Strength of hollow circular steel sections filled with fibre-reinforced concrete

2000 ◽  
Vol 27 (2) ◽  
pp. 364-372 ◽  
Author(s):  
Giuseppe Campione ◽  
Sidney Mindess ◽  
Nunzio Scibilia ◽  
Gaetano Zingone
Keyword(s):  
Reinforced Concrete ◽  
Plain Concrete ◽  
Fibre Reinforced Concrete ◽  
Steel Columns ◽  
Different Types ◽  
European Code ◽  
Steel Sections ◽  
Normal Strength ◽  
The Moment ◽  
Standard Tests

The strength of hollow circular steel sections filled with normal-strength plain concrete and fibre-reinforced concrete (FRC) was evaluated. First, the case of centrally loaded composite members was considered and the bearing capacity of the columns was calculated using the methods proposed by a European code (EC4) and an American code (LRDF). Some expressions in these codes were validated for the case of FRC by adapting experimental data to introduce the mechanical properties of the FRC. To do this, experimental results of standard tests on FRC (compression and splitting tension) were used as well as data on circular steel columns filled with 2% FRC by volume with different types of fibres (steel, polyolefin). Second, the moment - axial force diagrams for composite members, taking into account the residual tensile strength of FRC, were calculated, showing the advantages of using FRC compared with plain concrete for filling hollow steel sections.Key words: fibre-reinforced concrete, hollow steel columns, composite members, steel fibres, polyolefin fibres.

Fibre Reinforced Concrete Class Control via Fib Model Code 2010 Approach

2015 ◽  
Vol 1119 ◽  
pp. 672-676
Author(s):  
Vladimir E. Rusanov
Keyword(s):  
Reinforced Concrete ◽  
Synthetic Fibre ◽  
Wide Spectrum ◽  
Basic Research ◽  
Plain Concrete ◽  
Fibre Reinforced Concrete ◽  
New Approach ◽  
Model Code ◽  
Different Types ◽  
Model Code 2010

Fibre reinforced concrete (FRC) has wide spectrum of advantages in tunnelling. Post-cracking behaviour of FRC wasn’t taken into account by Russian engineers while structural design led to underestimation of material abilities. New approach is based on fib Model Code 2010, which provides residual tensile strength Class of FRC. Research Center “FRC” (http://rcfrc.com/) carried out tests with specimens of different types of FRC, which supported by Russian Foundation for Basic Research. Research involved different specimens – plain concrete and FRC with macro-synthetic fibre of different dosage and types. The results showed the efficiency of each type of fibre. The Class of FRC was defined for each specimen series according to results.

scholarly journals Fracture and Size Effect of PFRC Specimens Simulated by Using a Trilinear Softening Diagram: A Predictive Approach

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3795
Author(s):  
Fernando Suárez ◽  
Jaime C. Gálvez ◽  
Marcos G. Alberti ◽  
Alejandro Enfedaque
Keyword(s):  
Reinforced Concrete ◽  
Size Effect ◽  
A Priori ◽  
Plain Concrete ◽  
Specimen Size ◽  
Bending Test ◽  
Orientation Factor ◽  
Fibre Reinforced Concrete ◽  
Softening Function ◽  
Three Point Bending

The size effect on plain concrete specimens is well known and can be correctly captured when performing numerical simulations by using a well characterised softening function. Nevertheless, in the case of polyolefin-fibre-reinforced concrete (PFRC), this is not directly applicable, since using only diagram cannot capture the material behaviour on elements with different sizes due to dependence of the orientation factor of the fibres with the size of the specimen. In previous works, the use of a trilinear softening diagram proved to be very convenient for reproducing fracture of polyolefin-fibre-reinforced concrete elements, but only if it is previously adapted for each specimen size. In this work, a predictive methodology is used to reproduce fracture of polyolefin-fibre-reinforced concrete specimens of different sizes under three-point bending. Fracture is reproduced by means of a well-known embedded cohesive model, with a trilinear softening function that is defined specifically for each specimen size. The fundamental points of these softening functions are defined a priori by using empirical expressions proposed in past works, based on an extensive experimental background. Therefore, the numerical results are obtained in a predictive manner and then compared with a previous experimental campaign in which PFRC notched specimens of different sizes were tested with a three-point bending test setup, showing that this approach properly captures the size effect, although some values of the fundamental points in the trilinear diagram could be defined more accurately.

scholarly journals Comparison of Mechanical Properties of Normal and Fibre Reinforced Concrete (Grade M15)

2019 ◽  
Vol 5 ◽  
pp. 153-164
Author(s):  
Sagar Bista ◽  
Sagar Airee ◽  
Shikshya Dhital ◽  
Srijan Poudel ◽  
Sujan Neupane
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Steel Fibre ◽  
Residential Buildings ◽  
Fibre Reinforced Concrete ◽  
Cement Concrete ◽  
Normal Concrete ◽  
Steel Fibre Reinforced Concrete ◽  
Cracking Control ◽  
Different Types

