Deck Construction Research Articles

Behavior of FRP Link Slabs in Jointless Bridge Decks

The paper investigated the use of fiberglass-reinforced plastic (FRP) grid for reinforcement in link slabs for jointless bridge decks. The design concept of link slab was examined based on the ductility of the fiberglass-reinforced plastic grid to accommodate bridge deck deformations. The implementation of hybrid simulation assisted in combining the experimental results and the theoretical work. The numerical analyses and the experimental work investigated the behavior of the link slab and confirmed its feasibility. The results indicated that the technique would allow simultaneous achievement of structural need, lower flexural stiffness of the link slab approaching the behavior of a hinge, and sustainability need of the link slab. The outcome of the study supports the contention that jointless concrete bridge decks may be designed and constructed with fiberglass-reinforced plastic grid link slabs. This concept would also provide a solution to a number of deterioration problems associated with bridge deck joints and can be used during new construction of bridge decks. The federal highway administration provided funds to Louisiana Department of Transportation through the innovative bridge research and development program to implement the use of FRP grid as link slab.

GFRP Bridge Deck Panel

The aim of the research is design and analysis of new bridge deck panel made of glass fiber reinforced polymer (GFRP). Use of GFRP in construction is rapidly growing in last few years. The reason for use GFRP is its low self weight in compare of strength and high resistance against weather influenced degradation resulting in long life. Using GFRP for the construction of the bridge deck leads to lightweight construction that can pass the required wheel load. Lightweight design is appreciated for temporary bridge which is expected to be transported and assembled often on places of current need. Long durability and resistance against weather degradation also reduces maintenance costs of bridge deck. Design of deck panel will be done on the base of loading experiments and FEM analysis. The main use of GFRP bridge deck panel is for temporary bridge but it is possible to extend its use on permanent or movable bridges.

Technical Challenges of Large Movable Scaffolding Systems

The method of construction of decks of bridges and viaducts with several spans using movable scaffolding systems (MSS) is very efficient and competitive. This solution is generally used for the 40 to 60 m span range. Over the last few years, new experiences have been acquired and new solutions have been developed for the 70 to 90 m range (large MSS or LMSS). In this range, unexpected economical results may be achieved if the number of spans is high and/or if the costs of piers and foundations are relatively high. With LMSS it is possible to achieve very high productivity ratios.The application of LMSS implies significant technical challenges. Some are similar to the more common MSS, but others become more relevant.This paper discusses bridge–equipment interaction including main vertical loads on the bridge, horizontal forces on piers, wind actions, wind-induced vibrations on piers with MSS stabilization, accidental MSS-induced actions, thermally induced horizontal displacements, and deflection control. Two real examples are presented. The design criteria recommendations are listed in the conclusion section.

Deck construction and performance for impervious surface reduction

Decks or boardwalks are frame structures with plank surfaces for bearing pedestrian traffic. They offer a potential addition to the list of surfacing materials that maintain perviousness of land cover in the midst of urban development. In this study, using the same type of analysis used for grate inlets, it was determined that decks' minimum ‘worst case’ permeability is higher than common natural rainfall intensities and at least as high as that of competing permeable surfacing materials. Cost analysis demonstrated that the cost of deck construction is comparable to that of competing permeable surfacing materials. Diverse case studies illustrate that there is experience with decks in a variety of urban settings. Therefore it is recommended that decks be on any list of surfaces available for effectively reducing urban impervious cover, while continuing to limit their application to the traffic types for which they are suited.

메타카올린 콘크리트 교량바닥판의 장기 역학적 특성 및 내구성에 관한 연구

The requirement for durability of concrete bridge deck is increasing as the deterioration for the concrete bridge deck exposed to severe environment has been increased. For this reason, the concern about high-durable concrete is being high. Recently, a metakaolin is highly spotlighted as new admixture because its strength and durability are equivalent to silica fume. On the other hands, there are few researches for the metakaolin concrete bridge deck in domestic. So many various long-term data on the mechanical property and durability is needed to apply metakaolin concrete at the concrete bridge deck construction field. This study is aim to evaluate the long-term mechanical properties and durability of metakaolin concrete bridge deck with curing age. Mechanical properties are estimated by the compressive and flexural strength, and the drying shrinkage, the chloride resistance, the scaling, and freezing and thawing characteristics are compared with curing age. According to the results, when the metakaolin concrete is used, the development of compressive and flexural strength proceed in both the early and old ages. It is also improved the resistance of chloride penetration, freezing and thawing in concrete. It was showed that replacement of metakaolin was efficient for the reduction of the drying shrinkage.

