Glass Fiber Reinforced Polymer Deck Research Articles

Influencia de las Propiedades de un Tablero de Polímero Reforzado con Fibra de Vidrio en la Respuesta Dinámica de un Puente Carretero

The use of multicellular Glass Fiber Reinforced Polymer (GFRP) deck panels in the rehabilitation and construction of bridges has increased over the last 30 years due to several benefits, such as: low maintenance cost, fast installation, corrosion resistance, and high strength-to-weight ratio. Due to the orthotropic nature of GFRP decks and their complex cross-section geometry, expensive computational problems may be obtained when bridges that include these elements are analyzed under traffic loads. Therefore, this paper studies the dynamic response of a GFRP-steel road bridge modelling the multicellular GFRP deck as an orthotropic plate. For this purpose, a finite element model of the hybrid structure is developed, and a sensitivity analysis is carried out to investigate the influence of the mechanical properties of the orthotropic element on the bridge behavior. The roughness of the pavement, the degree of composite action between the deck and the stringers, the multibody dynamic model of a truck, and the vehicle-bridge interaction phenomenon are included in the analyses. Results indicate that the most relevant properties of the orthotropic plate on the response of the structure are the modulus of elasticity in the longitudinal direction, the modulus of elasticity in the transverse direction, and the shear modulus. Also, achieving a full composite action and avoiding deterioration of road are identified as key aspects to reduce the vibration levels on the hybrid bridge.

Analysis of Adhesive Joints in a GFRP Bridge Deck under Bidirectional Bending Due to Traffic Wheel Loads

Glass-fiber-reinforced polymer (GFRP) decks have been widely used in the rehabilitation and construction of bridges as a replacement for conventional deck materials, such as steel, concrete, and wood. In this study, an analysis method for checking the local safety of joints in adhesively connected GFRP decks under bidirectional bending due to traffic wheel loads is newly presented. This method can be applied for designing and evaluating the joints of other FRP decks. The orthotropic material properties of the deck were approximately assumed according to the test results and previous research. Three-dimensional solid elements were used to simulate the local behavior of the adhesive and deck substrates at the joints. Global deflections of the deck and local deformations of the adhesive were evaluated for serviceability. The local stresses in the adhesive and deck substrate are evaluated at the joint to check for local failure modes of the joint under serviceability and ultimate limit states. The analysis results indicate that local failures of the adhesive and deck substrate at the joint occurred. Recommendations for avoiding these local failures and performing more precise analysis are suggested.

Structural analysis and optimization of an advanced all-GFRP highway bridge

In this research, a relative novel type of composite structure for a glass fiber reinforced polymer (GFRP) highway bridge was analyzed that consisted of a multi-cell GFRP deck and two U-shaped GFRP girders, and the structural analysis and optimization of such advanced structure was presented. The deformation mechanism was analyzed using theoretical formulations. It was found that the deformation was mainly composed of flexural deformation rather than shear deformation. By employing laminated shell elements, a finite element (FE) analysis was carried out to investigate the structural behaviors of the bridge structure for various load cases. The results indicate that the structural indexes including the deflection, stress, dynamic frequency, and anti-overturning stability all met the requirements of the design code. By using the zero-order optimization method, the multi-parameter structural optimization was further conducted to obtain the minimum weight of the structure, in which four sectional parameters of the girder (i.e., top flange thickness, bottom flange thickness, web thickness, and girder depth) were considered the design invariables. The optimal structural schemes for various combinations of design variables were obtained. The results revealed that the thinner the top flange and the web were, or the thicker the bottom flange was, the lighter the optimized structure was. The achievements verified the applicability of such composite GFRP structures for highway bridges.

Characterization and structural performance of hybrid fiber-reinforced composite deck panels

This paper presents the experimental and analytical investigation on the behavior of hybrid fiber-reinforced composite deck made up of glass and jute fibers embedded in vinyl ester matrix. Finite element evaluation of the flexural performance of the composite decks was carried out using ANSYS, FE software. It was observed that analytical evaluation underestimates the value of deflection of deck panels 1 and 2 by 10.91% and 18.57%, respectively, when compared to the experimental results. However, the value of strain obtained by FEA is appreciably higher than that observed during the experiment. The analytical evaluation of deck panels was further extended to HYFRP and GFRP (glass fiber-reinforced polymer) decks with varied cross sections obtained by changing the location and shape of stiffeners. The specifications stipulated by Ohio Department of Transportation (ODOT), USA, for FRP decks were used for evaluating the performance of deck panels. The values of maximum deflection and strain experienced by the deck panels with stiffeners at the web-flange joint were found to be less than that of deck panels provided with stiffeners at the center of top flange of each cellular unit. Out of the various configurations examined, the performance of decks with V-shaped stiffeners and combination of U- and V-shaped stiffeners at top and bottom web-flange joint were found to be best with substantially lower deflection and strain.

