Reinforced Concrete Bridge Research Articles

Experimental Study on Flexural Resistance of UHPC Wet Joint Precast Reinforced Concrete Bridge Deck Slabs with Variable Cross-Section

With the convenient and fast requirements for construction in bridge engineering, prefabricated assembly technology is widely applied in engineering construction. Typically, prefabricated bridge decks are connected through cast-in-place wet joints. Wet joints, as the primary load-bearing parts of bridge decks, undergo complex stress and are prone to cracking and damage. Particularly in the negative bending moment region of bridges, the influence of tensile stress on wet joints is more severe, thus enhancing the mechanical performance and crack resistance of joints becomes crucial. This paper investigates the mechanical behavior of prefabricated reinforced concrete bridge deck panels with variable cross-sections under negative bending moments, focusing on the performance of Ultra High-Performance Concrete (UHPC) wet joints. Full-scale experimental tests were conducted on a 176 m steel truss composite continuous rigid bridge, employing C50 concrete panels with UHPC wet joints. Results show three distinct stages: elastic, crack initiation and propagation, and failure. The maximum failure load reached 822 kN, with a maximum displacement of 21.64 mm. Concrete strains indicate compressive stress near the wet joint and tensile stress near the loading positions. Cracks primarily develop at the wet joint interface and propagate under increasing load, ultimately leading to flexural–shear failure near the variable cross-section of the wet joint. Numerical simulations using ABAQUS/CAE (2020) corroborate experimental findings, closely matching load-displacement curves and identifying damage locations. The study demonstrates that UHPC wet joints significantly enhance crack resistance, meeting design requirements for improved mechanical performance in bridge structures subjected to negative bending moments.

Sustainability and Resilience Assessment of a Reinforced Concrete Bridge Subjected to Liquefaction-Induced Lateral Spreading

Sustainability and Resilience Assessment of a Reinforced Concrete Bridge Subjected to Liquefaction-Induced Lateral Spreading

Investigation of a Cathodic Protection Configuration for the Steel Casing Pipes in Reinforced Concrete Bridge in the Niger Delta

This paper details the Design of a Cathodic Protection System on the steel casing pipes of the 60m reinforced concrete bridge project in the Niger Delta, Nigeria. Galvanic anode cathodic protection system was provided for the submerged steel support piles on the newly reinforced concrete bridge to ensure adequate corrosion protection of the structures. A total of fifty-six (56) Aluminum Anodes (32 kg) were used. Two of the Aluminum anodes were installed on each of the twenty-eight (28) steel casing piles. The anode installation was achieved by means of clamping at the predetermined water depth of 37.2 m with purpose made carbon steel clamps. The bonding of the anode to the pile structure to make electrical contact was achieved through welding of the pre-installed anode steel core extension bar against the steel pile at the water splash zone area of the river. A pre- and post-installation test and survey activities were conducted on each of the steel piles to ascertain the integrity of the installation and degree of corrosion protection of the steel casing piles. The field test and measurement results indicated mean values of open circuit potential of 0.600 Volts and polarized corrosion potential of 0.850 Volts. The recorded corrosion potential for the installed cathodic protection system confirmed adequate corrosion protection for ten (10) years from anode life for the steel casing supports of the 60 m reinforced concrete bridge.

A global framework for data-informed bridge examination

Examining the performance of an existing bridge requires information on several aspects, such as design choices, material properties, and ongoing degradation processes. It often happens that some critical information is not available. The traditional approach in structural engineering is to take the most conservative assumption for each unknown, following new-design principles. It will often be concluded that structural safety is not ensured and that the bridge must be strengthened or replaced. This conclusion has important economic costs, impacts on users, and environmental burden associated. In this paper, a global data-informed framework is proposed to examine structural safety of existing bridges accurately. Multiple state-of-the-art methodologies are unified to provide a comprehensive framework for bridge examination. Observations, which can include visual inspection, non-destructive testing, and structural sensing, enable the development of more realistic models of structural behaviour. A case study of a reinforced-concrete bridge in Switzerland illustrates the potential of the novel framework. Although almost no information was initially available on the bridge, the monitoring results show that it can be rationally concluded that the bridge is safe. This framework supports engineers in examining existing structures when crucial information is missing based on observations and engineering judgment.