Concrete is weak in tension, hence some measures must be adopted to overcome this deficiency as well as to enhance physical and other mechanical properties but in more convenient and economical method. Through many research from the past, it has been observed that addition of different types of fibres has been more effective for this purpose. This report presents the work undertaken to study the effect of steel and hay fibre on normal cement concrete of M-15 Grade on the basis of its mechanical properties which include compressive and tensile strength test and slump test as well. Although hay fibres are abundantly available in Nepal, no research have been popularly conducted here regarding the use of hay fibres in concrete and the changes brought by it on concrete’s mechanical properties. Experiments were conducted on concrete cubes and cylinders of standard sizes with addition of various percentages of steel and hay fibres i.e. 0.5%, 1% and 1.5% by weight of cement and results were compared with those of normal cement concrete of M-15 Grade. For each percentage of steel and hay fibre added in concrete, six cubes and six cylinders were tested for their respective mechanical properties at curing periods of 14 and 28 days. The results obtained show us that the optimum content of fibre to be added to M-15 grade of concrete is 0.5% steel fibre for compression and 0.5% hay fibre content for tension by weight of cement. Also, addition of steel and hay fibres enhanced the binding properties, micro cracking control and imparted ductility. In addition to this, two residential buildings were modeled in SAP software, one with normal concrete and other with concrete containing 0.5% steel fibre. Difference in reinforcement requirements in each building was computed from SAP analysis and it was found that 489.736 Kg of reinforcement could be substituted by 158.036 kg of steel fibres and decrease in materials cost of building with 0.5% steel fibre reinforced concrete was found to be Rs. 32,100.

Tensile basic creep versus compressive basic creep at early ages: comparison between normal strength concrete and a very high strength fibre reinforced concrete

2013 ◽  
Vol 47 (10) ◽  
pp. 1773-1785 ◽  
Author(s):  
Pierre Rossi ◽  
Jean Philippe Charron ◽  
Maléna Bastien-Masse ◽  
Jean-Louis Tailhan ◽  
Fabrice Le Maou ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
High Strength ◽  
Basic Creep ◽  
Fibre Reinforced Concrete ◽  
Normal Strength Concrete ◽  
Strength Concrete ◽  
Normal Strength ◽  
Very High

Application of Cement Based Materials for Critical Infrastructure Protection

2015 ◽  
Vol 796 ◽  
pp. 99-110
Author(s):  
Jiří Štoller ◽  
Petr Dvořák
Keyword(s):  
Reinforced Concrete ◽  
High Performance ◽  
Critical Infrastructure ◽  
Field Tests ◽  
Plain Concrete ◽  
Lessons Learned ◽  
Fibre Reinforced Concrete ◽  
Critical Infrastructure Protection ◽  
Infrastructure Protection ◽  
Cement Based Materials

The article describes the characteristics of a selected cement based materials and the possibilities of their use for critical infrastructure protection. The material properties were studied during field tests on slabs made from different materials – plain concrete, fibre reinforced concrete and high performance fibre reinforced concrete. In the article there are also presented lessons-learned of the research team of the military structures laboratory, which is run by the Department of Engineer Technologies at the University of Defence.

scholarly journals Shear Behaviour of RC Beams Strengthened by Various Ultrahigh Performance Fibre-Reinforced Concrete Systems

2020 ◽  
Vol 2020 ◽  
pp. 1-18 ◽  
Author(s):  
Walid Mansour ◽  
Bassam A. Tayeh
Keyword(s):  
Reinforced Concrete ◽  
Mechanical Performance ◽  
Experimental Studies ◽  
Element Model ◽  
Shear Behaviour ◽  
Fibre Reinforced Concrete ◽  
Rc Beams ◽  
Shear Span ◽  
Depth Ratio ◽  
Normal Strength

This study presents a numerical investigation on the shear behaviour of shear-strengthened reinforced concrete (RC) beams by using various ultrahigh performance fibre-reinforced concrete (UHPFRC) systems. The proposed 3D finite element model (FEM) was verified by comparing its results with those of experimental studies in the literature. The validated numerical model is used to analyse the crucial parameters, which are mainly related to the design of RC beams and shear-strengthened UHPFRC layers, such as the effect of shear span-to-depth ratio on the shear behaviour of the strengthened or nonstrengthened RC beams and the effect of geometry and length of UHPFRC layers. Moreover, the effect of the UHPFRC layers’ reinforcement ratio and strengthening of one longitudinal vertical face on the mechanical performance of RC beams strengthened in shear with UHPFRC layers is investigated. Results of the analysed beams show that the shear span-to-depth ratio significantly affects the shear behaviour of not only the normal-strength RC beams but also the RC beams strengthened with UHPFRC layers. However, the effect of shear span-to-depth ratio has not been considered in existing design code equations. Consequently, this study suggests two formulas to estimate the shear strength of normal-strength RC beams and UHPFRC-strengthened RC beams considering the effect of the shear span-to-depth ratio.

