Deck Construction Research Articles

Pyrolysis models for pressure treated wood and wood–plastic composite

AbstractPressure treated wood (PTW) and wood–plastic composites such as Trex® are popular materials for the construction of decks and other auxiliary structures, which are known to significantly contribute to spread of wildland fires into communities. In this work, representative samples of these materials were studied to determine their pyrolysis and combustion properties to enable simulation of fire growth on the surface of these building products. The pyrolysis property development process followed a well‐established hierarchical approach where thermogravimetric analysis, differential scanning calorimetry, and microscale combustion calorimetry were used to parametrize kinetics and thermodynamics of the thermal decomposition and combustion, while controlled atmosphere pyrolysis and cone calorimetry tests performed on coupon‐sized samples were used to parameterize thermal transport properties and validate performance of the fully parametrized pyrolysis models. PTW decomposition was captured using four sequential reactions with one additional reaction used to model vaporization of water. Trex® board was found to consist of two distinct layers: a thin outer layer and an internal core. The pyrolysis model for this material was constructed using some known properties of high‐density polyethylene (PE) and the properties of PTW determined in this work. The outer layer was defined in the model to consist of PE and an inert additive, while the core was defined as a blend of PE and wood particles, which kinetics and thermodynamics of the thermal decomposition and combustion were successfully captured using the model developed for PTW.

Artificial Neural Network and Kriging Surrogate Model for Embodied Energy Optimization of Prestressed Slab Bridges

The main objective of this study is to assess and contrast the efficacy of distinct spatial prediction methods in a simulation aimed at optimizing the embodied energy during the construction of prestressed slab bridge decks. A literature review and cross-sectional analysis have identified crucial design parameters that directly affect the design and construction of bridge decks. This analysis determines the critical design variables to improve the deck’s energy efficiency, providing practical guidance for engineers and professionals in the field. The methods analyzed in this study are ordinary Kriging and a multilayer perceptron neural network. The methodology involves analyzing the predictive performance of both models through error analysis and assessing their ability to identify local optima on the response surface. The results show that both models generally overestimate the observed values. The Kriging model with second-order polynomials yields a 4% relative error at the local optimum, while the neural network achieves lower root mean square errors (RMSEs). Neither the Kriging model nor the neural network provides precise predictions but point to promising solution regions. Optimizing the response surface to find a local minimum is crucial. High slenderness ratios (around 1/28) and 40 MPa concrete grade are recommended to improve energy efficiency.

Replacement of the deck and rehabilitation of the viaduct at the link between M-40 and M-607 in Madrid (Spain)

The existing concrete viaduct 560 m long at the link between M-40 ring road and M-607 expressway in Madrid (Spain) was subjected to a very comprehensive process of evaluation and testing after high deck deflections and surface cracking were detected. As conclusion of these studies very severe damages and a process of concrete degradations were confirmed which led to the decision of dismounting the existing deck structure and constructing a new one supported on the existing substructure which had to be repaired and reinforced. Grupo Puentes has carried out both the process of deck disassembly and the construction of the new deck in a record time of approximately nine months. The viaduct is in a very traffic congested link to approach Madrid and crosses over not only the main roads, M-40 ring road and M-607 expressway, but also two approach ramps and two railway lines, one of them high-speed line.

Devising a procedure for integrated modeling of riverbed shape in the area of bridge crossing in order to avoid dangerous washing erosion

The object of research is a riverbed in the area of a bridge crossing, which is subject to the action of high water during the passage of a flood. The selection of parameters and contours of the scheme of the river section was carried out using a mathematical model of the flow and deformation of the bed of the riverbed before and after the change of its shape. It was established that the assignment of parameters of the operational slot should be performed on the basis of the principle of creating natural analogs of riverbed shapes, riverbed and floodplain terraces, with the use of mathematical modeling. To reduce erosion in the area of bridge crossings, it is proposed to regulate the riverbed by constructing a canalized riverbed. Modeling according to this option showed that the erosion in the span of a road bridge decreased and did not exceed 1.5 m. In addition, it was established that a significant role in ensuring the stability of the river is played by the vegetation cover in floodplain areas. Using the method of mathematical modeling, it was established that the area near the convex bank with a width of 150 m is subject to the strongest erosion in the design of the supports. Siltation of the existing left-bank bottom basin is also observed. It is recommended to make a decision to carry out restorative cutting of riverbed alignment annually after receiving a flood forecast from the local hydrometeorological station. In the case of a high flood warning, work should be carried out to clear the sleeves on the approach to the construction of the bridge deck. It was established that the most stable shape of riverbeds is in the form of curvilinear incomplete meandering when the radii of curvature R and the width of the riverbed B satisfy the ratio R=(4...7) B at riverbed-forming flow rate. At the same time, radii of curvature R<3.5 B should not be allowed, as this leads to separation of the flow from the convex bank and excessive erosion of the concave bank