Seismic Performance of Reinforced Concrete Bridge in Pan Borneo Highway Sarawak under the Influence of Seismic Loadings

Seismic Performance of Reinforced Concrete Bridge in Pan Borneo Highway Sarawak under the Influence of Seismic Loadings

Evaluation of Infrared Thermography Dataset for Delamination Detection in Reinforced Concrete Bridge Decks

Structural health monitoring and condition assessment of existing bridge decks is a growing challenge. Conventional manned inspections are costly, labor-intensive, and often risky to execute. Sub-surface delamination, a leading cause of deck replacement, can be autonomously and objectively detected using infrared thermography (IRT) data with developed deep learning AI models to address some of the limitations associated with manned inspection. As one of the most promising classifiers, deep convolutional neural networks (DCNNs) have not been utilized to their fullest potential for delamination detection, arguably due to the scarcity of realistic ground truth datasets. In this study, a common encoder–decoder semantic segmentation-based DCNN is adapted through domain adaptation. The model was tuned and trained on a publicly available dataset to detect subsurface delamination in IRT data collected from in-service bridge decks. The authors investigated the effect of dataset augmentation, class imbalance, the number of classes, and the effect of background removal in the training dataset, resulting in an overall number of seventy-five UNET models. Four out of five bridges were adopted for training and validation, and the fifth bridge was for testing. Most models averaged 80 iterations, and the training progress finally reached a training accuracy of 75% with a loss of about 0.6 without any overfitting. The result showed a substantial difference in the minimum and maximum values for the evaluated performance metrics (0.447 and 0.773 for global accuracy, 0.494 and 0.657 for mean accuracy, 0.239 and 0.716 for precision, 0.243 and 0.558 for true positive rate (TPR), 0.529 and 0.899 for true negative rate (TNR), 0.282 and 0.550 for F1-score. The results also indicated that the models trained on the raw annotated balanced dataset performed best for half of the metrics. In contrast, the models trained on raw data (with no dataset enhancement) performed better when only global accuracy was considered.

A Comparative Study of Fragility Model for RC Girder Bridges and Buildings

Field surveys and data on the earthquake reveal that RC (reinforced concrete) bridges and buildings have been widely found in engineering structures, with abundant samples at disposal. By taking actual seismically damaged samples in the Wenchuan Earthquake happened in 2008 as examples, the paper established probability models for fragility matrix within Intensity VH-X/XI for the said two engineering structures based on EMS-98, MSK-81 and CSIS-08, and analyzed the comparative models for failure ratio and exceedance probability curves defined by these three scales. The paper, according to these analytical findings, proposed relevant measures and methods for improving the earthquake resistance of RC bridges.

Softened Membrane Torsional Model for GFRP–Reinforced Concrete Bridge Box Girders

Softened Membrane Torsional Model for GFRP–Reinforced Concrete Bridge Box Girders

Structural Condition Assessment of Reinforced Concrete Bridge Using Operational Modal Analysis and Finite Element Model

The integration of Operational Modal Analysis (OMA) and Finite Element Model (FEM) techniques has proven to be a valuable approach for evaluating and maintaining the health of such structures. OMA extracts dynamic characteristics from a bridge's responses to ambient vibrations, while FEM employs computational models to simulate and compare these dynamic behaviours. This comprehensive methodology ensures an accurate representation of the bridge's behaviour and its correlation with real-world conditions. However, a significant challenge arises in assessing the Ultra High Performance Fiber Reinforced Concrete (UHPFRC) pedestrian bridge in Klang, Selangor, launched in October 2022, due to limited available information about OMA and FEM on UHPFRC. This research aims to develop FEM and conduct ambient vibration tests to obtain modal parameters. Moreover, the study investigates OMA techniques in the context of weak excitation sources, filling a critical knowledge gap. By comparing experimental results with FEM, this research provides insights into the feasibility and reliability of OMA under challenging environmental conditions. The principal results reveal significant percentage differences in natural frequencies between FEM and OMA, with the most notable disparities occurring in the first mode. Nevertheless, the mode shapes extracted from OMA closely resemble those from FEM. In conclusion, this research enhances the understanding of UHPFRC pedestrian bridge behaviour and modal analysis techniques.

