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1
Lie, T. T., e V. K. R. Kodur. "Thermal and mechanical properties of steel-fibre-reinforced concrete at elevated temperatures". Canadian Journal of Civil Engineering 23, n. 2 (1 aprile 1996): 511–17. http://dx.doi.org/10.1139/l96-055.
Testo completoAbstract (sommario):
For use in fire resistance calculations, the relevant thermal and mechanical properties of steel-fibre-reinforced concrete at elevated temperatures were determined. These properties included the thermal conductivity, specific heat, thermal expansion, and mass loss, as well as the strength and deformation properties of steel-fibre-reinforced siliceous and carbonate aggregate concretes. The thermal properties are presented in equations that express the values of these properties as a function of temperature in the temperature range between 0 °C and 1000 °C. The mechanical properties are given in the form of stress–strain relationships for the concretes at elevated temperatures. The results indicate that the steel fibres have little influence on the thermal properties of the concretes. The influence on the mechanical properties, however, is relatively greater than the influence on the thermal properties and is expected to be beneficial to the fire resistance of structural elements constructed of fibre-reinforced concrete. Key words: steel fibre, reinforced concrete, thermal properties, mechanical properties, fire resistance.
2
Jagtap, Siddhant Millind, Shailesh Kalidas Rathod, Rohit Umesh Jadhav, Prathamesh Nitin Patil, Atharva Shashikant Patil, Ashwini M. Kadam e P. G. Chavan. "Fibre Mesh in Reinforced Slabs". International Journal for Research in Applied Science and Engineering Technology 10, n. 5 (31 maggio 2022): 3539–40. http://dx.doi.org/10.22214/ijraset.2022.42986.
Testo completoAbstract (sommario):
Abstract: Fiber Reinforced Concrete is gaining attention as an effective way to improve the performance of concrete. Fibers are currently being specified in tunneling, bridge decks, pavements, loading docks, thin unbonded overlays, concrete pads, and concretes slabs. These applications of fiber reinforced concrete are becoming increasingly popular and are exhibiting excellent performance The usefulness of fiber reinforced concrete in various civil engineering applications is indisputable. Fiber reinforced concrete has so far been successfully used in slabs on grade, architectural panels, precast products, offshore structures, structures in seismic regions, thin and thick repairs, crash barriers, footings, hydraulic structures and many other applications. This study presents understanding srength of fibre reinforced conceret. Mechanical properties and durability of fiber reinforced concrete.
3
Hasham, Md, V. Reddy Srinivasa, M. V. Seshagiri Rao e S. Shrihari. "Flexural behaviour of basalt fibred concrete slabs made with basalt fibre reinforced polymer rebars". E3S Web of Conferences 309 (2021): 01055. http://dx.doi.org/10.1051/e3sconf/202130901055.
Testo completoAbstract (sommario):
In this paper, the flexural behaviour of M30 grade basalt fibred concrete slabs made with basalt fibre reinforced polymer rebars are studied and compared with slabs made with steel rebars. The optimum percentage of basalt is 0.3% for 50mm length basalt fibres. Due to high particle packing density in concrete made with basalt fibre micro cracks are prevented due to enhanced fatigue and stress dissipation capacity. Addition of basalt fibres to enhances the energy absorbtion capacity or toughness thereby enhancing the resistance to local damage and spalling. Addition of basalt fibres controlled the crack growth and crack width. Load at first crack of M30 grade basalt fibred concrete slabs made with basalt fibre reinforced polymer rebars is more than M30 grade conventional concrete slabs made with steel rebars because the with addition of basalt and BFRP bars will make either the interfacial transition zone (ITZ) strong or due to bond strength of concrete slabs made with basalt fibre reinforced polymer rebars. The ultimate strength in M30 grade basalt fibred concrete slabs made with basalt fibre reinforced polymer rebars is more than conventional concrete slabs made with steel rebars. Deflection at the centre of M30 grade basalt fibred concrete slabs made with basalt fibre reinforced polymer rebars is almost double than the conventional concrete slabs made with steel rebars. Toughness indices evaluated for M30 grade basalt fibred concrete slabs made with basalt fibre reinforced polymer rebars indicates that basalt fibre and BFRP bars will enhance the energy absorbtion capacity of slabs.
4
More, Florence More Dattu Shanker, e Senthil Selvan Subramanian. "Impact of Fibres on the Mechanical and Durable Behaviour of Fibre-Reinforced Concrete". Buildings 12, n. 9 (13 settembre 2022): 1436. http://dx.doi.org/10.3390/buildings12091436.
Testo completoAbstract (sommario):
Numerous studies have been conducted recently on fibre reinforced concrete (FRC), a material that is frequently utilized in the building sector. The utilization of FRC has grown in relevance recently due to its enhanced mechanical qualities over normal concrete. Due to increased environmental degradation in recent years, natural fibres were developed and research is underway with the goal of implementing them in the construction industry. In this work, several natural and artificial fibres, including glass, carbon, steel, jute, coir, and sisal fibres are used to experimentally investigate the mechanical and durability properties of fibre-reinforced concrete. The fibres were added to the M40 concrete mix with a volumetric ratio of 0%, 0.5%, 1.0%, 1.5%, 2.0% and 2.5%. The compressive strength of the conventional concrete and fibre reinforced concrete with the addition of 1.5% steel, 1.5% carbon, 1.0% glass, 2.0% coir, 1.5% jute and 1.5% sisal fibres were 4.2 N/mm2, 45.7 N/mm2, 41.5 N/mm2, 45.7 N/mm2, 46.6 N/mm2, 45.7 N/mm2 and 45.9 N/mm2, respectively. Comparing steel fibre reinforced concrete to regular concrete results in a 13.69% improvement in compressive strength. Similarly, the compressive strengths were increased by 3.24%, 13.69%, 15.92%, 13.68% and 14.18% for carbon, glass, coir, jute, and sisal fibre reinforced concrete respectively when equated with plain concrete. With the optimum fraction of fibre reinforced concrete, mechanical and durability qualities were experimentally investigated. A variety of durability conditions, including the Rapid Chloride Permeability Test, water absorption, porosity, sorptivity, acid attack, alkali attack, and sulphate attack, were used to study the behaviour of fiber reinforced concrete. When compared to conventional concrete, natural fibre reinforced concrete was found to have higher water absorption and sorptivity. The rate of acid and chloride attacks on concrete reinforced with natural fibres was significantly high. The artificial fibre reinforced concrete was found to be more efficient than the natural fibre reinforced concrete. The load bearing capacity, anchorage and the ductility of the concrete improved with the addition of fibres. According to the experimental findings, artificial fibre reinforced concrete can be employed to increase the structure’s strength and longevity as well as to postpone the propagation of cracks. A microstructural analysis of concrete was conducted to ascertain its morphological characteristics.
