Fiber Reinforced Polymer Bridge Decks Research Articles

Evaluation on mechanical properties of high‐performance biocomposite bridge deck structure: a review

AbstractNowadays, the problem of performance deterioration caused by the steel‐bar corrosion of reinforced concrete (RC) bridge decks has been serious gradually. Hence, fiber reinforced polymer (FRP) composites have already become alternative structural materials to traditional RC because of the characteristic of lightweight and high‐strength, better corrosion and fatigue resistance, and so forth. But they are also accompanied by some defects as being expensive and harmful to the environment and human health. Biocomposites have beneficial properties such as low density, less expensive, and reduced solidity while compared with synthetic FRP composite products, thus providing advantages for utilization in civil engineering structural applications. Furthermore, using natural fibers as reinforcement for composites introduces positive effects on the mechanical behavior of biocomposite structures. This paper mainly reports the research status of FRP and biocomposite bridge decks and their mechanical properties including flexural, shear, punch shear, and fatigue performances; summarizes some design methods and related innovative research results of FRP bridge deck to provide the design base for the biocomposite bridge deck, discusses the issue of insufficient mechanical properties of biocomposites applied to bridge deck structure, and introduces the high‐performance methods of natural fiber composites. It is conducive to the investigation and promotion of biocomposites as structural materials in civil engineering. In addition, there is some crucial reference significance and value for the development of a green and sustainable engineering structure.

Testing and evaluation of full scale fiber-reinforced polymer bridge deck panels incorporating a polyurethane foam core

A fiber-reinforced polymer (FRP) bridge deck panel that incorporates a polyurethane foam core was developed for accelerated bridge construction and repair. This low cost panel was tested under monotonic loading and compared to applicable FRP design equations. This new prototype system consisted of two stiff facesheets of stitch bonded plain-weave woven E-glass fabric with sloping webs of E-glass woven fabric that are separated by trapezoidal-shaped, low-density polyurethane foam. The polyurethane foam was used in an attempt to reduce initial costs. The panels used in this study were manufactured using a one-step, vacuum-assisted, resin transfer molding process (VARTM) using a newly formulated, two-part, thermoset, polyurethane resin developed by Bayer MaterialScience to facilitate the infusion process. The results of the flexural and shear testing indicated that the prototype panels significantly exceeded the AASHTO Design Code Strength requirements by nearly three times. Even more importantly, the panels behaved linearly-elastically throughout the full range of loading and possessed significant post-buckling strength. In addition, the results of these full-scale panels were used to evaluate the applicability of existing FRP design equations when used for the design of the VARTM- manufactured, prototype FRP bridge deck. Results showed that the existing FRP design equations correctly predicted a flexural failure due to local buckling of the compression flange and a bearing failure due local buckling of the webs beneath the concentrated load.

Temperature Induced Nonlinear Effect on Free Vibration Characteristics of Fibre Reinforced Polymer Bridge Deck

The present paper deals with free vibration analysis of fibre reinforced polymer (FRP) bridge deck considering temperature induced nonlinear behaviour of composite materials. The finite element formulation based on the third-order shear deformation theory using Green–Lagrange approach of nonlinearity by considering large deformation and large rotation is developed to model the FRP bridge deck panel. The bridge deck is modelled by using a laminated plate with closely spaced box stiffeners. The plate and the stiffeners elements are formulated separately and merged thereafter. The eight-noded isoparametric plate bending elements and the three-noded isoparametric beam elements are used to formulate deck plate and stiffeners, respectively. Compatibility between plate and stiffener elements is maintained by considering identical degrees of freedom per node for both. The effect of temperature rise on natural frequencies of a laminated composite plate is studied in the present paper. The free vibration modal analysis is carried out to identify the effect of temperature change with proper temperature distribution within the stiffened structures using 1D heat conduction model, and the solutions may be used as benchmark.

