Abstract: The concept, design and experimental validation of the new Avancon Bridge in Bex, Switzerland, are described. The lightweight glass fiber-reinforced polymer (GFRP) sandwich bridge deck adhesively bonded to steel girders reduced the traffic disruption period by approximately 40 days or 80% compared to a cast-in-place concrete bridge and also enabled the bridge to be widened to two lanes. The semi-integral bridge concept allows the application of a continuous asphalt layer across the abutments without expansion joints and thus facilitates and reduces maintenance. The GFRP sandwich deck with structural balsa core fulfils all the requirements concerning serviceability, ultimate limit state and fatigue.

Abstract: Failure of the Utatsu concrete girder highway bridge in Minamisanriku, Miyagi Prefecture during the 2011 Great East Japan Tsunami was puzzling because the bridge decks were not pushed off their piers but rather were flipped off the landward side of the bridge piers after being deeply submerged by the surging tsunami. To determine what caused this to happen, two simulations were conducted. The first was a large-scale Delft shallow-water simulation (beginning with published tsunami source free surface deviation) to determine the behavior of the tsunami (time series of flow depth and speed) at the bridge site. The second was a small-scale two-dimensional (2D) (profile view) software volume-of-fluid (VOF) simulation of flow over the bridge deck, with boundary conditions taken from the Delft model. The VOF model then allowed calculation of lift force, drag force, and overturning moment on the bridge deck. Results show that factors contributing to failure included the presence of a seawall near the bridge, inclination (superelevation) of the deck upward toward the ocean, sediment entrained in the water, and air trapped between girders.

Abstract: This study evaluated the effect of the pavement design parameters on the behaviour of orthotropic steel bridge deck pavements under traffic loading using a three-dimensional finite element model. Four types of paving materials were considered in this analysis: polymer concrete, epoxy asphalt concrete, polymer-modified stone mastic asphalt concrete and mastic asphalt concrete. The maximum transverse tensile strain was developed at the bottom of the pavement under a tyre of dual tyres or on top of the pavement between two tyres. From the sensitivity analysis, better interface bonding between the deck plate and pavement led to a significant enhancement of bottom-up fatigue cracking resistance, especially for 40-mm-thick pavements. As pavement temperature increased from − 20 to 60°C, critical tensile strain increased significantly, and corresponding locations moved from the bottom to the top of the deck pavement.

Abstract: One of the most important questions that structural engineers all over the world are dealing with is the safety of the existing structures. In the Netherlands, there are a large number of transversely prestressed bridge decks that have been built in the last century and now need to be investigated for their structural safety under the actual (increased) traffic loads, for the rest of their service life. This research is an attempt to investigate the bearing (punching shear) capacity of such bridge decks under concentrated loads (wheel loads). Using the actual design codes for the verification of the bearing capacity leads to values suggesting that the safety standards are not met. However, since the bridge decks are laterally restrained by the supporting beams it is expected that compressive membrane action (CMA) exists in such deck slabs, and that the transverse prestressing of the deck slab in combination with CMA will enhance the bearing capacity, making thinner deck slabs possible with no problems of serviceability and structural safety. This thesis begins with an introduction to the research topic, listing briefly the background and the objectives, and concluding with the research strategy. A literature review regarding the punching shear capacity of transversely prestressed concrete decks and compressive membrane action has also been carried out. First, the general mechanism of punching shear and compressive membrane action is explained along with the relevant analysis methods and code provisions and then important experimental investigations done on prestressed deck slabs are briefly described. It is concluded that there is a need to investigate the bearing capacity of transversely prestressed concrete deck slabs supported by and connected to concrete girders using a large scale model since most of the past research is either done on concrete decks with steel girders or on small scale models. In order to investigate the research problem experimentally, laboratory tests on a 1:2 scale bridge model of a real bridge in the Netherlands have been performed. The model bridge consisted of a thin, transversely prestressed concrete deck (with unbonded tendons), cast in-situ between the flanges of long prestressed concrete girders. Prestressed transverse beams were also provided close to either end of the bridge deck. The interface between the deck slab and the girder flanges was either straight or skewed and two types of loads were applied: single and double. Loads were applied at midspan and close to the deck slab-girder flange interface. All the tests showed failure in punching shear (either brittle punching or flexural punching) regardless of the type and position of the load. Failure always occurred in the span of the slab, whereas the interface remained undamaged. The effect of various parameters, like the transverse prestressing level (TPL), the type and position of the load(s), the inclination of the joint (interface), the size of the loading plate etc., on the bearing capacity were also studied. As part of the numerical investigation, a 3D solid, 1:2 scale model of the real bridge, similar to the experimental model, was developed in the finite element software DIANA and several nonlinear analyses were carried out. A comparison with the experimental results was made proving that satisfactory results were obtained that validated the finite element model. The normal forces arising from compressive membrane action were determined with the help of composed elements. A detailed parametric study was also carried out involving numerical modeling parameters, like the mesh size, displacement-load step size etc., and the material and geometrical parameters, similar to the experimental parametric study. In addition to that, the size effect was studied by carrying out a nonlinear analysis on a 3D solid model of the real bridge, showing that a size factor of 1.2 is appropriate to convert the results of the model bridge deck with 100 mm thickness to those for the real bridge deck with a thickness of 200 mm. A theoretical analysis of the model bridge deck was then carried out and it was demonstrated that the ultimate load carrying capacity as found from the experiments and the finite element analysis was much higher than predicted by governing codes and theoretical methods. The discrepancy was attributed to the lack of consideration of CMA in the theoretical approaches. In order to incorporate CMA in the analysis, the normal forces arising from compressive membrane action and determined via the finite element analysis were used in the fib Model Code 2010 punching shear provisions (based on the Critical Shear Crack Theory) to determine the ultimate bearing (punching shear) capacity. Calculations were performed at two Levels-of-Approximation (LoA); Elementary LoA (without CMA) and Advanced LoA (with CMA). Generally, it was observed that an increase in the TPL improved the behavior of the bridge deck with regard to both serviceability and ultimate limit state. An average safety factor of 3.25 was obtained when the projected model bridge design capacity and the real bridge design capacity were compared with the design wheel load. It can be concluded that the existing bridges still have sufficient residual bearing capacity considering the beneficial effect of CMA. Moreover it was shown that appropriate nonlinear finite element models can predict the load bearing capacity quite accurately. The research described in this thesis, resulting in methods for the analysis of bridge decks including compressive membrane action, has the potential to result in considerable cost savings, since the models are able to demonstrate that many existing bridge decks are safe enough, contrary to earlier expectations. A proposal has been prepared to introduce the effect of compressive membrane action into the calculation models for punching shear offered in the fib Model Code for Concrete Structures 2010. To this end two more Levels of Approximation are added to the first three given already in the code. The new level IV enables the use of the Critical Shear Crack Theory in combination with the calculation of the curvature of the area around the concentrated load with a nonlinear finite element analysis using shell elements. The level V enables the prediction of the punching shear capacity with a tailored NLFE-program using composed elements.

