Steel Composite Bridges Research Articles

Demountable Bolted Shear Connector for Easy Deconstruction and Reconstruction of Concrete Slabs in Steel–Concrete Bridges

Welded headed studs are used to connect steel girders and concrete slabs in steel composite bridges. However, environmental problems related to welded shear connectors have been reported, including noise and dust generation during the replacement and demolition of damaged or worn concrete slabs. To overcome these issues, demountable shear connectors that enable easy replacement of damaged or worn concrete slabs must be developed. However, conventional bolted shear connectors mainly use embedded nuts, which cannot be used in structures such as bridges because initial slip occurs and the stiffness and shear resistance strength are relatively low. To address these issues, this paper proposes a bolted shear connector that integrates the embedded nut part into the stud bolt and has a tapered shape at the bottom of the expansion column. For performance verification in regard to static shear strength and slip displacement, push-out tests were performed according to Eurocode-4, and the performance of the proposed stud bolt was compared to those of conventional welded headed studs and embedded nut-style bolted shear connectors. In addition, an analytical review was performed using the ABAQUS program for the 1/4 axisymmetric model of the push-out test. As a result of applying the material nonlinear model and the surface contact analysis, the load-slip displacement of each analysis model showed a tendency extremely similar to the experimental results. The proposed demountable bolted shear connector exhibited excellent shear performance and can be used as a satisfactory replacement for conventional welded studs because it meets slip displacement and ductility standards.

Numerical analysis on fatigue behavior of ultrahigh-performance concrete-Orthotropic steel composite bridge deck

Ultrahigh-performance concrete-orthotropic steel composite bridge deck is composed of the orthotropic steel deck and a thin ultrahigh-performance concrete (UHPC) overlayer. In the previous fatigue tests, two typical fatigue failure modes were found and identified. As a supplementary test after fatigue tests, air penetration method is capable of providing a reference to the quantitative and non-destructive damage detection of fatigue damage of UHPC. To further the previous study, a detailed numerical investigation is accomplished through complimentary finite element (FE) analysis. Compared with the solid element model, the refined shell-solid element model can better reflect the mechanical behavior. It is illustrated that the vertical stress can be adopted in assessing the fatigue strength of rib-to-diaphragm welded connection in the field test by means of nominal stress method. The combination of various factors would lead to fatigue shear failure of the short headed-studs. The fatigue strength of rib-to-diaphragm welded connection predicted by the hot spot stress method and the consistent nominal stress (CNS) method can basically meet the requirements of FAT90. The consistent nominal stress method can be used as the optimization method of nominal stress of fatigue detail. It is demonstrated that the fatigue life of UHPC can be estimated by S-N curves of ordinary concrete conservatively. The allowable equivalent maximum stress level can be taken as 0.55 for two million cycles of fatigue loading, and 0.52 for five million cycles of fatigue loading.

Cover Picture: Steel Construction 4/2021

AbstractSteel and composite bridges offer economic advantages, even for short and medium spans. To simplify and speed up the design process, ArcelorMittal now offers Advance Bridge Expert, a free preliminary design software that includes complex geometries and innovative solutions. The software is suitable for the pre‐dimensioning of curved and/or skewed composite road, railway and pedestrian bridges according to the Eurocodes and several National Annexes. It supports the predesign of steel composite bridges, filler beam bridges and PreCoBeam/composite dowel strips using the hot‐rolled section and modern steel grades libraries of ArcelorMittal up to S460, including HISTAR® grades and weathering steel (Arcorox®) according to EN 10025‐5:2019.The free version of Advance Bridge Expert can be downloaded from the following website: https://sections.arcelormittal.com/design_aid/design_software/EN (© ArcelorMittal)(Photo: Wirkowice composite bridge in Poland: Europe's first road bridge in Arcorox 460® weathering steel. © MOSTY ZAMOŚĆ Tomasz Czyż)

