Composite Bridge Deck Research Articles

Structural Damage Identification Using Response Surface-Based Multi-objective Optimization: A Comparative Study

Non-destructive structural damage identification (SDI) and quantification of damage are important issues for any engineering structure. In this study, a comparative assessment of the damage identification capability of different design of experiment (DOE) methods (such as, 2 k factorial design, central composite design, Box–Behnken design, D-optimal design and Taguchi’s OA design) used in response surface methodology (RSM) has been carried out. Three different structures (simply supported beam, spring mass damper system and fibre reinforced polymer composite bridge deck) have been used for various single and multiple damage conditions to access the comparative ability of the aforementioned methods in identifying damage addressing two critically important criteria: accuracy and computational efficiency. The study reveals that central composite design and D-optimal design are most recommendable among the five considered DOE methods for SDI. Two different input parameter screening methods (sensitivity analysis using RSM utilizing 2 k factorial design and D-optimal design, general sensitivity analysis) have been explored in this study, and their comparative performance is also discussed. It is found that both the methods used in sensitivity analysis for the purpose of input parameter screening in the damage identification process work satisfactorily. Performance of RSM-based damage identification algorithm for different DOE methods under the influence of noise has also been addressed in this paper.

Performance of a lightweight GFRP composite bridge deck in positive and negative bending regions

This paper presents results from an experimental and analytical study of a newly developed lightweight composite bridge deck system composed of pultruded trapezoidal GFRP tubes and outer wrap. Panels with different grout materials and grouting patterns were evaluated and compared in terms of flexural stiffness. Two-span tests were performed on non-grouted and epoxy grouted panels to simulate a multi-girder bridge configuration and to evaluate their structural behavior in both positive and negative bending regions. Test results showed that the epoxy grouted panel meets the AASHTO deflection requirement (L/800) and performed well under service loads. An analytical model was developed to predict the load–deflection response of grouted and non-grouted panels at incremental load steps, even beyond the uncracked stage. The proposed model shows that shear deformation must be considered in order to accurately predict the behavior of GFRP panels in multi-girder bridges.

The Influence of the Aspect Ratio on the Composite Material Bridge Deck Structures

Theories for composite material structures are too difficult for such design engineers for construction and some simple but accurate enough methods are necessary. The author has reported that some laminate orientations have decreasing values of <TEX>$D_{16}$</TEX>, <TEX>$B_{16}$</TEX>, <TEX>$D_{26}$</TEX> and <TEX>$B_{26}$</TEX> stiffnesses as the ply number increases. For such plates, the fiber orientations given above behave as specially orthotropic plates and simple formulas developed by the author. Most of the bridge deck structures on girders have large aspect ratios. For such cases further simplification is possible by neglecting the effect of the longitudinal moment terms <TEX>$M_x$</TEX> on the relevant partial differential equations of equilibrium. In this paper, the result of the study on the subject problem is presented.

Simplified load distribution factors for fiber reinforced polymer composite bridge decks

In recent years, researchers have investigated the load distribution factors due to vehicle wheel loads. Several load distribution factors for fiber reinforced polymer deck-steel stringer bridge systems have been proposed. Unfortunately, these load distribution factors are only used for each particular fiber reinforced polymer bridge deck system. Therefore, the objective of the research effort is to present the load distribution results of a parametric study using finite element analysis. The simplified load distribution factors were developed herein. The bridge parameters for this study were stringer spacing, bridge span, width of bridge models, types of fiber reinforced polymer bridge decks and numbers of traffic lanes. The bridge responses under various wheel loading conditions were investigated. The simplified distribution factors based on “S-over-factor” formula were proposed and compared with the load distribution factors obtained from specifications, analytical and field data. The load distribution results for this present study were correlated to the previous research data. The upper and lower bound limit of the load distribution factors were presented to purpose of preliminary guidelines.

Design and Testing of a Concrete Safety Barrier for Use on a Temporary FRP Composite Bridge Deck

AbstractFiber-reinforced polymer (FRP) composite materials can be used for the fabrication of lightweight, corrosion-resistant honeycomb sandwich panels, representing a convenient and economical alternative to traditional steel RC for bridge decks. Composite panels are particularly advantageous for the construction of temporary bridge structures in terms of both ease of construction and reusability of panels. Although FRP sandwich panels have been considered for the construction of bridge decks, no barrier system has been developed and crash tested for use with this specific type of deck. The objective of this research project was to develop a crashworthy concrete barrier system for use with temporary FRP composite bridge decks. Upon failure of a full-scale crash test with a New Jersey concrete safety shape barrier, an accurate analysis of the potential problems led to a series of design modifications to the barrier as well as to the attachment between the composite deck and both the bridge structure and ...