5
Li, Fang-Yuan, Liu-Yang Li, Yan Dang e Pei-Feng Wu. "Study of the Effect of Fibre Orientation on Artificially Directed Steel Fibre-Reinforced Concrete". Advances in Materials Science and Engineering 2018 (2018): 1–11. http://dx.doi.org/10.1155/2018/8657083.
Testo completoAbstract (sommario):
The fibre utilization efficiency of directionally distributed fibre-reinforced concrete is better than that of randomly distributed fibre. However, controlling the fibre direction is difficult, which limits its applications. In this paper, a method in which fibres were artificially directed was used to simulate the feasibility of orienting fibres during 3D concrete printing. Based on artificially directed steel fibre-reinforced concrete specimens, the orientation characteristics of directional fibre-reinforced concrete specimens were studied. The differences between the gravity and the boundary effects in ordinary fibre-reinforced concrete and artificially directed fibre-reinforced concrete were compared. The average orientation coefficient in randomly distributed fibre-reinforced concrete was 0.59, whereas this value in directionally distributed fibre-reinforced concrete was over 0.9. This result demonstrated the feasibility of manually orienting the fibres in steel fibre-reinforced concrete in layer-by-layer casting.
6
Goud, E. Giri Prasad, Dinesh Singh, V. Srinivasa Reddy e Kaveli Jagannath Reddy. "Stress-Strain behaviour of basalt fibre reinforced concrete". E3S Web of Conferences 184 (2020): 01081. http://dx.doi.org/10.1051/e3sconf/202018401081.
Testo completoAbstract (sommario):
This paper prophesies the stress strain behaviour of M30 grade concrete reinforced with basalt fibres of length 12 mm, 36 mm and 50 mm of amounts 0.4%, 0.4% and 0.3% by volume of concrete respectively. Modulus of elasticity and toughness of M30 grade basalt fibre reinforced concretes are also evaluated. It was found that BFRCC mixes show good resistance to impact and has superior dissipation capacity. The optimal basalt fibre volume fraction is 0.3% and length is 50 mm. For this case, toughness index and energy absorbed at fracture have considerably enhanced. With the volume fraction of basalt fiber exceeding the optimum volume fraction, the mechanical properties of basalt fiber are weakened.
7
Aslani, Farhad, Yinong Liu e Yu Wang. "Flexural and toughness properties of NiTi shape memory alloy, polypropylene and steel fibres in self-compacting concrete". Journal of Intelligent Material Systems and Structures 31, n. 1 (5 ottobre 2019): 3–16. http://dx.doi.org/10.1177/1045389x19880613.
Testo completoAbstract (sommario):
Self-compacting concrete presents good workability to fill complicated forms without mechanical vibrations. This concrete is often reinforced with fibres to improve the strength and toughness. This study investigated the use of nickel -titanium (NiTi) shape memory alloy fibres in comparison with polypropylene and steel fibres in self-compacting concrete. The performances of the fresh fibre–reinforced self-compacting concrete are explored by slump flow and J-ring experiments. Meanwhile, the static and cyclic flexural tests are conducted to estimate the bending resistance strength performance, residual deformation and recovering capacity of shape memory alloy, polypropylene and steel fibre–reinforced self-compacting concrete. Moreover, the flexural toughness of the shape memory alloy, polypropylene and steel fibre–reinforced self-compacting concrete is calculated using four different codes. The shape memory alloy fibre–reinforced self-compacting concrete with 0.75% volume fraction presents the largest flexural strength, re-centering ability and toughness in comparison with polypropylene and steel fibre–reinforced self-compacting concretes. The experimental results demonstrated the beneficial influence of the shape memory and superelastic properties of NiTi in postponing initial crack formation and restricting the crack widths.
8
Abdullah, Muhd Afiq Hizami, Mohd Zulham Affandi Mohd Zahid, Badorul Hisham Abu Bakar, Fadzli Mohamed Nazri e Afizah Ayob. "UHPFRC as Repair Material for Fire-Damaged Reinforced Concrete Structure – A Review". Applied Mechanics and Materials 802 (ottobre 2015): 283–89. http://dx.doi.org/10.4028/www.scientific.net/amm.802.283.
Testo completoAbstract (sommario):
Exposure of concrete to intense heat will cause deterioration of its strength and durability. Previously, the fire-damaged concrete was repaired using the shotcrete and normal concrete. Recent studies utilize fibre reinforced polymer (FRP) in repairing fire-damaged concrete. Ultra High Performance Fiber Reinforced Concrete (UHPFRC) mostly developed using fine size aggregate, cement, silica fume, super plasticizer and reinforced with steel fibre has an excellent mechanical properties compared to high strength concrete and with an addition of steel fibre in the UHPFRC enhances its ductility behaviour which is not possessed by normal concrete, hence, UHPFRC indicates a promising candidate as repair material to fire-damaged concrete. The aim of this paper is to review on the properties of UHPFRC to be utilized as repair material to fire-damaged concrete structure based on previous research on UHPFRC and fire-damaged structure.
9
Jothi Jayakumar, Vikram, e Sivakumar Anandan. "Composite Strain Hardening Properties of High Performance Hybrid Fibre Reinforced Concrete". Advances in Civil Engineering 2014 (2014): 1–9. http://dx.doi.org/10.1155/2014/363649.
Testo completoAbstract (sommario):
Hybrid fibres addition in concrete proved to be a promising method to improve the composite mechanical properties of the cementitious system. Fibre combinations involving different fibre lengths and moduli were added in high strength slag based concrete to evaluate the strain hardening properties. Influence of hybrid fibres consisting of steel and polypropylene fibres added in slag based cementitious system (50% CRL) was explored. Effects of hybrid fibre addition at optimum volume fraction of 2% of steel fibres and 0.5% of PP fibres (long and short steel fibre combinations) were observed in improving the postcrack strength properties of concrete. Test results also indicated that the hybrid steel fibre additions in slag based concrete consisting of short steel and polypropylene (PP) fibres exhibited a the highest compressive strength of 48.56 MPa. Comparative analysis on the performance of monofibre concrete consisting of steel and PP fibres had shown lower residual strength compared to hybrid fibre combinations. Hybrid fibres consisting of long steel-PP fibres potentially improved the absolute and residual toughness properties of concrete composite up to a maximum of 94.38% compared to monofibre concrete. In addition, the relative performance levels of different hybrid fibres in improving the matrix strain hardening, postcrack toughness, and residual strength capacity of slag based concretes were evaluated systematically.
