Experimental investigation of the role of reinforcement in the strength of concrete deck slabs

2000 ◽  
Vol 27 (3) ◽  
pp. 475-480 ◽  
Author(s):  
O Shervan Khanna ◽  
Aftab A Mufti ◽  
Baidar Bakht
Keyword(s):  
Steel Reinforcement ◽  
Scale Model ◽  
Transverse Reinforcement ◽  
Deck Slabs ◽  
Steel Bars ◽  
Failure Loads ◽  
Transverse Steel ◽  
Concrete Deck ◽  
Deck Slab

To study systematically the role of each layer of steel reinforcement in conventionally reinforced deck slabs of girder bridges, a full-scale model was built of a 175 mm thick concrete deck slab on two steel girders with a center-to-center spacing of 2.0 m. The 12 m long deck slab was conceptually divided into four 3 m long segments, identified as segments A, B, C, and D. Segment A contained isotropic steel reinforcement in two layers, conforming to the requirements of the Ontario Highway Bridge Design Code (OHBDC). Segment B contained only the bottom layer of steel reinforcement. Segment C contained only the bottom transverse steel bars. Segment D contained only bottom transverse glass fibre reinforced polymer (GFRP) bars having the same axial stiffness, but 8.6 times the axial tensile strength, as those of the steel bars in segment C. Each segment of the deck slab was tested to failure under a central concentrated load, simulating the dual tire footprint of 250 × 500 mm dimension of a typical commercial vehicle. All segments failed in the punching shear mode. The failure loads for the four segments were found to be 808, 792, 882, and 756 kN, respectively; these failure loads are similar in magnitude to that of a 175 mm thick steel-free deck slab with steel straps having nearly the same cross-sectional area per metre length of the slab as those of the bottom transverse steel bars in the first three segments. The tests on the four segments of the full-scale model have confirmed that (i) only the bottom transverse reinforcement influences the load carrying capacity of a reinforced concrete deck slab and (ii) the stiffness of the bottom transverse reinforcement, rather than its strength, is of paramount importance.Key words: arching, deck slab, FRP, shake down, slab-on-girder bridge.

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.

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.

Experimental investigation of fibre-reinforced concrete deck slabs without internal steel reinforcement

1993 ◽  
Vol 20 (3) ◽  
pp. 398-406 ◽  
Author(s):  
Aftab A. Mufti ◽  
Leslie G. Jaeger ◽  
Baidar Bakht ◽  
Leon D. Wegner
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Steel Reinforcement ◽  
Punching Shear ◽  
Fibre Reinforced Concrete ◽  
Reinforced Concrete Slab ◽  
Shear Connectors ◽  
Deck Slabs ◽  
Concrete Deck ◽  
Deck Slab

It is now well established that concrete deck slabs of slab-on-girder bridges subjected to concentrated loads develop an internal arching system provided that certain conditions of confinement of the concrete are met. Because of this arching system, the deck slab, being predominantly in compression, fails in punching shear rather than in flexure. This aspect of deck slab behaviour, coupled with the corrosion problems associated with steel reinforcement in concrete, has prompted the authors to investigate the feasibility of fibre-reinforced concrete decks that are entirely devoid of steel. Through tests on a small number of half-scale models, it has been established that fibre-reinforced concrete slab with inexpensive non-ferrous fibres is indeed feasible, provided that the top flanges of the steel girders are connected just below the deck by transverse steel straps and the concrete deck is joined to the girders and diaphragms by shear connectors. The straps and shear connectors together provide the restraint necessary for development of the internal arching system in the slab, whilst the fibres control cracking due to the effects of shrinkage and temperature in the concrete. This paper describes the exploratory model tests and presents their results. Key words: deck slab, fibre-reinforced concrete, internal arching, punching shear, slab-on-girder bridge.

Fibre-reinforced polymer composite bars for the concrete deck slab of Wotton Bridge

2003 ◽  
Vol 30 (5) ◽  
pp. 861-870 ◽  
Author(s):  
Ehab El-Salakawy ◽  
Brahim Benmokrane ◽  
Gérard Desgagné
Keyword(s):  
Field Test ◽  
Remote Monitoring ◽  
Concrete Bridges ◽  
Fibre Optic ◽  
Reinforced Polymer ◽  
Deck Slabs ◽  
Fibre Reinforced Polymer ◽  
Concrete Deck ◽  
Frp Bars ◽  
Deck Slab