Fiber Reinforced Polymer Culvert Bridges—A Feasibility Study from Structural and LCC Points of View

Soil–steel composite bridges (SSCB) have become increasingly popular for short-span bridges as an alternative to concrete slab bridges mainly due to their low initial cost, rapid manufacture, simplified construction, and geometrical adaptability. SSCBs have a variety of applications and can be used over waterways or roadways. While conventional bridges tend to lose their load-carrying capacity due to degradation, SSCBs gain strength because of backfill soil consolidation. However, the load carrying capacity and integrity of such structures highly depends on the condition and load-carrying capacity of the steel arch element. A major drawback of SSCBs, especially those located on waterways or with poor drainage, is corrosion and subsequent loss of cross-sectional capacity. Unfortunately, the inspection of such bridges is not straightforward and any damage/collapse will be very costly to repair/replace. Fiber reinforced polymer (FRP) composites offer an attractive alternative to replace the steel in these types of bridges. FRP composites have significantly improved durability characteristics compared to steel, which will reduce maintenance costs and improve life-cycle costs (LLCs). This paper presents a new concept to use glass FRP as a construction material to construct soil–FRP composite bridges (SFCB). Various aspects of design and manufacturing are presented along with results and conclusions from a case study involving alternative bridge designs in steel and FRP composites.

Use of thick, heavy plates for bridge construction

AbstractModern steel or steel composite bridges need modern solutions in steel: often thick heavy plates play a crucial role in bridge building, possibly used as flange plate in heavy bridge beams or as thick deck plate in a trough bridge. Depending on the application thick heavy plates allow efficient fabrication or potentially increase the sustainability of a bridge construction. As today especially fabrication efficiency and durability gain importance, it leads to an increase in the application of thick heavy plates. However, when designing with thick heavy plates often the designer reaches technical or regulatory limits. This report will show some solutions to overcome these existing restraints, e.g. improved possibilities in the production of thick thermomechanically rolled steels or extension of the simplified brittle fracture analysis according to Table 2.1 of EN 1993‐1‐10. The consistent exploitation of these possibilities opens a variety of new advantageous options in constructing road or railway bridges.

Study on interface shear characteristics of PVA-ECC composite steel bridge deck

There are various forms of damage caused by the insufficient shear stress of the bonding coat, if not handled properly, it will lead to serious early damage of the pavement structure. In order to improve the shear resistance of traditional bonding coat, a new pavement method for steel deck is proposed. According to the different particle size and content of crushed stone, 9 kinds of mix proportion were designed. The shear failure form of specimen with different mix proportion is analyzed. Based on the Popovics constitutive model and the piecewise simplified model, the Shear stress-Shear slip (τ-δ) curve of the specimen is described. In addition, a damage model based on interface shear stress and interface shear rigidity is proposed. Finally, based on the engineering case of Mafang bridge in Guangdong province, the effectiveness and potential value of the pavement method are verified.

Assessment of in-service stresses in steel bridges for high-frequency mechanical impact applications

The application of high-frequency mechanical impact (HFMI) treatment to improve the fatigue performance of composite steel and concrete road bridges was studied through a state-of-the-art review in conjunction with simulations of variable amplitude in-service stresses in four case-study bridges in Sweden. Empirical stress range spectra with associated mean stresses were characterised for HFMI-treated bridges. It was shown that the fatigue-critical locations in HFMI-treated bridges remain unchanged compared with conventional bridges and that compressive overloads pose no detrimental effect that requires additional attention in the fatigue assessment. Calculations also showed a considerably better fatigue performance if HFMI treatment is performed on site, after the application of self-weight stresses.