10
Annamaneni, Krishna Kiran, Bhumika Vallabhbhai Dobariya e Krasnikovs Andrejs. "CONCRETE, REINFORCED BY CARBON FIBRE COMPOSITE STRUCTURE, LOAD BEARING CAPACITY DURING CRACKING". ENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International Scientific and Practical Conference 2 (17 giugno 2021): 232–37. http://dx.doi.org/10.17770/etr2021vol2.6655.
Testo completoAbstract (sommario):
Different authors conducted studies on fiber reinforced concretes (FRC) with carbon fibres of different lengths and some results showed that concrete mix with homogeneously distributed short fibres in their volume have good strength and ultra-strain compared to normal plain concrete mix. However, this study is focused more on 3-dimensional (3D) carbon fibre reinforced plastic (epoxy) CFRP composite thin rods frame used as a reinforcement in concrete which shows good increase in loadbearing and ductility. Were investigated concrete mixes with superplasticizer, nano-silica, quartz sand, fine natural sand and gravels. Diagonal cross bracing carbon fibre epoxy frames were used as a reinforcement giving better ductility results. Proposed study approach is to show that the reinforced concrete with provided materials have an increased performance in terms of ductility, sustainability, and load bearing in cracked statement. Total, four groups of concrete and each group with three beams were casted and tested in this experiment, three groups with three different shapes of carbon frames and three beams without frames to compare the mechanical properties after 28 days. Failure mechanisms in any particular case were analysed.
11
Naraganti, Srinivasa Rao, Rama Mohan Rao Pannem e Jagadeesh Putta. "Influence of Hybrid Fibres on Bond Strength of Concrete". International Journal of Mathematical, Engineering and Management Sciences 5, n. 2 (1 aprile 2020): 353–62. http://dx.doi.org/10.33889/ijmems.2020.5.2.029.
Testo completoAbstract (sommario):
Bond strength between embedded bar and concrete plays vital role in the design of various reinforced concrete structural elements. Use of metallic and synthetic fibres has been shown to be an effective method to enhance tensile strength, reduce shrinkage and improve durability properties of concrete. However, making of synthetic fibres will not only deplete the natural hydrocarbon resources, but also add greenhouse pollutants to the environment. Hence, sisal fibre was considered as a potential alternative to polypropylene fibre. An experimental study was conducted to evaluate the influence of sisal fibres as mono-fibre and in combination with steel as hybrid fibre on bond strength of concrete. The performance of steel polypropylene fibre reinforced concrete (SPFRC) is compared with that of steel sisal fibre reinforced concrete (SSiFRC). Bond strength was conducted onM30 grade concrete for curing periods of 7, 28 and 90 days. Fibre dosages of 0.50%, 1.00%, 1.25% and 1.50% by volume of concrete were used. Results indicated that increase in steel fibre dosage improved the bond strength slightly. However, increase in fibre dosage of either PP fibres or sisal fibres resulted decrease in bond strength. Furthermore, sisal fibre reinforced concrete (SiFRC) showed inferior performance in bond strength as compared to polypropylene fibre reinforced concrete (PFRC). A detailed statistical analysis revealed that although no strong correlation between the compressive strength and the bond strength was evident from the experimental study, means of bond strength of both the hybrid groups did not differ significantly. In addition, empirical equations were proposed to predict the bond strength of fibre reinforced concrete (FRC) based on compressive strength.
12
Awoyera, Paul Oluwaseun, John Uduak Effiong, Oladimeji Benedict Olalusi, Krishna Prakash Arunachalam, Afonso R. G. de Azevedo, Flavia R. B. Martinelli e Sergio Neves Monteiro. "Experimental Findings and Validation on Torsional Behaviour of Fibre-Reinforced Concrete Beams: A Review". Polymers 14, n. 6 (15 marzo 2022): 1171. http://dx.doi.org/10.3390/polym14061171.
Testo completoAbstract (sommario):
Fibres have long been utilized in the construction sector to improve the mechanical qualities of structural elements such as beams, columns, and slabs. This study aims to review the torsional behaviour of various forms of fibre reinforced concrete to identify possible enhancements and the practicability of concrete structural beams. Concrete reinforced steel fibre, synthetic fibre, and hybrid fibre are examples of fibre reinforced concrete. The review found that the mixing, orientation, and volume of fibres, the size of coarse particles, the aspect ratio of fibres, and the stiffness of fibres all affect the torsional strength of fibre reinforced concrete. Nevertheless, the application of fibres to recycled self-consolidating concrete of various forms needs to be explored and studied to ascertain its feasibility to facilitate greener concrete. Thus, with the results compiled in this review paper, it was possible to delimit advances and gaps on the effect of editing reinforcement fibres in relation to the torsion of structural elements.
13
Simon, Seena, Arun Prathap, Sharanya Balki e R. G. Dhilip Kumar. "An Experimental Investigation on Concrete with Basalt Rock Fibers". Journal of Physics: Conference Series 2070, n. 1 (1 novembre 2021): 012196. http://dx.doi.org/10.1088/1742-6596/2070/1/012196.
Testo completoAbstract (sommario):
Abstract Basalt fibre is formed from basalt rock when melted at a high temperature making it a non-metallic fibre. Basalt fibre reinforced concrete are good fire resistance, strength and light weight. These properties making it highly advantageous in the future to the construction business. There are many applications of basalt fibre like industrial, bridges, residential and highway etc. Fibres of basalt rock are used to make Basalt fibre, is cheaper and have improved physicomechanical properties which is very similar to the fibre glass and the carbon. They can replace many expensive materials resulting in wide range of applications in the field. The raw materials are available in all countries, making their production very simple. The biggest difficulties of the concrete and cement industry’s can be solved by the usage of basalt fibres. It is also used as composite and in the aerospace, automotive industries and fibre proof textile. Basalt fibres have no hazardous reactions with water or air and are explosion-proof and non-combustible. No chemical reaction will be produced that may damage environment or health when in contact with other chemicals. Reinforced plastics and steel maybe replaced by the basalt base composites. One kg of basalt reinforces equals to 9.6 kg of steel. Differences in compressive strength and split tensile test for concrete with and without basalt fibre by using cubes and cylinders are studied in this paper.