Fatigue performance of ECC link slab incorporated full RC girder joint-free bridges

The use of link slab (LS) made of Engineered Cementitious Composite (ECC) in the construction of joint-free bridge deck can meet structural performance requirements and enhance durability to minimize life cycle costs. Studies documented in the literature to date have been limited to composite steel-concrete I-deck girder bridges despite their commonly used reinforced concrete (RC) girder counterparts in construction. This paper deals with two span full RC deck girder joint-free bridges with ECC link slab (ECC-LS) constructed and tested under static and fatigue loading up to 1,000,000 cycles at 4 Hz subjected to mean stress level of 40% of girder ultimate load, followed by post-fatigue static loading to failure. Residual load, deflection, moment, rotation, stiffness, and energy absorbing capacity of fatigued bridge specimens are compared with its virgin (non-fatigued) counterparts to assess structural performance. Experimental moment capacities are compared with those obtained from existing analytical equations. The comparative performance of joint-fee bridge with RC deck girder is compared with its composite steel-concrete I-girder counterpart to assess its feasibility of construction.

Application and Experimental Validation of Seven-Degree-of-Freedom Beam Element for Girder Bridges during Deck Construction

During bridge deck construction, the deck finishing machine and the fresh concrete often produce large vertical loads and torsional moments acting on the bridge girder system. In some cases, these loads can cause excessive vertical deflection and transverse rotation in the bridge girders, leading to many maintenance and safety problems, such as changes in deck thickness and local and global instabilities during construction. To minimize the potential problems caused by deck construction, the AASHOTO LRFD Bridge Design Specification requires consideration of these torsional moments during the design procedure, and a detailed three-dimensional finite element analysis may be conducted. However, for bridge girders with open-section thin-walled sections, only the solid or shell element can be used to recognize the warping of the girder since the torsional warping effect is not included in the classical beam element. In this research, a warping degree of freedom was added to a beam element, and a three-dimensional beam element with seven degrees of freedom (7-DOF) at each node was derived as an alternative method for analyzing girder bridges during deck construction. A computer program based on the 7-DOF beam element was also developed in MATLAB. To assess the 7-DOF beam element, one bridge was selected to measure the transverse rotation, vertical deflection, and stress of the exterior girder and the first interior girder during deck construction. Also, three full-scale numerical models using solid elements, classical three-dimensional beam elements, and 7-DOF beam elements were created based on the geometries and loads of the experimental bridge. A comparative study was conducted by comparing the results from the numerical models and experimental monitoring data to evaluate the 7-DOF beam element. The results showed that the 7-DOF beam element had excellent behavior in analyzing the girder bridges under construction load, especially in the torsional analysis of bridge girders. Also, unlike the solid element model, which also provided reasonable results, the 7-DOF beam element model can compute the internal forces of the cross-sections along the bridge, which allows the 7-DOF beam element to be an alternative approach for design and research requiring less modeling effort and computational complexity.

