Search

Experimental investigation of structural behavior of glass fiber reinforced polymer (GFRP) space truss bridge model subjected to static loading is discussed in this paper. Bridge prototype was assembled using GFRP profiles produced by Fiberline Composites Ltd , steel bolts and GFRP brackets. In order to load the structure, wooden bridge deck was installed. Total load of 13.3 kN was applied in four stages while measuring the bridge node displacement. Flexural behavior of the truss structure was monitored at every loading stage. In order to perform the comparison analysis of truss structural behavior, numerical model was created employing finite element software Solidworks . Comparative analysis has shown good agreement between experimental and numerical results (the margin of error varied from 0,3 up to 10,5%). The obtained results show, that designed and tested bridge model has a sufficient reserve of structural stiffness. Performed investigation reveals that GFRP profiles are suitable for real pedestrian bridge superstructures. [ABSTRACT FROM AUTHOR]

Energetically weak points in thermally insulated building envelopes are formed by thermal breaks that are implemented to structurally connect external balconies to internal slabs. Current thermal breaks comprise stainless steel bars that penetrate the insulation layer and thus cause significant thermal losses. A new thermal break composed of highly insulating aramid and glass fiber-reinforced polymer (AFRP and GFRP) components and aerogel granulate insulation materials was developed and the first prototypes of the load-bearing components were experimentally investigated. The use of AFRP leads to an excellent thermal performance with linear thermal transmittance values of below 0.15 W/m K. The experimental prototype investigations confirmed the targeted ductile failure mode through concrete crushing in the component–concrete interfaces. The serviceability limit state conditions are met for a targeted balcony cantilever span of 4.0 m. The material-tailored components can be manufactured by fully automated processes such as filament and tape winding and pultrusion to economically produce large quantities within a short time. [ABSTRACT FROM AUTHOR]

The objective of this article was to experimentally evaluate timber–concrete composite beams in two different situations – with and without glass fiber reinforced polymer (GFRP). Four full-scale composite beams (5.4 m in length) were produced, two of which had reinforcement (nominal thickness of 10 mm) and two with no reinforcement. The fiberglass reinforcement was formed from the impregnation of unidirectional fiberglass cloth – effective thickness of 0.5 mm – with epoxy resin. The connection system consisted of steel hooks inclined at 45 degrees, bonded with epoxy adhesive to the holes previously drilled on the wood, whose apparent density at 12% moisture content was 0.79 g/cm 3 . The reinforced timber–concrete composite beams tested had performance efficiency of 79% and average rupture strength of 142.5 kN. Finally, the reinforced timber–concrete composite beams were analytically evaluated using the proposed method in Eurocode5, showing reasonable agreement with the experimental results. [ABSTRACT FROM AUTHOR]

Abstract: The span limits of two glass fiber-reinforced polymer (GFRP) bridge concepts involving GFRP-balsa sandwich plates are discussed. The sandwich plates were either used directly as slab bridges or as decks of a hybrid sandwich-steel girder bridges. In the latter case, the potential of the sandwich decks to replace reinforced concrete (RC) decks was also evaluated. Taking the limits of manufacturing into account (800mm slab thickness), maximum bridge spans of approximately 19m can be reached with FRP-balsa sandwich slab bridges, if a carbon-FRP (CFRP) arch is integrated into the balsa core. Above this limit, hybrid sandwich-steel girder bridges can be used up to spans of 30m. RC deck replacement requires timber and steel plate inserts into the balsa core above the steel girders. GFRP-balsa sandwich slabs or decks exhibit full composite action between lower and upper face sheets. Stress concentrations occur at the joints between balsa core and timber inserts which however can effectively be reduced by changing from butt to scarf joints. [Copyright &y& Elsevier]

Abstract: In this study a total of 63 cubic specimens were prepared to investigate the pullout behaviors of the sand-coated and helically-wrapped GFRP bars as well as steel bars in concretes reinforced with structural fibers (steel, PP and PVA fibers). The results of direct pull-out testing were presented and analyzed with the aim of elucidating the effect of surface treatment of bar, fiber type, and fiber volume fraction in interface and suggesting the effective evaluation method for the improved ductility. The structural fibers in the interface changed the interfacial bond behaviors before and after the maximum stress and resulted in significant improvement of the relative bond strength, but bond failure modes largely depended on the interfacial property with the rebar. The fiber’s crack closing resistance, determined by evaluating both the residual bond strength and toughness indices, was used to determine optimum amount and type of fibers in the composites. The closing pressures due to PVA and hook end steel fibers had a good effect on resisting and controlling the interfacial crack initiation, growth, and propagation. [Copyright &y& Elsevier]

