Deck Profile Research Articles

Effect of Geometry and Size of Fiber Reinforced Plastic Deck Profile on Behavior of Bridges

Due to the important role that bridges play in rescue operations after an earthquake, it is necessary that these structures have a higher level of protection against seismic attacks. Earthquake identifies the weak points of the structure and causes the most damage there. Bridges are very vulnerable to these attacks due to their low degree of uncertainty. All bridges built before 1971 were designed with the elastic design method (permissible stress). In this method, the effects of plasticity, section cracking, and plastic deformation are not taken into account. The change of seismic locations based on the principles of elastic design is much less. It is because the structure experiences in a real earthquake, one of the consequences of which is the falling of the decks due to the loss of the support surface. The decision to strengthen the bridge was made when there were many bending and shear cracks on the king beams. The bridge was created. The use of FRP profiles can significantly prevent the damage caused by corrosion and is a good alternative to the traditional methods of strengthening the structure. In this study, a design for the deck of a steel bridge with I beams is presented. The shape of reinforcement using FRP fibers with vinyl ester resins has also been investigated, the effect of the geometry of FRP profiles has been investigated. The presented specifications are optimized to obtain a lasting shape and section, especially for the pultrusion process. FRP materials are light, resistant to corrosion and have high tensile strength. These materials come in different forms and range from multi-layer factory sheets to dry sheets that can be twisted on various structural forms before adding resin, is available. The durability and high tensile strength of FRP materials are among the advantages of these materials. The durability and long-term performance of FRP requires more research, which is ongoing and continues.

Mechanical performance assessment of sustainable coal plastic composite building materials

This paper presents a study for developing a high filler content coal plastic composite (CPC) for use in building and construction applications as a substitute for the state-of-the-art wood-plastic composites (WPCs). The influence of coal type (bituminous, sub-bituminous) and content (up to 70 wt%) on the mechanical performance was characterized and compared with predominant commercially available WPC products. SEM micrographs revealed good adhesion between coal and the polymer at the interface with less porosity than WPCs. Additionally, particle fracture and particle pull-out failure mechanisms were evident in the SEM micrographs, with the latter being more dominant. DSC thermal analyses revealed potential chemical reactions between the coal and HDPE interfaces, resulting in enhanced composite performance. Results indicate the tensile strength for CPC material had inverse proportionality with coal content. Despite the reduction, tensile strength for CPC with 60 wt% bituminous coal was not significantly different from a typical WPC formulation. Flexural strength increased to a maximum value, at 60 wt% for bituminous coal and 50 wt% for sub-bituminous coal, followed by a decrease. CPC with 60 wt% bituminous coal possessed higher flexural strength and, in some cases, comparable flexural modulus as compared to WPC products. Flexural properties indicated that a composite deck made from the CPC material could meet or exceed the loading and deflection requirements for decking boards. FEA models indicated that a hollow deck profile would potentially have a better load-deflection curve with less localized stresses compared to common decking board profiled sections.

Three-dimensional finite element modeling for bending and pull-out tests of composite slabs

This article introduces a novel modeling and simulation methodology that advances the understanding of steel deck and concrete slab micromechanics for bending and pull-out composite slab tests. Three-dimensional composite models detailed the embossment depth, slope, steel thickness, and tilting angle to overcome previous model simplification assumptions. Newton-Raphson was the simulation method that enabled the consideration of material non-linearities. The validity of each model was contrasted against the results from actual laboratory tests. The model incorporating the non-linearity of materials and a crack inducer was very consistent with the tests. The other two models, which did not account for non-linear behaviors, were partially consistent with test results at complementary bending stages and thus could be combined to reproduce the tests. The robustness of the simulation approach was leveraged to analyze the influence of parametric and boundary conditions in pull-out simulations. Also, micromechanics phenomena that cannot be observed during laboratory tests were investigated. The proposed computing method offers the opportunity to model, predict, and hence optimize the composite slab and steel deck profile design without the need to perform expensive and time-consuming tests on actual specimens.

