Segmental Concrete Bridge Research Articles

Bibliometric Analysis of Web of Science–Indexed Papers on Concrete Segmental Bridges

This paper provides a bibliometric analysis of indexed scientific papers on concrete segmental bridges. Two hundred forty-two papers published from 1900 through 2013 were extracted from the Web of Science. The analysis examines author information, journal and year of publication, WoS category, funding agency, topics, keywords, and content. This study shows that the main references on concrete segmental bridges were published in United States journals on concrete structures; more than half were by authors in the United States.

Collapse mechanism and robustness of precast segmental bridges

In the construction of multi-span precast concrete segmental bridges, in situ stitches are often cast to connect together adjacent cantilevers assembled from precast segments. Since the stitches are often lightly reinforced, the robustness of a segmental bridge could be adversely affected by the capability of the stitches to resist any large variations in moment during extreme events. While most previous studies have focused on methods to measure robustness, there has been little systematic examination of the effects of strength and behaviour of structural components on robustness of structures. As prestressed concrete is relatively non-ductile, finite-element analyses are carried out taking into account the full-range non-linear moment–curvature relationship to examine the formation of plastic hinges and possible collapse mechanisms. Three classes have been proposed for the evaluation of robustness, namely superb, adequate and inadequate. Recommendations to achieve good robustness are also put forward.

Seismic performance of precast hollow bridge piers with different construction details

Currently the design scheme of precast hollow concrete bridge piers will be adopted in bridge design in China, but there is no code including specific design details of precast segmental piers in high seismic risk area. For comparative study of seismic performance of the hollow bridge piers which had different design details, six specimens of hollow section bridge pier were designed and tested. The specimens consist of the monolithic cast-in-place concrete bridge pier, precast segmental prestressed pier with cast-in-place joint and precast segmental concrete bridge pier with dry joints. Results show that all specimens have good displacement capacity. The bridge pier with bonded prestressed strands exhibits better energy dissipation capacity and higher strength. The un-bonded prestressed strand bridge pier displays less residual plastic displacement and energy dissipation capacity. The bridge pier with both bonded prestressed strands at the edge of the section and un-bonded in the center of the section not only exhibits more ductility capacity and less residual plastic displacement, but also shows better energy dissipation capacity. Compared with experimental results of prestressed bridge columns, analytical result demonstrates the developed numerical analysis model would provide the reasonable and accurate results.

Simplification of Creep and Shrinkage Analysis of Segmental Bridges

AbstractThe time-dependent concrete creep and shrinkage effects on segmental bridges are more critical than on other types of concrete bridges. Creep strains develop more when concrete is loaded in a younger age than in an older age, and it affects more on loss of prestressing and displacements because of prestressing. Creep and shrinkage analyses are considered an essential part for segmental bridge design and analysis, especially for the cast in situ segmental bridges or concrete bridges with an application of large quantities of prestressing. The introduction of a creep/shrinkage mathematic model into the formation of a stiffness matrix limits the evolution of a finite-element analysis (FEA) package and the adoption of a new model. Based on the fact that the creep development is nonlinear only in the time domain and linear to loadings, this paper introduces a novel time incremental method for creep and shrinkage analysis and its implementation to a FEA package. The equilibrium after a tiny time step wi...

Ultrahigh-Performance Concrete Segmental Bridge Technology: Toward Sustainable Bridge Construction

AbstractThis paper presents the current state of practice in the development of ultrahigh-performance concrete (UHPC) bridge construction in Malaysia. Since 2006, Dura Technology (DT) has pioneered research in the optimal uses of UHPC in bridge construction through its Sustainable Bridge Construction Initiative. After several years of research and development work, DT has collaborated with the Malaysia Works Ministry to design and build bridges in some of their bridge projects, especially those bridges under the rural development program where sourcing of material, site access, and construction method are major challenges when using conventional methods. The most current information and details on the completed and ongoing UHPC bridge projects in Malaysia are presented. To date, a total of 26 segmental UHPC bridge projects have been constructed and opened for service. In this paper, a selected UHPC bridge case study is examined in terms of the design aspects, quality control, constructability, and of how ...

