Composite Deck Slabs Research Articles

Experimental investigation of fatigue behavior of UHPFRC – RC composite deck slabs subjected to moving wheel loading

UHPFRC has been increasingly used as a bridge deck overlay material. Since bridge decks are exposed to severe mechanical action and harsh environmental conditions, the application of UHPFRC to bridge decks is an effective and wise utilization of UHPFRC’s excellent properties such as high strength and low permeability. This paper presents the result of a full-scale fatigue test of a reinforced concrete (RC) deck slab overlaid with UHPFRC (UHPFRC – RC composite deck slab) using a moving wheel load. The fatigue behavior of the UHPFRC – RC composite deck slab was analyzed using measurement data from the experimental test and discussed. The failure mode of the UHPFRC – RC composite deck slab was punching shear accompanied by near-interface concrete cracking and double curvature bending of the UHPFRC layer. The fatigue life of the UHPFRC – RC composite deck slab was estimated using an existing S-N relation of RC deck slabs subjected to moving wheel loads and a 30 mm thick UHPFRC overlay was found to increase the fatigue life of RC deck slabs by about five times.

Vibration-based Bayesian FE-model updating of a curved approaching span of the Indiano Bridge

The development of accurate finite element (FE) models of existing bridges represents a challenging issue due to the uncertainties on boundary conditions (e.g., friction of the supports and their behavior with the traffic loads, out of plumb of piers, soil-structure interaction, etc.), material properties and damping estimations. Full-scale measurements are usually employed for updating a preliminary FE model through deterministic methods, although probabilistic approaches should be preferable due to the non-negligible uncertainties present in both modeling and measurements.This work deals with the Bayesian FE-model updating of a curved approaching span of the Indiano Bridge (Florence, Italy) through full-scale vibration tests. The case study is represented by a steel/concrete composite deck slab bridge with a span of about 25 m. A procedure based on the Bayes theorem has been developed and tested on the considered case study incorporating both model uncertainties and measurement errors.

Research on Ultra-High Performance Concrete (UHPC) overlay composite steel deck to repair Thang Long bridge deck

Thang Long bridge, after many years of operation with increasing traffic volume, leads to the steel face plate of the bridge not ensuring the conditions of stiffness and deflection within the allowable limit. After scientific conferences and experimental studies, it was shown that the solution "using Ultra High Performance Concrete (UHPC) technology associated with orthogonal steel decks to form composite lightweight deck slabs" design selection to repair Thang Long bridge deck. In order to successfully apply UHPC coating in this project, it is necessary to determine the technological parameters such as: flow, setting time, rheology and shrinkage according to actual construction conditions at site ( temperature and humidity). In addition, other physical and mechanical properties of UHPC must be determined such as compressive strength, tensile strength, elastic modulus and dry shrinkage. This study has determined the technological parameters for the construction of UHPC coating during the period from August 25, 2020 to December 31, 2020 to meet the technical requirements of the Thang Long bridge deck repair project.

Strength prediction methods in shear bond behaviour of composite slabs

Composite deck slabs are gaining wide acceptance in many countries as they promote faster, lighter and economical construction in buildings. The shear behaviour of composite deck slab is a complex phenomenon. Strength of composite deck slabs can be analyzed by different methods for restrained and unrestrained conditions. In this work various methods for determining the shear bond capacity of composite deck slab are studied by modelling composite deck slab for various shear spans in finite element analysis software. The main objective is to understand the deflection as well as slip characteristics of composite deck slab and to apply these values for calculating shear strength using different methods of the composite deck slab. A comparison between methods are also done to find out the best possible prediction method. It is found that Partial Shear Connection (PSC) method performs better than that of other methods considered.

Shear-bond behavior of nanocellulose-modified SHCC composite slabs: Translating material-level capacity into improved structural performance