Experimental study and numerical modelling of a novel two-way steel-concrete composite slab

This study proposes a new innovative two-way steel-concrete composite slab system. The experimental work investigates the structural capacity, shear behaviour and two-way load distribution of the proposed composite slabs consisting of a new profiled steel deck and concrete. The innovative deck is developed by providing 90° bends in corrugated steel sheets to form hat sections, which then are placed on a corrugated base sheet in the perpendicular direction. Five composite slabs were tested under uniform loading, in which three slabs contained shear studs, and the remaining two were tested without shear studs. The slabs failed by flexural failure and shear bond failure, and the composite slabs with and without studs showed comparable load-carrying capacity and two-way action. The unique geometry of the deck profile provides good longitudinal shear capacity in the main direction. The slip is absent in the main longitudinal direction of the slab due to the corrugated top-hats. The provided shear studs further complement the role of the top-hats by resisting interface shear failure in the perpendicular direction. Therefore, the new deck type can be used effectively in two-way composite slabs for shear and load capacity by reducing the quantity of additional shear connectors, which is a significant advantage of the proposed deck compared to conventional deck types. A finite element (FE) model of the composite slabs with and without shear connectors is developed and validated against the experimental results and then used to investigate the slab's performance in two-way load distribution.

Behavioural Study of Truss Bridge using Isogrid Members

The search for lightweight and highly efficient structural components is a continuing process. Reducing the structural weight and improving the load carrying capabilities of these structures will allow designers to append additional capabilities while reducing cost. Isogrid is a lattice of stiffened ribs forming an array of contiguous equilateral triangles. This rib pattern forms triangular trusses by maintaining isotropic property. Ribs when arranged in 60? pattern are known as Isogrid. The highly redundant nature of Isogrid stiffening concept provides high efficiency distributing loads and is less susceptible to impact damage, delamination, and crack propagation. Isogrid structure is typically found in stiffness critical components that resist buckling. The behavior and performance of Isogrid deck slab in a Bridge supported by the truss girders is studied. Isogrid is modeled, analyzed and designed using commercial Finite Element (FE) software. In the present work, a truss bridge is designed for a span of 10.305 m. The bridge is designed using three different kinds of deck configuration, rectangular section without skin, inverted T section with skin, and I section with skin. Commercial FE software is used for computing deflections and stresses. It is found that the deck profile of I section with skin is more preferable than other configurations for Truss Bridge.

Topology optimization of steel deck building diaphragms

This paper improves the roof diaphragm designs in steel buildings for lateral loads, such as those from wind and earthquakes, by maximizing the in-plane stiffness. The design of floors and roofs are typically dominated by gravity loads, however, the diaphragm's ability to transfer and resist in-plane shear forces is a key element in the structure's lateral force resisting system. The steel deck diaphragms are profiled steel sheet panels attached with fasteners and are typically placed with the same orientation throughout the entire diaphragm. Through variation of the layout of the steel profile and number of fasteners, the diaphragm's in-plane shear strength and stiffness cover a large range of values. In addition, the profiled nature of a steel panels results in different in-plane stiffnesses parallel and perpendicular to the deck profile. Through topology optimization, different roof diaphragm layouts are optimized for improved lateral stiffness by selecting a bare steel diaphragm type and orientation of the panel for each element. The optimized designs are complex and are interpreted into realizable steel diaphragm designs. Comparison of the designs finds that the optimized design is the stiffest followed by the realizable design. The traditionally designed diaphragms are much more flexible than both the realized and optimized designs. This work is part of a larger initiative (steeli.org) that aims to better understand and improve the role of diaphragms in the seismic response of steel buildings. Future work includes studying the non-linear behavior of optimized diaphragms and optimization that includes stress constraints to control initial yield.

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.

An experimental study of a shear connection of steel-reinforced concrete slabs with angle shear studs

Introduction. Angle shear studs, attachable by powder-actuated fasteners, are used as an alternative to traditional welded elements ensuring the shear connection of steel-reinforced concrete slabs. The objective is to revise their strength characteristics for different options of steel-reinforced concrete slab designs pursuant to SP 266.1325800.2016.
 Materials and methods. The programme of laboratory tests was developed in compliance with GOST R 58336-2018 to identify the strength behaviour of angle shear studs. Static shear testing of angle studs was performed at the LISMIiK laboratory of the Moscow State University of Civil Engineering using universal servo-hydraulic reconfigurable testing machine MTS.Multiaxial.DS1.4811.DS1.50019, designated for the testing of static and dynamic loads applied to large constructions. Displacements were measured by a tripod-mounted piston-type indicator.
 Results. The programme of theoretical and experimental research into the behaviour of a shear connection with angle shear studs in steel-reinforced concrete slabs that also had steel deck profile sheets was developed on the basis of the analysis of regulatory documents and sources of research information. Laboratory tests showed that the strength of the shear connection in an angle stud depends not only on the geometry of the steel deck, used as the stay-in-place formwork, but also on the position of a shear stud in the deck.
 Conclusions. The results of the theoretical and experimental research can be used to obtain new information about the strength and deformability of angle shear studs, connected by powder-actuated fasteners with the help of high strength expansion anchors; they allow to revise the currently used provisions governing the calculation of the reduction factor pursuant to SP 266.1325800.2016 with account taken of the design parameters of a shear connection.

