Performance Evaluation of FRP Composite Deck Considering for Local Deformation Effects

We examine here the replacement of a deteriorated concrete deck in the historic Hawthorne Street Bridge in Covington, Va. with a lightweight fiber-reinforced polymer (FRP) deck system (adhesively bonded pultruded tube and plate assembly) to increase the load rating of the bridge. To explore construction feasibility, serviceability, and durability of the proposed deck system, a two-bay section (9.45 by 6.7?m) of the bridge has been constructed and tested under different probable loading scenarios. Experimental results show that the response of the deck is linear elastic with no evidence of deterioration at service load level (HS-20). From global behavior of the bridge superstructure (experimental data and finite- element analysis), degree of composite action, and load distribution factors are determined. The lowest failure load (93.6?kips or 418.1?kN) is about 4.5 times the design load (21.3?kips or 94?kN), including dynamic allowance at HS-20. The failure mode is consistent in all loading conditions and observed to be localized under the loading patch at the top plate and top flange of the tube. In addition to global performance, local deformation behavior is also investigated using finite-element simulation. Local analysis suggests that local effects are significant and should be incorporated in design criteria. Based on parametric studies on geometric (thickness of deck components) and material variables (the degree of orthotropy in pultruded tube), a proposed framework for the sizing and material selection of cellular FRP decks is presented for future development of design guidelines for composite deck structures.     

Field Performance of the Fiber-Reinforced Polymer Deck of a Truss Bridge

The MD 24 Bridge over Deer Creek in Harford County, Md., was one of the projects chosen by the Federal Highway Administration’s Innovative Bridge Research and Construction Program for bridge deck replacement by fiber-reinforced polymer (FRP) composites. A thorough discussion is presented on Maryland State Highway Administration’s first bridge rehabilitation project utilizing a FRP deck. The discussion includes design details, installation procedure, construction methods and in situ load testing with a wireless monitoring system. The research team installed a monitoring system to record the effects of live loads on the bridge system, including truss members, steel stringers, and plate action of the FRP deck. Finite-element models were also used in this phase. Dynamic effects of the FRP system, composite action between steel stringers and the FRP deck as well as the effective width and distribution factors of stringers were obtained and compared with the AASHTO specifications. Recommendations are also offered on improving the design details based on this experience.     

Field Investigation on the First Bridge Deck Slab Reinforced with Glass FRP Bars Constructed in Canada

Recently, there has been a rapid increase in using noncorrosive fiber-reinforced polymers (FRP) reinforcing bars as alternative reinforcement for bridge deck slabs, especially those in harsh environments. A new two-span girder type bridge, Cookshire-Eaton Bridge (located in the municipality of Cookshire, Quebec, Canada), was constructed with a total length of 52.08 m over two equal spans. The deck was a 200-mm-thick concrete slab continuous over four spans of 2.70 m between girders with an overhang of 1.40 m on each side. One full span of the bridge was totally reinforced using glass fiber-reinforced polymer (GFRP) bars, while the other span was reinforced with galvanized steel bars. The bridge deck was well instrumented at critical locations for internal temperature and strain data collection using fiber optic sensors. The bridge was tested for service performance using calibrated truckloads as specified by the Canadian Highway Bridge Design Code. The construction procedure and field test results under actual service conditions revealed that GFRP rebar provides very competitive performance in comparison to steel.     

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 in 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 a 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 two-bay section of the bridge with three adhesively bonded panel-to-panel connections was constructed and tested in the Structures Laboratory at Virginia Tech. Test 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.     

FEA of Complex Bridge System with FRP Composite Deck

Innovative fiber-reinforced polymer (FRP) composite highway bridge deck systems are gradually gaining acceptance in replacing damaged/deteriorated concrete and timber decks. FRP bridge decks can be designed to meet the American Association of State Highway and Transportation Officials (AASHTO) HS-25 load requirements. Because a rather complex sub- and superstructure system is used to support the FRP deck, it is important to include the entire system in analyzing the deck behavior and performance. In this paper, we will present a finite-element analysis (FEA) that is able to consider the structural complexity of the entire bridge system and the material complexity of an FRP sandwich deck. The FEA is constructed using a two-step analysis approach. The first step is to analyze the global behavior of the entire bridge under the AASHTO HS-25 loading. The next step is to analyze the local behavior of the FRP deck with appropriate load and boundary conditions determined from the first step. For the latter, a layered FEA module is proposed to compute the internal stresses and deformations of the FRP sandwich deck. This approach produces predictions that are in good agreement with experimental measurements.     