Serviceability and Ultimate Safety Checks of Segmental Concrete Bridges through N-M and M-V Interaction Domains

AbstractIn current engineering practice, safety checks on serviceability and determinations of ultimate limit states of segmental bridges built by cantilevering are generally performed, either considering separately the contributions of axial force N, bending moment M, and shear force V, or considering the interaction effects through approximate expressions supplied by building codes. During construction stages and service life, the interaction between internal forces can be of fundamental importance in establishing the actual degree of structural safety and, for this reason, a different philosophy for performing checks in segmental bridges is proposed in this paper, plotting N-M and M-V interaction domains for cracking, construction stages, and serviceability (elastic domains) as well as M-V interaction domains for ultimate limit states (failure domains). Delayed deformations as a result of creep are considered, as are bonded and unbonded prestressing. A model is developed for plotting bending-shear doma...

Finite-Element Analysis of Shear-Off Failure of Keyed Dry Joints in Precast Concrete Segmental Bridges

© 2014 This work is made available under the terms of the Creative Commons Attribution 4.0 International license,. The structural behavior of precast concrete segmental bridges largely depends on the behavior of the joints between segments. The current practice of precast concrete segmental bridges is to use small keys that are usually unreinforced, normally dry, and distributed over the height of the web and the flange of concrete segments. In this study, a numerical analysis model was established based on finite-element code to investigate structural behavior of keyed dry joints under direct shear. The concrete damage plasticity model along with the pseudodamping scheme were incorporated to analyze the system for microcracks and to stabilize the solution, respectively. The numerical model was calibrated by full-scale experimental results described in the literature. It was found that the predicted ultimate load, cracking evolution history, and final crack pattern agreed reasonably well with experimental results. The validated numerical model was then used for parametric study on factors affecting shear behavior of keyed dry joints, in this case confining pressure. The authors found that shear capacity predicted by the AASHTO code equation diverges from that predicted by numerical analysis at high confining pressure, because the contribution of friction in the total shear capacity decreased with an increase in confining pressure. Hence, the authors recommend reducing the friction coefficient used in the AASHTO code equation when high confining pressure is applied. Moreover, the propagation of inclined crack was arrested at high confining pressure owing to the fact that the fracture propagation direction is governed by the criterion of the maximum energy release rate.

Field Verification of Simplified Analysis Procedures for Segmental Concrete Bridges

Load tests on segmental bridges are uncommon in the literature given their relatively short history and comparatively smaller presence in the national bridge inventory. This paper presents results from two segmental concrete bridge field tests and compares them with common simplified longitudinal and transverse analysis procedures. These single-cell structures, built with balanced cantilever construction, represent two significantly different segmental concrete bridges. Designers frequently use a beamline model for longitudinal analysis. When compared with the load test results, this simple method produces conservative predictions of longitudinal behavior within 20%, which is also reflected in the literature. Conversely, little information exists in the literature on transverse bending analysis. When analyzing the localized transverse bending from concentrated wheel loads, designers commonly use an equivalent frame model. Most frequently, designers use influence surfaces to estimate the scaled loads to apply to these two-dimensional frame models. This simplified approach is shown to be conservative overall but cannot always predict bending sense and frequently overpredicts demand in excess of 100%.