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Waghe, Uday Prakashchandra, e Sanjay Padmakar Raut. "Investigations into Synthetic Fibre Reinforced Concrete Beams". Advanced Materials Research 255-260 (maggio 2011): 284–88. http://dx.doi.org/10.4028/www.scientific.net/amr.255-260.284.
Testo completoAbstract (sommario):
Fibre is a small piece of reinforcing material described by a numerical parameter, called aspect ratio which is the ratio of its length to its equivalent diameter (l/d). In the Biblical period Romans introduced the concept of “Fibres” in the building material by using the “HORSE HAIR” as the fibrous material and since then the use of fibres was incorporated. Recently, however, the development of Fibre Reinforced Concrete (FRC) in various fields has provided a technical basis for improving the deficiencies in mortar and concretes. At hydration stage, water tends to escape through various routes and cracks develop on the surface. These leads to water penetration resulting in dampness and need repainting of walls and other repair. The aim of the present experimental investigation is to study the effect of addition of synthetic fibres on the ultimate strength and behavior of the concrete and mortar. The fibre content (by volume) is the main parameter considered in the study. A combination of a low ratio of conventional fibre reinforcement together with synthetic fibers may provide a practical solution, increasing the strength of the beams without causing congestion of the reinforcement. Fibres in the concrete act as crack arresters and considerably enhance the ductility. In the investigation a total of 240 full-scale specimens with and without fibre contents were casted, and tested to failure under symmetrically applied loads. The fibres volume Vf is vary from 0% to 1.5%. As the test was in progress, the development and propagation of cracks, the load at first crack and the mode of failure was noted. The results were compared to control sample and the viability of adding synthetic fibre to concrete and mortar was verified.
15
Bhat, Arooba Rafiq, e Ajay Vikram. "A Literature Study of Hybrid Fibre Reinforced Concrete". International Journal of Innovative Research in Engineering & Management 10, n. 1 (1 febbraio 2023): 6–8. http://dx.doi.org/10.55524/ijirem.2023.10.1.2.
Testo completoAbstract (sommario):
The drawbacks are that the concrete has been improved by using hybrid fibre in concrete. By hybridization benefits from two different fibres are utilized in a single concrete mixture. The hybrids fibres studied are basalt-polypropylene fibre, polypropylene-steel fibre, steel-coconut fibre, polypropylene-e-waste fibre, polypropylene-polyvinyl Alcohol and steel-glass- polypropylene fibre. The properties that are improved using hybrid fibres are compressive strength, tensile strength, flexural strength, limited crack propagation, and improved durability of the concrete structure. In maximum cases slump value decrease with an increase in fibre percentage.
16
Tiwari, Pankaj, R. S. Parihar, Abhay Kumar Jha, Barun Kumar e Rajesh Misra. "To Investigate How Well Industrial Waste Polymer Fibre Performs Physically and Mechanically When Utilised in Concrete Mixtures". International Journal for Research in Applied Science and Engineering Technology 10, n. 12 (31 dicembre 2022): 1641–44. http://dx.doi.org/10.22214/ijraset.2022.48305.
Testo completoAbstract (sommario):
Abstract: While the density of the fiber-reinforced concrete (FRC) is determined right away after the concrete mix has been prepared, the compressive strength and split tensile strength of the FRC are tested 7 and 28 days after it has been cured. As a result of adding polypropylene fibre, new fiber-reinforced concrete (FRC) has a marginally or barely decreased density from 2397 kg/m3 to 2393 kg/m3, according to the results in laboratory. Waste polypropylene fibre boosts the strength of fibre reinforced concrete for all curing ages up to a particular degree (FRC). After that, there is a rapid decline in the strength of the fiber-reinforced concrete (FRC). It is recommended to add 0.5% of polypropylene fibre for maximum strength and minimal brittleness. The inclusion of 0.5% waste polypropylene fibre raises the split tensile strength and compressive strength of the fiber-reinforced concrete by 16.9908% and 9.988470%, respectively (FRC).
17
Hubertova, Michala, e Rudolf Hela. "Lightweight Fibre Reinforced Concrete". Solid State Phenomena 249 (aprile 2016): 28–32. http://dx.doi.org/10.4028/www.scientific.net/ssp.249.28.
Testo completoAbstract (sommario):
The use of fibre reinforcement in normalweight concrete technology is commonly used in practice. In the area of lightweight concrete, for example with use of expanded clay aggregate, there is not widely used this type of technology. The paper describes the experimental verification of various doses of steel fibres in two types of bulk and compressive class of lightweight expanded clay aggregate concrete and its influence on the physical and mechanical properties of hardened concrete – compressive and flexural strength, stress-strain diagram.
18
Li, Fangyuan, Yunxuan Cui, Chengyuan Cao e Peifeng Wu. "Experimental study of the tensile and flexural mechanical properties of directionally distributed steel fibre-reinforced concrete". Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications 233, n. 9 (20 giugno 2018): 1721–32. http://dx.doi.org/10.1177/1464420718782555.
Testo completoAbstract (sommario):
Directionally distributed steel fibre-reinforced concrete has been proposed as a novel concrete because of its high tensile strength and crack resistance in specific directions. Based on the existing studies of the effect of the fibre direction on the mechanical properties of fibre-reinforced concrete, the authors in this paper performed further studies of the mechanical properties of directionally distributed steel fibre-reinforced concrete by conducting split tensile and bending tests. The split tensile strength of the directionally distributed fibre-reinforced concrete clearly exhibited anisotropy. The split tensile strength perpendicular to the fibre direction was much higher than that parallel to the fibre direction. The split tensile strength perpendicular to the fibre direction was almost twice the tensile strength of plain concrete. The flexural performance of directionally distributed fibre-reinforced concrete in the fibre direction significantly improved compared to that of randomly distributed fibre-reinforced concrete. Specifically, the flexural strength increased by as much as 97%. Gravity resulted in a deviation in the tensile properties of concrete prepared by manually and directionally placing fibres in a layered casting process. The test results can be utilised in subsequent concrete designs. The conclusions reached in this paper provide comprehensive mechanical design parameters for the application of directionally distributed fibre-reinforced concrete.
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Liu, Yanzhu, Liang Wang, Ke Cao e Lei Sun. "Review on the Durability of Polypropylene Fibre-Reinforced Concrete". Advances in Civil Engineering 2021 (4 giugno 2021): 1–13. http://dx.doi.org/10.1155/2021/6652077.
