Testing in isolation of transverse confining systems for steel-free deck slabs

1998 ◽  
Vol 25 (4) ◽  
pp. 789-796 ◽  
Author(s):  
Baidar Bakht ◽  
Ahmed Aly
Keyword(s):  
Mirror Image ◽  
Axial Stiffness ◽  
Connection Strength ◽  
Girder Bridges ◽  
Pull Out ◽  
Deck Slabs ◽  
Different Types ◽  
Image Models ◽  
Girder Bridge ◽  
Deck Slab

The provisions of the forthcoming Canadian Highway Bridge Design Code are noted for the design of the external transverse confining system for steel-free deck slabs of girder bridges; according to these provisions, the transverse straps comprising the confining system are required to have a certain minimum axial stiffness, and their connection strength with the deck slab is also specified. The axial stiffness of the straps and their connection strength were studied with the help of pull-out tests on mirror-image models of isolated segments of the deck slab and four different types of strap systems. Three of the tested systems were found to be adequate, and the fourth was considered inadequate because of insufficient connection strength.Key words: arching in slabs, cruciform strap, deck slab, girder bridge, partially studded strap, punching shear, steel-free deck slab, transverse confinement.

Revisiting arching in deck slabs

1996 ◽  
Vol 23 (4) ◽  
pp. 973-981 ◽  
Author(s):  
Baidar Bakht
Keyword(s):  
Design Method ◽  
Field Tests ◽  
Scale Model ◽  
Girder Bridges ◽  
Transverse Arch ◽  
Deck Slabs ◽  
Arching Action ◽  
Girder Bridge ◽  
Concrete Deck ◽  
Deck Slab

The arching action in concrete deck slabs of girder bridges is generally recognized and is utilized by the Ontario Highway Bridge Design Code, and some other codes, to specify an empirical design method which leads to considerable savings in the amount of reinforcement. Despite this general recognition, there are some aspects of the arching action that are yet to be explored. To the knowledge of the author, all reported laboratory and field tests on deck slabs exploring its arching action under applied loads have been conducted by measuring strains in the bottom transverse reinforcement midway between the girders. Based on the results of tests on a full-scale model of a deck slab, it has been confirmed in this note that the transverse bottom reinforcement in the deck slab acts as a tie to the internal transverse arch in the slab. Because of embedment in concrete, the force in this reinforcement is the smallest midway between the girders, and not the largest as would be the case if the slab were in pure bending. Key words: arching in slabs, deck slabs, girder bridge, punching shear, steel-free deck slabs.

Investigation of an externally restrained concrete bridge deck slab on a multi-girder bridge model

2011 ◽  
Vol 38 (2) ◽  
pp. 233-241 ◽  
Author(s):  
John Newhook ◽  
Judy Gaudet ◽  
Rahman Edalatmanesh
Keyword(s):  
Bridge Deck ◽  
Single Point ◽  
Point Load ◽  
Concrete Bridge ◽  
Simultaneous Application ◽  
Bridge Model ◽  
Deck Slabs ◽  
Concrete Bridge Deck ◽  
Girder Bridge ◽  
Deck Slab

The steel-free bridge deck system is an innovative solution in which the concrete deck slab is externally restrained by a series of steel straps. The ultimate strength characteristics of externally reinforced concrete bridge deck slabs were investigated in this paper. A 1/3 scale experimental model of a bridge with six girders was constructed for the study. This was the first known set of test results on a bridge model with more than four girders. A single point load, simulating the dual tire print of the CHBDC design truck, was applied at various locations on the deck and loading increased until punching failure occurred. The influence of different parameters including transverse diaphragms, proximity for the load to restraint straps, residual strength after strap removal, and simultaneous application of wheel loads in adjacent panels of the deck was tested to obtain a comprehensive understanding of the resistance of this deck system. The testing results confirmed that the interior panels of the deck have inherently higher punching resistance than the exterior panels. Most significantly, the study provided significant statistical data on the punching resistance of these deck slabs.