Multi-criteria decision support system for bridge construction system selection utilizing value engineering and TOPSIS

When selecting the appropriate bridge deck construction system, it is essential to consider many criteria such as the span length, geographical location, construction speed, cost, site conditions, resource availability, technology, ease of construction, and service life. The objective of this study is to optimize the decision-making process for selecting a bridge deck construction system in the preliminary design and planning stage. The proposed model allows designers or decision-makers to make an informed choice of an appropriate construction system according to project criteria through a decision support system. The model employs value engineering methodology and a multi-criteria decision-making method and utilizes the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS), a multi-criteria decision-making method. To gather modeling data from a focus group consisting of professional bridge engineers, a semi-structured interview and two questionnaires are conducted. When applying the proposed model to two active bridge construction projects in Egypt, it reveals that "Span by Span using launching girder" and "precast post tension girder" are better suited to cases one and two, respectively. The study makes a contribution by presenting a decision support system that combines value engineering methodology and a multi-criteria decision-making method (TOPSIS). This system empowers designers and decision-makers to make project decisions considering specific criteria and constraints.

Performance comparison of steel fiber reinforced concrete and conventional reinforced concrete cast-in-place half-scale concrete bridge decks under bending

The most time-consuming processes involved in bridge deck construction are laying and tying conventional reinforcement and verifying the required cover. Thus, there is a need within bridge construction technology to identify opportunities for utilizing steel fibers and replacing more conventional reinforcing bars on bridge decks and this could be a significant step in speeding up bridge construction. Although the bending strength performance of reinforced concrete decks has been the subject of many experiments and research, many considerations still need to be explored. Hence, the current experiment aims to compare and evaluate the bending strength and ductility of two half-scale concrete bridge decks reinforced by steel fiber reinforcement (SFRC) with two half-scale concrete bridge decks reinforced by conventional reinforcement (RC), 27.6 MPa (4000 psi) concrete compressive strength is used in this study, all four decks were tested under flexural loads. Load–displacement curves (P-∆) are recorded as a tool to measure the ductility index (μE) (Spadea et al.). The result showed that the flexural stiffness of the SFRC concrete deck specimens is improved and load carrying capacity increased by 12.3% compared to RC decks. Moreover, crack width and crack are reduced by 14% since the SFRC decks offer more concrete ductility than RC decks, meaning less future maintenance and corrosion. Therefore, the use of steel fiber in concrete mixtures could be a significant step in speeding up bridge construction since it does not require laying, tying, and verifying clear cover, in addition to increasing the lifespan of bridge decks.

Experimental study on optimization of continuous steel box girder bridge deck

ABSTRACT In order to accurately optimize the structural parameters of steel bridge deck(OSD), an optimal design method of continuous steel box girder bridge deck based on response surface method is proposed. Optimization design process includes full scale model test, finite element analysis, response surface function fitting and design parameter optimization. The orthotropic steel bridge deck’s deck thickness, stiffener thickness, diaphragm thickness, stiffener height, and diaphragm opening form are chosen as independent variables, and the internal forces of important structural components discovered are used as dependent variables. Design-Expert software created a five-factor, three-level response surface test. A multivariate quadratic response surface regression model between structural parameters and target response values was developed after the objective function and constraint criteria were identified. Numerical theory’s variance analysis was used to find the best combination, and Design Expert software was used to confirm it to make sure the design value was accurate. The findings indicate that optimized structural parameters are trustworthy because the difference between the predicted value and the theoretical value is less than 5%. An orthotropic steel bridge deck’s structural parameters can be optimized using the response surface approach. It serves as a reference for subsequent steel bridge deck design and construction.

Coupling Effect of Expansion Agent and Internal Curing Aggregate on Shrinkage of High-Modulus Ultra-High-Performance Concrete

In the realm of bridge structural engineering, it is customary to meticulously contemplate the material’s strength and rigidity attributes during the dimensioning phase. In recent years, there has been a burgeoning interest in employing Ultrahigh-Performance Concrete (abbreviated as UHPC) for the construction of bridge decks and wet joints. However, the large self-shrinkage of UHPC can easily lead to shrinkage cracking and affect its service life. This study delves into the utilization of a blend of basalt coarse aggregate and high-modulus aggregate (HMA) in the formulation of Ultrahigh-Performance Concrete (UHPC) with the objectives of achieving exceptional strength (>180 MPa), superior modulus of elasticity (>56 GPa), and synergistic effect of using prewetted internal curing aggregate (ICA), metallurgical ore sand (MOS), and calcium–magnesium composite-based expansion agent (EA) to reduce the shrinkage of UHPC. Furthermore, the mechanical properties, shrinkage, hydration process, and microstructure of UHPC prepared with EA and ICA were studied. The results show that UHPC prepared with both 3% EA and 20% ICA had the optimal volume stability (the shrinkage was only 273 με at 180 d). In contrast, the 180 d shrinkage of UHPC with 3% EA and 20% ICA separately was 287 με and 373 με, respectively. In addition, the incorporation of EA and ICA can effectively improve the flexural strength of UHPC, although it affects the compressive strength and modulus of elasticity of UHPC (small decrease).