Dynamic Response of Three Fiber Reinforced Polymer Composite Bridges

Fiber reinforced polymer (FRP) composite bridge decks are gaining the attention of bridge owners because of their light self-weight, corrosion resistance, and ease of installation. Constructed Facilities Center at West Virginia University working with the Federal Highway Administration and West Virginia Department of Transportation has developed three different FRP decking systems and installed several FRP deck bridges in West Virginia. These FRP bridge decks are lighter in weight than comparable concrete systems and therefore their dynamic performance is equally as important as their static performance. In the current study dynamic tests were performed on three FRP deck bridges, namely, Katy Truss Bridge, Market Street Bridge, and Laurel Lick Bridge, in the state of West Virginia. The dynamic response parameters evaluated for the three bridges include dynamic load allowance (DLA) factors, natural frequencies, damping ratios, and deck accelerations caused by moving test trucks. It was found that the DLA factors for Katy Truss and Market Street bridges are within the AASHTO 1998 LRFD specifications, but the deck accelerations were found to be high for both these bridges. DLA factors for Laurel Lick bridge were found to be as high as 93% against the typical design value of 33%; however absolute deck stress induced by vehicle loads is less than 10% of the deck ultimate stress.     

Strength and Serviceability of FRP Grid Reinforced Bridge Decks

The research presented in this paper evaluates the flexural performance of bridge deck panels reinforced with 2D fiber-reinforced polymer (FRP) grids. Two different FRP grids were investigated, one reinforced with a hybrid of glass and carbon fibers and a second grid reinforced with carbon fibers only. Laboratory measured load-deflection, load-strain (reinforcement and concrete), cracking, and failure behavior are presented in detail. Conclusions regarding failure mode, limit-state strength, serviceability, and deflection compatibility relative to AASHTO mandated criteria are reported. Test results indicate that bridge decks reinforced with FRP grids will be controlled by serviceability limit state and not limit-state ultimate strength. The low axial stiffness of FRP results in large service load flexural deflections and reduced shear strength. In as much as serviceability limits design, overreinforcement is recommended to control deflection violation. Consequently, limit-state flexural strength will be compression controlled for which reduced service stresses or ACI unified compression failure strength reduction factors are recommended.     

Characterization of a Low-Profile Fiber-Reinforced Polymer Deck System for Moveable Bridges

Moveable bridges in Florida typically use open steel grid decks due to weight limitations. However, these decks present rideability, environmental, and maintenance problems, as they are typically less skid resistant than a solid riding surface, create loud noises, and allow debris to fall through the grids. Replacing open steel grid decks with a lightweight fiber-reinforced polymer (FRP) deck can improve rideability and reduce maintenance costs, simultaneously satisfying the strict weight requirement for such bridges. In this investigation, a new low-profile, pultruded FRP deck system successfully passed the preliminary strength and fatigue tests per AASHTO requirements. Two two-span deck specimens were tested, one with the strong direction of the deck placed perpendicular to the supporting girders, whereas the other had a deck placed with 30° skew. This paper also describes a simplified finite-element approach that simulates the load–deformation behavior of the deck system. The results from the finite-element model showed a good correlation with the deflection and strain values measured from the tests.     

Development of FRP Short-Span Deployable Bridge—Experimental Results

For military and civilian applications, there exists a need for lightweight, inexpensive, short-span bridges that can be easily transported and erected with minimal equipment. Owing to its favorable properties, fiber-reinforced polymer (FRP) has been shown to be feasible for the construction of such bridges. Investigations into the behavior of a short-span bridge structural concept, adapted to the material properties of commercially available glass FRP (GFRP) pultruded products, are presented. A 4.8-m span prototype was built from GFRP sections, bonded throughout to form a tapered box beam, with a width of 1.2?m and a height at midspan of approximately 0.5?m. The box beam represents a single trackway of a double-trackway bridge, whose trackways could be connected by light structural elements. The quasi-static and dynamic behavior of the prototype box beam was investigated in ambient laboratory and field conditions to assess the design and construction techniques used, with a view to designing a full-scale 10-m GFRP bridge. Laboratory testing of the prototype box beam used single and pairs of patch loads to simulate wheel loading. These tests confirmed that the box beam had sufficient stiffness and strength to function effectively as a single trackway of a small span bridge. Field testing of the structure was undertaken using a Bison vehicle (13,000?kg), driven at varying speeds over the structure to establish its response to realistic vehicle loads and the effects of their movement across the span.     