Abstract: Hybrid reinforcement for concrete bridge-deck slabs is being investigated through a collaboration project between the Ministry of Transportation of Quebec (MTQ) and the University of Sherbrooke. This paper presents design concepts, construction details, and results of live-load field tests of the twin hybrid-reinforced bridges (P-15502N and P-15502S) on Sainte Catherine Road in Sherbrooke, Quebec (Canada). These hybrid-reinforced slab-on-girder bridges are simply supported over a single span of 43,415 mm. Their 200-mm-thick concrete deck slabs are continuous over four spans of 2,650 mm each, with an average overhang of about 1,000 mm on both sides (measured perpendicular to the girder axis). The deck slabs were reinforced with glass fiber–reinforced polymer (GFRP) reinforcing bars in the top mat and with galvanized steel bars in the bottom mat. One of the two bridges (P-15502S) was instrumented with fiber-optic sensors (FOSs) in the bridge-deck slab (over and between the girders). The instrumented...

Abstract: A treadmill may comprise a base and a deck comprising a treadbelt. A front of the deck may be rotatably coupled to the base, and the deck may be rotatable between an operating position and a storage position. A front deck height adjustment mechanism may be located at a front portion of the deck, and a rear deck height adjustment mechanism may be located at a rear portion of the deck.

Abstract: The state-of-the-art of fiber-reinforced polymer (FRP) composite stay-in-place (SIP) structural form systems for bridge decks is presented in this paper. This technique involves constructing a concrete deck whereby prefabricated FRP components act as both the permanent formwork and the bottom flexural reinforcement. The advantages and limitations of the technology are presented, along with the current progress of experimental and analytical investigations. Extensive laboratory investigation is presented covering numerous aspects of the system, including strength, fatigue, and environmental performance. A variety of system configurations are discussed. Examples of field applications are presented, along with evaluations of cost effectiveness and inspection considerations. The result of these investigations show that FRP SIP formwork systems can be both constructible and meet applicable code requirements for strength and serviceability. Preliminary cost assessments suggest that increases in material costs can be partially offset by savings in labor during installation. Finally, future research needs are identified.

Abstract: A Longitudinal opening is used to construct hollow core beam is a cast in site or precast or pre stressed concrete member with continuous voids provided to reduce weight, cost and, as a side benefit, to use for concealed electrical or mechanical runs. Primarily is used as floor beams or roof deck systems. This study investigate the behavior of six beams (solid or with opening) of dimension (length 1000 x height 180 x width120mm) simply support under partial uniformly distributed load, four of these beam contain long opening of varied section (40x40mm) or (80x40mm). The effect of vertical steel reinforcing, opening size and orientations are investigated to evaluate the response of beams. The experimental behavior based on load-deflection measured at central and quarter of tension zones. The experimental test result shows the presence of Hollow decrease the load carrying capacity by about (37.14% to 58.33%) and increased the deflections by about (71.6% for (Hollow ratio 7.4%) to 75.5% for (Hollow ratio 14.8%)) for same applied load compared with solid beams with the same properties. The increase shear steel reinforcing will decrease all the deformations at all stages of loading, but particularly after initial cracking and give enhancement in ultimate load capacity of beams by about 31.5% with increasing the amount of shear steel reinforcing by about 50%. Finally, ductility is increased in all cases under partial uniformly distributed load when hollow ratio decreased by about 50% or increased in shear steel reinforcing by about 50%.