Orthotropic composite slabs for road bridges

AbstractLarge increases in traffic loads led to extensive fatigue damages to existing orthotropic steel deck slabs of road bridges. Reinforced concrete bridges and conventional composite bridges are less susceptible to fatigue but considerably heavier. The ortho‐composite slab is a lightweight and robust alternative construction method, which retains the advantages of the previously mentioned construction methods, but eliminates their disadvantages. Within the framework of the AiF‐FOSTA research project P1265 [1], the construction of the bridge deck was developed using dowel strips as composite elements with high load‐bearing capacity and fatigue resistance. The principle of area composite with loading of the dowel strips in longitudinal and transverse direction was used. Extensive experimental and structural mechanics studies were conducted, particularly investigating the load‐bearing capacity and fatigue strength of the ortho‐composite slab under local load application. The following article describes the load‐bearing structure of the ortho‐composite slab and the motivation for the research project P1265. It gives an overview of the experimental investigations carried out. Finally, the article presents pilot projects that were carried out to apply the construction method. In further articles on Eurosteel, the experimental investigations and structural‐mechanical calculations are described in more detail (see [2] and [3]).

FRAMEWORK FOR IDENTIFYING INFLUENCING FACTORS FOR STAY-IN-PLACE FORMWORK IN BRIDGE CONSTRUCTION

The formwork system (FWS) adopted for construction is the most important and crucial part of any structure, as it contributes about 40% to 60% of the cost of concrete and 10% of the total cost of construction. Formwork activity also consumes 50% to 70% of the total time requires in RC construction. Particularly in bridge construction, conventional FWS is used for the construction of the bridge's deck, which requires the assembly of multiple FWS components. Conventional FWSs for deck construction are time and labor-intensive. Recently, there is a rise in the use of Stay-in-Place (SIP) formwork for bridge superstructure construction. SIP FWS eliminates the use of falsework, resulting in a reduction in labor input and time. The present study attempts to identify influencing factors affecting the selection of SIP FWS over the conventional FWS in bridge deck construction using the Delphi method. Firstly, based on the literature review, 7 main factors and 28 sub-factors influencing the selection of SIP FWS are identified. Three rounds of the Delphi method are conducted to finalize the main factors and sub-factors by creating a questionnaire and gathering responses from 10 qualified experts. Subsequently, the main 7 factors (Flexibility, Economy, Quality, Safety, Completion Time, Local Condition, and Organizational Support) and 27 sub-factors are shortlisted. Cronbach’s alpha is calculated to check the internal consistency of the main factors. The proposed framework can be extended for estimating the acceptability of SIP FWS compared to the conventional FWS in the Indian Construction Industry.

Fatigue Life Assessment of Deck Barge Construction Using Numerical Simulation Methods

Barges are used as the main means of transporting heavy goods such as nickel, wood, coal and other materials that are placed on the main deck and have implications for stress values ​​and construction fatigue life. This study uses a numerical simulation method with the help of ANSYS software. The load simulations given to the main deck construction of the barge are 50% load, 75% load, and 100% load (full load). The results of the numerical simulation detected that the largest stress occurred when the 100% load condition was 190.7 MPa. The stress with 75% load is 160.21 MPa and the stress for 50% load is 129.73 MPa. The fatigue life at 100% load is 10.66 years with a stress cycle of 170000 times, 75% load is 13.49 years with a stress cycle of 300000, and a 50% load is 21.16 years with the a stress cycle of 700000. -

Capacity assessment of segment-to-segment joints in precast unbonded segmental bridge decks under vertical seismic mainshock and aftershocks

