Showing papers on "Deck published in 2019"

Experimental study on fatigue performance of UHPC-orthotropic steel composite deck

Abstract: UHPC-orthotropic steel composite deck is an innovative and efficient bridge deck system, however the failure mode of this composite bridge deck under fatigue load is still not well understood, particularly when the deck is in hogging bending. To investigate the fatigue behavior of the UHPC-orthotropic steel composite deck, two multi-span full scale composite bridge decks in hogging bending were experimentally studied. To simulate the bridge deck under negative bending, the specimens were designed with the mid-span deck simply supported and two overhanging decks each side. Each specimen was tested twice. In the first test phase, the specimen was loaded with a vertical force acting on one side span, while in the second test phase, the specimen was vertically loaded on another side span. Tests revealed that among the all fatigue-prone details of an orthotropic steel deck, only the longitudinal cracks were observed occurring in the low portion of rib web which was near the weld toe of the rib to the transverse diaphragm. The fatigue strength of these specific cracks longitudinally orientated can be evaluated in a term of the vertical stress range of the rib below the weld toe under the fatigue details category C of AASHTO or category 71 MPa of Eurocode3. Shear connection failure of the composite deck was also found featuring with delamination between UHPC and steel bridge deck. Fatigue damage of the short headed studs was further inspected and evaluated by means of drilling test. It is found that the fatigue life of the shear connection is governed by the fatigue shear strength of the short headed studs, which is much longer than the fatigue life codified in the specifications for studs of conventional composite beams. The fatigue shear connection strength of the composite bridge deck can be assessed conservatively in a term of the fatigue shear strength of the headed studs.

Development of Fully Prefabricated Steel-UHPC Composite Deck System

Abstract: This paper proposes a novel fully prefabricated composite deck system to achieve green and accelerated construction in bridge engineering. Ultra-high-performance concrete (UHPC), which has ...

Automated visualization of concrete bridge deck condition from GPR data

Abstract: Ground-penetrating radar (GPR) is one of the most commonly used technologies for condition assessment of concrete bridge decks. However, there have been no fully automated algorithms to visualize the data collected with this technique. In such context, the current paper presents a method for a full automation of GPR data visualization and analysis. Based on the background removal, depth correction, synthetic aperture focusing technique (SAFT), and interpolation algorithms, this automated method produces a plan view map of amplitude of GPR signals. In the obtained map, two types of information are observed at the same time. First, as the strongest reflectors of electromagnetic energy, rebars will appear as the most visible. Second, the areas of corrosive environment and, thus, likely corrosion, will be detected as having low amplitude rebar reflections. As a proof of concept, the proposed method was implemented for two bare concrete bridge decks and two concrete bridge decks with asphalt overlays. In all cases, the results obtained were excellent where the maps pinpointed the areas affected by corrosion. These areas were confirmed by other methods of evaluation, such as electrical resistivity (ER), half-cell potential (HCP), chloride analysis of core samples, or visual inspection. With the demonstrated performance, the proposed method is expected to be an excellent alternative to the available methods of GPR data evaluation and visualization. In the future, it should be improved to provide an indication of corrosion severity/probability at each deck location.

Marine Plastic Pollution in Asia: All Hands on Deck!

Abstract: Marine plastics pollution (MPP) is an alarming problem affecting many countries, particularly in the Asia-Pacific region, and generated mostly from land-based sources. Five Asian countries (i.e. China, Indonesia, the Philippines, Vietnam and Sri Lanka) have been identified as the largest sources of MPP globally. This article presents two cases studies focused on the two largest polluters: China and Indonesia. Both countries face similar challenges in dealing with plastic pollution. They have weak legal and institutional frameworks in place to deal with MPP. The two case studies also show that there have been more creative and effective measures taken at the domestic level by local governments and non-state actors, many of which involve partnerships among different stakeholders. This article argues that governance efforts to address MPP require an ‘all hands-on deck’ approach, involving multi-level and multi-actor strategies and targeted regulatory and non-regulatory measures. However, our findings also suggest that most efforts should be directed at the subnational level, from which the problem mainly originates. This article proposes a number of legal and policy recommendations, based on the lessons learned from the case studies, which can be instrumental in reducing the global MPP crisis.