Owing to their exceptional tensile properties, strain-hardening cementitious composites (SHCC) are indispensable for building and maintaining sustainable and resilient civil infrastructure. As such, to propel the structural implementation of SHCC, it is critical that their intriguing tensile characteristics be effectively translated into improved structural performance. Herein, we capitalize on the intrinsic pseudo-ductility of a novel SHCC—incorporating nanocellulose fibers and post-consumption glass powder (hereafter referred to as “nSHCC-GP”)—to mitigate shear-bond failure caused by the relative slip between steel and concrete in composite deck slabs. Twelve full-scale composite deck slabs, six with conventional high-performance concrete (HPC) incorporating steel mesh and six steel-mesh-free nSHCC-GP slabs, were subjected to monotonic bending. With the concrete for both slab sets designed for similar compressive strengths, the influence of concrete type (HPC or nSHCC-GP), decking profile (trapezoidal or reentrant), and shear span (520–770 mm) on the flexural capacity and shear-bond resistance was examined. The use of nSHCC-GP as a concrete topping improved the flexural capacity of composite slabs by >50 % and the shear-bond resistance by up to 40 %. Thus, the strain-hardening characteristics of nSHCC-GP were effectively translated into the structural scale, providing steel-mesh-free, high-performance composite deck slabs.

Influence of parameters in flexural behavior of composite slabs

Composite steel–concrete deck slabs are used in floor construction in steel-framed buildings where the connection between steel beam and the concrete slab through shear connectors exploits the best combination of each component. The behavior of composite steel deck slab is investigated based on different parameters such as presence of embossments, shape and thickness of profile sheets, thickness of concrete slab, loading constraints, steel–concrete contact and end anchorages. Performance is evaluated on the basis of load carrying capacity, end slip, and the end anchorage contributions to the behavior of composite deck slabs. The finite element analysis is done using ANSYS software by varying different parameters and the influence factor of each parameter in the performance of composite deck slab is found by regression analysis and finally experiments are conducted to validate the study. Based on the parameters studied the trapezoidal sheets of 1.2 mm thickness with stiffeners shows a better performance.

Strength prediction of composite metal deck slabs under free drop weight impact loading using numerical approach and data set machine learning

Strength prediction of composite metal deck slabs under free drop weight impact loading using numerical approach and data set machine learning

An Experimental Study on the Flexural Performance of a Steel-ECC Composite Bridge Deck Sheet in the Negative Moment Zone

This paper seeks to solve the problem of orthotropic anisotropic steel deck pavement being prone to damage and fatigue, and to study the negative moment performance of steel-ECC concrete composite deck slabs. In this work, four groups of eight specimens were designed for the negative moment four-point bending test study, which included four variables of two ECC slab thicknesses and two bolt spacings. By analyzing the damage mode, crack distribution characteristics, bending load capacity, load-deflection curve, and load-strain curve, the effects of different ECC slab thicknesses and bolt spacings on the bending performance, deformation capacity, and cracking behavior of the steel-ECC composite bridge deck were investigated. The test showed that the combined structure of the ECC and steel plate showed good integrity and good ductility under a negative bending moment, and the damage mode of the member was pure bending of a section of the ECC with concrete cracking damage. When the thickness of the ECC plate increased from 50 mm to 75 mm, the ultimate flexural load capacity of the specimen increased by 92.6%, and when the distance between bolts was reduced from 200 mm to 150 mm, the ultimate flexural load capacity of the specimen increased by 13.4%. The increase in the ECC layer thickness increases the ultimate bearing capacity of the specimen significantly, and the decrease in the bolt spacing increases the ultimate bearing capacity of the specimen less.

A Simple Mechanical Model for Steel Beam – Column Slab Subassembly Nonlinear Cyclic Behaviour

ABSTRACT A simple strut-and-tie macro-model has been developed to represent the seismic behaviour of a composite deck slab, acting as part of a steel moment-frame beam-column-slab joint. The moment frame is subject to large lateral deformations, representing those from a strong earthquake, and yielding occurs at the beam ends. The frame sub-assemblies were modelled as elastic line elements connected with non-linear/linear spring elements. The model behaviour was compared to experimental test results. It was found that the model developed satisfactorily represented the envelope cyclic behaviour of the test frame sub-assembly with the different slab configurations. It is easy to implement in practice using widely used commercial software available to practising engineers.

Analysis of composite bridge deck considering the effects of concrete cracking

Abstract Cracking in composite steel-concrete bridge decks is a common problem in civil engineering. Before, or shortly after, the bridge is subjected to live loads; various levels of cracking can appear, mostly due to plastic shrinkage and temperature effects. This paper presents an investigation of the behavior of cracked concrete in a composite deck slab of a railway bridge supported by steel girders using the finite element method. Eurocode 4-2 proposes a few simplified methods for calculating shrinkage and cracking effects in concrete. Through the proposed methods of analysis, an analytical simulation of a continuous composite steel-concrete bridge deck is performed and some practical recommendations for analyzing beam girders of this type are given.