Successful Seismic Performance of Bridges after Sivrice Earthquake

Most bridges in Turkey were proven to have successful seismic performance during recent earthquakes such as the Van earthquake, Mw 7.1, in 2011 and the Sivrice earthquake, Mw 6.7, in 2020. All bridges close to the epicenter of the earthquakes were still in service immediately after the catastrophic events, even though some of them were located near the vicinity of the fault line. This paper reports the performance of inspected bridges in the Sivrice earthquake zone, including the soil stability around abutments, and investigated the seismic performance of an old composite steel bridge that survived the earthquake. Field trips were conducted to the area for the postinspection of selected bridges. The geometric design of the old steel bridge was identified through classical measurement tools and point cloud models obtained from digital drone pictures in the absence of original design documents. The modern structural analysis of the old lightweight steel bridge with real-time earthquake records indicated that the bridge remained in the elastic state due to its flexibility.

The Influence of Arch Flexibility On The Floor Deck Structural Characteristics For Composite Arch Steel Bridge

This paper presents an optimizing design for the floor deck for the composite arch steel bridge depending on the arch flexibility (the bridge’s main component). The design is based on second-order effects using nonlinear p-delta analysis. Many variables are considered in the parametric study, which is the arch’s in-plane flexibility, the out-of-plane flexibility of the arch, and the number and stiffness of the lateral bracing between the twin arches. The design has been done by graphical design software SAP2000 and based on AISC and AASHTO specifications. A numerical example is studded herein for the new proposed bridge of Batta in Al-Hilla city in Iraq which crossover Al-Hilla river for a width of 108m from bank to bank, the bridge has an overall width of 18 m including two lane-two way of 15.6 m width and walkways of 1.2 m on both sides. This study’s main objectives are the number and size of floor beams, deck thickness, and hence the overall weight of the bridge will be minimum, the goal of design is to select the lightest and most economical and practical composite floor decks. It has been concluded that the deflection decreases with the increase in the number of the floor beam, and the best result was the case of the distance between the floor beam is 1.95 m with a deflection of 71.95 mm, meaning that the flexibility is less as the number of floor beam increases. As for the change of the arch’s cross-section, the best result of the lesser girder deflection was in the case that the arch section with dimensions (0.8 x1.2x0.035) m. This indicates that the greater the moment of inertia, which leads to less deflection for cross over the main girder.

Simulation of Partial Interaction for Composite Deck of “Al-SABTEA Bridge” Taking The Influence of Static Vehicle loads

The composite bridge has consisted of different materials such as the girder to be steel or precast that connected with deck concrete slab using shear connectors for working as one. In the present study ALSABTEA bridge rehabilitation of the space of the bridge using the composite steel girder existing composite bridge constructed in Diyala-Iraq in 1981 that designed and constructed to behave as full interaction. Representation of composite steel bridge using finite element approach with different parameters to assess the doing of the composite bridge under the effects of static loading using actual dimensions and mechanical properties. The representation of channel shear connectors through elements of COMBIN39 provided simple and powerful modeling of the connectors in comparison with using elements of the 3D solid types. Examining the push-out test and comparing results with the model established by ANSYS proved the proposed numerical model could represent the shear connector's behavior. The difference is small (2.5% to 3.7%) between the model by using the representation shear connector as solid element and combined 39 also, the difference in the results of displacement is small (5%) between the experimental test and model established by ANSYS. The effect has been studied included. Partial and full interaction of Al-SABTEA Bridge under the effects of Static loadings applied at bridge based on Iraqi specification where the final assessment the results deflection within permissible limits according to all models.

Experimental study on behavior of corrugated steel-concrete composite bridge decks with MCL shape composite dowels

In this paper, corrugated steel-concrete composite bridge decks with perfobond ribs (PBL) and modified clothoid (MCL) shape shear connectors have been experimentally studied. Six specimens were designed, push-out tests were performed, load-slip curves were drawn and static mechanical property indices of two types of shear connectors were analyzed. Two full-scale deck slab specimens with MCL shape shear connectors were fabricated and flexural tests were conducted on them. The following conclusions were drawn from the experiments. Both types of shear connectors showed ductile failure mode. The ultimate bearing capacity, shear stiffness and ductility of MCL shape composite dowels were higher than those of PBL shear connectors. When elliptical holes were made in MCL shape composite dowels, ultimate bearing capacity was significantly increased. Full-scale flexural test results indicated that MCL shear connectors were effective for corrugated steel composite bridge decks.

