Glass Fiber Reinforced Polymer Bridge Deck Research Articles

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.

Web buckling mechanism of pultruded GFRP bridge deck profiles subjected to concentrated load

The web’s local buckling is a major failure type of pultruded glass fiber-reinforced polymer (GFRP) bridge deck subjected to concentrated wheel loads. Three kinds of external actions-that is, in-plane shear force, local compressive force and bending moment-are coupled at web. Besides, the couple ratio of those three external actions is changed due to varied wheel’s loading position, resulting in a more complicated web buckling mechanism. Hence, a study of the web buckling behavior was firstly conducted through two experiments with different concentrated loading cases, namely mid-span loading and quarter-span loading. After then, parametric analysis of FE model with detailed simulated web-flange junctions (WFJ) were performed to reveal a more comprehensive understanding. The experimental results showed that both specimens went through buckling failure of middle web, post-buckling strengthening owing to structural redundancy, and final failure caused by crack propagation on the top flange. The parametric analysis showed that the compression buckling and shear buckling coupled together, and that the compression buckling is dominant. In addition, as the shear-span ratio decreased, the principal compressive stress and the shear buckling became more pronounced, and consequently the GFRP bridge deck’s bearing capacity reduced.

Experimental and numerical investigation on in-plane compression and shear performance of a pultruded GFRP composite bridge deck

The in-plane compression and shear performance plays a significant role in achieving an optimum and reliable design of pultruded glass fiber-reinforced polymer (GFRP) bridge deck supported on steel girders that have been used in bridge decks retrofit application or new construction in the past decade. This paper presents a summary of several laboratory experiments that were performed on a pultruded GFRP bridge deck for pedestrian or light vehicular loading in order to evaluate both the deck’s in-plane compression and shear properties. The experimental results showed that the average web thickness has a relatively larger influence on the in-plane shear behavior than the in-plane compressive behavior. Three-dimensional finite element models utilizing the Hashin’s theory laminate failure, adhesive layers failure via cohesive element and initial geometry imperfections by using limited critical eigenmodes multiplied by empirical coefficient were employed to numerically simulate both the deck’s in-plane compression and shear ultimate capacity and stiffness based on elastic engineering constants obtained from micromechanics. The numerical results agreed well with experimental results that could provide a reference for the design and construction of such type of pultruded composite bridge decks.

Modeling and Analysis of GFRP Bridge Deck Panels Filled with Polyurethane Foam

This paper presents finite-element analyses and analytical models of innovative, small-scale, prototype deck panels examined under monotonic bending. The deck panels consisted of two glass fiber–reinforced polymer (GFRP) facesheets separated by webs formed from E-glass–woven fabric placed around trapezoidal-shaped, low-density, polyurethane foam segments. The proposed panel exhibited a higher structural performance in terms of flexural stiffness, strength, and shear stiffness than those of conventional sandwich panels. Analytical models were used to predict critical facesheet wrinkling in the sandwich panel. Furthermore, a three-dimensional model using simulation software was developed for analysis of the proposed panel system under monotonic four-point loading. The finite-element results in terms of strength, stiffness, and deflection were found to be in good agreement with those from the experimental results. A parametric study was also conducted to further evaluate the effects of the stiffness of the top facesheet fiber layers, the mass density of the polyurethane foam, the existence of web layers, and the introduction of an overlay above the top facesheet. A flexural beam theory approach was used to predict the flexural strength of the sandwich panel.

GFRP Bridge Deck Panel

The aim of the research is design and analysis of new bridge deck panel made of glass fiber reinforced polymer (GFRP). Use of GFRP in construction is rapidly growing in last few years. The reason for use GFRP is its low self weight in compare of strength and high resistance against weather influenced degradation resulting in long life. Using GFRP for the construction of the bridge deck leads to lightweight construction that can pass the required wheel load. Lightweight design is appreciated for temporary bridge which is expected to be transported and assembled often on places of current need. Long durability and resistance against weather degradation also reduces maintenance costs of bridge deck. Design of deck panel will be done on the base of loading experiments and FEM analysis. The main use of GFRP bridge deck panel is for temporary bridge but it is possible to extend its use on permanent or movable bridges.

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.