Shear Behavior of Dry Joints with Castellated Keys in Precast Concrete Segmental Bridges

Precast concrete segmental bridges with dry joints have the advantages of rapid construction speed and low cost. The shear strength and shear behavior of dry joints with castellated keys in precast concrete segmental bridges are still debatable. In this paper, full-scale dry joints with castellated keys were tested under different confining stress levels. The main parameters for tests were the number of keys, the confining stress, the depth in key geometry, and the distance between two keys. For comparison purposes, flat joints, monolithic joints, and joints with steel fibers were also tested. The shear behavior, shear capacity, and crack pattern of the joints were investigated as well. Two crack modes for the single-keyed joints are explicitly proposed. The phenomenon of sequential failure of multikeyed dry joints from the inferior key to the superior one was observed in the tests and verified by finite-element simulation. The experimental results obtained in these tests were compared with the design provisions. A shear failure mechanism of sequential failure for multikeyed dry joints is presented to explain the differences between the test results and the formula used. Based on the new explanation and test results, a reduced coefficient of 0.7 is recommended for the shear strength of three-keyed dry joints. Pending more test data, this conclusion could be extended to the shear strength of multikeyed dry joints to improve the formula.

Time-Variant Flexural Reliability of Posttensioned, Segmental Concrete Bridges Exposed to Corrosive Environments

Posttensioned (PT) bridges are used on major thoroughfares because they are economical structures for traversing long spans. Special inspections of these bridges have revealed corrosion of the strands at void locations in the tendons. The integrity of these strands has significant influence on the safety of these bridges. Inspections indicate that many ducts (parts of the tendon that is supposed to protect strands from exposure to aggressive environments) are cracked and many grout holes and vents are opened, allowing direct ingress of moisture and chlorides. This paper presents a framework for assessing the flexural reliability of PT bridges exposed to various environmental conditions. The moment capacity of a PT girder is formulated using probabilistic models for the tension capacity of corroding PT strands exposed to various void and environmental conditions. Using Monte Carlo simulations, the flexural reliability of an example PT bridge is assessed. The research indicates that the flexural reliability index reaches a value below the recommended value within a relatively short period of time when moisture and chlorides infiltrate the tendons. These findings emphasize the critical need for new inspection, assessment, and repair methods for these bridge types.

Large-Scale Seismic Testing of a Hybrid Sliding-Rocking Posttensioned Segmental Bridge System

AbstractIn this paper, a novel precast concrete segmental bridge system is introduced and experimentally investigated. The system consists of segmental members incorporating hybrid sliding-rocking (HSR) joints and internal unbonded posttensioning (PT). The HSR joints are plane interfaces that are oriented normal to the member axis and do not include shear keys or epoxy adhesives. The HSR joints are designed to exhibit sliding (slip-dominant, SD) or rocking (rocking-dominant, RD) to mitigate the applied seismic loading and reduce damage. The joint response is affected by the PT system, which can include straight or curved tendons. Two types of HSR members are developed and investigated: (1) members with SD joints and straight tendons, intended for substructure columns (HSR-SD columns), and (2) members with RD joints and curved tendons, intended for superstructure girders (HSR-RD girders). The SD joints are shown to offer energy dissipation with low damage through sliding in addition to moderate self-center...

Measuring Displacement of Tall Concrete Columns during Construction

Multiple-span, segmental concrete bridges built by balanced cantilever construction demand precise geometric control so that adjoining tips align at the time the closure segment is cast. When this type of bridge superstructure is cast monolithically on tall piers, moment redistribution, as well as creep, shrinkage, and temperature effects, can cause excessive demand on the exterior end spans and piers of the structure. To compensate, designers often use horizontal forces (jacking) to induce a counteractive moment in the pier columns. However, designers often do not make the effort to ensure that the intended displacement is realized at the needed structural elements. A methodology for measuring deflections of tall pier elements with tiltmeters during construction is presented in this paper for the Jeremiah Morrow Replacement Bridge, Interstate 71, Lebanon, Ohio. Fast-sampling data collection systems and postprocessing algorithms, including thermal effect removal, are detailed. In addition to the deflections from unbalanced cantilever moment during the casting cycle, fast-sampling data for the first horizontal jacking event are discussed and compared with the data collected through traditional laser survey techniques. The data were valuable information. They allowed the designer to fine-tune the geometry setup during the segment casting cycles, and they provided real-time displacement readings that permitted field decisions about the final force application during the jacking event.