Precast segmental construction of concrete bridge decks has become increasingly popular due to short construction time and low cost compared with other construction methods. However, during earthquake excitation the segment-to-segment joints in post-tensioned bridge decks may constitute a weak part of the superstructure, particularly due to the lack of continuous rebar that is present in cast-in-place decks. This research investigates the effects of the vertical component of earthquakes on the joints of the superstructure of bridges in near-fault regions. Specifically, a sample non-continuous precast segmental bridge with unbonded cables and constructed with the span-by-span method, has been studied using a detailed two-dimensional non-linear Incremental Dynamic Analysis (IDA) and Nonlinear Pushover Analysis (NPO). The results indicate that the vertical component of the earthquake could significantly adversely affect the joints’ behavior, especially in the upward direction. This may cause failure in the critical joints at midspan earlier than other common collapse prevention (CP) limit states such as deck sliding on the seat. The joint failure occurs easier in the mainshock-damaged bridge than in the intact one. Hence, the collapse probability can increase by up to 47% for the considered cases.

Strength, Ductility, and Collapse Response of UHPC Waffle Slabs

Waffle slabs made of ultra-high performance concrete (UHPC) are now being widely used in bridge deck construction. However, to date, no research has been conducted to study their failure behavior. Two one-way waffle slab strips made of UHPC were load-tested under four-point bending to investigate their strength, ductility, and failure patterns. An identical set made of high strength concrete (HSC) was also tested to provide a comparison to specimens made with traditional construction materials. The UHPC specimens exhibited multiple fine cracks prior to rebar yielding and failed by steel rebar rupture after a single crack localized. In contrast, the HSC slab strips exhibited several large cracks and substantially larger ductility than the UHPC slab strips, although their strength was about 40% less than the corresponding UHPC specimens. The experimental results were used to validate a three-dimensional finite element model, which was then employed to investigate the two-way response of UHPC waffle slabs. The simulation study revealed that the yield line design method is applicable to UHPC waffle slabs despite their markedly different behavior compared to concrete slabs. Like the HSC slabs, the UHPC slabs also exhibited displacements and load carrying capacities well in excess of those predicted by flexural theories, due to formation of membrane action.

Field Implementation and Performance of Fiber-Reinforced Low-Shrinkage Concrete for Bridge Deck Construction

Field Implementation and Performance of Fiber-Reinforced Low-Shrinkage Concrete for Bridge Deck Construction

Experimental Investigation on Flexural Strength Enhancement of Eucalyptus based Bamboo Composite Deck Board

The study investigates the effect of the relative height position of specimen and bamboo layering in the preparation of composite flexural material from Eucalyptus Globules and Oxytenanthera abyssinica bamboo for the purpose of floor deck construction. Furthermore, flexural improvement was tested by laminating bamboo beneath eucalyptus, which has a high tensile stress resistance, using unsaturated polyester resin as the bonding medium. The experiment was carried out on specimens taken from the bottom and middle parts of the sample with regard to total height. The results of the tests revealed that single and double-layer bamboo laminated eucalyptus in the bottom part showed an increase in flexural strength by 26.5% and 33.06%, respectively, and that the bottom portion strength had improved due to the addition of bamboo. However, in the case of the middle part specimen, the addition of a bamboo lamination on the Eucalyptus resulted in a (20.31%) increase for single and (−41.79%) decrease for double layer in strength compared to the non-laminated middle part Eucalyptus.

Preparation and properties of a novel waterborne epoxy resin modified emulsified asphalt

Waterborne epoxy resin is one alternative to enhance bond strength and storage stability for waterproof adhesive layer. Grafting copolymerization is selected in this paper as one experimental case to investigate its properties and also a feasible innovative preparation. The impact of the preparation process on the grafting rate of acrylic monomer was also considered. Moreover, the effect of the amount of acrylic monomer on the centrifugation stability and particle size of the emulsions was studied, where the infrared spectra were used to verify that hydrophilic groups incorporated into the main body of the aqueous epoxy resin. Main tests for modified emulsified asphalt are designed as it pulls out strength and storage stability under various temperature. The results showed that the highest grafting rate of acrylic monomer was achieved at the grafting temperature of 110℃ and grafting time of 2 h. The centrifugal stability of the emulsion was optimum when the amount of acrylic monomer reached 30%, at this time, the median particle size of the emulsion was 160 nm; the infrared spectrum showed that the epoxy resin main chain successfully introduced hydrophilic group (–COOH) at 1720 cm−1. When the amount of water-borne epoxy resin exceeded 40%, the pull-out strength of waterborne epoxy resin modified emulsified asphalt increased significantly at 25℃ and 40℃, and its storage stability was optimized when the content of waterborne epoxy resin reached 50%. The waterproof adhesive layer material prepared in this study has potential application value for improving the quality of bridge deck pavement and construction projects.