FEA of Deck Corner Cracking on Skewed Bridge Structures

Based on a nationwide survey and deck inspection in Michigan, the phenomenon of more severe corner cracking on skewed bridge decks was commonly observed. A series of FEA by DIANA were carried out to identify the possible causes and viable cures for such cracking. Prior to the FEA, the accuracy of FEM modeling was calibrated by two skew bridge decks instrumented using temperature and strain sensors for the deck concrete and the ambient environment. Test and FEA results found that the cracking has been mainly caused by thermal and shrinkage stress, and that possibly propagated and worsened by repetitive truck wheel loading. According to current Michigan practice of skew deck design and construction, additional reinforcement in the corner areas is therefore recommended to reduce concrete stresses. Further research is also recommended to develop solutions using optimal combinations of ingredients in concrete and to minimize the constraint between the deck and the supporting superstructure.

The Transmission Line for the SPIDER experiment

The 100 keV Ion Source Test facility – Source for the Production of Ions of Deuterium Extracted from RF plasma (SPIDER) – is aimed to test the full scale prototype of the Ion Source for the ITER 1 MeV Neutral Beam Injector (NBI). The SPIDER facility requires the construction of a High Voltage Deck (HVD) and of a High Voltage Transmission Line (TL) respectively to host the Ion Source Power Supplies system polarized at 100 kV and to carry the power and signal conductors to the beam accelerator. In already existing NBI systems with beam energy above 100 keV, the TL is realized with the SF 6 Gas Insulated Line technology. In the SPIDER TL case, the presence of a large inner conductor (half meter diameter), would make the pressurized TL a complex and costly component; therefore a free air insulated solution has been proposed. The paper focuses on the design of this TL, which has to host inside the complex high potential (100 kV) inner electrode a number of power and measuring conductors and has to minimize the Electro Magnetic Interferences (EMI) produced by the frequent grids breakdowns. Finite Element (FE) analyses have been performed to verify the configuration from the electrostatic point of view, to evaluate EMI screening effectiveness and to assess the impact of the relatively high thermal dissipation of power conductors located inside the high potential electrode. Moreover, an experimental test campaign has been carried out on a TL mockup to validate the TL electrostatic configuration under DC voltage. Finally, the paper reports on the status of procurement activities for the Transmission Line.

Modified Yield Line Theory for Full-Depth Precast Concrete Bridge Deck Overhang Panels

Full-depth precast deck slab cantilevers also referred to as full-depth precast concrete bridge deck overhang panels are becoming increasingly popular in concrete bridge deck construction. To date, no simple theory is able to estimate the overhang capacity of full-depth concrete bridge deck slabs accurately. Observations suggest that interaction between flexure and shear is likely to occur as neither alone provides an accurate estimate of the load-carrying capacity. Therefore, modified yield line theory is presented in this paper, which accounts for the development length of the mild steel reinforcing to reach yield strength. Failure of the full-depth panels is influenced by the presence of the partial-depth transverse panel-to-panel seam. When applying a load on the edge of the seam, the loaded panel fails under flexure while the seam fails in shear. Through the use of the modified yield line theory coupled with a panel-to-panel shear interaction, analytical predictions are accurate within 1–6% of experimental results for critical cases.

Penang Bridge widening: design and construction challenges

The Penang Bridge is a 13·5 km long road crossing connecting Penang Island to peninsular Malaysia. In order to increase traffic capacity, approximately 6 km of low-level viaduct sections of the crossing were widened by the addition of a new lane and hard shoulder in each direction. This challenging project invovled the construction of new decks, piers and deep-piled foundations in close proximity to the existing structure, with extensive use of heavy plant and machinery mounted on marine barges. Key project objectives were to maintain an operational highway at all times and to safeguard the existing structure during the works. The latter invovled the development of a construction sequence designed to minimise the load transfer from the new works onto the existing structure, and the implementation of a rigorous monitoring regime during pile constrution.