Long-Term Monitoring of FRP-Concrete Composite Bridge Deck for Cable-Stayed Bridges Using Optical Fiber Sensors

The Korea Institute of Construction Technology has developed a precast FRP-concrete composite deck to be applied to cable-stayed bridges. This deck is a precast structural system in which concrete is disposed at the upper part and a hollow FRP tube is disposed at the bottom to play the role of tensile reinforcement and form. This paper presents the prototype of the so-developed FRP-concrete composite deck fabricated for trial construction. Electrical resistance sensors and optical fiber sensors were installed on the prototype to evaluate its structural stability and serviceability during the 17 months of operation through a series of field loading tests. From the field loading test results, the FRP-concrete composite deck was verified to secure sufficient structural stability and serviceability along the 17 months of operation even after the repeated passage of the heavy construction trucks. Besides, it appeared also that, for long-term monitoring, the optical fiber sensor provided more reliable measurement than the electrical resistance sensor glued to the structure.

Experimental study of static behaviour of stud shear connectors

An experimental program involving the test of 25 push-out specimens was conducted to study the behaviour and strength of shear studs in the application of composite bridge decks and to assess the detailing requirement specified in the code practice. Testing parameters included reinforcement mesh position, presence of stud head, and stud height. An alternative type of shear studs, referred to as adjustable studs, was also studied and its capacity was compared with conventional studs. Results showed that the position of reinforcement mesh affected the specimen failure mode and ultimate load. Comparing with the cases where the mesh was placed either flush with the stud head or above the stud, the maximum ultimate load was reached and the failure was by stud shear-off when the mesh intercepted the studs. Shear studs with heads resulted in a higher ultimate load in specimens than unheaded shear studs. In the comparison between conventional and adjustable shear studs, while they shared similar failure modes, adjustable studs showed on average lower load capacity than their conventional counterparts. For all specimens studied, only specimens with reinforcement mesh satisfying the detailing requirement were able to attain the code specified strength.

FRP-Balsa Composite Sandwich Bridge Deck with Complex Core Assembly

The aim of this work was to investigate to what extent the performance of a glass fiber–reinforced polymer (GFRP) sandwich slab-bridge with a uniform high-density balsa core could be improved in terms of structural efficiency and weight by using a more complex core assembly. This core consisted of high-density and low-density balsa and a fiber-reinforced polymer (FRP) arch inserted into the balsa high/low density interface. Quasi-static load-bearing experiments on sandwich arch-beams with complex core assemblies under symmetric four-point and asymmetric three-point loading were performed. The FRP arch reduced the force in the upper face sheet in the mid-span region and thus prevented compression failure of the latter, which led to a higher ultimate load. It also contributed to the shear resistance by up to 20% for symmetric loading. The best overall performance in terms of structural efficiency (stiffness and resistance) and weight resulted from a core configuration with a GFRP arch between an upper high-density and lower low-density balsa core.

Fatigue analysis and life prediction of composite highway bridge decks under traffic loading

STEEL AND COMPOSITE (STEEL-CONCRETE) HIGHWAY BRIDGES ARE CURRENTLY SUBJECTED TO DYNAMIC ACTIONS OF VARIABLE MAGNITUDE DUE TO CONVOY OF VEHICLES CROSSING ON THE DECK PAVEMENT. THESE DYNAMIC ACTIONS CAN GENERATE THE NUCLEATION OF FRACTURES OR EVEN THEIR PROPAGATION ON THE BRIDGE DECK STRUCTURE. PROPER CONSIDERATION OF ALL OF THE ASPECTS MENTIONED POINTED OUR TEAM TO DEVELOP AN ANALYSIS METHODOLOGY WITH EMPHASIS TO EVALUATE THE STRESSES THROUGH A DYNAMIC ANALYSIS OF HIGHWAY BRIDGE DECKS INCLUDING THE ACTION OF VEHICLES. THE DESIGN CODES RECOMMEND THE APPLICATION OF THE CURVES S-N ASSOCIATED TO THE MINERRS DAMAGE RULE TO EVALUATE THE FATIGUE AND SERVICE LIFE OF STEEL AND COMPOSITE (STEEL-CONCRETE) BRIDGES. IN THIS WORK, THE DEVELOPED COMPUTATIONAL MODEL ADOPTED THE USUAL MESH REFINEMENT TECHNIQUES PRESENT IN FINITE ELEMENT METHOD SIMULATIONS IMPLEMENTED IN THE ANSYS PROGRAM. THE INVESTIGATED HIGHWAY BRIDGE IS CONSTITUTED BY FOUR LONGITUDINAL COMPOSITE GIRDERS AND A CONCRETE DECK, SPANNING 40.0M BY 13.5M. THE ANALYSIS METHODOLOGY AND PROCEDURES PRESENTED IN THE DESIGN CODES WERE APPLIED TO EVALUATE THE FATIGUE OF THE BRIDGE DETERMINING THE SERVICE LIFE OF THE STRUCTURE. THE MAIN CONCLUSIONS OF THIS INVESTIGATION FOCUSED ON ALERTING STRUCTURAL ENGINEERS TO THE POSSIBLE DISTORTIONS, ASSOCIATED TO THE STEEL AND COMPOSITE BRIDGERS SERVICE LIFE WHEN SUBJECTED TO VEHICLERS DYNAMIC ACTIONS.

