Polymer Composite Bridge Decks Research Articles

Structural damage identification: A random sampling-high dimensional model representation approach

Structural damage identification and quantification of damage using non-destructive methods are important aspects for any civil, mechanical and aerospace engineering structures. In this study, a novel damage identification algorithm has been developed using random sampling-high dimensional model representation approach. A global sensitivity analysis based on random sampling-high dimensional model representation is adopted for important parameter screening purpose. Three different structures (spring mass damper system, simply supported beam and fibre-reinforced polymer composite bridge deck) have been used for various single and multiple damage conditions to validate the proposed algorithm. The performance of this method is found to be quite satisfactory in the realm of damage detection in structures. The random sampling-high dimensional model representation-based approach for meta-model formation is particularly useful in damage identification as it works well when large numbers of input parameters are involved. In this study, two different optimization methods have been used and their relative capability to identify damage has been discussed. Performance of this damage identification algorithm under the influence of noise has also been addressed in this article.

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.

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.

Load and resistance factor design of fiber reinforced polymer composite bridge deck

The majority of our bridges were constructed with conventional civil engineering materials of steel and concrete in a typical slab on girder or truss construction. Reinforced concrete bridge decks have approximately 40% life of the steel girders that support these structures. In order to support the use of alternative materials to replace deteriorating concrete decks, this paper outlines the Load and Resistance Factor Design (LRFD) of Fiber Reinforced Polymer composite (FRP) panel highway bridge deck. The deck would be of a sandwich construction where 152.4mm×152.4mm×9.5mm square pultruded glass FRP (GFRP) tubes are joined and sandwiched between two 9.5mm GFRP plates. The deck would be designed by Allowable Stress Design (ASD) and LRFD to support AASHTO design truckload HL-93. There are currently no US standards and specifications for the design of FRP pultruded shapes including a deck panel therefore international codes and references related to FRP profiles will be examined and AASHTO-LRFD specifications will be used as the basis for the final design. Overall, years of research and laboratory and field tests have proven FRP decks to be a viable alternative to conventional concrete deck. Therefore, conceptualizing the design of FRP bridge decks using basic structural analysis and mechanics would increase awareness and engineering confidence in the use of this innovative material.

Field Issues Associated with the Use of Fiber-Reinforced Polymer Composite Bridge Decks and Superstructures in Harsh Environments

There has been ample time for the United States to evaluate the use of fiber-reinforced polymer (FRP) composites to serve as bridge decks and superstructures under real-world environmental and operating conditions. This provides a great opportunity to weigh in on the decision to move forward with these materials. By studying the successes and failures, materials and techniques used for the design and construction of these bridges can be improved so that we can move closer to the goals of maintenance-free bridges and service lives exceeding 100 years. Though only a few of these structures are instrumented for structural health monitoring, there are a sufficient number of lessons that can be gleaned from the experiences of various owners during the fabrication, installation, operation, and inspection of these structures. By addressing these issues head-on, advocates will be better equipped to have direct dialogue with those in the profession who remain skeptical about the hidden potential for a construction material that is strong, light, and corrosion resistant.

Detection of subsurface defects in fiber reinforced polymer composite bridge decks using digital infrared thermography

Fiber reinforced polymer (FRP) bridge decks are rapidly emerging as potential alternatives to conventional reinforced concrete (RC) bridge decks. The FRP decks offer higher strength-to-weight ratios compared to RC decks. However, presence of subsurface defects such as debonds and delaminations formed during initial construction and in service can adversely affect the structural integrity and service performance of the FRP bridge decks. Hence, a field monitoring technique such as infrared thermography is required to evaluate the in situ condition of these FRP decks. This paper investigates the use of digital infrared thermography for subsurface defect detection in FRP bridge decks. Air-filled and water-filled debonds were inserted between the wearing surface and the underlying FRP deck in the laboratory. Simulated subsurface delaminations (of various sizes and thickness) were also created at the flange-to-flange junction between two FRP deck modules. The infrared technique was used to detect these embedded subsurface defects. Surface temperature–time curves were established for different sizes of delaminations and debonds. In addition, field study was conducted on a FRP bridge deck to detect debonds between the wearing surface and the underlying deck. The laboratory and field testing results show that infrared thermography is a potentially useful tool for defect detection in FRP composite bridge decks. The technique can possibly be used for several applications such as quality control during pultrusion of new decks (in factories), during field construction, and for field inspection of in-service decks.

Reliability-Based Optimization of Fiber-Reinforced Polymer Composite Bridge Deck Panels

A reliability-based optimization procedure is developed and applied to minimize the weight of eight fiber-reinforced polymer composite bridge deck panel configurations. The method utilizes interlinked finite element, optimization, and reliability analysis procedures to solve the weight minimization problem with a deterministic strength constraint and two probabilistic deflection constraints. Panels are composed of an upper face plate, lower face plate, and a grid of interior stiffeners. Different panel depths and stiffener layouts are considered. Sensitivity analyses are conducted to identify significant design and random variables. Optimization design variables are panel component ply thicknesses, while random variables include load and material resistance parameters. It was found that panels were deflection governed, with the optimization algorithm yielding little improvement for shallow panels, but significant weight savings for deeper panels. The best design resulted in deep panels with close stiffener spacing to minimize local upper face plate deformations under the imposed traffic (wheel) loads.