Testo completoAbstract (sommario):
Polypropylene fibre (PPF) is a kind of polymer material with light weight, high strength, and corrosion resistance. The crack resistance of concrete can be improved by adding PPFs. PPF can optimize the pore size distribution of concrete. As a result, the durability of concrete is significantly enhanced since PPF can block the penetration of water or harmful ions in concrete. This paper summarizes the influence of polypropylene fibre on the durability of concrete, including drying shrinkage, creep, water absorption, permeability resistance, chloride ion penetration resistance, sulfate corrosion resistance, freeze-thaw cycle resistance, carbonation resistance, and fire resistance. The authors analysed the effects of fibre content, fibre diameter, and fibre hybrid ratio on these durability indexes. The durability property of concrete can be further improved by combining PPFs and steel fibres. The drawbacks of PPF in application in concrete are the imperfect dispersion in concrete and weak bonding with cement matrix. The methods to overcome these drawbacks are to use fibre modified with nanoactive powder or chemical treatment. At last, the authors give the future research prospects of concrete made with PPFs.
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Bamigboye, Gideon, Ben Ngene, Omotolani Aladesuru, Oluwaseun Mark, Dunmininu Adegoke e Kayode Jolayemi. "Compressive Behaviour of Coconut Fibre (Cocos nucifera) Reinforced Concrete at Elevated Temperatures". Fibers 8, n. 1 (1 gennaio 2020): 5. http://dx.doi.org/10.3390/fib8010005.
Testo completoAbstract (sommario):
Fire outbreaks in buildings have been a major concern in the world today. The integrity of concrete is usually questioned due to the fact that after these fire outbreaks the strength of the concrete is reduced considerably. Various methods have been adopted to improve the fire resistance property of concrete. This study focused on the use of coconut fibre to achieve this feat. In this study, varying percentages of treated and untreated coconut fibres were incorporated into concrete and the compressive strength was tested for both before heating and after heating. The percentages of replacement were 0.25, 0.5, 0.75 and 1% fibre content by weight of cement. Concrete cubes that had 0% fibre served as control specimens. After subjecting these concrete cubes to 250 °C and 150 °C for a period of 2 h, the compressive strength increased when compared to the control. The compressive strength increased up to 0.5% replacement by 3.88%. Beyond 0.5% fibre, the compressive strength reduced. Concrete having coconut fibre that had been treated with water also exhibited the highest compressive strength of 28.71 N/mm². It is concluded that coconut fibres are a great material in improving the strength of concrete, even after it was exposed to a certain degree of elevated temperature.
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Zhang, Y., L. Yan, S. Wang e M. Xu. "Impact of twisting high-performance polyethylene fibre bundle reinforcements on the mechanical characteristics of high-strength concrete". Materiales de Construcción 69, n. 334 (15 marzo 2019): 184. http://dx.doi.org/10.3989/mc.2019.01418.
Testo completoAbstract (sommario):
The quasi-static and dynamic mechanical behaviours of the concrete reinforced by twisting ultra-high molecular weight polyethylene (UHMWPE) fibre bundles with different volume fractions have been investigated. It was indicated that the improved mixing methodology and fibre geometry guaranteed the uniform distribution of fibres in concrete matrix. The UHMWPE fibres significantly enhanced the splitting tensile strength and residual compressive strength of concrete. The discussions on the key property parameters showed that the UHMWPE fibre reinforced concrete behaved tougher than the plain concrete. Owing to the more uniform distribution of fibres and higher bonding strength at fibre/matrix interface, the UHMWPE fibre with improved geometry enhanced the quasi-static splitting tensile strength and compressive strength of concrete more significantly than the other fibres. The dynamic compression tests demonstrated that the UHMWPE fibre reinforced concrete had considerable strain rate dependency. The bonding between fibres and concrete matrix contributed to the strength enhancement under low strain-rate compression.
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Bhoi, Ghanshyam, Vinay Pate e Mahesh Ram Patel. "Study on the Effect of Glass Fibre Reinforced Concrete and Concrete Tiles Reinforced Concrete". International Journal for Research in Applied Science and Engineering Technology 10, n. 5 (31 maggio 2022): 2564–69. http://dx.doi.org/10.22214/ijraset.2022.42753.
Testo completoAbstract (sommario):
Abstract: The objective of this research is to explore the compressive strength, split-tensile strength and flexural strength properties of concrete reinforced with short discrete fibers. The study will be carried out on M-20 grade concrete and the size of glass fibers will be used 30mm and variation of fibre will be 0% to 0.3% of the total weight of concrete. also the effect of glass fiber on cement and concrete tiles will be studied whose fibre content will be varied from 0% to 0.7% of the total weight of concrete. Keywords: GFRC, Concrete tiles, Cement Matrix, MORTH
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Krassowska, Julita, e Marta Kosior-Kazberuk. "Failure mode in shear of steel fiber reinforced concrete beams". MATEC Web of Conferences 163 (2018): 02003. http://dx.doi.org/10.1051/matecconf/201816302003.
Testo completoAbstract (sommario):
Experimental tests were carried out to assess the failure model of steel fiber reinforced concrete beams. Experimental research was focused on observing changes in the behavior of the tested elements depending on the amount of shear reinforcement and the fiber. Model two-span beams with a cross-section of 80x180 mm and a length of 2000 mm were tested. The beams had varied stirrup spacing. The following amounts of steel fibres in concrete were used: 78.5 kg/m3 (1.0%) i 118 kg/m3 (1.5%). Concrete beams without fibres were examined at the same time. The beams were loaded in a five-point bending test until they were destroyed. Shear or bending capacity of the element was observed. Fibre reinforced concrete beams were not destroyed rapidly, but they kept their shape consistent under load. Larger number of diagonal cracks with a smaller width were observed in fibre reinforced concrete beams. Failure of concrete beams without fibres was rapid, with a characteristic brittle cracking. Steel fibres revealed the ability to transfer significant shear stress after cracking in comparison to plain concrete.
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Cleven, Simon, Michael Raupach e Thomas Matschei. "Electrical Resistivity of Steel Fibre-Reinforced Concrete—Influencing Parameters". Materials 14, n. 12 (20 giugno 2021): 3408. http://dx.doi.org/10.3390/ma14123408.