A new concrete bridge in the Municipality of Wotton, Quebec, Canada, was constructed using fibre-reinforced polymer (FRP) bars as reinforcement for the deck slab. The new bridge is a girder type with four main girders simply supported over a span of 30.60 m. One half of the concrete deck slab was reinforced with carbon and glass FRP bars, and the other half with conventional steel bars. The design of the reinforced concrete deck slab was made according to sections 8 and 16 of the new Canadian Highway Bridge Design Code. The bridge was well instrumented at critical locations for long-term internal temperature and strain data collection using fibre optic sensors. The construction of the bridge was completed and the bridge opened for traffic in October 2001. The bridge was then tested for service performance using standard truckloads. Design, construction details, and the results of the field test and 1 year of remote monitoring are discussed. Under the same real service and environmental conditions, very similar behaviour was obtained from the FRP (glass and carbon) and steel bars.Key words: concrete bridges, deck slabs, FRP bars, field test, fibre optic sensors, remote monitoring, serviceability.

scholarly journals NUMERICAL INVESTIGATION OF THE BEARING CAPACITY OF TRANSVERSELY PRESTRESSED CONCRETE DECK SLABS

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Sana Amir ◽  
Cor van der Veen ◽  
Joost Walraven ◽  
Ane de Boer ◽  
Joost C. Walraven
Keyword(s):  
Finite Element ◽  
Prestressed Concrete ◽  
Numerical Models ◽  
Experimental Studies ◽  
Shear Capacity ◽  
Punching Shear ◽  
Scale Model ◽  
Fe Model ◽  
Deck Slabs ◽  
Concrete Deck

The paper investigates the effect of various geometrical and material parameters on the bearing (punching shear) capacity of transversely prestressed concrete deck slabs by numerical methods. Experiments on a 1:2 scale model of such a bridge were carried out in the laboratory and a 3D nonlinear finite element (FE) model was developed in the finite element analysis software package TNO DIANA (2012) to study the structural behavior in punching shear. A comparison of the experimental and numerical ultimate loads show that the non-linear FE models can predict the load carrying capacity quite accurately with a standard deviation of 0.1 and the coefficient of variation of only 10%. The effect of varying the transverse prestressing level, the presence and size of the ducts, size of the loading plate and the concrete class is also described as part of the parametric study. It was observed that sufficient saving in cost could be made if calibrated numerical models are employed to investigate existing structures rather than doing expensive experimental studies.

Finite element investigation of fibre-reinforced concrete deck slabs without internal steel reinforcement

1994 ◽  
Vol 21 (2) ◽  
pp. 231-236 ◽  
Author(s):  
Leon D. Wegner ◽  
Aftab A. Mufti
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Plain Concrete ◽  
Experimental Tests ◽  
Failure Criteria ◽  
Steel Reinforcement ◽  
Nonlinear Finite Element ◽  
Fibre Reinforced Concrete ◽  
Deck Slabs ◽  
Failure Loads

Experimental tests on half-scale models have demonstrated that polypropylene-fibre-reinforced concrete (PFRC) bridge deck slabs completely devoid of conventional steel reinforcement will fail by punching shear under concentrated loads considerably greater than those specified for design, provided the top flanges of the supporting girders are adequately restrained from moving laterally. Similar models were analyzed using nonlinear finite element techniques in order to reproduce experimentally observed load–deflection behaviours and failure loads. Commonly available concrete failure criteria for plain concrete was incorporated into the material model used for the PFRC deck slab. Results of the finite element analyses are presented. It is shown that while predicted load–deflection paths were less than satisfactory, accurate predictions of failure loads were achieved, but only after considerable tuning of various modelling parameters. Key words: nonlinear finite element method, bridge decks, fibre-reinforced concrete.

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.

Seismic Performance of High Titanium Heavy Slag High Strength Concrete Columns

2012 ◽  
Vol 174-177 ◽  
pp. 455-459 ◽  
Author(s):  
Xiao Wei Li ◽  
Xue Wei Li ◽  
Xin Yuan
Keyword(s):  
Reinforced Concrete ◽  
Seismic Performance ◽  
High Strength Concrete ◽  
Load Ratio ◽  
High Strength ◽  
Scale Model ◽  
Transverse Reinforcement ◽  
Reinforced Concrete Column ◽  
Displacement Ductility ◽  
Strength Concrete

For expedite the development of high titanium heavy slag concrete, eight high titanium heavy slag high strength reinforced concrete (HTHS-HSRC) scale model column are studied. The eight HTHS-HSRC model columns are tested under reversed horizontal force. Primary experimental parameters include axial load ratio varying from 0.3 to 0.5, volumetric ratios of transverse reinforcement ranging from 1.38% to 1.56%, strength of high titanium heavy slag high strength concrete varying from 55.9 to 61.6 N/mm2 and configurations of transverse reinforcement. It is found from the test result that HTHS-HSRC model columns provides comparable seismic performance to those usually used reinforced concrete column in terms of member ductility, hysteretic and energy dissipation capacity. Primary Factors of Displacement Ductility of Model Columns are also discussed.

Sign in / Sign up

Export Citation Format

Share Document