Durability of glass fiber-reinforced polymer bridge panel based on differential thermal analysis, dynamic mechanical analysis, and differential scanning calorimetry analysis

Modern bridge structures need light decks with long durability and promising technical parameters. Glass fiber-reinforced polymer orthotropic bridge deck creates unconventional possibilities in bridge designing. Parallel identification of glass fiber-reinforced polymer deck panel by differential thermal analysis, spectroscopy analysis, scanning and optical microscope monitoring, dynamic mechanical analysis and differential scanning calorimetry analysis, tensile and flexural tests will be presented in the paper. Differential thermal analysis was carried out for estimation of the physical and chemical transformation of glass fiber. The differential scanning calorimetry experiments were performed in the glass fiber-reinforced polymer–bridge deck material for determining the mass variation and the energy changes suffered by the materials, as a function of temperature and time. Dynamic mechanical analysis was allowed to detect thermal effects based on the changes in the modulus or damping behavior. Tensile and flexural tests allowed the observation of the decomposition process and information about the basic stress parameters of glass fiber-reinforced polymer material used in bridge applications was taken. Aforementioned analyses are necessary to examine the durability description of the composite element.

Reinforcing Fibre Reinforced Polymer Bridge Decks with Steel Rods

Fibre reinforced polymer (FRP) bridge decks have become an innovative alternative and they have offered many advantages and this has been increasing attention for applications in not only reinforcement of existing bridges decks but also construction of new bridges decks. The advantages of these FRP decks are; lightweight, high-strength FRP materials, corrosion resistance. However, this high strength deck is not ductile. In this study, the behaviour of hybrid FRP-steel decks are investigated. All FRP decks was analysed with the commercial package ABAQUS. In the FE model, the webs and flanges were discretised by 4 nodes shell elements. A full composite action between the steel and the FRP composite was assumed in the FE analysis because the bond-slip behaviour was unknown at that time. The performance of the proposed hybrid FRP deck panel was evaluated by means of FE analysis.

An approach to the development of connections between fibre reinforced polymer bridge decks

The use of fibre reinforced polymer (FRP) bridge decks has attracted increasing interest as a competitive alternative to traditional decking solutions. Even though the use of FRP decks started in the early 1990s, the uptake of these decks has been slow in bridge construction and there remains a need for research in diverse technical areas to promote the widespread use of these decks. One such area is the detailing and design of deck panel level connections which enable rapid on-site assembly. The development of connections in FRP decks is a somewhat complex process, which should take account of not only the structural performance and durability of the joint but also the ease of application and the tolerances this necessitates. It should therefore be regarded as a process in which the bridge owner, the designer, the manufacturer and the contractor are all involved. This process has been applied in the development of a novel joint configuration for panel level connections presented in this paper. The collaboration between the bridge owner, designer, manufacturer and contractor led to the development of a connection concept, in which expectations originating from the views of all parties were included. In this way, a concept focusing on meeting the requirements of all bodies was designed.

Parametric Study on Dynamic Response of Fiber Reinforced Polymer Composite Bridges

Because of high strength and stiffness to low self-weight ratio and ease of field installation, fiber reinforced polymer (FRP) composite materials are gaining popularity as the materials of choice to replace deteriorated concrete bridge decks. FRP bridge deck systems with lower damping compared to conventional bridge decks can lead to higher amplitudes of vibration causing dynamically active bridge deck leading serviceability problems. The FRP bridge models with different bridge configurations and loading patterns were simulated using finite element method. The dynamic response results under varying FRP deck system parameters were discussed and compared with standard specifications of bridge deck designs under dynamic loads. In addition, the dynamic load allowance equation as a function of natural frequency, span length, and vehicle speed was proposed in this study. The proposed dynamic load allowance related to the first flexural frequency was presented herein. The upper and lower bounds’ limits were established to provide design guidance in selecting suitable dynamic load allowance for FRP bridge systems.