Nonlinear Rail-Structure Interaction Analysis of an Elevated Skewed Steel Guideway

The use of continuous welded rail (CWR) with direct fixation of track on concrete deck is typical of most modern light-rail aerial structures. The interaction between the CWR and the elevated structure takes place through direct-fixation rail fasteners, which have a nonlinear force-displacement relationship. Factors that have significant influence on this interaction include the following: the bearing arrangement at the substructure units, trackwork terminating on the aerial structure, type of deck construction, and type of rail fasteners. To better understand the interaction mechanism, a nonlinear three-dimensional (3D) finite-element analysis of a straight, skewed, elevated steel guideway was carried out using the commercially available software GT STRUDL. The load cases considered in this study are temperature change, temperature change with rail breaking, and train braking. Results are presented in the form of rail axial stresses along the length of the bridge and normal bearing forces at both abutments and at all pier locations. The study shows that nonlinear 3D modeling can give a comprehensive insight into the rail-structure interaction (RSI) forces.

Local Bending Stresses in Stay Cables with an Elastic Guide

Cable-stayed bridges, like no other civil engineering structure, combine functionality and exotic architectural design that are often used as a symbol of distinction for the city or even for the region where they are situated. However, their attractive design requires special attention for multiple factors such as the occurrence of bending stresses in the stay cables due to vibration phenomena, displacements and rotations at the deck or pylon and construction tolerances. Therefore, in this scenario, stay cables are normally subjected to bending stresses at the anchorages or when passing through a saddle. In this paper both fixed end and elastic guide are considered and a set of analytical solutions is given. The development of the analytical solutions is accompanied by a detailed description and thorough discussion of some particular observations.

Nonlinear Finite-Element Analysis of Critical Gusset Plates in the I-35W Bridge in Minnesota

Reported evidence suggests that failure of gusset plates initiated the collapse of the I-35W Bridge in Minneapolis, Minnesota. The particular gusset plates were at a panel point designated as U10. Therefore, an analytical investigation was conducted on the condition of the U10 gusset plates at the time of bridge collapse. The forces delivered to panel point U10 were reproduced using available information of the bridge. These forces were introduced to detailed nonlinear three-dimensional finite-element models to calculate stress and strain states of the gusset plates. The results indicate that substantial portions of the U10 gusset plates were yielded at the time of collapse, confirming earlier findings from federal and state investigations. Weight increase due to past deck reconstruction and construction material and equipment staged on the day of collapse, along with insufficient thickness of the gusset plate, were identified as the main contributing factors to the substantial yielding. The results also suggest that the interaction of compression and shear played an important role in the gusset plate failure.

Improved methods for decreasing stresses of concrete slab of large-span through tied-arch composite bridge

Mechanical behavior of concrete slab of large-span through tied-arch composite bridge was investigated by finite element analysis (FEA). Improved methods to decrease concrete stresses were discussed based on comparisons of different deck schemes, construction sequences and measures, and ratios of reinforcement. The results show that the mechanical behavior of concrete slab gets worse with the increase of composite regions between steel beams and concrete slab. The deck scheme with the minimum composite region is recommended on condition that both strength and stiffness of the bridge meet design demands under service loads. Adopting in-situ-place construction method, concrete is suggested to be cast after removing the full-supported frameworks under the bridge. Thus, the axial tensile force of concrete slab caused by the first stage dead load is eliminated. Preloading the bridge before concrete casting and removing the load after the concrete reaching its design strength, the stresses of concrete slab caused by the second stage dead load and live load are further reduced or even eliminated. At last, with a high ratio of reinforcement more than 3%, the concrete stresses decrease obviously.

Shear capacity and tension capacity of arc-spot welds for multi-overlap deck panels