Testo completoAbstract (sommario):
This paper presents a systematic study of the electrical resistivity of different steel fibre-reinforced concretes with fibre contents from 0 kg/m3 to 80 kg/m3 in order to identify possible effects of interactions among concrete composition and fibre type and content regarding electrical resistivity. Based on a literature review, four parameters, w/c ratio, binder content, ground granulated blast-furnace slag (GGBS) and fineness of cement, which show a significant influence on the electrical resistivity of plain concrete, were identified, and their influence on the electrical resistivity as well as interaction effects were investigated. The results of the experiments highlight that the addition of fibres leads to a significant decrease in electrical resistivity, independent of all additional parameters of the concrete composition. Additionally, it was shown that a higher porosity of the concrete, e.g., due to a higher w/c ratio, also results in a lower electrical resistivity. These results are in agreement with the literature review on plain concrete, while the influence of the concrete composition on the electrical resistivity is weaker with the increase in fibre content. The influence of fibre reinforcement is thus not affected by changes in the concrete composition. In general, a higher fibre dosage leads to a decrease in electrical resistivity, but the impact on the electrical resistivity varies slightly with different types of steel fibres. Based on this study, the potential of determining the fibre content using electrical resistivity measurements could be clearly presented.
25
Dineshkumar, Dr G., e Dr R. Bharathimurugan. "Performance Evaluation On Structural Behaviour Of Sisal Fibre Reinforced Concrete". Journal of University of Shanghai for Science and Technology 23, n. 12 (22 dicembre 2021): 393–400. http://dx.doi.org/10.51201/jusst/21/121045.
Testo completoAbstract (sommario):
All over the world, construction industries looking forward for the green materials to meet the structural integrity and sustainability in terms of arresting micro cracks in the concrete and also for a secondary reinforcement materials for addition in the concrete. Internal micro cracks in the concrete will reduce the longetivity of the structure and also it results in structural failure. The use of fibres in the concrete is currently used as a secondary reinforcement for strengthening the reinforced concrete members. To make the concrete as a sustainable material and to improve structural integrity in this research Sisal Fibre was used as a secondary reinforcement. Natural fiber such as sisal fibre, appears as an one of the good alternative since they are available in fibrous form and can be extracted from plant leaves at very low cost. In this work, effect of sisal fiber on the strength of concrete for M 25 grade has been studied by varying the percentage of fibers in concrete. Fiber content were varied by 0.05%, 0.10%, 0.15%, 0.20%, 0.25%, 0.30%, 0.35% and 0.40% by volume of concrete. Cubes, Cylinder and Prism were cast to evaluate the Strength Characteristics and to optimize dosage level of fibre in concrete. The reinforced concrete beam was cast by optimum dosage level of fibre to evaluate structural behavior of concrete such as Load deflection, Ductility factor and Stiffness. The result proven, there is significant improvement in structural behavior of Sisal Fibre added Reinforced Concrete when compared to control concrete.
26
Prabakaran, E., D. Vasanth Kumar, A. Jaganathan, P. Ashok Kumar e M. Veeerapathran. "Analysis on Fiber Reinforced Epoxy Concrete Composite for Industrial Flooring – A Review". Journal of Physics: Conference Series 2272, n. 1 (1 luglio 2022): 012026. http://dx.doi.org/10.1088/1742-6596/2272/1/012026.
Testo completoAbstract (sommario):
Abstract Fiber composites are the having an good scope in construction industry as they are light in weight, durable, economic, and resistant to temperatures. Many researchers concentrate on the composites for the industrial flooring with the fibers. The main objective of this paper is to review the fiber reinforced epoxy for industrial flooring. Epoxy can be used as flooring elements in industries as they deliver good performance. Since, natural and synthetic fibres can be used with filler matrices, which are very much cheaper than the conventional steel fibres reinforced composite concrete flooring and other type of composites here fibre is considered for reinforcing with epoxy or polymer concrete filler matrix. Fibre-polymer and fibre-concrete composite properties has been reviewed for testing procedure for flexural test, bending test, tensile test and based on the results, it is clear that the fibre-polymer concrete composite, which has good mechanical properties and performance than the mentioned composites, can be made for industrial flooring
27
Hao, Yi Fei, Hong Hao e Gang Chen. "Experimental Tests of Steel Fibre Reinforced Concrete Beams under Drop-Weight Impacts". Key Engineering Materials 626 (agosto 2014): 311–16. http://dx.doi.org/10.4028/www.scientific.net/kem.626.311.
Testo completoAbstract (sommario):
Concrete is a brittle material, especially under tension. Intensive researches have been reported to add various types of fibres into concrete mix to increase its ductility. Recently, the authors proposed a new type of steel fibre with spiral shape to reinforce concrete material. Laboratory tests on concrete cylinder specimens demonstrated that compared to other fibre types such as the hooked-end, deformed and corrugated fibres the new fibres have larger displacement capacity and provide better bonding with the concrete. This study performs drop-weight impact tests to investigate the behaviour of concrete beams reinforced by different types of steel fibres. The quasi-static compressive and split tensile tests were also conducted to obtain the static properties of plain concrete and steel fibre reinforced concrete (FRC) materials. The quasi-static tests were carried out using hydraulic testing machine and the impact tests were conducted using an instrumented drop-weight testing system. Plain concrete and concrete reinforced by the commonly used hooked-end steel fibres and the proposed spiral-shaped steel fibres were tested in this study. The volume dosage of 1% fibre was used to prepare all FRC specimens. Repeated drop-weight impacts were applied to the beam specimens until total collapse. A 15.2 kg hard steel was used as the drop-weight impactor. A drop height of 0.5 m was considered in performing the impact tests. The force-displacement relations and the energy absorption capabilities of plain concrete and FRC beams were obtained, compared and discussed. The advantage and effectiveness of the newly proposed spiral-shaped steel fibres in increasing the performance of FRC beam elements under impact loads were examined.
28
M P, Dr Rudraswamy, e Dr B. R. Patagundi. "Strength Characteristics of Hybrid Fiber Reinforced Concrete Produced with Different Aspect Ratios". International Journal for Research in Applied Science and Engineering Technology 11, n. 2 (28 febbraio 2023): 129–38. http://dx.doi.org/10.22214/ijraset.2023.48984.
Testo completoAbstract (sommario):
Abstract: Nowadays, fibre reinforced concrete is more popular due to its improved ductility properties. It can be transformed into a useful construction material in areas where earthquake pressures are likely to cause harm. The ability of the materials to absorb energy in these situations is crucial. The addition of various fibres, such as carbon, steel, polypropylene, or any other type of fibre, will increase the concrete's ability to absorb energy. There isn't enough research on the effects of using hybrid fibres with various aspect ratios to concrete. This experimental study sheds some information on how hybrid fibre reinforced concrete behaves when fibres of different aspect ratio are used. Strength characteristics like compressive strength, tensile strength, flexural strength, shear strength, and impact strength are determined for concrete produced by using fibers of different aspect ratios
29
Mariak, Aleksandra, e Marzena Kurpińska. "The effect of macro polymer fibres length and content on the fibre reinforced concrete". MATEC Web of Conferences 219 (2018): 03004. http://dx.doi.org/10.1051/matecconf/201821903004.