A novel connection for fibre reinforced polymer bridge decks: Conceptual design and experimental investigation

In the past two decades, the use of fibre reinforced polymer (FRP) decks has attracted a great deal of attention when it comes to the refurbishment of existing bridges and the construction of new ones. FRP materials offer superior properties, such as high specific strength and stiffness, light weight, high fatigue and corrosion resistance and good durability. Because of their low self-weight and prefabrication potential, FRP composites lend themselves to accelerated bridge construction, thereby leading to minimised traffic interference. However, one challenge that is posed by FRP deck systems is the detailing and design of panel level connections. Today, a common practice for joining deck panels on site is adhesive bonding, which compromises the benefit of rapid FRP deck installation due to the time-restricted curing required for structural adhesives. As a result, there is a need for the development of joints which enable more rapid assembly. In this paper, a novel joint configuration for panel level connections is proposed. Numerical analyses and static experimental tests were conducted to evaluate the behaviour and load-carrying capacity of the connection. The overall investigation showed that the presented joint concept is a potential alternative for panel level connections in FRP decks.

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.

Durability simulation of FRP bridge decks subject to weathering

Fiber Reinforced Polymer (FRP) composite panels are particularly attractive as bridge decks due to their high strength, low density, and durability, which are of importance in the bridge industry. Although the short term performance of FRP decks is satisfactory, the long-term performance under weather conditions still awaits future testimony and remains a major concern in their use as primary load bearing members. Since the load capacity and structural stiffness of FRP decks deteriorate over time at different rates, it is necessary to develop robust mechanics models to simulate the long-term performance of FRP deck structures subject to the combined effects of mechanical and environmental loading. To this end, a comprehensive mechanics framework has been developed, taking into account the critical deterioration rates of the FRP constituents. Such deterioration relationships were obtained by calibrating the accelerated laboratory durability test data with the in-service field measurements. Simulation results agree well with the 4-year performance data of a FRP-deck road bridge. Long-term validation data is, however, still needed.

Evaluation of effective flange width by shear lag model for orthotropic FRP bridge decks

Abstract In bridge engineering, the three-dimensional behavior of a bridge system is usually reduced to the analysis of a T-beam section with a reduced width of deck in relation to center-to-center spacing of stringers, over which the longitudinal normal stresses are assumed to be uniformly distributed, which is termed as effective flange width. It is defined in the AASHTO specifications primarily for concrete slabs and has inherent applicable limitations because of its empirical nature. This paper provides an analytical shear lag model for effective flange width for orthotropic bridge decks, applicable to various materials including Fiber-Reinforced Polymer (FRP) and concrete decks. To verify this solution, a Finite Element (FE) parametric study is conducted on 44 simply-supported FRP deck-on-steel girder bridges. The results from the shear lag model correlate well with the FE results. The accuracy of this model is further verified by close correlations with an existing empirical solution. It is also illustrated that the shear lag model, with the introduction of a reduction factor, can be applied to predict effective flange width for FRP deck-on-steel girder bridges with partial composite action, by favorable comparisons between the analytical and testing results for a T-beam section cut from a one-third scaled bridge model, which consists of an FRP sandwich deck attached to steel girders by mechanical connectors.

Stiffness and Strength Evaluations of a Shear Connection System for FRP Bridge Decks to Steel Girders

This paper reports on research investigating a nongrouted sleeve-type connection used to attach fiber-reinforced polymer (FRP) decks to steel girders. The connection system was investigated for stiffness, strength, fatigue resistance, and degree of composite action. Static and fatigue tests were conducted first at the component level on push-out specimens to obtain P-Δ (load-displacement) and S-N (stress range–fatigue life) relationships, from which design formulas were developed. Then tests were conducted at the system level on a 1∶3 scaled-bridge model by using this sleeve-type connection, and the results showed this shear connection can satisfy requirements from AASHTO specifications for fatigue, strength, and function. Further, three-point bending tests were conducted on a T-section model cut from the scaled bridge, and approximately 25% composite action was achieved for two different connection spacings. The structural efficiency of this shear connection is shown, and this connection design is applie...