Safety assessment of existing prestressed reinforced concrete bridge decks through different approaches

AbstractThe assessment of existing reinforced concrete (RC) structures, especially, bridges and viaducts, nowadays is one of the most relevant aspects for infrastructural engineers. Due to the old age of a large part of the railways and roadways assets, their safety, especially, with respect to the Ultimate Limit States (ULS) may result compromised. Safety assessment can be performed following different approaches as well as the most sophisticated methodologies based on the application of safety formats for non‐linear finite element (FE) analyses. This study presents the safety assessment at the ULS of existing prestressed RC bridge decks regarding bending moment and axial force failure mechanism adopting different methodologies. Specifically, the safety assessment will be performed through five different approaches (i.e., Courbon theory, elastic FE analysis, and NLFEAs according to the three global safety formats). The decks are modeled using, first, Courbon theory and then, girder FE model composed only of beam elements. The safety assessment is performed by comparing the design resisting moment and design acting moment in the section of interest, therefore, through a local approach. Within the local approach, design values are calculated using the partial safety factors. Afterwards, the decks are modeled with a 3D non‐linear FE model. Three different global safety formats are implemented within a global approach. The application of the different approaches leads to significantly different conclusions about the safety assessment. The two local approaches are the most conservative, therefore, lead to a lower safety margin. The application of global approaches based on global safety formats leads to a safety margin gain compared to local approaches, with significant variability in terms of safety margin gain depending on the specific global safety format.

Seismic resilience assessment of extended pile shaft supported coastal bridges considering scour and uniform corrosion effects

The resilience-informed assessment for coastal highway bridges exposed to multiple hazards plays a crucial role in the decision-making process for their operation, maintenance, and management during the bridge’s long-term service period. This study performs a seismic resilience assessment for a coastal reinforced concrete (RC) bridge under the combined effects of scour and uniform corrosion. Toward this goal, an extended pile shaft supported coastal RC bridge is taken as the benchmark and fifteen scenarios are generated to cover three regular scour conditions and five different corrosion levels. To inform the bridge management, the probabilistic distribution of the bridge service time corresponding to different corrosion levels is developed. Subsequently, the finite element model (FEM) for each scenario of the benchmark coastal highway RC bridge is developed, involving the soil-pile interaction and considering the uncertainty of structural and geotechnical parameters, as well as earthquake ground motions. The failure mode of the corroded extended pile shaft is identified as a flexural failure by comparing their flexural and shear capacities. Finally, a resilience loss ratio is proposed in this study for the first time to quantify the impacts of corrosion level and scour depth changes on seismic resilience across different ground motion intensities. Results indicate that both the seismic fragility and resilience decrease as the corrosion intensifies over time. Specifically, at a given intensity measure (IM) level, the resilience loss ratio increases as the corrosion level intensifies. For the studied benchmark bridge, the scour significantly increases the structural fundamental period, consequently reducing the curvature demand on the pile shaft. As a result, the scour generally decreases the failure probability and the earthquake-induced functionality loss for the extended pile shaft. As scour depth increases, the resilience loss of the bridge at a given corrosion level decreases.

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.

Reinforced Concrete Bridge Column Multihazard Performance: A Computational Tool to Assess Response to Vehicle Impact, Air Blast, and Fire

Reinforced Concrete Bridge Column Multihazard Performance: A Computational Tool to Assess Response to Vehicle Impact, Air Blast, and Fire

Framework for assessing bridge quality index based on the correlation of non-destructive test results

This paper presents the new method for quality indexing of bridge components on the basis of non-destructive tests (NDT) for the assessment of the structural condition of Reinforced Concrete (RC) bridges. For the purpose of establishing indexing values, results obtained from the Electrical Resistivity Test (ERT), Rebound Hammer Test (RHT), Ultrasonic Pulse Velocity Test (UPVT), and visual inspection were used as the NDT variables. The radar plot for index determination is based on the area of the polygon whose vertices are formed on the basis of the correlation coefficient between NDT variables. Then, using the radar plot formulation, a bridge quality index is introduced to evaluate the corrosion and strength properties of in-service RC bridges to determine their structural health. The bridge quality index ranges from 0 to 1, representing low to high levels of deterioration. Based on simply non-destructive testing, the bridge quality index can serve as a framework for evaluating the present condition of the bridge and its components.