Construction and Testing of an Innovative Concrete Bridge Deck Totally Reinforced with Glass FRP Bars: Val-Alain Bridge on Highway 20 East

The Val-Alain Bridge, located in the Municipality of Val-Alain on Highway 20 East, crosses over Henri River in Québec, Canada. The bridge is a slab-on-girder type with a skew angle of 20° over a single span of 49.89?m and a total width of 12.57?m. The bridge has four simply supported steel girders spaced at 3,145?mm. The deck slab is a 225-mm-thick concrete slab, with semi-integral abutments, continuous over the steel girders with an overhang of 1,570?mm on each side. The concrete deck slab and the bridge barriers were reinforced with glass fiber reinforced polymer (GFRP) reinforcing bars utilizing high-performance concrete. The Val-Alain Bridge is the Canada’s first concrete bridge deck totally reinforced with GFRP reinforcing bars. Using such nonmetallic reinforcement in combination with high-performance concrete leads to an expected service life of more than 75?years. The bridge is well instrumented with electrical resistance strain gauges and fiber-optic sensors at critical locations to record internal strain data. Also, the bridge was tested for service performance using calibrated truckloads. Design concepts, construction details, and results of the first series of live load field tests are presented.     

Structural Behavior of FRP Composite Bridge Deck Panels

Fiber-reinforced polymer (FRP) composite bridge deck panels are high-strength, corrosion resistant, weather resistant, etc., making them attractive for use in new construction or retrofit of existing bridges. This study evaluated the force-deformation responses of FRP composite bridge deck panels under AASHTO MS 22.5 (HS25) truck wheel load and up to failure. Tests were conducted on 16 FRP composite deck panels and four reinforced concrete conventional deck panels. The test results of FRP composite deck panels were compared with the flexural, shear, and deflection performance criteria per Ohio Department of Transportation specifications, and with the test results of reinforced concrete deck panels. The flexural and shear rigidities of FRP composite deck panels were calculated. The response of all panels under service load, factored load, cyclic loading, and the mode of failure were reported. The tested bridge deck panels satisfied the performance criteria. The safety factor against failure varies from 3 to 8.     

Designing and Testing of Concrete Bridge Decks Reinforced with Glass FRP Bars

In addition to their high strength and light weight, fiber-reinforced polymer (FRP) composite reinforcing bars offer corrosion resistance, making them a promising alternative to traditional steel reinforcing bars in concrete bridge decks. FRP reinforcement has been used in several bridge decks recently constructed in North America. The Morristown Bridge, which is located in Vermont, United States, is a single span steel girder bridge with integral abutments spanning 43.90 m. The deck is a 230 mm thick concrete continuous slab over girders spaced at 2.36 m. The entire concrete deck slab was reinforced with glass FRP (GFRP) bars in two identical layers at the top and the bottom. The bridge is well instrumented at critical locations for internal temperature and strain data collection with fiber-optic sensors. The bridge was tested for service performance using standard truck loads. The construction procedure and field test results under actual service conditions revealed that GFRP rebar provides very good and promising performance.     

Failure Study of an Aluminum Bridge Deck Panel

Aluminum bridge decks may prove to be an alternative to concrete decks for improving the performance of structural bridge systems. Combining excellent corrosion resistance with extremely low density, aluminum decks can prolong surface life, facilitate the construction process, and expand rehabilitation capabilities. Reynolds Metals Company, Richmond, Va., has invested considerable resources to develop a proprietary aluminum deck system. The Virginia Department of Transportation agreed to employ the Reynolds deck system in two projects. Using Federal Highway Administration sponsorship, the Virginia Transportation Research Council initiated a study to evaluate the aluminum deck system. The first phase of this project analyzed the static response of a 2.74 × 3.66 m (9 × 12 ft) deck panel. Both service-load tests and ultimate-load tests were performed on the panel at the Turner-Fairbank Structural Laboratory. The experimental and analytical evaluation of the ultimate load static tests is the subject of this paper. The failure load and failure mechanism were predicted with great accuracy. The model data predicted panel failure at a load of 911.89 kN (205 kips) by yielding under the load patch while failure during the laboratory test occurred at a load of 872.07 kN (196.05 kips) by gross yielding underneath the load patch.     