Abstract: As part of an innovation project funded by the FHWA Highways for LIFE program, a full-depth precast, ultrahigh-performance concrete (UHPC) waffle deck panel and appropriate connections suitable for field implementation of waffle decks were developed. After a successful full-scale validation test on a unit consisting of two panels with three types of connections under laboratory conditions, the waffle deck was installed on a replacement bridge in Wapello County, Iowa. The subsequent load testing confirmed the desirable performance of the UHPC waffle deck bridge. With lessons from the completed project and outcomes from a series of simple and detailed finite element analyses of waffle decks, a design guide was developed to help broaden the design and installation of the UHPC waffle deck panel cost-effectively in new and existing bridges. This paper describes the waffle deck design introduced in the guide as it is applied to new bridges. To minimize the cost of this new bridge deck system, information on max...

Abstract: This paper presents extensive temperature measurements obtained during a period of 4 years in an integral solid slab prestressed concrete bridge deck. There is very little experimental information available for this bridge typology. The quality of the measured temperature data are validated by comparing experimentally measured displacements at the ends of the bridge with theoretical displacements determined with the recorded temperature components. The measured temperatures are also compared with common design parameters made considering the specifications for thermal actions proposed by Eurocode 1. The results corroborate that the Eurocode 1 formulations are generally adequate to represent thermal actions on bridges; however, it may need to be complemented to define maximum and minimum temperatures for bridges in locations with daily temperature variations greater than 10°C.

Abstract: The failure of tack coat on orthotropic steel bridge decks is of concern because the loss of bonding ability between layers jeopardizes the deck overlay. This study investigated tack coat failure on an orthotropic steel bridge deck overlay. A field survey on overlay distress was first conducted on a regular double-layered epoxy asphalt concrete overlay to identify the major distresses. A follow-up survey was conducted by using infrared spectroscopy to detect the changes in chemical functional groups that may respond to distress. Contact analysis in a finite element platform was used to analyze the influence of the tack coat on the mechanistic characteristics of the deck overlay. Finally, shear clamps were used to evaluate the shear resistance performance of the tack coat. Comparisons of tack coat materials were made to support maintenance strategies for deck overlays.

Abstract: Cable-stayed bridges are key points in transport networks and at present one of the most challenging structures for the civil engineering community. The integrity of these bridges should be guaranteed even under extremely large earthquakes. This paper begins with a discussion of the advantages of a new non-linear static “Pushover” procedure that includes the three-dimensional contribution of the governing vibration modes. The efficacy and the accuracy of the proposed Pushover in the non-linear seismic analysis of bridges with significant coupling between the towers, deck and cable system is verified. In the second part of this paper, the seismic responses of several cable-stayed bridges have been studied, verifying the influence of the tower shape, cable arrangement and the main span length on the structural behaviour under strong ground motions. Severe damage is identified at critical tower sections by means of extensive non-linear dynamic analyses. Finally, retrofit solutions with viscous dampers (VDs) and yielding metallic dampers (MDs) connecting the deck and the tower in the transverse direction are explored. The proposed connection with dampers effectively prevents yielding of the reinforcement and cracking in the tower legs.

Abstract: The development of hybrid structures is constantly being pushed forward because of the need for more efficient components that incorporate multiple functions. Structural requirements lead to state-of-the-art timber-concrete-composite (TCC) floor systems, which consist of a concrete layer on top of timber beams or decks. In bending, the TCC concrete layer is in compression and the timber is in tension. When multifunctionality requirements such as building physics or fire protection are added, other solutions of the structural form of hybrid systems can emerge that challenge common engineering conceptions. This paper presents research on the connection system of a novel TCC setup that integrates thermal and fire protection functionality, in which timber beams are placed at the top and a concrete layer at the bottom. The results from full-scale bending tests, and shear and tension tests on a subsection of the system, show that the grooves cut into the timber beams transmit the shear forces and sufficiently connect the concrete deck vertically to the timber. Subsequently, the structural behavior was numerically modeled and the agreement between experimental and numerical results allow for the validated model to be used for geometric optimizations, and predicting the performance of optimized systems.

Abstract: Concrete bridge decks overlaid with asphalt wearing courses often witness early distresses, such as shoving, potholes, raveling, and slippage cracking resulting from poor bonds between the two layers with different modulus. Frequently used laboratory tests, including direct shear test, pull-off test, and torsional shear test, can not fully represent the critical conditions happening in the fields. In this study, a shear fatigue test under repetitive loads at an angle of 45° was developed instead. Three tack coat materials, including styrene–butadiene–styrene-modified asphalt, emulsified asphalt, and epoxy resin, were chosen as binding materials to form multilayer deck pavement specimens. Their performances were evaluated through shear fatigue test on a universal test machine. The shear stress and shear displacement of each specimen at failure were first identified, and then four levels of stress were selected to perform the shear fatigue test, based on which a fatigue prediction model was develope...