Numerical analysis on the effect of the intermediate diaphragm on the concrete bridge to the acceleration and frequency under moving load

For the goal of construction simplicity, when considering the addition of an intermediate diaphragm (ID) to the bridge deck construction, particularly for beam-to-slab bridges, the majority of engineers were found to be passive. This took place as a result of the perception that ID does not significantly contribute to improving structural capacity, particularly for bridge deck structures and structurally as a whole. The constructability issue now is also playing an issue for this beam-to-slab bridge, which has been thought to slow down the construction speed since its location in the middle of the span is an unsupported region, which makes it a bit difficult to fix and cast both reinforcement and concrete. As a result of the omittance of ID, adverse impacts have taken place on the beam slab bridge, particularly on the medium span where moderate vibration has been triggered, which is categorized as minor resonance due to traffic crossing, primarily big trucks being loaded, on the bridge deck itself. The results of the numerical study using Abaqus software, it was revealed that the presence of ID improved the vibration level in terms of acceleration and natural frequency, resulting in significant improvements in riding comfort.

Analysis on Deck Ship Conversion SPOB to LCT 234 GT Using Finite Element Method

Landing Craft Tank (LCT) is a sea transportation that serves to carry various types of cargo and heavy mining equipment and has a large size. In shipbuilding, the construction structure on the ship is not only designed to be able to accept the load from the cargo being transported but also must be able to withstand external loads caused by waves. With the modification of the Self-Propelled Oil Barge (SPOB) ship into a Landing Craft Tank (LCT), the calculation and planning process on the deck structure of the Landing Craft Tank (LCT) ship really needs to pay attention to the stress and strain strength in order to meet the safety factors that have been set in accordance with the applicable rules. This study aims to determine the maximum allowable stress value and the safety factor of the modified structure of the Landing Craft Tank (LCT) ship deck construction. The method used in this research is the finite element method. In this study uses 2 variations of the type of support "Tee Bar" and "Angle Bar". The results of this study the value of material deformation that occurs on the ship's deck with a variation of "Angle Bar" of 1.1497 mm and the value of material deformation that occurs on the deck of a ship with a variation of "Tee Bar" of 0.97269 mm. The maximum stress value acting on the ship's deck with the "Angle Bar" profile variation is 152.64 MPa and the maximum strain value is 0.00072686 mm/mm. The maximum stress value acting on the ship's deck for the "Tee Bar" profile variation is 147, 63 MPa and the maximum strain value is 0.000703 mm/mm. The value of the Safety Factor based on the criteria for the material on the ship's deck is obtained by comparing the yield stress value of the material and the maximum working stress must be greater than 1, then the deck construction with the variation of the "Angle Bar" profile is 2,326 and for the variation of the "Tee" profile type. Bar” 2,405 are categorized as safe. As for the Safety Factor based on BKI rules for the variation of the "Angle Bar" profile of 1,638 and for the variation of the "Tee Bar" profile of 1,693 it is categorized as safe. then the deck construction with the variation of the profile type "Angle Bar" is 2,326 and for the variation of the profile type "Tee Bar" 2.405 is categorized as safe. As for the Safety Factor based on BKI rules for the variation of the "Angle Bar" profile of 1,638 and for the variation of the "Tee Bar" profile of 1,693 it is categorized as safe. then the deck construction with the variation of the profile type "Angle Bar" is 2,326 and for the variation of the profile type "Tee Bar" 2.405 is categorized as safe. As for the Safety Factor based on BKI rules for the variation of the "Angle Bar" profile of 1,638 and for the variation of the "Tee Bar" profile of 1,693 it is categorized as safe.