An Emulative Precast Segmental Concrete Bridge Column for Seismic Regions

This work proposes a new precast segmental concrete bridge column. The lower region of the column is built using cast-in-place (CIP) construction. The height of the CIP region and level of post-tensioning force in the precast region are selected such that the ultimate condition of the column under seismic loading is governed by a conventional plastic hinge mechanism in the CIP region. A tall column was constructed and subjected to cyclic loading. Test results indicate that the column has excellent ductility and energy dissipation. A pushover analytical method was proposed and applied to the proposed column. This method captured joint opening through the joint rotation length and the amount of curvature exceeding the cracking curvature. Analytical results agree well with test results in predicting the envelope of hysteretic behavior, the increase in axial force in the precast region, and the contribution of precast and CIP regions to column displacement.

Simplified Analytical Pushover Method for Precast Segmental Concrete Bridge Columns

Precast construction is an increasing trend of concrete bridge technology to fulfill the demand of innovative technique that yields accelerated, durable and safe bridge construction. Although precast bridge superstructures are widely used in bridge construction projects from the U.S. to Asia, precast substructures are seldom used. The lack of in-depth understanding of seismic behavior of precast substructures causes concern about their performance in high seismicity area. A simplified analytical method for pushover analysis of precast segmental concrete bridge columns is proposed in this study. The method is validated through comparison with test and fiber model analysis results. A parametric study is conducted to investigate the seismic behavior of precast segmental concrete bridge columns using the proposed simplified analytical method. The influences of the aspect ratio, axial load ratio and energy dissipation (ED) bar ratio on the force-displacement response characteristics, i.e., displacement ductility, joint opening drift, failure drift, maximum ED bar strain and concrete strain at the extreme compression fiber are investigated. The simplified analytical method shows superior ease for use with acceptable precision in comparison with the fiber model or three-dimensional finite element model.

Evaluation of the static and dynamic structural performance of segmental pre-stressed concrete box girder bridge after repairing and strengthening

The objectives of this study are to explain the repairing and strengthening methods which are used to improve the structural performance of the bridge structure, to analyze the static and dynamic responses after strengthening, and to evaluate the performance of the bridge structure after repairing and strengthening. The methods of repairing and strengthening include reconstruction the deck of the bridge by casting 10 cm layer of concrete, strengthening the web and bottom floor of box girders of middle spans and side spans by sticking the steel plates, strengthening the whole bridge structure by using external pre-stressing tendons, and treatment the cracks. The results of theoretical analysis show that the values of tensile stress and vertical deflection are decreased and the compressive stress is increased after strengthening. There are not tensile stresses are appeared in the sections of the bridge structure. The modal analysis results show that the value of natural frequency is equal to 2.09 Hz which is more than the values before strengthening which is equal to 1.64 Hz, indicating that the stiffness of the bridge structure is improved and the strengthening process is effective to improve the cracks resistance and bearing capacity of the bridge structure.

Serviceability of segmental concrete arch-frame bridges built by cantilevering

The evaluation of the safety degree in service life for a segmental prestressed concrete bridge built by the cantilever method presents different aspects related to strength, deformability, durability and to effects of time-dependent phenomena as creep and shrinkage. The case-study of a prestressed concrete frame bridge with inclined piers is presented, built by cantilevering, with precast segments. By considering the fundamental items of design and construction stages, the implications due to the arch effect in this static scheme are investigated, with respect to an equivalent bridge with a final scheme of continuous girder on vertical piers. The birth of a significant value of axial force in the main span is considered and the stress redistribution in time due to the effects of creep on the static scheme change during construction is analysed. The main parameters involved are underlined and results in terms of serviceability and ultimate limit state are obtained. Finally, aspects related to durability are considered and analysed in the presented case-study.