Fatigue and Strength Evaluation of Two Glass Fiber-Reinforced Polymer Bridge Decks

The use of glass fiber-reinforced polymer (GFRP) bridge decks is appealing for applications where minimizing dead load is critical. This paper describes fatigue and strength testing of two types of GFRP decks being considered for use in the retrofit of an aging steel arch bridge in Snohomish County, Washington, where a roadway expansion is necessary and it is desirable to minimize the improvements to the arch superstructure. Each test used a setup designed to be as close as practicable to what will be the in situ conditions for the deck, which included a 2% cross slope for drainage. The fatigue testing consisted of a single 116 kN (26 kip) load applied for 2 million cycles, which corresponds to an AASHTO HS-25 truck with a 30% impact factor, and the strength testing consisted of multiple runs of a monotonically applied minimum load of 347 kN (78 kips). Results from the fatigue testing indicated a degradation of the stiffness of both deck types; however, the degradation was limited to less than 12% over the duration of loading. Further, the results showed both deck types accumulated permanent deck displacement during fatigue loading and one deck type used a detail with poor fatigue performance. That detail detrimentally impacted the overall deck performance and caused large permanent deck deformations. It was also found that degradation of composite behavior between the deck and girders occurs during fatigue loading and should be included in design.

Field Monitoring and Repair of a Glass Fiber-Reinforced Polymer Bridge Deck

This paper reports on the monitoring and repair of a pilot field deployment of a glass fiber-reinforced polymer (GFRP) deck on a small steel girder bridge in the Washington State. Deck deflections were monitored periodically over a 10-month period and were found to increase significantly over that time. The GFRP deck is an adhesively bonded assembly of GFRP tubes and top and bottom plates. After 9 months of service, wearing surface cracking was observed, and upon closer inspection, the top GFRP plate was found to be delaminated from the tubes over a fairly large area. Deck deflections in the area of delamination were found to be considerably larger than those observed during previous monitoring in undamaged locations. A retrofit solution was employed where the top plate was reconnected to the tubes using screws coated with a two-part epoxy that mixed when they were driven. At the time of writing the retrofit was successful in reattaching the delaminated top plate.

Iterative neural network strategy for static model identification of an FRP deck

This study proposes a system identification technique for a fiber-reinforced polymer deck with neural networks. Neural networks are trained for system identification and the identified structure gives training data in return. This process is repeated until the identified parameters converge. Hence, the proposed algorithm is called an iterative neural network scheme. The proposed algorithm also relies on recent developments in the experimental design of the response surface method. The proposed strategy is verified with known systems and applied to a fiber-reinforced polymer bridge deck with experimental data.

Performance Evaluation of FRP Bridge Deck Under Shear Loads

Shear behavior of glass fiber reinforced polymer (FRP) bridge deck components has been experimentally and theoretically studied under in-plane shear, out-of-plane shear, punching shear, shear of web—flange junction, and system racking shear. Experimental data revealed that the shear modulus of FRP bridge decks ranged from 2.66 to 4.14 GPa and the shear stress to failure ranged from 20.7 to 96.6 MPa. In-plane shear behavior is studied under V-notched and racking shear test (parallel and perpendicular to cell direction). Experimental results under in-plane shear loading are compared with the results from the classical finite element method. Out-of-plane shear strength and stiffness of an FRP composite deck are experimentally evaluated utilizing test data from the short beam shear test, and the beam bending test. Using experimental and numerical results, the reduction in bending rigidity due to shear deformation under several loading conditions is calculated. In addition, size limits (span to depth ratio) under transverse loading are established as: L/d>22 (for multi-cell specimen with and without joints). A theoretical model based on FRP deck types for predicting punching shear capacity is proposed and validated through experimental data. In addition, the failure modes of test specimens are identified and reported. To study the web—flange junction behavior, closed FRP sections were tested under shear-bending effect. It is clear that the web—flange junction shear strength is only one half of the shear strength obtained from flange specimens under V-notched beam testing. While testing, cracks and layer delaminations around web—flange junctions were initiated and extended along the thickness of the web portion with increasing applied loads, which eventually led to web shear-off failure. In addition, it is found that shear strengths of test specimens depend on modes of shear failures induced by different shear test methods. Higher shear strength is found on failure modes that have more influence of fiber shear.