Numerical and analytical methods for the design of beam-column sub-assemblies with composite deck slab

A finite element numerical model is used to estimate the force displacement backbone curve of steel moment frame beam-column-joint subassemblies tested at large scale under repeated cyclic loading with different composite deck slab configurations. The slab configurations included: no-slab; fully isolated slab; two configurations for detailing the slab near the region between the column flanges; and a full depth reinforced slab. Then, a simple analytical model was developed so that designers can estimate the likely peak strength due to slab effect. This analytical model considers the common deformation modes and the strength hierarchy. It was found that the finite element numerical model captured the backbone envelope of experimental tests done on different slab configurations for the bare frame, isolated slab and full depth slab configurations, but overestimated the strength at larger displacements for the other configurations due to difficulty in considering the slab modes of failure. The simple analytical model considered the nonlinear deformation modes of steel beam plastic hinging, concrete crushing both outside the column flange and within the beam flanges, slab shear fracture between the column flange tips, slab longitudinal and lateral reinforcement yielding as it carried the subassembly moments and transferred forces between the steel frame and the slab, and shear stud deformation. The proposed analytical model matched the experimental strengths and failure modes. The proposed finite element model is suitable for research, and the analytical model matched the experimental results, and is suitable for consideration in design.

Performance of semi lightweight concrete composite deck slabs under falling mass

In the present scenario probability of unexpected and accidental loading is high for the infrastructures. There is an urgent need to analyse these structures to check their viability against impact load. Composite structures are currently used to utilize the benefits of different materials. Past research works focused on the response of composite slabs under static load. Studies related to the impact response of composite slabs are limited, and the behaviour of less dense slabs is still to be explored. There is a demand to focus on the reaction of semi-lightweight aggregate concrete for composite grooved trapezoidal decking slabs subjected to drop mass impact. The study focused on the cushioning effect of six composite slab specimens (1000 mm × 930 mm × 80 mm) along with welded wire mesh and steel fibers as secondary reinforcements. Two were cast using control concrete (NC), and four were cast using lightweight concrete (LC). The collision was achieved by dropping a 55 kg steel cylinder to hit the center of the slab from a height of 1 m. Numerical modeling and analysis of similar slabs under impact load were carried out in ANSYS. The parameters concentrated are impacted force–time history, acceleration, crack pattern, bond-slip behaviour, and stress contours. The results show that lightweight concrete with welded wire mesh as secondary reinforcement could be effectively utilised as a cushioning layer for the composite deck system under falling mass scenarios.

Karakteristike posmične veze u spregnutoj ploči od čelika i betona

Steel-concrete composite slabs with cold-formed, profiled steel deck sheets are popularly used in steel-framed buildings. In these slabs, the deck platform acts as a working platform during construction and also as tensile reinforcement under in-service load conditions. The shear bond capacity of the composite slab is evaluated in this study for two different profile steel deck sheets. Specifically, their composite behaviour is investigated by casting and testing twelve full-scale composite deck slab specimens using the two-point loading system. In addition, based on the shear span length and profile height, the structural performance of the composite deck slab is analysed in terms of load-displacement response, shear bond capacity, ductility index, and load-slip behaviour. The results show that the most common failure of all tested specimens occurs due to the longitudinal shear failure between the concrete and profile deck sheets. As the longitudinal shear is a complex phenomenon, empirical approaches are used to evaluate the shear bond mechanism between the concrete and profile deck. The verification and comparison of experimental test results are performed with conventional and simplified m-k models based on the profile deck depth. The validated results reveal an acceptable level of reliability for prediction of each profile height based on the m and k interaction values.

Vertical shear capacity of steel-concrete composite deck slabs with steel ribs

The design of steel-concrete composite (SCC) deck slabs is likely governed by the vertical shear under small shear span-depth ratios. This paper aims to propose the calculation method of the vertical shear capacity of the SCC deck slab (Vu). Firstly, Vu is computed as the summation of the contributions of concrete layer (Vc,u) and steel members (Vs,u). Vc,u is treated as the product of the shear capacity of an equivalent reinforced concrete member without web reinforcement and a coefficient that reflects the effects of steel ribs. The formula of Vs,u is developed based on the force equilibrium conditions between the concrete layer and steel members and the section analysis considering the steel-concrete slips. Later, an iterative calculation method is proposed and verified against experiments and finite element (FE) models established via validated simulation techniques. Lastly, an extensive parametric analysis is implemented using the iterative method, from which a simplified calculation method was proposed and proved. Results indicate the iterative method is able to capture the effects of material and geometric parameters, shear span-effective depth ratio, and the degree of steel-concrete interaction. The increases in the heights of concrete layer and steel rib, as well as the rib thickness, can effectively enlarge Vu, while the influences of the steel plate’s thickness and the steel-concrete slips are relatively minor. The iterative method produces accurate predictions with a mean error of 1% and a coefficient of variation of 0.05. The simplified method is more engineer-friendly and yields the average FE/test-predicted ratio being 1.11 as well as the percentage of safe predictions being 95%.