Vertical and horizontal push tests on specimens with a Trefoil decking profile

The vertical push test has historically been the primary means used to evaluate the strength of shear connectors used in steel-concrete composite floors; however, these tests can be difficult to conduct and generally their results have been shown to not well represent the behaviour of shear connectors in a full sized composite beam. This paper describes a series of twenty-four push tests on composite beam specimens with Trefoil profile steel decking and headed, through-deck welded shear connectors (shear studs) using two different test set-ups. Twelve push tests on specimens with 19 mm and 22 mm shear studs were conducted using the double sided vertically oriented setup from AS/NZS 2327 and Eurocode 4, with transverse load applied across the slab faces. Twelve further push tests were conducted on specimens with 19 mm diameter studs using a new horizontal set-up. The results of the vertical tests suggest that the equations in Eurocode 4 for the determination of design shear resistance may be unconservative for 19 mm and 22 mm shear studs in 80 mm deep Trefoil decking ribs. The horizontal test specimens showed the same poor post-peak load retention that is characteristic of push tests conducted using the vertical test set-up without the application of transverse load. These parallel test programs are an exploratory step towards understanding the differences in behaviour observed in vertical and horizontal push tests and are the initial efforts in a continuing research program to develop a horizontal push test that provides a close approximation of the behaviour observed in full-beam tests.

Experimental study and mathematical modeling on the unsteady galloping of a bridge deck with open cross section

Galloping instability can potentially threaten the modern launching of steel-concrete composite bridge girders, due to light weight and bluff shape of the steel box, which is normally launched first. A bridge deck with typical open cross section was selected and investigated in smooth flow through wind tunnel techniques. Aeroelastic tests showed that the classical instability arising from the interaction between vortex-induced vibration and galloping may occur for a mean flow incidence of 4°, fixing the actual galloping onset at the Kármán-vortex-resonance wind speed up to a high value of the mass-damping parameter. In contrast, a different and more complicated behavior was observed for a mean flow incidence of 0°, where the actual galloping instability occurs at a wind speed clearly higher than the Kármán-vortex-resonance wind speed even for a very low value of the mass-damping parameter. Static tests further indicated that the most evident difference between the two cases is the magnitude of the vortex shedding force, which is much lower for a null angle of attack. A rectangular cylinder with the same side ratio was also tested for the sake of comparison. Finally, Tamura’s wake-oscillator model was implemented for the bridge deck at a mean flow incidence of 4°, following a recently proposed parameter identification method. The mathematical model was found to be able to give some promising predictions even for a complex bridge deck profile.

Experimental investigation into acceptable design methods for cold-formed metal deck

Cold-formed metal deck is commonly used in the construction of modern buildings. It is readily available and cost effective in many applications. Conservative design tables provided by metal deck producers aid the engineer of record and encourage use of the product.The American Iron and Steel Institute has embraced advanced analysis techniques, particularly the Direct Strength Method and Effective Width Method, which can be used to analyze a variety of thin gage, cold-formed structural shapes, presumably including deck. These methods have become popular with designers, as they have shown to reflect accurate flexural capacities for many standard cold-formed shapes. Until recently, these methodologies have not been applied to the analysis of metal deck. The objective of this research initiative is to compare the results of both the Direct Strength Method and Effective Width Method to experimental results for several metal deck profiles and gages and evaluate the numerical methods' applicability to metal deck.The experimental program comprises 54 full-scale tests of several depths and gages of roof and floor deck. Experimental results are compared to results from numerical methods. It was found that both numerical approaches reasonably predicted the flexural capacity of shallow roof deck, but numerical predictions deviated from experimental results as deck became deeper. Thickness of the deck (gage) played a role, and as deck became thinner the numerical methods showed a larger discrepancy from experimental results.