Experimental assessment of flexural strength and serviceability of prestressed SCC bridge I-girders with composite decks

This paper examines the flexural behavior of prestressed Self-Consolidating Concrete (SCC) bridge I-girders when subjected to monotonic and cyclic loading. Three full-scale prestressed bridge girders were constructed with limestone aggregate concrete and tested until failure. One of the girders was made with Conventional Concrete (CC) and served as a control specimen, while the other two girders were made with SCC. The girders were fitted with composite CC thickening over the top flange to represent composite bridge decks. The control girder and one of the SCC girders were subjected to monotonically increasing load until failure. The remaining SCC girder was subjected to a sequence of cyclic loads with increasing load amplitudes until failure. The results show that prestressed SCC and CC bridge girders exhibit similar flexural stiffness and strength and that the current code methods for determining transfer length, effective prestress, flexural strength, and flexural stiffness can be used for prestressed SCC girders.

Determination of Stiffness of the Connections of Composite Steel and Concrete Bridge Deck by the Limit Permissible Deflections

The composite steel and concrete structures are used for constructing bridge floors and others buildings. The joint action of composite structures as well as their economic efficiency depends on the connection between the layers, i.e. stiffness of the steel beam and the concrete slab. Under the effect of external load in the connection of steel and concrete the shear deformations occur. The size of these deformations depends on the effective shear stiffness of the connection of layers. When designing the composite steel and concrete structures it is very important to accurately calculate their deflections. Deflection is largely dependent on the stiffness of the connection of steel and concrete. In isolated cases it is purposive to calculate the necessary stiffness of the connection of steel and concrete taking into consideration the permissible deflection of the composite steel and concrete structure. This paper gives the methodology which, based on the known permissible deflection of the structure, allows to calculate the necessary equivalent effective shear modulus of the steel-concrete connection. Experimental investigations of the composite steel and concrete beams were carried out. Deflections of the composite beams, also the shear deformations of steel and concrete connections and the effective shear stiffness of this connection were determined. Theoretical calculations of the effective shear stiffness of the connection of concrete slab and steel beam of the experimental composite steel and concrete beams were conducted. Investigations showed a rather good correspondence between the experimental and theoretical investigation results.

Experiments on a Hybrid-Composite Beam for Bridge Applications

This paper details a study of the structural behavior of hybrid-composite beams (HCBs), which consist of a fiber-reinforced polymer (FRP) shell with a tied concrete arch. The HCB offers advantages in life-cycle costs through reduced transportation weight and increased corrosion resistance. Through a better understanding of system behavior, the proportion of load in each component can be determined, and each component can be designed for the appropriate forces. A long-term outcome of this research will be a general, structural analytical framework, which can be used by transportation departments to design HCBs as rapidly constructible bridge components. This study focused on the identification of the load paths and load sharing between the arch and FRP shell in an HCB and on the test of an HCB with a composite bridge deck. Tests were performed through the application of point loads on simple span beams (before the bridge deck was placed) and with a three-beam, skewed composite bridge system, which resulted in strain data for the arch and FRP shell. The test results showed that strain behavior was linear elastic at service loads, and the FRP shell had a linear strain profile. Curvature from strain data was used to find internal bending forces, and the proportion of load within the arch was found. A stress integration method was used to confirm the internal force contributions. The arch carried about 80% of the total load for the noncomposite case without a bridge deck. When composite with a bridge deck, the arch made a minimal contribution to the HCB stiffness and strength, because most of the arch was below the neutral axis and cracked under the maximum live load expected for the bridge. For this composite case, the FRP shell and prestressing strands resisted about 80% of the applied load, while the bridge deck carried the remaining 20% to the end diaphragms and bearings.