Deck slabs of skew girder bridges

1995 ◽  
Vol 22 (3) ◽  
pp. 514-523 ◽  
Author(s):  
Baidar Bakht ◽  
Akhilesh C. Agarwal
Keyword(s):  
Reinforced Concrete ◽  
Cross Section ◽  
Shear Failure ◽  
Highway Bridges ◽  
Steel Reinforcement ◽  
Fibre Reinforced Concrete ◽  
Girder Bridges ◽  
Deck Slabs ◽  
Concrete Deck ◽  
Deck Slab

Canadian codes allow the design of concrete deck slabs of slab-on-girder bridges by taking account of the internal arching action that develops in these slabs under concentrated wheel loads in particular. Provided that certain prescribed conditions are met, a deck slab is deemed to have met the design criteria if it is provided with a top and a bottom layer of steel reinforcement with each layer consisting of an orthogonal mesh of steel bars in which the area of cross section of the bars in each direction is at least 0.3% of the effective area of cross section of the deck slab. For deck slabs of bridges having skew angles greater than 20°, the codes require the minimum amount of reinforcement to be doubled in the end zones near the skew supports. Model testing has shown that need for such an increase can be eliminated by providing composite end diaphragms with high flexural rigidity in the horizontal plane. The proposed concept is tested on a model of fibre-reinforced concrete deck without steel reinforcement in which deficiencies in the confinement of the deck slab readily manifest themselves in form of a bending, rather than punching shear, failure. Key words: highway bridges, bridge decks, deck slabs, skew deck, skew bridges, fibre-reinforced concrete decks.

scholarly journals Analysis of Deck Slab of Reinforced Concrete Gerber-Girder Bridge Widened by Addition of Continuous Steel-Concrete Composite Girders

2019 ◽  
Vol 14 (2) ◽  
pp. 271-284
Author(s):  
Wojciech Siekierski
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Bending Moment ◽  
Continuous Steel ◽  
Bending Moments ◽  
Girder Bridges ◽  
Concrete Girders ◽  
Moment Distribution ◽  
Girder Bridge ◽  
Deck Slab

Many Gerber-girder bridges have become obsolete in terms of deck width and load carrying capacity. If bridge replacement is not necessary, additional girders are installed. Sometimes, due to erection convenience, the added girders do not replicate the static scheme of the refurbished structure. Such an arrangement requires special attention to preserve structural durability. An example of the inappropriate arrangement of the widening of a Reinforced Concrete Gerber-girder road bridge is presented together with an alternative concept of refurbishment based on the addition of the continuous steel-concrete girders as the outermost ones. The added deck slab connects the added and the existing parts of the structure. Attention is drawn the static analysis of the added deck slab and the influence of the added outermost girders that do not replicate the static scheme of the existing ones. Due to different static schemes of the existing and the added girders, the traditional method of the deck slab analysis is inappropriate. The Finite Element 3D model is to be applied to access bending moments in the deck slab spans correctly. It is shown that: a) the analysis of the distribution of the bending moments in the existing and the added slab spans, especially near Gerber-hinges, should be based on the Finite Element 3D modelling; b) the analysis should consider live loads acting on the whole width of the Gerber-hinge span; c) the bending moment distribution in the widened deck slab is sensitive to the distance to the Gerber hinge.

scholarly journals Experimental Investigation on Composite Deck Slab Made of Cold-Formed Profiled Steel Sheeting

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 229
Author(s):  
Siva Avudaiappan ◽  
Erick I. Saavedra Flores ◽  
Gerardo Araya-Letelier ◽  
Walter Jonathan Thomas ◽  
Sudharshan N. Raman ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Test Results ◽  
Shear Connectors ◽  
Modes Of Failure ◽  
Deck Slabs ◽  
Load Carrying ◽  
Composite Slabs ◽  
Ultimate Load Carrying Capacity ◽  
Ductility Ratio ◽  
Deck Slab