Performance Comparison of Four Fiber-Reinforced Polymer Deck Panels

In an effort to assess the constructability and performance of bridges with fiber-reinforced polymer (FRP) composite decks, the short-term and long-term responses of a 207 m, five-span bridge retrofitted with four different FRP panel systems were monitored. The overall aspects of the panel systems, connection details, and construction techniques are presented prior to presentation of the observed and measured responses. Key design parameters (impact factors, girder distribution factors, and level of composite action) for FRP and reinforced concrete decks are evaluated. This paper demonstrates that FRP replacement decks are a viable alternative to reinforced concrete decks and identifies the differences in performances of various FRP deck systems. Two of the FRP panel systems were found to perform considerably better than the other deck systems. Issues that may reduce the service life of FRP deck systems are presented and discussed.     

Construction, Inspection, and Maintenance of FRP Deck Panels

Composite materials are clearly having a major impact on how facilities are designed, constructed, and maintained. In order to enhance the application of fiber-reinforced composites in infrastructure renewal, it will be important to understand the constructability, maintainability, operability, and inspection issues related to the use of fiber-reinforced polymer (FRP) structural components. This paper identifies these issues as well as fabrication issues, construction methods, quality, man-hour requirements, cost and productivity issues, and the skill level required to install FRP bridge deck panels. The data required for this research were collected through two questionnaire studies, personal interviews with two manufacturers of FRP bridge deck panels (i.e., Hardcore Composites and Martin Marietta Composites), and candidate projects for FRP bridge deck construction.     

Flexural Performance of Carbon Fiber-Reinforced Polymer Prestressed Concrete Side-by-Side Box Beam Bridge

The effect of varying transverse posttensioning levels and arrangements on the load response of a one-half scale 30° skewed seven box beam bridge model was investigated. The effective span of the bridge model was 9.45?m (31?ft) with a width of 3.35?m (11?ft) and depth of 355.6?mm (14?in.). The bridge model was prestressed and reinforced with carbon fiber composite cables (CFCCs). CFCCs were also used as shear reinforcement. The bridge model was provided with five transverse diaphragms equally spaced along the length of the bridge. The experimental investigation included load and strain distribution tests and a flexural ultimate load test. The load and strain distribution tests were conducted on the bridge model with and without full-depth longitudinal cracks at the shear-key locations. The investigation showed that the application of an adequate transverse posttensioning force was successful in restoring the load distribution of the bridge model with full-depth longitudinal deck cracks to that of the case without deck cracks. The ultimate load and the associated compression-controlled failure mode of the bridge model agreed well with that predicted according to ACI 440.4R-04 and numerical analysis. The behavior of the bonded pretensioned and reinforced CFCC strands was linear elastic and remained intact throughout the collapse of the bridge model. The unbonded transverse posttensioned CFCC strand also remained intact.     

Construction of a Pultruded Composite Structure: Case Study

In a recent research and development project a novel prototype pultruded composite structure was designed, fabricated, and tested. The bargelike, box-girder type structure measured approximately 24-ft long by 15-ft wide by 5-ft high (7.3 × 4.6 × 1.5 m). The structure was constructed from commercially available off-the-shelf pultruded structural profiles and panel sections. Tubular steel structural members and steel hardware were used to connect and join the different sections and subassemblies. The structure consisted of three 24-ft-long by 5-ft-wide by 5-ft-high (7.3 × 1.5 × 1.5 m) rectangular box-girder modular units and six 4-ft (1.2-m) wide modular deck panels. A design requirement was that the structure be capable of being transported by conventional, nonpermit trucking and be assembled at a remote site for subsequent testing. The structure was fabricated at a ship building and repair shop in Norfolk, Va., whose primary expertise was with conventional steel ship-structure fabrication methods and which had no prior experience with fabricating a large pultruded structural system. To fabricate and assemble the structure, a set of construction documents was produced. These included a set of written construction and assembly specifications, a set of detailed construction drawings, a detailed parts list, and a schedule. This case study details the construction process and provides a step-by-step explanation of how the engineering design team developed the construction documents for a relatively complex pultruded composite structure. Details of the design, analysis, and testing of the system are provided elsewhere.     