The Design and Analysis of Internally Stiffened GFRP Tubular Decks—A Sustainable Solution

The aim of this paper was to find an optimal stiffener configuration of thin-wall tubular panels made by glass fiber reinforced polymer (GFRP) composite material, which is a low carbon emission, low life cycle cost, and sustainable material. Finite-element analysis (FEA) was used to investigate the flexural and torsional stiffness of various internally stiffened sections of thin-wall GFRP decks. These decks consist of internally stiffened tubular profiles laid side by side and bonded together with epoxy to ensure the panel acts as an assembly. Three-dimensional models of the seven proposed decks were assembled with tubular profiles of different stiffener patterns. First, the non-stiffened tube profile was tested experimentally to validate the parameters used in the subsequent numerical analysis. Then, the finite element software, ANSYS, was used to simulate the flexural and torsional behavior of the decks with different stiffener patterns under bending and torsional loads. The decks with stiffener patterns such as “O” type, “V” type, and “D” type were found to be the most effective in bending. For torsion, there was a distinct tendency for deck panels with closed shaped stiffener patterns to perform better than their counterparts. Overall, the “O” type deck panel was an optimal stiffener configuration.

Static and fatigue load performance of a pultruded GFRP deck panel reinforced with steel wires

This paper presents an experimental study of the quasi-static and fatigue load performance of a pultruded GFRP (glass fiber-reinforced polymer) deck panel that can be used to furnish the roadway surface of temporary detour bridges. The flanges of the GFRP deck panel were reinforced with uniformly spaced steel wires to increase the flexural stiffness of the panel. A total of nine full size GFRP deck panel specimens were tested under static and fatigue loadings. The load-deflection behavior and ultimate strength of the deck specimens were compared with those of the unreinforced specimens. The test results were also compared with the results of finite element analysis. The steel reinforcement of the steel reinforced GFRP panels was only 2.5% of the cross-sectional area of the GFRP composite. The test results indicated that, at the design load level, the flexural stiffness of the steel reinforced GFRP panels was approximately 12.3% greater than that of the unreinforced GFRP panels. The test results further revealed that the fatigue loading up to 120% of the design load did not influence the stiffness of the steel reinforced GFRP deck panel.

Flexural Behavior of Pultruded GFRP Deck Panels with Snap-Fit Connections

This paper presents experimental, analytical and numerical investigations about the flexural behavior of glass fiber reinforced polymer (GFRP) pultruded panels for footbridge decks. The analyzed panels, made of isophthalic polyester and E-glass fibers, comprise a multicellular thin-walled cross-section with panel-to-panel vertical snap-fit connections at their lateral edges. As part of a comprehensive study about the mechanical and structural behavior of this type of footbridge decks, the experimental study presented here addresses: (i) the mechanical characterization of the laminated material, and (ii) the quasi-static flexural behavior of the panels for both service and failure conditions. The experimental data obtained is used to validate and assess the accuracy of three-dimensional shell finite element (FE) models and analytical formulae. Particular focus is given to the serviceability and failure performance of the panels, in terms of their deformability and susceptibility to buckling phenomena, respectively. Regarding the serviceability behavior, the results obtained in this study demonstrate the importance of duly specifying the shear coefficient of the multicellular cross-section on Timoshenko beam theory, in order to obtain accurate deflection predictions. In terms of failure performance, both the flexural tests and the analytical formulae indicate that the local buckling of the compressive flanges seems to have triggered the collapse of the tested panels, thus limiting their load carrying capacity. The geometrically nonlinear FE analyses allowed understanding in further depth the ultimate behavior of the panels, providing further insights about their failure mechanisms.