Arc-spot welds fabricated in multi-overlap configurations are found in roof deck construction when steel sheets are stacked at a sidelap or endlap. A welding technique that maximizes the quality of arc-spot welds fabricated through several layers of thick sheets is presented. Weld specimens were fabricated through 1, 2 or 4 layers of steel sheets with thicknesses ranging from 0.76 to 1.52 mm (22 to 16 gauge). The most important factors to control during the welding are the current (high intensity), the electrode type (E4311) and the welding technique. Various sheet steel/weld configurations found in roof deck construction were included. Adequate weld quality could be achieved in all cases except that welds were undersized when the ratio of the thickness of the underlying material to total sheet thickness was less than 0.7. A total of 72 tension tests and 107 shear tests were completed. Of those, 31 shear specimens were loaded with a reversed cyclic protocol to examine the behaviour of arc-spot welds subject to seismic loading. All other specimens were loaded under monotonically increasing displacement. The results were compared with the provisions of the CSA S136 North American Specification for the Design of Cold-Formed Steel Structural Members. The CSA S136 equations for shear and tension resistance of arc-spot welds are generally conservative, even for welds fabricated through multi-overlap configurations with total sheet steel thicknesses exceeding the 3.81 mm limit. Nonetheless, modifications to the equation for the effective diameter and to Equations E2.2.1.2-2, E2.2.2-1, and E2.2.2-2 are recommended.

Flexural Lateral Load Distribution Characteristics of Sandwich Plate System Bridges: Parametric Investigation

The sandwich plate system (SPS) is a relatively new bridge deck system that consists of steel face plates bonded to a rigid polyurethane core. The decks are thin, lightweight, and modular in design and can be tailored to numerous applications. This system provides an excellent alternative for the rapid construction and rehabilitation of bridge decks. With any new system, there exists some uncertainty in the design procedures as a result of the limited population for comparison. This paper presents the results of a finite-element parametric investigation of the lateral load distribution characteristics of SPS bridges. The parametric study primarily focuses on the influence of deck thickness on distribution behavior as compared to conventional reinforced concrete decks. Results from the study demonstrate that the inherent flexibility of a thin SPS deck yields larger distribution factors (up to 20%) than a typical reinforced concrete deck, but these distribution factors can still be conservatively estimated with current AASHTO LRFD methods. Additional comparisons indicate that the distribution behavior of SPS bridges can also be estimated with the equations proposed by the NCHRP 12-62 project.

Development and Application of Maturity Method for Prediction of Concrete's Resistance to Chloride Ion Penetration

The applicability of the maturity method for prediction of the resistance of concrete to chloride ion penetration as measured by the ASTM C1202 Rapid Chloride Permeability Test was examined. Predictive capability of the method was successfully validated for laboratory-made, continuously moist cured ternary concrete containing 20% fly ash and 5% silica fume and was found to be excellent. Applicability of the developed maturity method was also verified for field-made and field-exposed ternary concrete used during a two-phase construction of a pilot high-performance concrete bridge deck in Indiana. Although agreement between the predicted and measured coulomb values was good for Phase 2 (constructed in spring), the rapid chloride permeability (RCP) values for Phase 1 (constructed in late fall) were consistently underestimated. Reasons for these disparities were thoroughly investigated. It was concluded that the measured values were higher than the predicted ones mainly because of the reduced degree of cement hydration and the potential increase in the water-to-cementitious materials ratio of concrete. Finally, two additional applications of the developed maturity method were demonstrated. The first application enables prediction of RCP values of concrete subjected to an accelerated curing procedure. This result may prove particularly useful for quality control, as 56-day RCP values may be obtained in about 13 days if temperature is elevated to 38°C. The second application allows for estimation of RCP values at a predefined age of first exposure to deicing salts as a function of construction date (assuming certain temperature history).

Strength Analysis of Precast Bridge Decks with Full-Depth Precast Overhang Panels

The use of full-depth precast overhang panels provides an alternative to modern bridge deck construction by eliminating the need to form a full-depth cast-in-place (CIP) overhang. Additional benefits from these precast panels include improving worker safety conditions during construction and accelerating construction. To validate the capacity of a full-depth precast bridge deck system compared with a conventionally constructed concrete bridge deck, the Texas Department of Transportation sponsored an experimental investigation. For both, the failure loads exceeded the maximum factored 2007 AASHTO load and resistance factor design for decks and deck overhangs. Observations suggest that there is an interaction between flexure and shear to estimate the capacity of full-depth concrete bridge deck overhangs or slabs constructed with stay-in-place (SIP) panels and a CIP topping. This paper shows how a modified yield line theory, which accounts for the development length of the mild steel reinforcing to reach yield strength, is used to analyze precast bridge decks with full-depth precast overhang panels. For the full-depth overhangs, the internal work equation is further modified to allow for the panel-to-panel seam that exists within the system. At the interior portions of the bridge deck, a compound shear–flexure mechanism is proposed. This is an additive model of a flexural yield line failure in the lower SIP precast panels and punching shear in the upper CIP portion of the deck. Therefore, a strength method of analysis is used to design the exterior portion (overhang) that incorporates the concurrent effects of flexure and shear in panelized precast deck systems.