Performance Assessment of Reinforced Concrete Bridges Under Coupled Horizontal and Vertical Ground Motions Using Fragility Surfaces

ABSTRACT The objective of this study is to explore the seismic fragility of reinforced concrete bridges, specifically in response to the vertical components of ground motions, utilizing fragility surfaces. The examination of bridge responses involves the application of optimally selected intensity measures through three-dimensional nonlinear time-history analyses, encompassing uncertainties in both superstructure materials and soil–structure interaction effects. In this investigation, an extended Probabilistic Seismic Demand Model (e-PSDM) is employed, leveraging fragility surfaces to concurrently consider vertical and horizontal excitations. The results obtained from this approach are compared with traditional fragility curves. This study emphasizes Pile-cap displacement and drift ratio as pivotal engineering damage parameters, acknowledging their sensitivity to the influences of both soil–structure interaction effects and vertical ground motion. The fragility surfaces derived from the study reveal a correlation between increased vertical spectral accelerations and elevated probabilities of surpassing both slight damage and collapse limit states. These observations underscore the critical significance and practical utility of fragility surfaces in the context of performance-based seismic assessment and design for reinforced concrete bridges. The findings from this research contribute valuable insights into the nuanced behaviour of reinforced concrete bridges under seismic conditions, emphasizing the relevance of incorporating vertical components in fragility assessments for a more comprehensive understanding of structural vulnerability.

The Bridge Through the College (Part-1): Conception and Construction of Reinforced Concrete Bridge Across College Campus

“The bridge through the college” highlights how contracts and agreements signed many decades ago have to still be respected and fulfilled. A public highway planned to originally be laid on top of a filled-out irrigation canal passing through the campus of a college that commenced in 1977 was later replaced with a elevated bridge that has finally finished completion in 2023 and is now open to public. The bridge is designed as reinforced concrete girder bridge with concrete slab top poured composite with the girders. This article explains in detail the engineering, design and construction of a reinforced concrete girder bridge through the campus of Velagapudi Ramakrishna Siddhartha Engineering College in Vijayawada city of India. The challenges associated with design and construction are also discussed. Finally, the lessons learnt at the end of the completion of the bridge are enlisted and recommendations to improve efficiency of our design and construction methods are made. Keywords: Concrete, Bridge, Engineering, Construction, Pier, Girder, Reinforcement

Resilience Analysis of Different Retrofitting Solutions for a Prestressed Concrete Viaduct

This article introduces a resilience analysis conducted on Greece’s prestressed Polyfytos viaduct. As the nation’s second longest bridge, spanning 1,372 meters, it was conceptualized by Prof Riccardo Morandi and built between 1972 and 1975, marking it as an iconic structure at 48 years old. Notably, the bridge has strong interdependencies with key power plants, dams and solar pars in the region. Evaluating both risk and resilience, the study employed visual inspections and digital data collection methods. These methods involved a digital twin, offering current asset geometry and a dynamic model for advanced simulations; satellite imagery for ongoing updates on the structure’s deformations and geometry; and advanced numerical modeling aimed at interpreting current deflections via back analysis. The bridge shows signs of degradation commonly found in reinforced concrete (RC) and prestressed RC (PRC) bridges, specifically concerning corroded tendons and concrete bonding. Prior research focused on evaluating various retrofitting approaches and their lifecycle impacts, whereas this study integrates the resilience assessment of such retrofit solutions. This contribution represents a new step in the direction of a holistic approach to identifying the appropriate retrofit of an existing viaduct aiming to inform decision-making about the benefits of different restoration investments.