Comparative study of LightWeight and Normal Concrete composite slabs behaviour under fire conditions

This paper presents the experimental study of lightweight concrete (LWC) and normal concrete (NC) composite slabs with steel decking profile exposed to standard time-temperature curve. LWC composite slabs are very efficient in terms of energy savings and sustainability due to their low values of thermal transmittance. In this study NC is used to compare the fire behaviour of LWC composite slabs. Dimensions of the slab are 160 mm thick, 1120 mm wide and 2030 mm long. In order to perform fire tests in the intermediate-scale samples, a non-standard furnace was designed and assembled. The furnace is composed of a heating chamber, a gas evacuation system and a portal frame. The heating chamber is made of a steel framework and refractory layers. The evacuation system, which has an auxiliary vein with a fan to introduce air, extracts hot gases. The portal frame is composed of steel profiles with a rotating beam equipped with a linear actuator to apply the load on the samples. This beam is opened to allow the slabs to be placed and closed during the test. Finally, experimental results show that the time of fire resistance is close to 30 min for both types of slabs. Free water within the slabs affects the temperature increase of concrete. Thus, the temperature distribution inside the slab follows a non-constant trend, due to the movement and evaporation of the free water. Furthermore, although there is de-bonding between the steel and the slabs, no spalling is detected.

Forming Challenges of Extruded Wood Plastic Composite Products in a Post-Production Process

Wood Plastic Composites (WPC) have developed rapidly in recent years and are experiencing fast market growth. Such products can include recycled polymers and fibers as material ingredients. The majority of the product shapes are currently limited to simple deck profiles. Expensive injection molding is the most commonly used method of manufacturing for more complex geometries. The forming pressure and the press cycle length can be reduced in the press forming method with a simpler and less expensive toolset. This article investigates the effect of key forming parameters and related challenges in press forming of WPC sheets pressed into circular shaped specimens. From the results, it can be determined that the forming temperature and dwell time play a major role in forming process.

Effect of Stamping Clearance in Rapid CNC Punching of WPC Sheets

Wood Plastic Composites are gaining momentum due to their ability to contain recycled materials. The material usage is mostly limited to extruded deck profiles. This paper investigated if punching tools typically used in sheet metal stamping could be directly utilized in feasible post-processing of WPC sheets to enable a wider array of WPC products. A set of punches and dies with variable clearances and various punching speeds were tested and the results were investigated using 3D measurement macroscope. The results indicated that typical sheet metal punch clearances and speeds are suitable for WPC materials with some material specific considerations.

Experimental study of the composite steel deck in terms of geometric and mechanical parameters

The behavior of the composite steel deck is conditioned, mainly, to the interaction that exists between the concrete and the steel deck, the shear connection between these two materials is provided by the mechanical adherence, which exists in its interface. In order to study these characteristics, a series of full-scale slab tests have been carried out, such as bending tests to identify the slipping load, which is directly related to the shear bond strength of the slab. The study of the shear bond strength is very important because in most cases the geometric conditions of the section and the slenderness of the slab will lead to this type of failure. For this reason, this research will be in charge of studying this failure condition, based on previously full-scale slab tests and newly constructed specimens, in order to cover as many situations as possible. The experimental results of these tests, such as the slipping load and the corresponding deflection, will allow establishing a new relationship between the slipping load, the geometric and mechanical parameters. This proposed relationship will be carried out for each of the steel deck profiles under study and this formulation will be validated as an alternative proposal to the "m y k method".

Insulation effect of the concrete slab-steel deck interface in fire conditions and its influence on the structural fire behavior of composite floor systems

Composite slabs often use steel decks, which act as a formwork as well as bottom reinforcement to the slab. When such slabs are exposed to fire, the steel deck debonds and separates from the concrete and the gap generated due to this separation provides a layer of insulation. To study the insulation effect generated by this gap, an interface element between the steel deck and the concrete slab is modeled. Two different analysis methods namely, sequentially coupled iterative approach and fully coupled heat transfer and stress analysis are employed to predict the gap between the steel deck and concrete slab. Both of these approaches simulate radiation and conduction through the layer of air at the interface. The results obtained from both these methods are validated by comparing them with the experimental results available in the literature on this topic. The work presented in this paper demonstrates that considering the insulation effect of the gap between the steel deck and concrete slab is critical for an accurate prediction of temperatures in the concrete slab and this can significantly change the predicted fire resistance rating of the slab. In addition, a detailed parametric study suggests that the distance between the locations of embedment and the shape of the deck profile have a significant effect on the thermal insulation, whereas the thickness of the deck or the slab have little influence on the rate of heat flow through the interface. Finally, an empirical equation to predict the concrete temperatures based on such parameters is proposed.