An experimental investigation is performed on various cold-formed profiled sheets to study the connection behavior of composite deck slab actions using bolted shear connectors. Various profiles like dovetailed (or) re-entrant profiles, rectangular profiles and trapezoidal profiles are used in the present investigation. This experimental investigation deals with the evaluation of various parameters such as the ultimate load carrying capacity versus deflection, load versus slip, ductility ratio, strain energy and modes of failure in composite slab specimens with varying profiles. From the test results the performance of dovetailed profiled composite slabs’ resistance is significantly higher than the other two profiled composite deck slabs.

Study on Crack Causes and Strengthening Measures of Large Span PC Continuous Box Girder Bridges

2010 ◽  
Vol 163-167 ◽  
pp. 3551-3554
Author(s):  
Wei Peng ◽  
Zhi Xiang Zha
Keyword(s):  
Prestressed Concrete ◽  
Load Test ◽  
Box Girder Bridges ◽  
Element Analysis ◽  
Box Girder ◽  
Girder Bridges ◽  
Long Span ◽  
Concrete Box Girder Bridges ◽  
Girder Bridge ◽  
Engineering Projects

This template Based on cracks observation and finite element analysis of real engineering projects as well as bridge load test after reinforcement, causes and types of cracks in prestressed concrete box girder bridges and treating measurements are systematically studied. The results obtained from the calculation are presented to demonstrate the effect of sensitive factors, such as arrangement of longitudinal prestressed tendons, the magnitude of vertical prestressed force, temperature gradient, etc. The results show that the arrangement of longitudinal prestressed tendons and the magnitude of vertical prestressed force take key roles in cracks control of box girder webs. Lots of treating measurements are presented in accordance with different types of cracks, some of them are applied to a reinforcement engineering of a long span pretressed concrete continuous box girder bridge with cracks. Load test after reinforcement of the bridge demonstrates the reasonability of the treating measurements. Several design recommendations and construction measures about reinforcements and some sensitive factors mentioned above are proposed to control cracks.

Vibration Analysis of the Continuous Truss Girder Bridge by the Finite Truss Elements

2011 ◽  
Vol 268-270 ◽  
pp. 557-560
Author(s):  
Shi Ruo Yang
Keyword(s):  
Composite System ◽  
Elastic System ◽  
Total Potential Energy ◽  
Time Varying ◽  
Girder Bridges ◽  
Total Potential ◽  
Vibration Responses ◽  
Pass Through ◽  
Girder Bridge ◽  
Set Up

The train and the continuous truss girder bridge are coupled together as one composite system. Truss girder bridge is idealized as an assemblage of finite truss element. The equations of the train and truss girder bridges time varying system are set up by using the principle of total potential energy with stationary value in elastic system dynamics and the“set-in-right-position”rule for forming structural matrices. This method is more convenient than the finite elements. The vibration responses of the train and bridge are calculated when the the passenger trains pass through a continuous truss girder bridge at speeds of 90km/h and 120km/h The results show that the passenger train can pass it safely and comfortably

Analytical study on repair method for steel I-girder bridges with corrosion damage considering its structural system behavior

2021 ◽  
Author(s):  
Ryoga Oura ◽  
Takashi Yamaguchi ◽  
Kentaro Arimura
Keyword(s):  
Carrying Capacity ◽  
Corrosion Damage ◽  
Load Carrying Capacity ◽  
Structural Members ◽  
Structural System ◽  
System Behavior ◽  
Girder Bridges ◽  
Load Carrying ◽  
Girder Bridge ◽  
The Individual