Slab Cracking Control in Continuous Steel-Concrete Bridge Decks

This paper presents a study on the effectiveness of various casting techniques used to control slab tensile stresses during the construction of continuous steel-concrete composite bridge decks. The main features describing the early age behavior of concrete are outlined and available modeling options are considered. A practical procedure is presented for the evaluation of the slab stress state taking place at various construction stages based on the modular ratio approach suggested by Eurocode 4. The method, which can be implemented using commercial software, requires the evaluation of suitable modular ratios and creep coefficients to estimate the time-dependent effects of the concrete slab weight and the thermal, endogenous, and drying shrinkage components. This simplified procedure is then applied to a case study to evaluate, for various casting sequences, the contributions of the concrete weight and shrinkage components to the slab early cracking. Finally, the efficiency of various casting techniques in controlling the slab tensile stresses is presented and discussed.

The Applicability Study on the FRP-Concrete Composite Bridge Deck for Cable-Stayed Bridges

This study is related to the FRP-concrete composite bridge deck for cable-stayed bridges developed by the Korea Institute of Construction Technology since 2007. This deck disposes a FRP panel at the bottom and is orthotropic owing to its fabrication through pultrusion process. In the cable-stayed bridge applying precast deck, support conditions occur at the cross beam and edge girder. Therefore, need is to verify the performances in the longitudinal and transverse directions when applying the orthotropic deck to cable-stayed bridges. Accordingly, specimens enabling to verify the performance in each direction are fabricated and subject to structural performance test. Based on the test results, the serviceability and applicability of the FRP-concrete composite deck to cable-stayed bridges are evaluated.

Structural performance of light weight multicellular FRP composite bridge deck using finite element analysis

Fiber reinforced polymer (FRP) composite materials having advantages such as higher strength to weight than conventional engineering materials, non-corrosiveness and modularization, which should help engineers to obtain more efficient and cost effective structural materials and systems. Currently, FRP composites are becoming more popular in civil engineering applications. The objectives of this research are to study performance and behavior of light weight multi-cellular FRP composite bridge decks (both module and system levels) under various loading conditions through finite element modeling, and to validate analytical response of FRP composite bridge decks with data from laboratory evaluations. The relative deflection, equivalent flexural rigidity, failure load (mode) and load distribution factors (LDF) based on FE results have been compared with experimental data and discussed in detail. The finite element results showing good correlations with experimental data are presented in this work.

Moisture diffusion in glass–fiber-reinforced polymer composite bridge under hot/wet environment

In literatures, researches on degradation of composites due to environmental effects were well documented on fiber-reinforced polymer (FRP) composites for Aerospace Engineering; for FRP composites utilized in Civil Engineering field, the available information was very limited. In order to keep pace with the application of FRP composites in Civil Engineering field, this research was undertaken to reveal more knowledge about the environmental degradation of FRP composite bridge under hot/wet environment. By gravimetric experiments, the moisture diffusion in thin-section of FRP composites and adhesives were characterized. Based on the analytical model of one-dimensional moisture diffusion theory, the diffusion coefficients were determined by the best least-square curve fitting to the experimental data. The finite element (FE) models of test specimens were developed and validated against experimental results. Through transient FE diffusion analysis, the moisture diffusion into the FRP-steel composite bridge deck system under a hot/wet environment was numerically predicted up to 100-year aging duration. The moisture uptake in adhesive connection was fully saturated after 26-year aging. The area between FRP composite sections and the adhesive layer was confirmed to be the most sensitive part to moisture effects. This research developed a step towards the prediction of long-term performance and life-time estimation of FRP-steel composite bridges.

Experiment Study on Static Mechanical Behavior of Plain Steel Plate-Light Weight Concrete Hollow Composite Decks

Steel plate-light weight concrete hollow composite deck was a type of novel composite deck which composed of steel plate, perforbond ribs connectors (PBL connectors) and light weight concrete and steel pipe. In order to understand the hollow composite decks mechanical performance, Static experiments of five specimens of this hollow composite slabs were conducted, among which two specimens were composed with longitudinal steel pipes and three specimens were composed with transversal steel pipe, with the aim to study the difference of the mechanical behaviors of the composite decks at the two orthogonal directions. Based on the experiment results, the effects of the direction of steel pips and the nominal shear-span of the slabs on the composite decks mechanical performance were especially studied. During the experiment process, the failure modes, strains of concrete and steel plate, cracking type, slippage of interface and the bearing capacity of the decks were studied in detail. From the experimental study, it could be found that there were no slippage between the steel plate and concrete were measured at the composite bridge decks, and the composite bridge decks showed high flexural rigidity, good ductility as well as better bearing capacity with the strength of bottom steel plate and top concrete both fully utilized. Therefore, it could be concluded that this type of composite bridge decks have good advantages at mechanical behaviors.