Testo completoAbstract (sommario):
The paper presents studies of a ready-mix concrete containing polymer fibres of three different lengths: 24, 38 and 54 mm. The performed tests allowed to determine the effect of fibre volume fraction and length on the concrete strength. The basic parameters of concrete mixture (consistency, air content and bulk density) were identified. Fibre reinforced concrete belongs to a group of composite materials. The polymer fibres are applied in the concrete in structures where the reduction of shrinkage cracking as well as corrosion resistance and fire temperatures are required. It is widely known, that the cracking behaviour of concrete structures depends on flexural tensile strength of concrete. The addition of fibres significantly improves the tensile strength. The experimental study, including axial compressive strength and center-point loading flexural tensile strength, was carried out. The scope of the research was also expanded by the usage of a scanning microscope. The test results showed the effect of fibre length and fibre combinations on mechanical properties of concrete. The effect of the research is to formulate guidelines due to the quantity of macro polymer fibres. In general, appropriate fibre content brings a beneficial effect e.g. improves better workability of a concrete mixture.
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Kiss, Imre, Ilare Bordeasu, Andrei Mihai Baciu, Vasile Alexa, Vasile George Cioata e Gabriel Ursu-Neamt. "Comparative Analysis on Use of Polymer Fibres from Recycled Polyethylene Terephthalate into Reinforced Concrete Solutions". Materiale Plastice 57, n. 4 (6 gennaio 2021): 216–24. http://dx.doi.org/10.37358/mp.20.4.5421.
Testo completoAbstract (sommario):
Fibre-reinforced concrete cannot replace the ordinary reinforced concrete. However, there are areas of use in which fibre-reinforced concrete can be used alternatively or in addition to the ordinary reinforced concrete, offering several advantages, some of that being presented in this study. The basic idea is that reinforcements create a multi-directional �mesh� within the cementitious matrix that will make concrete stronger. In fact, adding the fibrous material to concrete will increase the strength. In this sense, the micro-fibres primarily work to prevent micro- or shrinkage cracking, which mostly occurs during the initial curing process of the concrete, or those critical first 28 days. By contrast, the macro-fibres provide load-bearing strength after the concrete cracks. But, in fact, the subject is more complex. The types and size of fibres, their distribution and orientation are a hugely complex topic. Fibres, of whatever nature, have been found to improve the properties of concrete. Fibre-reinforced concrete provides an alternative to conventional reinforcement, with the advantage of time and reduced costs of performing maintenance work. The complexity of various fibre use presents challenges for the construction sectors that may be beyond current levels of expertise. In this study, particularities of concrete reinforced with polymer fibres are presented. Also, a comparative study is presented, based on our previous works in area of the concrete reinforcing with recycled polyethylene terephthalate (PET).
31
Abousnina, Rajab, Sachindra Premasiri, Vilive Anise, Weena Lokuge, Vanissorn Vimonsatit, Wahid Ferdous e Omar Alajarmeh. "Mechanical Properties of Macro Polypropylene Fibre-Reinforced Concrete". Polymers 13, n. 23 (25 novembre 2021): 4112. http://dx.doi.org/10.3390/polym13234112.
Testo completoAbstract (sommario):
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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Vodička, Jan, Vladimír Křístek e Václav Ráček. "Strength Classes of Concrete versus Strength Classes of Fibre Concrete". Solid State Phenomena 249 (aprile 2016): 112–18. http://dx.doi.org/10.4028/www.scientific.net/ssp.249.112.
Testo completoAbstract (sommario):
Basic characteristics of each produced concrete and fibre reinforced concrete are characterized by the compression strength recorded by the standard sets of tests performed on cylinders and cubes. In addition, for the fibre reinforced concrete, the characteristic tensile strength at formation of microcracks and cracks of standard widths is required. Proofs of the referred characteristic tensile strength should be carried out also by the destructive tests on standard specimens including the methodology provided for their implementation.The rapid development of fibre reinforced concrete, accelerated by manufacturers of fibres and their interest to apply the fibre reinforced concrete in structural practice from where the beneficial effects of the tensile strength can be obtained, resulted in conclusion that there is currently no uniform methodology for evaluation of the tensile strength. Tensile strength studies are performed, for example, according to National standardization Committees and research institutes.At present, the two very different methodologies can be applied to test tensile characteristics of fibre reinforced concrete - MODEL CODE and the Czech national standard – ČSN P 73 2452. The results of the destructive tests, obtained in accordance with the mentioned methodologies are so different that the same strength class for the tested fibre reinforced concrete is not possible to be defined.The paper proves the diversity of methodologies to perform destructive testing, by which it is possible to obtain the tensile characteristics of fibre reinforced concrete needed to define the same strength class. Procedures for evaluation of tensile characteristics from results of destructive tests are also assessed. Significance of the obtained strengths from the point of view of objectivity for the practical application of the fibre concrete in the load-carrying structures are discussed.
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Cleven, Simon, Michael Raupach e Thomas Matschei. "A New Method to Determine the Steel Fibre Content of Existing Structures—Evaluation and Validation". Applied Sciences 12, n. 1 (4 gennaio 2022): 454. http://dx.doi.org/10.3390/app12010454.
Testo completoAbstract (sommario):
The in-situ measurement of the content and orientation of steel fibres in concrete structures is of great importance for the assessment of their specific mechanical properties, especially in the case of repair. For existing structures, the actual fibre content as well as the orientation of the fibres, which is based on many factors such as casting or compacting direction, is typically unknown. For structural maintenance or rehabilitation, those factors have to be determined in order to apply meaningful structural design calculations and plan necessary strengthening methods. For this reason, a new method based on the analysis of drilling cores of concrete structures has been established. The newly developed non-destructive test setup used in this research consists of a framework for cylindrical specimens in combination with an LCR meter to determine the electrical resistance of the fibre reinforced concrete. In combination with a suitable FEM model, concretes with fibre contents up 80 kg/m3 were analysed to derive a first model to assess the actual fibre content of steel fibre reinforced concretes. After a calibration of the literature’s equation by use of an adjusted aspect ratio for the analysis of drilling cores, the estimation of the fibre content is possible with high accuracy for the tested material combination. The results show that the newly developed test method is suitable for the rapid and non-destructive structural diagnosis of the fibre content of steel fibre reinforced concrete based on drilling cores using electrical resistivity measurements.