scholarly journals Shrinkage Behaviour of Fibre Reinforced Concrete with Recycled Tyre Polymer Fibres

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Marijana Serdar ◽  
Ana Baričević ◽  
Marija Jelčić Rukavina ◽  
Martina Pezer ◽  
Dubravka Bjegović ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Drying Shrinkage ◽  
Fibre Reinforced Concrete ◽  
Restrained Shrinkage ◽  
Polypropylene Fibres ◽  
Concrete Mixtures ◽  
Shrinkage Behaviour ◽  
Different Types ◽  
Waste Tyre ◽  
Recycled Polymer

Different types of fibres are often used in concrete to prevent microcracking due to shrinkage, and polypropylene fibres are among the most often used ones. If not prevented, microcracks can lead to the development of larger cracks as drying shrinkage occurs, enabling penetration of aggressive substances from the environment and reducing durability of concrete structures. The hypothesis of the present research is that polypropylene fibres, used in concrete for controlling formation of microcracks due to shrinkage, can be replaced with recycled polymer fibres obtained from end-of-life tyres. To test the hypothesis, concrete mixtures containing polypropylene fibres and recycled tyre polymer fibres were prepared and tested. Experimental programme focused on autogenous, free, and restrained shrinkage. It was shown that PP fibres can be substituted with higher amount of recycled tyre polymer fibres obtaining concrete with similar shrinkage behaviour. The results indicate promising possibilities of using recycled tyre polymer fibres in concrete products. At the same time, such applications would contribute to solving the problem of waste tyre disposal.

scholarly journals Effect of Jute Fibre Orientation and Percentage on Strength of Jute Fibre Reinforced Concrete

2020 ◽  
Vol 9 (3) ◽  
pp. 1767-1770
Keyword(s):  
Tensile Strength ◽  
Reinforced Concrete ◽  
Dynamic Properties ◽  
Low Cost ◽  
Plain Concrete ◽  
Natural Fibre ◽  
Fibre Reinforced Concrete ◽  
Jute Fibre ◽  
Micro Cracks ◽  
Crack Arrester

The demerits of plain concrete are its lesser tensile strength, not significant ductility and poor resistance to cracking. Due to propagation of internal micro cracks in plain concrete causes decrease in tensile strength, hence leads concrete to brittle fracture. Addition of fibres behaves like crack arrester and enhances the dynamic properties of concrete. In India natural fibres such as bamboo, coir, jute, sisal, pineapple, banana, ramie etc are high available. Jute is a useful natural fibre for concrete reinforcement due to its easy availability and low cost. In this research, the experiments related to Jute fibre reinforced concrete (JFRC) are done by taking different fibre percentage and the compressive strength and modulus of rapture value observed. This JFRC can replace plain concrete and wood in many cases for example in door and window panels, inclined roof slabs, partition walls etc

scholarly journals Mechanical Properties of Macro Polypropylene Fibre-Reinforced Concrete

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4112
Author(s):  
Rajab Abousnina ◽  
Sachindra Premasiri ◽  
Vilive Anise ◽  
Weena Lokuge ◽  
Vanissorn Vimonsatit ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Plain Concrete ◽  
Modulus Of Rupture ◽  
Fibre Reinforced Concrete ◽  
Empirical Formulas ◽  
Pull Out ◽  
Mechanical And Microstructural Properties

Adding fibers to concrete helps enhance its tensile strength and ductility. Synthetic fibres are preferable to steel ones which suffer from corrosion that reduces their functionality with time. More consideration is given to synthetic fibres as they can be sourced from waste plastics and their incorporation in concrete is considered a new recycling pathway. Thus, this work investigates the potential engineering benefits of a pioneering application using extruded macro polyfibres in concrete. Two different fiber dosages, 4 kg/m3 and 6 kg/m3, were used to investigate their influence based on several physical, mechanical and microstructural tests, including workability, compressive strength, modulus of elasticity, splitting-tensile strength, flexural test, CMOD, pull-out test and porosity. The test results revealed a slight decrease in the workability of the fibre-reinforced concrete, while all the mechanical and microstructural properties were enhanced significantly. It was observed that the compressive, splitting tensile and bonding strength of the concrete with 6 kg/m3 fibre dosage increased by 19.4%, 41.9% and 17.8% compared to the plain concrete specimens, respectively. Although there was no impact of the fibres on the modulus of rupture, they significantly increased the toughness, resulting in a progressive type of failure instead of the sudden and brittle type. Moreover, the macroporosity was reduced by the fibre addition, thus increasing the concrete compressive strength. Finally, simplified empirical formulas were developed to predict the mechanical properties of the concrete with fibre addition. The outcome of this study will help to increase the implementation of the recycled plastic waste in concrete mix design and promote a circular economy in the waste industry.

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