Abstract: This paper describes a detailed assessment of the structural safety, serviceability, capacity rating and long-term durability of a fiber-reinforced polymer (FRP) vehicular slab bridge superstructure. This first all-FRP slab bridge was installed in Korea on May the 22nd, 2002. The FRP slab bridge superstructure is a simply supported, its length is 10.0m, and is designed to carry two-lane traffic and has an overall width of 8.0m. The FRP slab bridge is a sandwich structure with a corrugated core, fabricated by a hand lay-up process with E-glass fibers and vinyl ester resins. The assessment includes a visual inspection, field load test identical to that performed in 2002. The field load test under actual service conditions was conducted as specified by the Korean Highway Bridge Design Code. In this first part, the field load test results performed in 2002, 2004 and 2011 are presented and the capacity-ratings of FRP slab bridge was evaluated. The assessment indicates that the FRP slab bridge has no structural problems and is structurally performing well in-service as expected. The assessment may provide a baseline data for the FRP slab bridge capacity rating assessment and also serve as part of a long-term performance of all-FRP bridge superstructure. [Copyright &y& Elsevier]

Abstract: In the last decades, FRP composites have been widely used for constructing entire civil structures. One of the challenging issues for building with pultruded FRP composites is understanding the behaviour of bolted joints. In this paper, the results of a numerical analysis performed on different types of bolted composite joints with different geometry and subjected to tensile loads are reported. The aim of this study is to examine the distribution of shear stresses among the different bolts by varying the number of rows of bolts as well as the number of bolts per row. The study also considers the presence of variable diameter washers and their influence on the bearing stresses of composites with different fibre orientations. For verification of the validity of the analytical models, numerical results are compared to experimental results reported elsewhere. The results of this study showed that in multi-bolt joints, the load is not distributed equally due to varying bolt position, bolt-hole clearance, bolt-torque or tightening of the bolt, friction between member plates and at washer-plate interface. The results also indicated that in the presence of washers, the stress distributions in the fibre direction, varying fibre inclinations, are decreasing for each value of washer pressure. [Copyright &y& Elsevier]

Abstract: This paper presents the structural behavior of an innovative hybrid Fiber Reinforced Polymers (FRP) beam consisting of carbon/glass fibers and vinyl-ester resin. The advanced feature of this hybridization is the optimum use of carbon and glass fibers in the flanges to maximize structural performance while reducing the overall cost by using only glass fibers in the web section. A series of beam tests were conducted under four-point bending varying ratio of flange to web width (b f/b w) and volume content of carbon and glass fiber in the flanges. Experimental investigations revealed that the ratio of flange to web width of hybrid FRP I-shaped beams plays an important role in their structural behavior. Small flange beams (b f/b w =0.43) showed stable and linear behavior under bending moment and failed in a brittle manner by delamination of the compressive flange at the interfacial layers while wide flange beams (b f/b w =1.13) exhibited unstable and nonlinear behavior in the buckling and post-buckling region leading to delamination failure of the compressive flange. The experimental and analytical results discussed in this paper emphasize on the best composition of carbon and glass fibers for the optimum design of such hybrid beams. It is found that the maximum strength of hybrid FRP beams can be obtained with the volume content of carbon fiber to be 25–33%. Furthermore, the results of this study show the potential of applying hybrid FRP beams for bridge components. [Copyright &y& Elsevier]

Abstract: This paper focus on the design of a GFRP truss-like structure for dismountable bridges with maximum span of 30m. The bridge structure is composed of a deck supported by prestressed trussed beams which are mounted by assembling GFRP tubular profiles and steel joints with bearing type connections. Experimental tests were carried out on short profiles to determine their compressive strength at the connections and on two 1:2.3 reduced models of the trussed beam structure: a short 1.3m span cantilever beam and a 13.0m span simple supported beam. The main results obtained from the performed experimental tests on short profiles and on the cantilever beam are presented herein. It is shown that a non-linear behaviour can be generated on the trussed cantilever beam by decompression of tubular members and that collapses are induced by buckling of diagonal members. [Copyright &y& Elsevier]

Presents information on a study which described finite-element models of a variety of joints between glass fiber reinforced plastic pultruded members. Experimental program summary; Finite element models; Results; Conclusions.