Determining the Dynamic Loading on a Semi-wagon When Fixing IT with a Viscous Coupling to a Ferry Deck

Abstract: We have modeled the dynamic loading of a semi-wagon body when it is fixed by a viscous coupling relative to the deck of a railroad ferry. The relevance of this research relates to the fact that the movement of wagons by sea on railroad ferries is accompanied by the effect of significant magnitudes of loads on the load-bearing structures of their bodies. The numerical values of these loads are significantly higher than those that act on a wagon under operation along a railroad. In addition, the current scheme does not ensure the reliability of Fastening the body and thus causes damage to its structural elements. This necessitates conducting unplanned repairs of wagons that are transported on railroad ferries. It is therefore proposed to improve the scheme of fixing a wagon relative to the deck of a railroad ferry. In order to mitigate the effect of loads exerted by chain couplers on a wagon body, it is suggested that they should be connected by a flexible link, rather than rigid, by installing a specialized device ‒ a damper between a body and a deck.To simulate the dynamic loading of a wagon body taking into consideration the proposed technical solutions, a mathematical model has been constructed and the magnitudes of accelerations acting on the body have been determined. The model accounts for the movement of a railroad ferry with wagons under side rocking motion as one of the main types of vessel fluctuations. It was established that it becomes possible, by taking into consideration the proposed scheme of fixing a wagon body relative to the deck, to reduce the magnitude of its dynamic loading by 30 %.We have also determined the dynamic loading on a wagon body by computer simulation in the programming environment CosmosWorks. Numerical values and the fields of deployment of semi-wagon body's accelerations have been determined. The constructed models were verified based on an F-criterion. The present research will contribute to maintaining the bearing structures of wagons' bodies when they are transported on railroad ferries, as well as improving the efficiency of their operation along International transport corridors

Diaphragm effectiveness of precast concrete structures with cladding panels under seismic action

Abstract: The seismic performance of precast frame structures strongly depends on the mechanical devices connecting both structural and non-structural elements. Following recent post-earthquake field observations of unintended seismic interaction of the cladding panels with the frame structure, the seismic design of the cladded system is currently being critically examined by the scientific community. Design solutions involving a controlled cladding–structure interaction have been proposed to address this problem. However, the frame–panel interaction may draw high stresses into the roof diaphragm, as a consequence of the stiffening of the external frames only. This paper presents a parametric study based on linear and non-linear dynamic analyses investigating different levels of interaction among frames, panels, and diaphragm system. The results show how the deck and cladding connections influence the seismic behaviour of the structure. Innovative fastening systems aimed at enhancing the seismic performance of the structure are proposed based on the use of dissipative connection devices inserted into both cladding and deck components.

Innovative Steel-UHPC Composite Bridge Girders for Long-span Bridges

Abstract: Steel and steel-concrete composite girders are two types of girders commonly used for long-span bridges. However, practice has shown that the two types of girders have some drawbacks. For steel girders, the orthotropic steel deck (OSD) is vulnerable to fatigue cracking and the asphalt overlay is susceptible to damage such as rutting and pot holes. While for steel-concrete composite girders, the concrete deck is generally thick and heavy, and the deck is prone to cracking because of its low tensile strength and high creep. Thus, to improve the serviceability and durability of girders for long-span bridges, three new types of steel-UHPC lightweight composite bridge girders are proposed, where UHPC denotes ultra-high performance concrete. The first two types consist of an OSD and a thin UHPC layer while the third type consists of a steel beam and a UHPC waffle deck. Due to excellent mechanical behaviors and impressive durability of UHPC, the steel-UHPC composite girders have the advantages of light weight, high strength, low creep coefficient, low risk of cracking, and excellent durability, making them competitive alternatives for long-span bridges. To date, the proposed steel-UHPC composite girders have been applied to 14 real bridges in China. It is expected that the application of the new steel-UHPC composite girders on long-span bridges will have a promising future.