Impact response of pedestrian bridge multicellular pultruded GFRP deck panels

The impact behaviour of pultruded glass fibre reinforced polymer (GFRP) multicellular footbridge deck panels was investigated via instrumented drop weight testing. Force-displacement history, maximum force, and displacement and absorbed energy at perforation were recorded. The effects of two damage protections (a resin-sand surface coating, and polyurethane foam-filled sections) and of alternative target specimen geometries (3-cells, 1-cell and single laminated flange) were investigated. Previous quasi-static test results were successfully used to estimate the impact incident energies required for perforation, thus saving material resources. The impact force-displacement behaviour was of a similar form to that of the quasi-static tests. Before damage, coated deck sections alone exhibited a strain rate effect, with the impact response stiffer than the quasi-static response. However, a similar stiffening strain rate effect was seen for all specimens after the onset of damage, which is believed to be due to rate sensitive damage propagation. The surface coating increased the perforation energy by 25%, but foam-filled sections gave no significant impact resistance improvement. Alternative geometries could be used in specific cases, but a 3-cell wide target was found to be preferable. It was shown that even relatively mild impact events such as tool drops could result in damage, or even perforation.

Rotational stiffness of web-flange junctions of pultruded GFRP decks

The rotational behavior of the web-flange junctions (WFJs) of a pultruded glass fiber-reinforced polymer (GFRP) bridge deck system with trapezoidal cell cross-sectional geometry was investigated. The rotational response of three WFJ types, in two bending moment directions each, was characterized. An experimental procedure based on three-point bending and cantilever experiments conducted on the web elements and simple analytical models was used. The WFJs generally exhibited non-rigid and nonlinear behavior. The overall moment-rotation relationships, rotational stiffness, strength and failure modes differed depending on the web type, the location of the WFJ within the deck profile, the existing initial imperfections and the direction of the bending moment applied. This evidenced the relevance of separately characterizing the response of all WFJ types in the two possible bending directions. Simplified expressions to model the WFJ rotational behavior were derived. The validity of the experimental and idealized rotational responses was assessed by means of numerical simulations of full-scale experiments conducted on the GFRP deck.

Quasi-static indentation response of pedestrian bridge multicellular pultruded GFRP deck panels

This paper presents an experimental study of the quasi-static indentation behaviour of a pultruded glass fibre reinforced polymer (GFRP) multicellular deck panel used in footbridges. To simulate the applied loads to be experienced by such a deck during its service life, various sets of specimens extracted from the panel cross-section were perforated statically across its top flange thickness using different indenters. Load-displacement responses, failure modes and absorbed energies were analysed concerning the influence of the following parameters: (i) specimen geometry (single laminated flange, 1-cell and 3-cells); (ii) indenter type (size – 6/10mm and shape – hemispherical/flat), and (iii) damage protection (surface coating and filling of the section cavities with polyurethane foam). The results obtained show that simpler specimen geometries are able to predict the quasi-static indentation behaviour of the bridge deck in particular cases and for specific measured responses; nonetheless, they are not able to simulate the effects of damage protections. The application of a surface coating proved to be the only successful protection method in delaying the first significant damage, giving higher absorbed energy levels. However, regarding the onset of perforation, both protection strategies considered did not provide any appreciable improvement. The results obtained also show that penetration failure modes due to “standard” high-heel loads are not likely to occur on the bridge deck even if its surface is not protected. Nevertheless, in this case, both initial damage and perforation may be easily inflicted by heavier pedestrians walking or running upon “stiletto-type” high-heels.

Flexural creep response of pultruded GFRP deck panels: Proposal for obtaining full-section viscoelastic moduli and creep coefficients

Abstract Glass fiber reinforced polymer (GFRP) pultruded flexural members are generally analyzed for serviceability limit states using shear-deformable beam theories, considering their short-term full-section moduli. However, regarding long-term design, for which the effect of viscoelasticity must be taken into account, the time-dependency of those full-section properties were not yet properly defined, namely for multicellular panels used in bridge decks. To address this issue, this paper describes an experimental study about the flexural creep response of full-scale multicellular GFRP pultruded deck panels subjected to uniformly distributed loads for about 5 months under normal laboratory environmental conditions. The creep behaviour of the panels was first successfully modelled using Findley's power law, confirming the ability of this empirical approach to simulate the viscoelastic response of multicellular deck panels. Next, an experimental methodology involving the measurement of creep deflections in panels with different spans and applying the Timoshenko beam theory in the time domain was proposed in order to characterize simultaneously the full-section flexural and shear moduli over time. The results obtained, including design formulae for the time-dependent creep coefficients for shear and bending, indicate that the creepocity due to shear is much higher, with reductions after 50-years in the effective flexural and shear stiffness of 22% and 43%, respectively. Finally, a comparison is made between these creep coefficients and those suggested in the most relevant design guidelines.