Flexural fatigue mechanism of steel-SFRC composite deck slabs subjected to hogging moments

This paper aims to investigate the flexural fatigue mechanism of the steel-steel fiber reinforced concrete (SFRC) composite deck slab under hogging moments. Firstly, fatigue tests were implemented on two full-size slab specimens reinforced by different steel fibers, i.e. mill-cut steel fibers (MF) and corrugated steel fibers (CF). The failure mode, steel-concrete composite action, and crack behavior were measured and discussed. It finds that the fatigue failure of the composite slab under hogging moments was governed by the fracture of rebar in tension. Under service loads, the use of MF achieves lower stress amplitude of rebar in tension (Δσs) by 6–9% and higher slab stiffness by 2–7%, compared with CF. Subsequently, both finite element and theoretical analysis are employed, through which the influence mechanisms of SFRC’s strength parameters (fL, fR1, fR3) and slab’s structural parameters on Δσs are clarified, and the calculation method of Δσs is developed. Results showed that Δσs can be reduced by up to 7% with a 1.19 MPa increase in fL and by 12% as fR1/fL is raised by 0.4, whereas the effects of the fR3 are minimal where a reduction of lower than 1% is obtained as fR3/fR1 goes up by 0.4. The advantage of MF can be attributed to its better improvement on fL and fR1 than CF. It also reveals that steel members with greater bending stiffness can attract higher moments, which decreases the moment sustained by the SFRC layer and thus reduces Δσs. The proposed calculation method yields satisfactory prediction accuracy and is capable of capturing the effects of strength and structural parameters.

Experimental and Finite Element (FE) Studies on the Behaviour of Horizontally Curved Composite Bridges Deck

This paper aims to study the behaviour of horizontally curved composite steel-concrete bridges deck slab and beams under static load, using experimental tests and nonlinear finite element analysis. Two different specimens were examined in the structure laboratory, one of them was horizontally curved composite deck slab and steel girders with full interaction between the concrete deck and the steel girders, while the other with partial interaction. Each specimen has three curved I-girders acted parallel connected with X shape cross frames. Linear Variable Differential Transducers (LVDT) and strain gauges were used at critical points to measure deflections and strain respectively. Three dimensional finite element (FE) models with 137119 elements were built and analysed using ANSYS software version 14. Models dimensions were 1/10 in both length and radius of curvature of the Federal Highway Administration (FHWA) full scale model. Numerical results have been compared with the experimental test results. Maximum values and distribution of both stresses and strains at top flanges, bottom flanges and the web tension zone for numerical modelling results, showed close agreement with the experimental tests results in both full and partial interaction models. Also, similar failure modes were encountered from both numerical modelling and experimental tests. Maximum deflection values obtained from numerical modelling were slightly below the experimental values and this was attributed to the stiffer numerical model. Further, mesh refinement could have increase accuracy of numerical predictions.

Flexural behavior of wet joints in steel-UHPC composite deck slabs under hogging moment

A new type of steel-UHPC composite slabs (SUCS) with PBL shear connectors are used as bridge decks in an ultra-long-span composite cable-stayed bridge under construction in China. SUCS can be prefabricated in the factory and then transported to the construction site for assembly. The steel parts of the adjacent SUCS shall be welded together and UHPC wet joints, which are the weak parts of the bridge deck, shall be cast in-situ to finish the assembly. Full-scale tests of three SUCS with dovetail-shaped wet joint or newly-proposed construction-friendly rectangular wet joint were conducted to investigate the flexural behavior under hogging moment. Flexural failure of the interface section occurred in all specimens. The ultimate capacity and crack resistance of rectangular wet joints can be close to the dovetail-shaped wet joints with the same notch length. The phenomenon that tenons were pulled out from the rectangular notch appeared in rectangular wet joints during loading, which was especially prominent when the notch length was short, and the ultimate capacity and crack resistance would be reduced. Experimental results showed significant differences between cracking behavior of the interface and the non-interface, revealing the importance influence of wet joints on durability. The ultimate capacity was analyzed theoretically, and discussions were made on the reduction of ultimate capacity caused by wet joints. In addition, a crack width prediction model was obtained by modifying the model in GB50010-2010, which was based on the comprehensive analysis method combining bond-slip method and non-slip method. The modified model can give satisfactory prediction results of crack width for both interfacial and non-interfacial cracks.