Creep deflection of Wood Polymer Composite profiles at demanding conditions

Durability and low maintenance make Wood Polymer Composite (WPC) profiles popular in decking applications. EN 15534-4 specifies minimum performance levels to guarantee WPC quality. However, despite such quality specifications, occasionally high temperature creep issues are reported. This paper evaluates the creep performance of three commercial WPC decking profile grades. All three WPC grades meet the requirements specified in EN 15534-4. Nevertheless, at slightly more demanding load conditions, some WPC samples fail around the creep deflection limits specified in the standard, and which are supposed safe. Reference outdoor testing in the moderate climate of the Netherlands shows creep deflection rates which are expected to lead to fatal failure of these WPC samples in a couple of years. It is concluded that predictive testing requires insight in progressive creep strain development relative to fatal failure strain level.

Effects of different steel-concrete composite slabs on rigid steel beam-column connection under a column removal scenario

Trapezoidal and Reentrant are two ordinary deck profiles in modern steel-concrete composite floor system in China. The progressive collapse resistance of rigid steel beam-column connections with these two different composite deck profiles was experimentally investigated. This research addressed progressive collapse behavior of components evaluated by removing columns through the alternate load path method where the connections simulated the behavior of connections from a multi-bay steel moment-resisting frame. Also, collapse resistance of the connection above the removed column and the adjacent connection was considered. The results were compared with a bare steel subassembly, which has the same configuration but without composite slab, the load carrying capacity of the specimen with trapezoidal steel deck is improved by 28% and the specimen with reentrant steel deck is improved by 44%. The type of steel decks influenced the degree of restraint to the beam top flange and resistance of the connection. The specimen with trapezoidal steel deck had a higher plastic rotation capacity than the reentrant one, but the specimen with reentrant steel deck had improved composite behavior in the large deformation range and, therefore, developed more catenary action than the specimens with trapezoidal steel deck. Overall, the specimens with reentrant steel deck had a better performance under the progressive collapse situation, however, some constructional measures must be made to delay the bottom beam flange fracture.

Fibre waviness in pultruded bridge deck profiles: Geometric characterisation and consequences on ultimate behaviour

Abstract Conventional tests cannot be used to establish the important influence of fibre waviness, a manufacturing legacy at the flange-web joints (FWJs) of pultruded GFRP bridge decks, on the local ultimate behaviour of such decks. Hence a novel, simple and reliable three-step experimental scheme for that purpose is presented herein, using one pultruded deck profile as an exemplar. First, the joints to be targeted for testing - namely those within the single deck unit and the hybrid joints formed by bonding deck units together - are identified. Second, an effective manual method is put forward to map this waviness at the FWJs. Third, a test is introduced which enables statically determinate loading (via an adjoining flange) of one joint at a time, while also ensuring continuity between this joint and the remaining deck so that the real load paths within the deck are preserved. During the tests failure always occurred by fracture of the wavy fibre-resin interfaces within the FWJs. In the hybrid joints, this failure occurred on the same side of the adhesive layer as the load. The strongest joint had the least waviness. For the flange-single web (but not the flange-double web) joint, bonding transformed the wavy fracture pattern and quadrupled the failure load. It is concluded that this simple test, which also reveals the influence of fibre waviness on the flange's local flexural stiffness, can be further used to characterise joint fatigue performance.

Experimental and finite element study of ultimate strength of continuous composite concrete slabs with steel decking

Composite one-way concrete slabs with profiled steel decking as permanent formwork are commonly used in the construction industry. The steel decking supports the wet concrete of a cast in situ reinforced or post-tensioned concrete slab and, after the concrete sets, acts as external reinforcement. In this type of slab, longitudinal shear failure between the concrete and the steel decking is the most common type of failure at the ultimate load stage. Design codes require the experimental evaluation of the ultimate load capacity and longitudinal shear strength of each type of steel decking using full-scale tests on simple-span slabs. There is also no procedure in current design codes to evaluate the ultimate load capacity and longitudinal shear strength of continuous composite slabs and this is often assessed experimentally by full-scale tests. This paper presents the results of three full-scale tests up to failure on continuous composite concrete slabs cast with trapezoidal steel decking profile (KF70) that is widely used in Australia. Slab specimens were tested in four-point bending at each span with shear spans of span/4. The longitudinal shear failure of each slab is evaluated and the measured mid-span deflection, the end slip and the mid-span steel and concrete strains are also presented and discussed. Redistribution of bending moment in each slab is presented and discussed. A finite element model is proposed and verified by experimental data using interface element to model the bond properties between steel decking and concrete slab and investigate the ultimate strength of continuous composite concrete slabs.