Highway Steel Composite Bridge Design using Limit State Design Method

Bridges are the pathways constructed over the obstacles without changing the alignment of the way beneath. While considering the design of steel composite bridges, Indian code is in the revision process; from Working Stress Method, it is updated to Limit State Design under IRC 24:2010. This paper illustrates a design example of a steel composite highway bridge with both longitudinal girders and cross girders under Limit State Design using IRC 24:2010 and IRC 22:2015. The concrete deck slab and steel girders together act as a composite structure which is connected using shear connectors. The effective span of the bridge is taken as 35m. There are four longitudinal girders having a spacing of 2750 mm c/c and cross girders are considered with spacing 5500mm c/c.

Optimizing the steel girders in a high strength steel composite bridge

The use of high strength steel has the potential to reduce the amount of steel used in bridges and thereby, facilitate a more sustainable construction. In this study, an optimization of a composite steel and concrete bridge is presented. The study aimed at identifying the potential benefits of using high strength steel, compared to conventional steel, in terms of weight, material cost and environmental impact. The optimization routine followed what is outlined in the Eurocode and satisfied both ultimate and serviceability limit state conditions, with exception of fatigue. To study the influence of fatigue a separate verification was performed on the solutions found from the optimization. The study showed that substantial savings in weight, environmental impact and material cost could be made by implementing high strength steel. However, when the fatigue verification according to Eurocode was considered, the potential benefits of using steels of higher grade vanished completely.

Prolonging the Lifetime of Old Steel and Steel–Concrete Bridges: Assessment Procedures and Retrofitting Interventions

The structural analysis of existing bridges is not widely covered by the various codes and standards, resulting in the insecure and, in some cases, critical condition of this type of structure. Regarding national regulation, few states include compulsory codes that define the methods and procedures of inspection, assessment, maintenance and retrofitting of bridges. Although an accurate retrofitting procedure can prolong the life of an existing bridge, the more accurate management of national infrastructure assets can result in financial savings in the long term. This article deals with: (a) the assessment step-level procedure, (b) suggestions for bridge load tests and bridge categories, (c) bridge material analysis, (d) structural testing analysis, and (e) the main retrofitting interventions to prolong the life of existing steel and steel composite bridges. Furthermore, a representative case study is analysed and discussed, including examples of the retrofitting solutions implemented to prolong the service life of the bridge.

Evaluation of short span bridge projects with a focus on sustainability

This work applies life cycle sustainability assessment techniques in the superstructures of small-span bridges for rural and vicinal roads by integrating them into the decision-making process to include sustainability indicators. The study subsequently investigated the potential environmental impacts of three bridge configurations as proposed by Brazilian public agencies, including steel and concrete composite bridges, standard precast concrete bridges, and standard wood bridges. The life cycle assessment and the ReCiPe endpoint methodology were used for three damage categories -ecosystems, human health, and resources’ surplus costs- at the midpoint, and one potential impact category (global warming). The study was conducted using 27 bridges, including 11 precast concrete bridges, 13 steel and concrete composite bridges, and 3 wooden bridges. The best indexes were obtained in all categories for bridges composed of steel and concrete. The results reveal indexes that can serve as guides in bridge planning and construction, as this technique can be applied to several types of structures provided they have the same function to determine which is the most environmentally sustainable.