Analytical Investigation of Composite Structure in Comparison of RCC Structure

High rise structures becoming very common everywhere due to scarcity of land and increasing population. Though we have RCC structure system as high-rise buildings, but in RCC buildings due to bulky size of the components of the structure self-weight will be more due to the heavy density of materials. By observing the difficulties and challenges in the field of high-rise structures engineers are using efficient structural system that is Steel Concrete Composite Structure. Composite structure consists composite deck slab, composite beam and composite column. Composite Structure complies of Concrete which is good in compression and structural steel which good in tension and composition of these material makes structure better in ductility which comparatively on higher side than RCC structure. Here G+7 high rise structure is considered for analysis by ETABS software. This paper involves Analysis of Commercial building by Equivalent static method on Composite structure and RCC structure with same plan of building and same design data. The structure is in earthquake zone III and wind speed 44m/s. Analytical comparisons of both Composite and RCC frame based on structural parameters are made with help of graphs and tables. By comparing the results, we found that Steel-Concrete Composite Structures are more desirable than RCC structures.

Fatigue behavior and failure mechanism of steel-concrete composite deck slabs with perforated ribs

This paper aims at investigating the variable-amplitude fatigue behavior and failure mechanism of the steel-concrete composite (SCC) deck slab with perforated ribs. Firstly, two identical full-scale specimens were tested under different fatigue loading procedures. Test results reveal that the fatigue failure process starts with the initiation of cracks at the welding part between the steel plate and perforated rib, after which the slab could sustain tens or hundreds of thousands of load cycles until the crushing of concrete. As load amplitude increases by 54%, the crack propagation rate is accelerated by 300%, and the fatigue life from the crack initiation to the crushing of concrete is reduced by 79%. Higher load amplitude applied in the earlier service stage leads to the irreversible and a higher level of degradation on the stiffness, deformation recovery, and composite action. Further, the finite element (FE) model is established and verified, through which the stress state of the welding part is analyzed. It reveals that owing to the shear transfer between the steel members and concrete layer, the welding part is in the multiaxial stress condition where longitudinal normal stress, vertical normal stress, and shear stress coexist. Subsequently, the crack initiation position is predicted using the critical plane approach based on the SWT parameter, which shows good consistency with experimental results. Finally, by conducting the parametric analysis, the effects of geometric parameters and shear-span ratio on the SWT parameter of the welding part are clarified.

Flexural strength test on new profiled composite slab system

This research presents an experimental study on the flexural strength and failure behaviour of a newly developed composite metal decking system. The newly developed metal decking system with a thickness of 0.75 mm and 1.0 mm produced by the industry requires a detailed study in strength and performances before it is launched for commercialization. A simply supported conventional reinforced concrete slab is used as the control specimen and two composite slabs with different metal thickness of steel sheet profiles were constructed and tested under a four points flexural strength test. The strength and behaviour of the slabs are recorded and comparisons with conventional slabs with composite deck slabs are made to achieve the objectives. The recorded results of three different slabs were then used to plot a load-displacement graph and deflection profiles are to be analysed and compared. The yield flexural capacity and average yield displacement of specimens for the composite slabs were 28.0 kN and 0.80 mm respectively. The 1.0 mm metal thickness composite slab has the highest ultimate flexural capacity among all specimens which is 84 kN followed by a 0.75 mm metal thickness composite slab with 58 kN and ends with the lowest 9.1 kN of conventional slab. Two cracking patterns were found during the experimental test which includes shear cracking and flexural cracking`. Besides that, two major failure modes under bending which are flexure failure at the centre point of the specimen and bond or longitudinal slip failure along the side of the specimen were found in the experimental test. Bond failure results in slippage between the concrete and metal deck, which can result in cancellation of the composite action at interface. In conclusion, the strength of slabs improved, and ductility was remarkably increased when slabs acted as a composite structure.