Laboratory and Field Performance of Cellular Fiber-Reinforced Polymer Composite Bridge Deck Systems

This paper addresses the laboratory and field performance of multicellular fiber-reinforced polymer (FRP) composite bridge deck systems produced from adhesively bonded pultrusions. Two methods of deck contact loading were examined: a steel patch dimensioned according to the AASHTO Bridge Design Specifications, and a simulated tire patch constructed from an actual truck tire reinforced with silicon rubber. Under these conditions, deck stiffness, strength, and failure characteristics of the cellular FRP decks were examined. The simulated tire loading was shown to develop greater global deflections given the same static load. The failure mode is localized and dominated by transverse bending failure of the composites under the simulated tire loading as opposed to punching shear for the AASHTO recommended patch load. A field testing facility was designed and constructed in which FRP decks were installed, tested, and monitored to study the decks’ in-service field performance. No significant loss of deck capacit...

Experience in the United States with Fiber-Reinforced Polymer Composite Bridge Decks and Superstructures

Research on the use of fiber-reinforced polymer (FRP) composite materials for bridge decks and superstructures has been ongoing since the 1980s. Vehicular bridges have been in service since 1996, and pedestrian bridges, longer than that. This paper focuses on vehicular bridges, of which many were funded by FHWA's Innovative Bridge Research and Construction Program or other funding initiatives. The objective is to summarize where the projects are, who supplied them, how they were constructed, what the benefits of using FRP were, what lessons can be learned, and what the projects cost. A review of this information should be useful to civil engineers or bridge owners who want to assess the state of the practice and make a judgment about using FRP for bridge decks or superstructures.

Joining techniques for fiber reinforced polymer composite bridge deck systems

Bridge decks made from fiber reinforced polymer (FRP) composites have been increasingly used in rehabilitation and new construction of pedestrian and highway bridges. For each application, connections are inevitable due to limitations on shape size and the requirements of transportation. Connections for FRP bridge decks include primary and secondary load-carrying joints and non-structural joints. Primary and secondary load-carrying connections are most concerned in construction, which include component–component connection, panel–panel connection, and deck-to-support connection. Unfortunately, the technical background, development and design guides of FRP bridge deck connections have not been documented adequately in literature. This paper attempts to provide technical background, developed joining techniques, and design principles concerning the joining of FRP decks. Design requirements, characteristics, performances, advantages and disadvantages of developed FRP deck connection techniques are discussed. Design principles for adhesively bonded joints and mechanical fixing and hybrid joints involving cutouts are also provided.

Close Look at Construction Issues and Performance of Four Fiber-Reinforced Polymer Composite Bridge Decks

Four different fiber-reinforced polymer (FRP) panel systems were installed in a 207 m, five-span, three-lane bridge in an effort to assess the constructability, performance, and applicability of bridges with fiber-reinforced polymer composite decks. This paper examines whether four common deck systems are able to realize many of the anticipated benefits of using FRP composites in lieu of conventional reinforced concrete bridge decks. Particular installation issues, connection details, and specific construction techniques for each deck system are described, along with a discussion of the shortcomings in terms of handling, performance, and serviceability. Other factors such as key design parameters (e.g., impact factor and thermal characteristics) and unexpected responses are used to further quantify the performance of four FRP representative deck systems under identical traffic and environmental constraints.

Connection of concrete barrier rails to FRP bridge decks

The paper investigates the viability of use of conventional joining concepts between reinforced concrete barrier rails to fiber-reinforced polymer composite bridge decks. The concept is tested and implemented as part of a FRP bridge system incorporating concrete filled carbon/epoxy shells as girders and a pultruded core E-glass/vinylester–polyester deck. The barrier was anchored into the deck using polymer concrete filled cavities within the deck at discrete locations. Experimental results indicated that the configuration provides excellent anchoring capacity and a mode of failure that is more stable and capable of greater energy absorption than the conventional system due to the encapsulation of the anchorage within the composite deck. Failure was initiated through yield in the bars at a load of 129 kN compared to a demand level of 44.5 kN. No damage accrues to the deck itself with minimal damage in the anchorage. Analytical predictions of onset of yield and failure are shown to match experimental results as well. The testing validates the use of the system pursuant to specification mandated criteria.

Advances in fibre‐reinforced polymer composite bridge decks

AbstractUtilization of thermoset or thermoplastic resins binding glass and/or carbon fabrics has led to advanced fibre‐reinforced polymer (FRP) composite materials, structural shapes, and systems. Innovative FRP composite bridge deck production processes have been developed and perfected. Two of these processes are pultrusion and resin transfer moulding. A number of structural systems implemented as bridge decks are described. Construction and design details of composite decks are also provided.