Towards a model of dry shear keyed joints: modelling of panel tests

This paper presents a study on the behaviour of the joints of segmental concrete bridges with external prestressing, focusing on the structural response of dry non-epoxied joints with shear keys. A Finite Element joint model to study such structures is validated modelling eight concrete panel tests. The most important feature of this model is that it has been validated with experimental tests on concrete panels which were specifically designed to fail in shear. Interface elements are used to reproduce the non linear behaviour of the joint and parameters deduced from the tests are used to define the constitutive law of these elements. This joint model is of great importance because it will permit the development of a structural model that faithfully reproduces the behaviour of these structures under combined flexure and shear and the study of its global behaviour after the opening of the joints. Interesting conclusions about the behaviour of the dry joints, about the contribution of the different mechanisms transferring shear (friction and cohesion) and about the shear stress distribution in the joint have been reached.

Combined Shear and Bending Behavior of Joints in Precast Concrete Segmental Beams with External Tendons

Precast concrete segmental bridges with external tendons are becoming widely constructed all over the world. The main objective of this study is to obtain a further understanding of the behavior of joints when they are subjected to combined shear and bending. Nine specimens of precast concrete segmental beams (PCSBs) with external tendons were match cast and tested: six of the specimens were tested under combined shear and bending; two specimens were tested under pure bending; and one specimen was tested under direct shear. Failure processes and modes, joint resistance, and strains of stirrups and prestressing tendons were recorded in the tests. Based on the results of the experiment, the study analyzed the mechanism of combined shear and bending resistance for dry and epoxied joints when loads were located in the immediate vicinity of the joint. Additionally, simplified failure modes of dry and epoxied joints subjected to combined shear and bending were presented in this paper. On the basis of the simplified failure modes, formulas were deduced for evaluating the resistance of joints when failure occurred in a joint section with loads applied in the immediate vicinity of the joints. The formulas provided a rational prediction of the joint resistance under combined shear and bending, which in turn verified the rationality of the proposed failure modes.

Performance evaluation of dry and epoxy jointed segmental prestressed box girders under monotonic and cyclic loading

A large number of post-tensioned prestressed concrete segmental bridges are being constructed worldwide. Use of different materials and shear keys will have varying effects on the performance of segmental girders even during the service load. The type of joints, quality of joint, degree of mechanical actions and the joint materials will contribute to the variation in the behaviour of the segmental girders. Hence, the need for investigation on the epoxy jointed segmental box girder and dry jointed segmental box girder becomes necessary. This paper presents the experimental investigations carried out in laboratory environment on a scaled model of a simply supported precast post-tensioned box-girder bridge deck that is cast using segmental construction method. Performance of box-girders with dry and epoxy joints is evaluated under static and cyclic loading. It is observed from the results that the flexural strength of dry jointed specimen is less than the epoxy joint due to high concentration of rotation and deflection at individual joints of segmental girder. Upto design load, segmental box girder specimen with dry and epoxy joints behaved like monolithic beam. However, it is found from the study that first joint opening load of the dry jointed specimen is 27% less than the epoxy jointed specimen due to lack of resistance to tension between the joints. Due to high concentration of rotation and deflection at individual joints in the dry jointed specimen, the maximum load and failure load are 8.6% and 16.7% less than that of the epoxy jointed specimen. The study will help in understanding the role of type of joint and the material used on the performance of the segmental bridges.

Fault-Tree Model for Risk Assessment of Bridge Failure: Case Study for Segmental Box Girder Bridges

Over the past few decades, the design capacity and service condition of many bridges, which are vital components of the surface transportation infrastructure reliability and functionality, have been challenged by rapid traffic growth and scarce maintenance funds. Numerous incidents of bridge collapse call for an urgent need to develop a systematic method of assessing the failure risks and identifying the initiating events that can lead to a bridge collapse. This paper presents a process of bridge failure risk analysis through fault-tree modeling for a common type of bridge known as segmental concrete box girder bridge. The process was applied to a segmental box girder bridge in South Carolina and was found to effectively identify causal factors of bridge failure and estimate overall failure risk. However, to comprehensively assess the probability of bridge failure, fault-tree analysis can best be used in combination with current risk assessment methods, such as visual inspections and structural health monitoring sensors.