Low-Cracking, High-Performance Concrete Bridge Decks

Cracks in concrete bridge decks provide easy access for water and deicing chemicals that shorten the life of the deck, and field surveys show that the problem has become progressively more severe since at least the 1980s. A two-phase, 10-year Pooled Fund study to minimize cracking in bridge decks is now under way. Twenty bridge decks have been constructed in the program to date. Comparison with conventional decks shows that the techniques embodied in low-cracking, high-performance concrete (LC-HPC) bridge deck specifications have been highly successful in reducing cracking in bridge decks. The results also show that high-slump high-strength concretes result in greater cracking in bridge decks than low-slump, moderate-strength concretes and that concrete temperature control and early application of curing counteract the negative effects of casting concrete under high-temperature conditions. Early owner and contractor buy-in is needed for successful LC-HPC bridge deck construction, and top performance requires the adherence to all aspects of the specifications.

Framework for Multiobjective Optimization of Launching Girder Bridges

A framework is presented for optimizing the construction of decks of bridges using launching girder systems. The framework assists contractors in performing a time-cost trade-off analysis to optimize the use of resources. The proposed framework consists of three main components which interact in a cyclic manner. These components are simulation, optimization, and reporting modules. Processes and tasks of launching girder systems are described in order to illustrate the mechanism of the simulation module which utilizes STROBOSCOPE as a general purpose simulation language. The developments made in the optimization module are extensively detailed. The optimization module uses ant colony optimization and it accounts for seven optimization variables; location of casting yard, time lag, number of casting forms, number of preparation platform, curing method, number of yard reinforcement crews, and number of stressing crews. Two optimization approaches are coded in the optimization module in two algorithms (ant colony multiobjective optimization I and II) to carry out multiobjective optimization. These are function-transformation and modified distance approaches. A numerical example is presented to illustrate the practical use of the developed framework.

China: Innovative Use of Materials for Highway Construction

Ever since the Open Door Policy was set forth, China has been developing rapidly and infrastructure construction has been booming and leaping forward with the economy. The highway network is developing at an unprecedented speed and turns out to be successful and fruitful, reaching almost all cities throughout the country in a decade. The freeway length increases by several thousand kilometers annually. By the end of 2007, the freeways nested inside the entire roadway system of 3.57 million km had reached the length of 53,600 km. The fast development of the highway network improves mobility throughout China, while effectively supporting the economic development in both cities and countryside. Highway development relies heavily on current advanced technologies and applied science, and the innovation and renovation of construction techniques accelerate highway construction in China. In recent years, many important innovations and technical breakthroughs with renovations have occurred in various aspects of highway construction in China. The Global Positioning System GPS , remote sensing RS , and computer-aided design CAD have been integrated for road surveying; in particular, this integrated system is used for scenic design of mountain roads and ramp design of mountain highways. In addition, a single radio station is incorporated into a network-based GPS with a multipleantenna sensing technique. Recently, new techniques have been applied to construct a subgrade/subbase on deserts, freeze-susceptible soils, yellow soils, expansive soils, and soils with substrata rich in calcite and/or dolomite. Mixtures of large-size crushed stones and soils have been used to construct roadway bases. Moreover, new methods are being innovated for stabilizing roadway cut slopes, mitigating embankment settlement and deformation, designing roadway drainage systems, and constructing transition segments connecting highways to bridges. Asphalt paving technologies have been renovated by using modified bituminous binders with polymers, rubber powders, and rubber particles. Also being put into practices are new pavement maintenance strategies, pavement distress survey and assessment using advanced technologies, accelerating bridge deck construction, fire-resistant materials for pavements through tunnels, ultrathin asphalt pavement construction, emulsified asphalt binders for interface coating, and lean concrete treatment to subgrade. These construction technologies incorporated with current environmental protection and safety improvement plans in the road network throughout China will greatly enhance the performance of the entire roadway system.