Delamination of GFRP Panels in Bridge Decks

Modern bridge structures need light decks with long durability and promising technical parameters. GFRP bridge deck creates possibilities in bridge designing. Parallel identification of GFRP deck panel: DTA analysis, spectroscopy analysis, scanning and optical microscope monitoring according to own investigation will be presented, in the paper. Modal, vibrations analysis is very important for bridge structures using light Glass Fiber Reinforced Polymer decks. The three 1stmodes and corresponding frequencies have been showed for chosen footbridges with GFRP ASSET system decks. The footbridges were excited by impact and human-induced vibrations. Good exploration of new material, like composite GFRP, generates potential to improve technology and make comparison analysis with traditional standard of materials. The dynamic behavior of damaged footbridge structures under moving loads has been studied. The paper is concerned with a micromechanical theory of macroscopic crack propagation due to stress-corrosion cracking in unidirectional glass-fiber-reinforced polymer composites, for bridge decks applications. The first form of damage in laminates is usually matrix micro cracks, which are intralaminar or ply cracks that traverse the thickness of the ply and run parallel to the fibers in that ply. The identification of early delamination process in footbridges GFRP deck is very important by them durability feature. Improving system for polymer resin using nanostructures is useful by aspect of reducing micro cracks and then macro cracks propagation.

Structural monitoring and 8-year load test on Europe's first fibre-reinforced polymer highway bridge

In October 2002 the first all-fibre-reinforced polymer (FRP) composite bridge on the public highway network in Europe, West Mill Bridge, UK, was installed. The design and construction of this bridge was the culmination of a 4-year EU research project called Asset, to develop a heavy-duty FRP bridge decking system for use in repairing, upgrading and new civil infrastructure. As part of this project, a monitoring system was installed on the bridge during fabrication. In addition to an initial controlled load test on installation of the bridge, further controlled load tests using a 30 t lorry have been undertaken after 3 years and 8 years. The results from these load tests confirmed the medium-term structural behaviour to be essentially unchanged from the original structural behaviour. In particular, a high level of composite action between the glass fibre reinforced polymer deck, FRP main beams, and concrete parapet beams was still present after 8 years of service.

GFRP 보강근으로 보강된 바닥판의 보강비에 따른 정적 및 피로성능 평가

The corrosion of steel reinforcement in reinforced concrete bridge decks significantly affects the degradation of the capacity. Due to the advantageous characteristics such as high tensile strength and non-corrosive property, fiber reinforced polymer (FRP) has been gathering much interest from designers and engineers for possible usage as a alternative reinforcement for a steel reinforcing bar. However, its application has not been widespread, because there data for short- and long-term performance data of FRP reinforced concrete members are insufficient. In this paper, seven full-scale decks with dimensions of were prepared and tested to failure in the laboratory. The test parameter was the bottom reinforcement ratio in transverse direction. The decks were subjected to various levels of concentrated cyclic load with a contact area of to simulate the vehicle loading of DB-24 truck wheel loads acting on the center span of the deck. It was observed that the glass FRP (GFRP) reinforced deck on a restraint girder is strongly effected to the level of the applied load rather than the bottom reinforcement ratio. The study results showed that the maximum load less than 58% of the maximum static load can be applied to the deck to resist a fatigue load of 2 million cycles. The fatigue life of the GFRP decks from this study showed the lower and higher fatigue performance than that of ordinary steel and CFRP rebar reinforced concrete deck. respectively.

A steel-reinforced hybrid GFRP deck panel for temporary bridges

This paper presents the design, analysis, and fabrication of a steel-reinforced hybrid GFRP (glass-fiber-reinforced polymer) deck panel that can be used to furnish the roadway surface of temporary bridges. Two hybrid cross-sectional profiles were proposed to increase the flexural stiffness of the GFRP deck panel, and the structural performance of the hybrid deck profiles was compared on the basis of finite element analysis. The results indicate that the flexural stiffness of the GFRP deck panel can be effectively increased by the proposed method of hybridization presented in this paper. The results and findings are summarized.