Nondestructive Testing of GFRP Bridge Decks Using Ground Penetrating Radar and Infrared Thermography

As glass fiber-reinforced polymer (GFRP) bridge decks are becoming a feasible alternative to the traditional concrete bridge decks, an innovative methodology to evaluate the in situ conditions are vital to GFRP bridge decks’ full implementation. Ground penetrating radar (GPR) typically performs well in detecting subsurface condition of a structural component with moisture pockets trapped within the material. On the other hand, infrared thermography (IRT) is traditionally known for its ability to detect air pockets within the material. In order to evaluate both nondestructive testing methods’ effectiveness for subsurface condition assessment of GFRP bridge deck, debonds of various sizes were embedded into a GFRP bridge deck module. A 1.5 GHz ground-coupled GPR system and a radiometric infrared camera were used to scan the deck module for condition assessment. Test results showed that both GPR and IRT retained their respective effectiveness in detecting subsurface anomalies. GPR was found to be capable of d...

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.

Glass fiber-reinforced polymer/steel hybrid honeycomb sandwich concept for bridge deck applications

Glass fiber-reinforced polymer (GFRP) bridge decks possess inherently high strength-to-weight ratios, but relatively low effective elastic moduli . As a result, serviceability issues govern GFRP bridge deck design. Therefore, the objective of this study was to increase the stiffness of a commercial GFRP honeycomb sandwich panel through the inclusion of steel within the cross section. GFRP-steel hybrid parametric studies were conducted to evaluate improvements on the GFRP honeycomb deck panel stiffness. Possible configurations included the embedment of steel plates within the face sheets and the placement of steel tubes within the core. Core stiffness analyses were also performed, leading to the development of the steel hexagonal honeycomb core concept. An experimental study, including large-scale beam tests, was conducted. The large-scale tests were performed to assess the equivalent flexural and shear stiffness , comparing the hybrid steel core concept and the current GFRP core design. From the large-scale beam test results, an overall stiffness increase was observed.

An experimental study on static behavior of a GFRP bridge deck filled with a polyurethane foam

Abstract The static behavior of an orthotropic bridge deck made of glass fiber reinforced polymer (GFRP) and polyurethane foam was investigated experimentally. The bridge deck consisted of GFRP unit modules with rectangular holes filled with foam to improve the structural behavior in the transverse direction. It was found that, although the elastic modulus of the foam compared to the homogenized modulus of the GFRP deck was about the order of 10 −3 , the structural behaviors in the transverse direction such as the nominal strength, stiffness, etc. were greatly improved when the GFRP bridge deck was filled with foam. Because of the low mass density of the foam used in this study, the bridge deck was still light enough while the structural properties were improved significantly. Webs of the foam-filled modules did not significantly contribute to strength development of the deck. However, propagation of a crack initiated in a module was caught by the webs so as to limit the crack to the inside of that cell only. This made the load–displacement behavior of the foam-filled GFRP deck less brittle. The longitudinal response of the GFRP deck was improved with the foam. The strength was increased about 20% but the elastic modulus was not improved.

Thermal Compatibility and Durability of Wearing Surfaces on GFRP Bridge Decks

The paper investigates thermal compatibility between wearing surface (WS) materials and glass fiber reinforced polymer (GFRP) bridge decks, and proposes a more durable hybrid WS system for GFRP decks. Wearing surface delamination problems observed on many existing GFRP bridge decks motivated the investigation and the search for a durable WS material that could alleviate the problems. Several WS materials were bonded to GFRP panels, with and without surface preparation, and tested under various environmental conditions. In addition to the standard ASTM C884 method, the testing program included two new methods for thermal compatibility testing to reflect the in-service conditions of WSs on GFRP bridge decks. The proposed methods were developed to account for the influence of freeze–thaw–heat and submerge–freeze cycles on thermal compatibility and durability. The investigation concluded that a hybrid WS system, consisting of two-layered WS materials, has the best bond quality. Applied directly on top of a GFRP deck, the top layer of the hybrid WS system had the best tire resistance, forming a nonskid riding surface.

