scholarly journals RESIDUAL STRENGTH AND POST-CRACKING BEHAVIOUR OF GLASS WOOL FIBRE-REINFORCED CONCRETE EMBEDDED WITH STEEL REINFORCEMENT

2020 ◽  
Author(s):  
Olutoge Festus ◽  
Ogundeji Oluwaseun
Keyword(s):  
Reinforced Concrete ◽  
Residual Strength ◽  
Glass Wool ◽  
Steel Reinforcement ◽  
Wool Fibre ◽  
Fibre Reinforced Concrete

scholarly journals Performance of ultra-high performance fibre reinforced concrete plates under impact loads

2021 ◽  
Author(s):  
Hesham Othman
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Fracture Energy ◽  
High Performance ◽  
Steel Reinforcement ◽  
Fibre Content ◽  
Fibre Reinforced Concrete ◽  
Concrete Plates ◽  
High Performance Fibre

The next generation of concrete, Ultra-High Performance Fibre Reinforced Concrete (UHP-FRC), exhibits exceptional mechanical characteristics. UHP-FRC has a compressive strength exceeding 150 MPa, tensile strength in the range of 8-12 MPa, and fracture energy of several orders of magnitudes of traditional concrete. The focus of this research is to investigate and analyze the advantage of using UHP - FRC in impact resistance structures. To achieve these goals, two experimental testing programs and major numerical investigations have been conducted. The material experimental investigation has been conducted to determine the effects of strain rate on UHP - FRC. Two parameters are investigated, namely: compressive strength (80, 110, 130, and 150 MPa); and steel fibre content (0, 1, 2, and 3%). Experimental results showed that the rate sensitivity decreases with the increase in the compressive strength ; and the dynamic enhancement of tensile strength is inversely proportional to the fibre content. The structural impact testing program focuses on the dynamic response of full - scale reinforced concrete plates as well as generating precise impact measurements. Twelve reinforced plates with identical dimensions are tested under high-mass low-velocity multi-impacts. The investigated parameters include: concrete type (NSC, HSC, and UHP - FRC), fibre volume content, and steel reinforcement ratio. The results showed that the use of UHP -FRC instead of NSC or HSC is able to change the failure mode from punching to pure flexural; and UHP -FRC containing 3% fibre has superior dynamic properties. For plates with identical steel reinforcement, the total impact energy of UHP-FRC plate containing 3% fibres is double the capacity of UHP - FRC plate containing 2% fibres , and 18 times the capacity of NSC plate. A three-dimensional finite element analysis has been performed using ABAQUS/Explicit to model multi-impacts on RC plates and the applicability is verified using existing experimental data. Concrete damage plasticity (CDP) model is adapted to define UHP - FRC. The CDP constitutive model parameters for the new material are calibrated through a series of parametric studies. Computed responses are sensitive to CDP parameters related to the tension, fracture energy, and expansion properties. The analytical results showed that the existing CDP model can predict the response and crack pattern of UHP - FRC reasonably well.

scholarly journals Experimental investigation of cracking behaviour of concrete beams reinforced with steel fibres produced in Lithuania

2017 ◽  
Vol 12 (2) ◽  
pp. 82-87 ◽  
Author(s):  
Adas Meškėnas ◽  
Viktor Gribniak ◽  
Gintaris Kaklauskas ◽  
Aleksandr Sokolov ◽  
Eugenijus Gudonis ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Residual Strength ◽  
Steel Fibre ◽  
Concrete Beams ◽  
Full Scale ◽  
Reinforced Concrete Beams ◽  
Fibre Reinforced Concrete ◽  
Structural Behaviour ◽  
Steel Fibre Reinforced Concrete ◽  
Straightforward Application

Concrete is the most widely used material for bridge structures in Lithuania. A case study performed by the authors revealed that application of fibres might improve serviceability of such structures. However, adequacy of prediction of the post-cracking behaviour of steel fibre reinforced concrete might be insufficient. The latter issue is closely related to the assessment of the residual strength of steel fibre reinforced concrete. The residual strength, in most cases, is considered as a material property of the cracked concrete. However, in the prediction of the structural behaviour of the concrete members with bar reinforcement, a straightforward application of the residual strength values assessed by using standard techniques might lead to incorrect results. The present study deals with the post-cracking behaviour of structural elements made of concrete with aggregates and fibres provided by Lithuanian companies. Test results of three full-scale and sixteen standard steel fibre reinforced concrete beams with two different content of fibres (23.6 kg/m3 and 47.1 kg/m3) are presented. The full-scale beams were reinforced with high-grade steel bars. Effectiveness of the application of the minimum content of the fibres in combination with bar reinforcement was revealed experimentally.

scholarly journals Flexural Capacity Prediction Model For Steel Fibre-Reinforced Concrete Beams

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Aocheng Zhong ◽  
Massoud Sofi ◽  
Elisa Lumantarna ◽  
Zhiyuan Zhou ◽  
Priyan Mendis
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Prediction Model ◽  
Steel Fibre ◽  
Concrete Beams ◽  
Steel Reinforcement ◽  
Reinforced Concrete Beams ◽  
Fibre Reinforced Concrete ◽  
Steel Fibre Reinforced Concrete ◽  
Conventional Steel

AbstractSteel fibre (SF) reinforcement has been shown to improve the ductility of high strength concrete (HSC), which is known to be brittle. Research conducted to date on steel fibre reinforced concrete and its effects have emphasised post-failure performance and cracking mechanism. The difficulty in predicting the behaviour of fibres is due to the randomly distributed nature of the material within the matrix leading to a probability distribution of results. Published literature has shown a benefit of adding steel fibres in terms of the ductility performance of structures. Clearly, there is a potential for such material as replacement of conventional steel reinforcement. This study proposes a theoretical model of evaluating the potential of using steel fibres as a replacement material to conventional steel reinforcement bars based on the case study, laboratory and theoretical methodologies. The compressive strength of the concrete at key dates, the effective fibre cross-sectional were measured, and a prediction model was created based on the measurement parameters. The use of four-point flexural testing, standard compressive testing and software image modelling provided the study with relevant data used to analyse and compare to the prediction. Greater ductility performance and toughness were observed with increased fibre volumes, confirming proposed predictions and conclusion drawn from published literature. No consistent or conclusive correlations between fibre volumes and the compressive strength of concrete were found. A relationship between fibre volumes and predicted moment capacities of steel fibre reinforced concrete beams was found based on the proposed theoretical flexural analysis method.

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.

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