Fatigue strengthening of steel structures using high modulus CFRP plates: Development of a life-cycle analysis approach

With an ageing bridge stock and in order to limit economic and environmental costs, developing preventive maintenance, repair and strengthening strategies will help asset owners to make efficient decisions in a sustainable way. For steel and composite steel bridges, preventing fatigue failure is at stake. In this context, easy-to-apply preventive strengthening techniques should be developed to extend fatigue life-time of steel bridges and delay resource-consuming major interventions such as traditional steel strengthening, rehabilitation, or decommissioning and new construction.This paper investigates the cost and environmental burdens associated with several strategies to extend steel bridges fatigue life-time. In particular, one details the needed information and the methodology for the implementation of an overall life-cycle analysis of an adhesively bonded CFRP solution compared with traditional techniques (use of steel plates). This is carried out considering economic, environmental and social benefits of the preventing policy and illustrating the developed methodologies with a case study corresponding to the strengthening of an existing steel bridge during its service life.

Experimental study on the shear resistance of a comb-type perfobond rib shear connector

A comb-type perfobond rib shear connector that can be applied to a prefabricated steel and concrete composite bridge is proposed in this paper by arranging perfobond rib shear connectors (hereinafter referred to as PBL shear connectors) at intervals. The mechanical property of shear resistance is investigated through experimental and numerical methods. Push-out tests covering various design variables and a comparison between comb-type and conventional PBL shear connectors are conducted. FEM models are established to simulate the test and for further studying the mechanism during entire loading process. The proposal mechanism of connectors under shear load was developed according to the analysis based on numerical simulation. It was concluded that comb-type connectors exactly performed better in stiffness and shear capacity than conventional ones, and a conceivable reason was given according to the analysis on mechanism.

Research on Global Stability Design of Lower Flange of Steelconcrete Composite Beams under Negative Bending Moment

The instability problem of steel-concrete composite beams will occur in the negative bending area, and different codes get different results for beams bearing negative bending moment on stability. In this paper, the MATLAB is used to analyse the parameter sensitivity of span, height-thickness ratio of web, concrete slab reinforcement ratio based on Eurocode 4 and China Code for Design of Steel and Concrete Composite Bridges. Through a large number of data analysis, the influence degree of each parameter on the stability is determined, and the results of the two codes are compared, which provides a basis for the design of the stability in the negative moment zone of steel-concrete composite beams.

Experimental and Numerical Study on Shear Resistance of Notched Perfobond Shear Connector.

In steel and concrete composite bridges, it is difficult to perforate the reinforcing bars through the circular holes of conventional perfobond shear connectors with multi-ribs. To ease the installation of perforating rebars, an alternative notched perfobond shear connector was proposed by cutting out the edge of the circular hole. This paper presents the push-out test results of six specimens which were fabricated and loaded to failure. The main purpose was to compare the failure mode, shear capacity and slip behavior of perfobond shear connectors using circular holes and notched holes. Furthermore, 43 nonlinear finite element simulations were performed to further study the effects of several variables, including the hole diameter, the hole distance, the hole number, the cut width, the perfobond thickness, the concrete strength, the rebar diameter, the rebar strength, and the steel strength. The parametric results were generated to evaluate the shear capacity equations for perfobond shear connectors. Finally, an analytical model was developed to estimate the shear capacity of notched perfobond shear connectors.

Probabilistic-based assessment of existing steel-concrete composite bridges – Application to Sousa River Bridge

This paper presents a framework to assess the safety of existing structures, combining deterministic model identification and reliability assessment techniques, considering both load-test and complementary laboratory test results. Firstly, the proposed framework, as well as the most significant uncertainty sources are presented. Then, the developed model identification procedure is described. Reliability methods are then used to compute structural safety, considering the updated model from model identification. Data acquisition, such as that collected by monitoring, non-destructive or material characterization tests, is a standard procedure during safety assessment analysis. Hence, Bayesian inference is introduced into the developed framework, in order to update and reduce the statistical uncertainty. Lastly, the application of this framework to a case study is presented. The example analyzed is a steel and concrete composite bridge. The load test, the developed numerical model and the obtained results are discussed in detail. The use of model identification allows the development of more reliable structural models, while Bayesian updating leads to a significant reduction in uncertainty. The combination of both methods allows for a more accurate assessment of structural safety.