismic response of the sample bridge have been assessed and discussed in details. Fragility curves are derived using both Cloud analysis and Incremental Dynamic Analysis (IDA) and considering two limit states, i.e. damage limitation and collapse. The outcomes of the refined numerical simulations show that the near-source strong motions tend to impose higher inelastic demand on fragile components of the bridge system than far-field records, nevertheless fragility curves relative to the latter records exhibit higher probability of failure than the near-source strong motion counterparts. For the damage assessment, it is found that the Cloud analysis lead to fragility curves similar to those derived through the IDA procedure. Finally, a new approach facilitating the preliminary identification of the weakest link of the bridge, namely the pier-by-pier fragility, is presented.

Experimental response of an existing RC bridge with smooth bars and preliminary numerical simulations

The paper discusses the experimental seismic performance assessment of a structural prototype simulating typical existing highway bridges which were designed with poor seismic details. The structural system is a reinforced concrete (RC) 1:3 scale single span bridge which has been tested dynamically with shaking tables by considering strong motions of the 1980 Irpinia (Italy) earthquake. Low-strength concrete and smooth bars were used for the RC circular bridge piers of the tested prototype. Comprehensive modal response analysis has been carried out for the single piers and for the bridge sub-assemblage to estimate period elongations and variations of equivalent viscous damping coefficients at increasing levels of strong motions. The effects of cumulative damage induced by earthquake sequences have also been investigated experimentally. The sample bridge pier possesses low aspect ratio; nevertheless the piers exhibited a flexural response. Fixed-end rotations, with significant longitudinal reinforcement slip, were observed at the base of the bridge pier at about 0.40% lateral drift ratio. As a consequence, a rocking mechanism of the bridge pier initiated; such mechanism affected significantly the pier response at large shaking intensities. An in-depth analysis of local and global response quantities has been provided in order to accurately identify the structural behaviour. Finally, available analytical formulations and refined numerical models were considered to simulate the earthquake response of the tested bridge. The pier lateral response has been investigated by means of push-over analysis and nonlinear time histories. The accuracy of the proposed models, the differences and recommendations for numerical modelling of bridge piers with smooth internal reinforcements are also discussed.