Theoretical and Experimental Analysis of GFRP Bridge Deck under Temperature Gradient

The temperature difference between the top and bottom of a glass fiber reinforced polymer (GFRP) composite deck, ∼65°C (∼122°F) , is nearly three times that of conventional concrete decks ∼23°C (∼41°F) . Such a large temperature difference is attributed to the relatively lower thermal conductivity of GFRP material. In this study, laboratory tests were conducted on two GFRP bridge deck modules (10.2 and 20.3 cm deep decks) by heating and cooling the top surface of the GFRP deck, while maintaining ambient (room) temperature at the deck bottom. Deflections and strains were recorded on the deck under thermal loads. Theoretical results (using macro approach, Navier-Levy, and FEM) were compared with the laboratory test data. The test data indicated that the GFRP deck exhibited hogging under a positive temperature difference (i.e., Ttop > Tbottom , heating test; Ttop and Tbottom are temperatures at top and bottom of the deck, respectively) and sagging under a negative temperature difference (i.e., Ttop < Tbottom...

Evaluation of Effective Width and Distribution Factors for GFRP Bridge Decks Supported on Steel Girders

Glass fiber-reinforced polymer (GFRP) bridge deck systems offer an attractive alternative to concrete decks, particularly for bridge rehabilitation projects. Current design practice treats GFRP deck systems in a manner similar to concrete decks, but the results of this study indicate that this approach may lead to nonconservative bridge girder designs. Results from a number of in situ load tests of three steel girder bridges having the same GFRP deck system are used to determine the degree of composite action that may be developed and the transverse distribution of wheel loads that may be assumed for such structures. Results from this work indicate that appropriately conservative design values may be found by assuming no composite action between a GFRP deck and steel girder and using the lever rule to determine transverse load distribution. Additionally, when used to replace an existing concrete deck, the lighter GFRP deck will likely result in lower total stresses in the supporting girders, although, due to the decreased effective width and increased distribution factors, the live-load-induced stress range is likely to be increased. Thus, existing fatigue-prone details may become a concern and require additional attention in design.

Critical Evaluation of Strain Measurements in Glass Fiber-Reinforced Polymer Bridge Decks

An experimental study of principal strains and deflections of glass fiber-reinforced polymer (GFRP) composite bridge deck systems is presented. The experimental results are shown to correlate well with those of an analytical model. While transverse strains and vertical deflections are observed to be consistent, repeatable, and predictable, longitudinal strains exhibit exceptional sensitivity to both strain sensor and applied load location. Large, reversing strain gradients are observed in the longitudinal direction of the bridge deck. GFRP deck system geometry, connectivity, material properties, and manufacturing imperfections coupled with the observed strains suggest that the performance of these structures should be assessed under fatigue loading conditions. Recommendations for accurately assessing longitudinal strain in GFRP bridge decks are made, and a review of existing data is suggested.

Fire endurance of loaded and liquid-cooled GFRP slabs for construction

This paper presents an experimental study on the fire behavior of glass fiber-reinforced polymer (GFRP) load- carrying slabs for building and bridge applications. Fire experiments were performed on cellular full-scale slabs with and without internal liquid cooling. The slabs were subjected to serviceability limit state loads during ISO 834 fire exposure from the underside. Liquid cooling was demonstrated to be an effective way of improving the fire endurance. The code-required 90-minute fire resistance for buildings was met. After an increase in the first 20 min, temperatures, deflections, and axial strains of the liquid- cooled slabs approached a nearly steady-state condition in the 70–100 min that followed. The remaining total safety factor in post-fire experiments was greater than 3.3 and therefore still sufficient to prevent structural collapse. The non-liquid cooled reference specimen provided structural resistance during fire exposure for 57 min. For bridge applications, it was concluded that the fire endurance of non-liquid cooled cellular GFRP bridge decks is sufficiently high in the case of fire from the underside.

In situ structural evaluation of a GFRP bridge deck system

An 18.3 m (60 ft) simple span bridge is South Carolina's first use of a glass fiber reinforced polymer (GFRP) bridge deck system. This paper describes the initial preparation and instrumentation of this structure including the use of surveying techniques to determine overall bridge deflections. Also outlined are the procedures used for in situ load testing the bridge. Critical design criteria such as overall deflections, effective deck widths, bending of the GFRP deck and moment distribution factors are reported for this structure. Data collected indicates that the GFRP deck and steel girders are acting in a composite manner and that the deck system is relatively stiff despite the large girder spacing used. Over the course of the next several years this bridge will be tested on a regular basis to establish the long-term performance of the GFRP deck system.