Vibration Characteristics of K?mürhan Highway Bridge Constructed with Balanced Cantilever Method

K?mürhan Highway Bridge is a reinforced concrete box girder bridge located on the 51st km of Elaz??–Malatya Highway over the F?rat River. Because of the fact that the K?mürhan Bridge is the only bridge in this part of F?rat, it has major logistical importance. So, this paper aims to determine dynamic characteristics such as natural frequencies, mode shapes, and damping ratios of the bridge using experimental measurements and finite-element analyses to evaluate current behavior. The experimental measurements are carried out by ambient vibration tests under traffic loads. Due to the expansion joint in the middle of the bridge, special measurement points are selected and experimental test setups are constituted. Vibration data are gathered from the both box girder and bridge deck. Measurement time, frequency span, and effective mode number are determined by considering similar studies and literature. The peak picking method in the frequency domain is used for the output-only modal identification. An analytical modal analysis is performed on the developed two- and three-dimensional finite-element model of the bridge using SAP2000 software to provide the analytical frequencies and mode shapes. At the end of the study, dynamic characteristics of the Elaz?? and Malatya parts of the bridge obtained from the experimental measurements are compared with each other and transverse effects on the bridge are determined. Also, experimental and analytical dynamic characteristics are compared. Good agreement is found between dynamic characteristics in the all measurement test setups performed on the box girder and bridge deck and analytical modal analyses.     

Durability of FRP Composite Bridge Deck Materials under Freeze-Thaw and Low Temperature Conditions

Fiber-reinforced polymer (FRP) composites, especially lightweight sandwich structures, are rapidly finding their way into civil infrastructure application. FRP composite panels are particularly attractive as bridge deck systems due to their high strength, low density, and durability, which are of importance to the bridge industry. Most of the vast amount of durability data for FRP has been generated for aerospace and automotive applications, which involve very different service conditions than civil infrastructure. For civil engineering applications, it is essential to examine the durability performance of FRP materials under weathering conditions. The ultimate goal of this research is to develop a reliable framework for durability assessment of FRP decks, including laboratory testing procedure and finite-element simulation capability. Such a framework should be applicable to all types of FRP deck construction. In this paper, specimens of typical FRP bridge deck skin materials are subjected to freeze-thaw cycling between 4.4 and ?17.8°C in media of dry air, distilled water, and saltwater, and constant freeze at ?17.8°C . The selected deck is used as an example for demonstration purposes. In addition, selected specimens are subjected to simultaneous environmental exposure conditions and sustained loading of 25% ultimate strain. It should be emphasized that most of the environmental conditions reported in the literature produce minor deterioration of a single composite property, and the assessment of such effect on this single property becomes unreliable because of a large property variation. Therefore, in this paper we use multiple mechanical properties as performance indices for damage evaluation. Based on findings from this work, it is concluded that freeze-thaw cycling between 4.4 and ?17.8°C alone and up to 1,250 h and 625 cycles caused very insignificant or no change in the flexural strength, storage modulus, and loss factor of the FRP specimens conditioned in dry air, distilled water, and saltwater. Small reductions in storage modulus (about 1% or less) were observed when specimens were prestrained and subjected to 250 freeze-thaw cycles in distilled water and saltwater. Changes in flexural strength were statistically insignificant, since they were within the data scatter.     

Light-Weight Fiber-Reinforced Polymer Composite Deck Panels for Extreme Applications

Currently within the military there is a need for a universal light-weight bridge deck system capable of supporting extreme loads over a wide temperature range. This research presents the development, testing, and analysis of five different fiber-reinforced polymer (FRP) webbed core deck panels. The performance of the FRP webbed decks are compared with an existing aluminum deck and with a baseline balsa core system, which has previously been tested as part of the development of the composite army bridge for the US Army. The study shows that for one-way bending, the FRP webbed core can exceed the shear strength of the baseline balsa core by a factor of 3.2 at a core’s density, which is 28% lighter than the balsa baseline. In addition, weight savings in excess of 30% are shown for using FRP decking in place of conventional aluminum decking. Based on test results and finite-element analysis, the failure modes of the different FRP webbed cores are discussed and design recommendations for FRP webbed core decks are provided.