Design Recommendations for a FRP Bridge Deck Supported on Steel Superstructure

No appropriate provisions from either AASHTO Standard (2002) or AASHTO LRFD (2004) bridge design specifications are available for the design of fiber-reinforced polymer (FRP)-deck-on-steel-superstructure bridges. In this research, a parametric study using the finite-element method (FEM) is conducted to examine 2 design issues concerning the design of FRP-deck-on-steel-superstructure bridges, namely, deck relative deflection and load distribution factor (LDF). Results show that the strip method specified in AASHTO LRFD specification as an approximate method of analysis, can also be applied to FRP decks as a practical method. However, different strip width equations have to be determined by either FEM or experimental methods for different types of FRP decks. In this study, one such equation has been derived for the Strongwell deck. In addition, both FEM results and experimental measurements show that the AASHTO LDF equations for glued laminated timber decks on steel stringers provide good estimations of LDF for FRP-deck-on-steel-superstructure bridges. Finally, it is found that the lever rule can be used as an appropriately conservative design method to predict the LDF of FRP-deck-on-steel-superstructure bridges.

Modeling Technique for Honeycomb FRP Deck Bridges via Finite Elements

Honeycomb structures have been used in different engineering fields. In civil engineering, honeycomb fiber-reinforced polymer (FRP) structures have been used as bridge decks to rehabilitate highway bridges in the United States. In this work, a simplified finite-element modeling technique for honeycomb FRP bridge decks is presented. The motivation is the combination of the complex geometry of honeycomb FRP decks and computational limits, which may prevent modeling of these decks in detail. The results from static and modal analyses indicate that the proposed modeling technique provides a viable tool for modeling the complex geometry of honeycomb FRP bridge decks. The modeling of other bridge components (e.g., steel girders, steel guardrails, deck-to-girder connections, and pier supports) is also presented in this work.

Development and Evaluation of an Adhesively Bonded Panel-to-Panel Joint for a FRP Bridge Deck System

A fiber-reinforced polymer (FRP) composite cellular deck system was used to rehabilitate a historical cast iron thru-truss structure (Hawthorne St. Bridge, Covington, VA). The most important characteristic of this application is reduction in self-weight, which raises the live load-carrying capacity of the bridge by replacing the existing concrete deck with an FRP deck. This bridge is designed to HL-93 load and has a 22.86 m clear span with a roadway width of 6.71 m. The panel-to-panel connections were accomplished using full width, adhesively (structural urethane adhesive) bonded tongue and groove splices with scarfed edges. To ensure proper construction, serviceability, and strength of the splice, a full-scale 2-bay section of the bridge with 3 adhesively bonded panel-to-panel connections was constructed and tested. Results showed that no crack initiated in the joints under service load and no significant change in stiffness or strength of the joint occurred after 3,000,000 cycles of fatigue loading. The proposed adhesive bonding technique was installed in the bridge in August 2006.

Life-cycle cost assessment model for fiber reinforced polymer bridge deck panels

To enhance the application of fiber reinforced polymer (FRP) bridge deck panels in the infrastructure area, a practical method is required that would allow probable assessment of the life-cycle cost of advanced composite applications in construction compared with that of conventional materials, at various discount rates, while integrating the available reference data. The overall objective of this research is to develop a performance-based probable life-cycle cost assessment model for FRP bridge deck panels. The life-cycle cost assessment model for FRP bridge deck panels comprises a life-cycle performance module (module-1) and a life-cycle cost optimization module (module-2). The model thus developed in this paper can then be used for other applications of composites in construction. The objective of module-1 is to develop an analytical model that is capable of predicting the structural deterioration over time to assess the deterioration rating per year of FRP bridge deck panels. The objective of module-2 is to develop an analytical model that is capable of assessing the optimal life-cycle cost of FRP bridge deck panels. Three case studies were conducted to validate the logic and results of the process algorithm for the life-cycle cost assessment. The model will be very helpful for the construction industry in evaluating various material options and to justify or deny the feasibility of using composite materials on specific construction projects. Since the life-cycle cost assessment of composite materials in construction has not been dealt with as proposed, it is anticipated that many of the procedures and systems mentioned would include fundamental research and possible innovations.Key words: fiber reinforced materials, Monte Carlo method, life-cycle cost, performance valuation.