GFRP 교량 바닥판의 정적거동에 관한 연구

본 연구에서 교량바닥판용으로 조립식(Modular) 유리섬유 보강(GFRP) 바닥판의 개념을 제안하였다. 본 조립식 GFRP 바닥판시스템은 GFRP 주 단위모률(unite module)과 연결 단위모듈로 구성되어 있다. 본 GFRP 바닥판의 구조성능을 평가하기 위해 정적하중실험을 실시하였다. 그리고 구조성능 결과에 대해서 범용 유한요소 프로그램인 LUSAS을 이용한 수치해석 결과와 비교 분석하였다. 본 연구에서 제안한 조립식 GFRP 바닥판은 교량적용에 매우 유용할 수 있음을 확인할 수 있었다. 제안된 GFRP 바닥판의 파괴모드가 개발된 다른 상용화된 GFRP 바닥판의 파괴모드와 매우 유사한 파괴모들 나타내었다. A concept of Modular GFRP(Glass Fiber Reinforced Polymer) deck panel was proposed for bridge decks. The modular GFRP bridge deck system is comprised of main unit module and connector unit module with GFRP flanges and web. Its structural performance under static loading was evaluated and compared with the LUSAS finite element predictions. It was found that the presented GFRP modular panel was very efficient for use in bridges. The failure mode of the proposed GFRP deck was similar when compared with that of commercial other GFRP decks developed.

Interface Shear Force of Steel and GFRP Deck Composite Beam under the Effect of Temperature and Creep

A new type steel and glass fiber reinforced polymer (GFRP) deck composite beam has been proposed. The relative slip and shear force on the interface of steel and GFRP deck composite beam appears to a certainty with the external loading, which induced internal force redistribution between GFRP deck and steel beam and shear connector, especially GFRP is a resin material, its physical and mechanical properties will change with temperature and time. According to the structure and bearing characteristics, the interface shear force differential equations that considering the temperature and creep effects were presented, the theoretical calculating formula of shear force were given under the uniform load. Results of calculation showed that the shear force of composite cross-section would increases with the increase of the connection stiffness, the increase of load, the change of temperature and the time. Loading effect and temperature changes creates a relatively larger impact on the shear force of the composite beam, while the stiffness of the connective interface and the creep effect of the GFRP material to composite beam shear force were much little.

Ultimate strength of a GFRP deck panel for temporary structures

To overcome the steel corrosion and fatigue problems of conventional steel deck panels, a reusable glass-fiber-reinforced polymer (GFRP) deck panel has been developed for temporary structures. This paper deals with a series of full-scale tests conducted to experimentally validate the structural performance of the GFRP deck panel. The test program consists of a failure test under quasi-static loading and a fatigue test under cyclic loading. The results of the tests indicate that the GFRP deck panel satisfies both the strength and service design limits.

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.

Steel Hexagonal Honeycomb Core Equivalent Elastic Moduli for Bridge Deck Sandwich Panels

Glass fiber-reinforced polymer (GFRP) materials possess inherently high strength-to-weight ratios, but their effective elastic moduli are low relative to civil engineering (CE) construction materials. While elastic modulus may be comparable to that of some CE materials, the lower shear modulus adversely affects stiffness. As a result, serviceability issues are what govern GFRP deck design in the CE bridge industry. An innovative solution to increase the stiffness of a commercial GFRP reinforced-sinusoidal honeycomb sandwich panel was proposed; this solution would completely replace the GFRP honeycomb core with a hexagonal honeycomb core constructed from commercial steel roof decking. The purpose of this study was to perform small-scale tests to characterize the steel hexagonal honeycomb core equivalent elastic moduli in an effort to simplify the modeling of the core. The steel core equivalent moduli experimental results were compared with theoretical hexagonal honeycomb elastic modulus equations from the literature, demonstrating the applicability of the theoretical equations to the steel honeycomb core. Core equivalent elastic modulus equations were then proposed to model and characterize the steel hexagonal honeycomb as applicable to sandwich panel design. The equivalent honeycomb core will enable an efficient sandwich panel stiffness design technique, both for structural analysis methods (i.e., hand calculations) and finite-element analysis procedures.