New Conception of the Shear Connector for Composite Bridge Decks

The research deals with a composite steel and concrete slab used as a bridge deck. The main task is to ensure the suitable connection between two parts of composite plate – steel and concrete. Well known and widely spread are headed studs as the shear connectors. This work describes the behavior of the alternative shear connector especially the utilization of modified concrete reinforcement mesh. The concrete reinforcement mesh is suitable curved and welded on the top of the steel plate in some places and after that the mesh is embedded in concrete. The paper introduces the first phase of the investigation; the preparations for push out tests.

Basic Performance of the Composite Deck System Composed of Orthotropic Steel Deck and Ultrathin RPC Layer

Fatigue damage in a conventional orthotropic steel bridge deck system poses a formidable challenge to bridge engineers all over the world because of ever-increasing heavy traffic volumes and higher wheel loads over the past decade. An effective solution may be to enhance the stiffness of the bridge deck to reduce the fatigue stress amplitude of its components. This paper proposes an innovative composite bridge deck system that consists of an orthotropic steel deck stiffened with a 45-mm reactive powder concrete (RPC) layer. Based on the analysis of HuMen Bridge in China (a suspension bridge with a conventional orthotropic steel bridge deck system with span length of 888 m) and two types of full-scale model tests, a comparison investigation is conducted between a conventional orthotropic deck system where the asphalt wearing course has been ignored and the proposed orthotropic deck system that includes an integral concrete wearing course, and the proposed composite bridge deck system proves to be considerably effective in reducing the stress range caused by service vehicle loads when applied to long-span steel suspension bridges. The thin RPC layer can be reliably integrated with the deck plate through stud shear connectors, and no shrinkage cracking occurs on the surface of the RPC layer that is cast on the deck plate. The fact that the tensile stress of the RPC layer is up to 42.7 MPa before cracking occurs demonstrates that cracking will not appear in the RPC layer under service vehicle loads. The analysis, which is investigated on the premise that the dead load weight of the bridge deck of HuMen Bridge is approximately the same for the two different deck systems, demonstrates that the stress of the orthotropic steel deck is significantly reduced with the application of the proposed composite deck system. Analysis with a three-dimensional finite-element model indicates that the transverse tensile stress of the deck plate is reduced by 71%, while that of the connection between the deck plate and the longitudinal troughs is reduced by 72%. This indicates that the risk of causing fatigue cracks in the steel bridge deck system can be considerably reduced during the entire life cycle of the bridge.

Control of cracking in composite bridge decks in regions in biaxial tension

AbstractDeck slabs of bridges of composite construction can in places be stressed in biaxial tension throughout their thickness. Rules for control of crack width in codes such as EN 1994‐2 are based on tests in uniaxial tension. Crack‐width measurements are reported from tests in 1977 on slabs in biaxial tension, acting as flanges of composite beams. A theoretical model for prediction of crack width is explained, and a method is given for applying the rules of EN 1994‐2 to biaxial tension. It gives results slightly more conservative than characteristic values deduced from the test results.Rissbreitenbeschränkung in Bereichen unter zweiachsialer Zugbeanspruchung für Fahrbahnplatten von VerbundbrüKen. Fahrbahnplatten von Verbundbrücken können teilweise über ihre gesamte Dicke durch zweiachsiale Zugbeanspruchungen belastet werden. Regelungen zur Rissbreitenkontrolle in Normen wie EN 1994‐2 beruhen auf Versuchen unter einachsialer Beanspruchung. Zu Versuchen aus dem Jahr 1977 liegen Ergebnisse von Rissbreiten‐Messungen an Platten unter zweiachsialer Beanspruchung vor, bei denen die Platten als Gurte von Verbundträgern wirkten. Es wird ein theoretisches Modell zur Vorhersage von Rissbreiten erläutert und eine Methode zur Anwendung der Vorschriften der Norm EN 1994‐2 auf zweiachsige Zugbeanspruchung vorgestellt. Die Ergebnisse des Modells sind etwas konservativer als die charakteristischen Werte, die aus den Versuchen ermittelt wurden.