Stiffness and strength evaluation of a novel FRP sandwich panel for bridge redecking

Abstract: The objective of the research described in the paper was the structural development of a FRP composite bridge deck intended for manufacturing and application in road bridges in Poland, mainly for redecking the deteriorated bridge slabs. The appropriate shape of the sandwich bridge deck panel, its overall structure, constituent materials and the associated cost-effective manufacturing technology were determined following a comprehensive analysis of the similar solutions recently developed worldwide. In the first stage three different small-scale deck panel prototypes were designed and fabricated, assuming the various core configuration of the sandwich structure. Based on manufacturing tests and initial static tests the feasibility and stiffness of all prototypes were assessed to select the optimal deck solution in terms of material, structure and technology. In the second stage of the research a full-size 2.0 × 5.0 m bridge deck panel was designed taking into account the bridge loading according to Eurocode 1. The full-size bridge deck prototype was subjected to a series of static load tests simulating the relevant load. The tests confirmed the appropriate stiffness and load carrying capacity of the novel FRP bridge deck panel, quite similar to performance characteristics of other FRP bridge decks implemented worldwide. However, the necessary technological and research works on the novel sandwich bridge deck panel in order to increase its safety level were also outlined.

Interlaminar Bonding Properties on Cement Concrete Deck and Phosphorous Slag Asphalt Pavement.

Abstract: The slippage damage caused by weak interlaminar bonding between cement concrete deck and asphalt surface is a serious issue for bridge pavement. In order to evaluate the interlaminar bonding of cement concrete bridge deck and phosphorous slag (PS) asphalt pavement, the shear resistance properties of the bonding layer structure were studied through direct shear tests. The impact of PS as a substitute of asphalt mixture aggregate, interface characteristics, normal pressure, waterproof and cohesive layer types, temperature and shear rate on the interlaminar bonding properties were analyzed. The test results indicated that the interlaminar bonding of bridge deck pavement is improved after asphalt mixture fine aggregate was substituted with PS and PS powder, and the result indicated that the shear strength of grooved and aggregate-exposed interfaces is significantly higher than untreated interface, the PS micro-powder or anti-stripping agent can also improve the adhesion between layers when mixed into SBS asphalt. This study provided important theoretical and practical guidance for improving the shear stability of bridge deck pavement.

Characterization and structural performance of hybrid fiber-reinforced composite deck panels

Abstract: This paper presents the experimental and analytical investigation on the behavior of hybrid fiber-reinforced composite deck made up of glass and jute fibers embedded in vinyl ester matrix. Finite element evaluation of the flexural performance of the composite decks was carried out using ANSYS, FE software. It was observed that analytical evaluation underestimates the value of deflection of deck panels 1 and 2 by 10.91% and 18.57%, respectively, when compared to the experimental results. However, the value of strain obtained by FEA is appreciably higher than that observed during the experiment. The analytical evaluation of deck panels was further extended to HYFRP and GFRP (glass fiber-reinforced polymer) decks with varied cross sections obtained by changing the location and shape of stiffeners. The specifications stipulated by Ohio Department of Transportation (ODOT), USA, for FRP decks were used for evaluating the performance of deck panels. The values of maximum deflection and strain experienced by the deck panels with stiffeners at the web-flange joint were found to be less than that of deck panels provided with stiffeners at the center of top flange of each cellular unit. Out of the various configurations examined, the performance of decks with V-shaped stiffeners and combination of U- and V-shaped stiffeners at top and bottom web-flange joint were found to be best with substantially lower deflection and strain.