A Physics‐Informed Neural Network for the Nonlinear Damage Identification in a Reinforced Concrete Bridge Pier Using Seismic Responses

The condition assessment of reinforced concrete (RC) bridge piers after an earthquake using measured responses is important for ensuring the safety of road and railway users. The problem is nonlinear, and the locations and extents of damages are various. However, previous research works focused on linear structural identification or model updating assuming a limited number of nonlinear materials for reasonable estimates. Leveraging the ability of deep learning (DL) for robustly estimating a large number of unknown parameters, this study proposes an ALL nonlinear spring multi‐degree‐of‐freedom (MDOF) damage identification algorithm based on a physics‐informed neural network (PINN). The algorithm is applied to a stacked bilinear rotational spring and damper model of a pier. The number of unknown parameters reaches about 50. The errors of estimated elastic stiffnesses, damping coefficients, and ductility factors (DFs) using simulated responses added with noises are 0.4%, 0.6%, and 3.1%, respectively. Using full‐scale RC bridge pier shaking table experiments, the algorithm revealed the distributions of elastic stiffnesses and DFs along the pier height and their deteriorations. The effects of different types of local damages are quantitatively evaluated and visualized on the distributions.

Half-joints degradation: analysis of some case studies

Existing Reinforced Concrete (RC) bridges, due to their age, are very often affected by significant deterioration phenomena, also intensified by lack of maintenance, which strongly reduces their strength with respect to the design load combinations.In particular, half-joints were widely used in the RC bridge typology until the end of the 20th century. As well known, due to the static scheme adopted, and recurrent failure due to fragile mechanisms, to date these elements are recognized as critical, since their strength is particularly affected by degradation frequently provoked by erosion caused by rainwater infiltration from the roadway. This phenomenon, definitively, leads to a marked concrete cover reduction and corrosion of the reinforcing bars.This paper deals with the analysis of certain types of half-joints employed in existing reinforced concrete bridges. To this scope, some case studies are illustrated and discussed to highlight weakness points of the typologies analyzed and causes of defects observed.

Revitalizing an Existing Reinforced Concrete Bridge: Deficiencies, Repair Techniques and the Role of FRPs

Italy, known for its large historical and cultural building heritage, boasts a vast network of reinforced concrete (RC) bridges that plays a crucial role in connecting various regions. However, over the time and due to the exposure to harsh environmental conditions, these bridges have exhibited structural deficiencies, including deterioration, cracking, and loss of load- carrying capacity. In a deeper scale, corrosion of the steel-reinforcement due to chloride ingress and carbonation are both evident. The latter leads to the deterioration of the concrete, the loss of the bond between steel-reinforcement and concrete, and the reduction of the structural integrity. Furthermore, bridges may experience excessive deflection, which compromise their serviceability performance. To address these drawbacks, a range of repair techniques have been employed. These include, among the others, conventional methods such as crack sealing, surface patching, and cathodic protection to mitigate corrosion.On the other side, advanced materials like fiber-reinforced polymer (FRP) have been relatively recent favored. It consists of high-strength fibers embedded in a polymer matrix (generally epoxy-based), which have gained prominence as a viable solution for the structural rehabilitation of RC-bridges. In fact, FRP offers several advantages including a high strength-to-weight ratio, corrosion resistance, and excellent durability. FRP-composites can be used for strengthening and retrofitting bridge components, such as beams, columns, slabs, and shear walls, to enhance their load-carrying capacity and structural performance. Various FRP- based rehabilitation techniques are commonly employed in Italy, including externally bonded FRP sheets/strips, near-surface mounted FRP rods, and FRP wraps for the confinement of concrete columns. The techniques involve the application of FRP materials to the external or internal surfaces of deteriorated elements, effectively enhancing their strength and/or stiffness.The present paper aims to report a success case-study concerning the external strengthening of a RC-bridge carried out using FRP-materials in the perspective of demonstrating the validity of the FRP-application for bridge strengthening and maintenance based on a proper design and time-dependent visual observations.