<p>Bridges are composed by many structural members which interact with each other to resist against various load combinations. Considering damage repair of one of its structural members, the relationship between the recovery of the individual load-carrying capacity due to the repair of a single member and the improvement of the load-carrying capacity of the structural system is not clear. In the present study, a full-scale FE analysis has been conducted for a steel I-girder bridge system with corrosion damages which have been repaired. The analysis considered, the structural system behavior, varying the repaired areas and the type of patch members. From the analytical results, it was found that, compared to the method in which the damaged portion is completely repaired, the amount of repair can be reduced by taking into account the structural system behavior and partially repair both the damaged and the adjacent intact girders.</p>

Assessment and identification of concrete box-girder bridges

2019 ◽  
Author(s):  
Edward A. Baron
Keyword(s):  
Neural Network ◽  
Health Monitoring ◽  
Concrete Bridge ◽  
Fe Model ◽  
Box Girder Bridges ◽  
Box Girder ◽  
Damage Scenarios ◽  
Girder Bridges ◽  
Concrete Box Girder Bridges ◽  
Girder Bridge

<p>This work consists in identify and assess the properties related to material, geometry and physic sources, in a pre-stressed concrete bridge through a surrogate model. The use of this mathematical model allows to generate a relationship between bridge properties and its dynamic response, with the purpose to develop a tool to predict the analytical values of the studied properties from measured eigenfrequencies. Therefore, it is introduced the identification of damage scenarios, giving the application for validate the generated metamodel (Artificial Neural Network). A FE model is developed to simulate the studied structure, a Colombian bridge called "El Tablazo", one of the higher in the country of this type (box-girder bridge). Once the damage scenarios are defined, this work allows to indicate the basis for futures plans of structural health monitoring.</p>

Research of the Load Bearing Capacity of Shape-Optimized Metal Inserts Embedded in CFRP under Different Types of Stresses

2017 ◽  
Vol 742 ◽  
pp. 636-643 ◽  
Author(s):  
Florentin Pottmeyer ◽  
Markus Muth ◽  
Kay André Weidenmann
Keyword(s):  
Bearing Capacity ◽  
Residual Strength ◽  
High Speed ◽  
Systematic Research ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Temperature Cycles ◽  
Pull Out ◽  
Different Types ◽  
Impact Energies

An efficient implementation of lightweight design is the use of continuous carbon fiber reinforced plastics (CFRP) due to their outstanding specific mechanical properties. Embedded metal elements, so-called inserts, can be used to join metal-based attachments to structural CFRP parts in the context of multi-material design. They differ from other mechanical fasteners and have distinctive benefits. In particular, drilling of the components to be joined can be avoided and, depending on the preforming, fiber continuity can be maintained using such elements. Thus, no local bearing stress is anticipated. Previous work published by the authors [1] dealt with a systematic research of the influence of different types of stresses on the load bearing capacity of welded inserts. This contribution aims at the investigation of the performance of shape-optimized inserts under the same types of loading to compare with the results of the welded inserts serving as a reference. For that purpose, the respective load bearing capacities were evaluated after preinduced damages from impact tests and thermal cycling. In addition, dynamic high-speed tensile tests (pull-out) were conducted under different loading velocities. It is shown that the load bearing capacities increased up to 19% for high velocities (250 mm/s) in comparison to quasi-static loading conditions (1.5 mm/min) showing an obvious strain rate dependency of the CFRP. Quasi-static residual strength measurements under tensile loading identified the influence of the respective preinduced damages of the insert. Influence of the thermal loading condition was evaluated by placing the specimens in a climate chamber and exposing it to various numbers of temperature cycles from-40 °C to +80 °C with a duration time of 1.5 hours each. Here, it turned out that already 10 temperature cycles decreased the quasi-static load bearing capacity up to 31%. According to DIN EN 6038 the specimens were loaded with different impact energies and the residual strength were measured carrying out pull-out tests. It could be shown that the damage tolerance is significantly lower for the shape-optimized insert due to failure-critical delamination. The optimized insert also endured lower impact energies and the influence on the performance was higher.

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