34
Hao, Yifei, Xin Huang e Hong Hao. "Mesoscale modelling of concrete reinforced with spiral steel fibres under dynamic splitting tension". Advances in Structural Engineering 21, n. 8 (10 ottobre 2017): 1197–210. http://dx.doi.org/10.1177/1369433217734654.
Testo completoAbstract (sommario):
The addition of discrete steel fibres into concrete has been widely recognised as an effective measure to enhance the ductility, post-cracking resistance and energy absorption of the matrix subjected to impact loads. Despite useful information from experimental studies that investigate the macro-scale performance of steel fibre–reinforced concrete under dynamically applied loadings, results from a series of tests or from tests by different researchers are often found to be scattered. Besides variations in testing conditions, random variations of size, location and orientation of aggregates and fibres in steel fibre–reinforced concrete are deemed the fundamental reason of the scattering test data. High-fidelity modelling of concrete and steel fibre–reinforced concrete in mesoscale has been widely adopted to understand the influence of each component in the composite material. Numerical studies have been published to discuss the behaviour of steel fibre–reinforced concrete under dynamic splitting tension. Different shapes, for example, circles, ovals and polygons, of coarse aggregates were considered in different studies, and different conclusions were drawn. This study investigates the influence of the shape of aggregates on numerical prediction in mesoscale modelling of steel fibre–reinforced concrete materials with spiral fibres under dynamic splitting tension in terms of the strain distribution, cracking pattern and strength. The numerical model is validated by experimental results. It is found that the shape of aggregates in mesoscale modelling of splitting tensile tests has negligible influence. Furthermore, steel fibre–reinforced concrete specimens with different volume fractions of spiral fibres from 0.5% to 3.0% under various loading rates are simulated. Results from parametric simulations indicate the optimal dosage of spiral fibres in steel fibre–reinforced concrete mix with respect to the construction cost and mechanical property control.
35
Köroğlu, Mehmet Alpaslan, e Nebi Özdöner. "Behavioural Study of Steel Fiber and Polypropylene Fibre Reinforced Concrete". Key Engineering Materials 708 (settembre 2016): 59–63. http://dx.doi.org/10.4028/www.scientific.net/kem.708.59.
Testo completoAbstract (sommario):
Fibres are generally used as resistance of cracking and strengthening of concrete. The purpose of this research is to investigate the strength and mechanical properties of plain concrete, steel fibre reinforced concrete and polypropylene fibre reinforced concrete. The main focus of this investigation is to understand the reinforcement material’s behaviour on concrete and to compare the effect of increasing fibres on the concrete. The percentages of fibre used for both types of concrete were 0.5%, 1%, 1.5% and 2%. Details and results of the experimental study are provided and discussed.
36
Wolf, Benjamin, Andrea Kustermann, Christian Schuler, Christoph Dauberschmidt e Ömer Bucak. "Basalt reinforced concrete structures for retrofitting concrete surfaces". MATEC Web of Conferences 199 (2018): 09014. http://dx.doi.org/10.1051/matecconf/201819909014.
Testo completoAbstract (sommario):
Reinforced concrete facades exist since decades exposed to natural weather conditions. Thus nowadays lot of them are damaged by carbonation induced corrosion and therefor require repairing and retrofitting. The aim of this research project is to investigate the possibilities of basalt fibre reinforced concrete as repairing material and also basalt rebars as additional strengthening reinforcement. Investigations with basalt fibre reinforced mortar prisms showed best results in 3 point bending tests, tensile strength and also compressive strength using 0.3 Vol.-% basalt fibres in mixture. The mechanical properties of basalt rebars made of basalt fibre reinforced polymer were tested, showing higher values in tensile strength and Young´s Modulus than comparable steel reinforcement samples. The basalt rebar reinforced concrete samples achieved higher ultimate loads in three-point bending test compared to SRC samples. But after failure in the bonding area no residual load capacity remained. Finally basalt reinforcement bars seems to be well suited for use as retrofitting material for facade elements, but numerous properties have to be examined in further investigations.
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Bywalski, Czesław, e Mieczysław KamiIński. "RHEOLOGICAL STRAINS IN CONCRETE MODIFIED WITH STEEL FIBRE REINFORCEMENT". Journal of Civil Engineering and Management 19, n. 5 (29 ottobre 2013): 656–64. http://dx.doi.org/10.3846/13923730.2013.803497.
Testo completoAbstract (sommario):
This paper discusses the rheological properties of normal (ordinary) strength concrete. The results of tests aimed at determining the creep strains and shrinkage strains in normal strength concretes modified with steel fibre reinforcement are presented. The tests were divided into three groups. Steel fibre reinforced concretes (SFRCs) with a different composition were studied in each of the groups. Hook steel fibres, 50-mm long and 0.8 mm in diameter, were used in the tested SFRCs. The latter had an average compressive strength of 35.17–59.18 MPa and a steel fibre content of 0, 25, 35, 50 and 65 kg per 1 m3 of the concrete mixture respectively. Functional dependences for the increase in shrinkage and creep strains over time are given. The problem of the effect of aggregate grading on creep strains is addressed. Conclusions concerning the rheological deformability of steel fibre reinforced concrete are drawn.
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Friedrich, K., N. Glienke, J. Flöck, F. Haupert e S. A. Paipetis. "Reinforcement of Damaged Concrete Columns by Filament Winding of Thermoplastic Composites". Polymers and Polymer Composites 10, n. 4 (maggio 2002): 273–80. http://dx.doi.org/10.1177/096739110201000402.
Testo completoAbstract (sommario):
An experimental study was conducted to compare various composite systems with different fibres (E-glass and carbon) in two different thermoplastic matrices (PPS, PEEK) for their strengthening efficiency for wrapped concrete columns. The results indicated that the use of E-glass fibres within a polyphenylenesulfide matrix to externally reinforce concrete columns is quite effective. The carbon fibre PEEK based system does not show much improvement in the load carrying capacity. The thickness of wrap/radius of concrete column-ratio also has an influence on the strengthening efficiency. For example ten layers of glass fibre/PPS-tapes resulted in a five fold improvement of the compressive strength of the non-reinforced concrete. Predamaged samples with the same amount of reinforcement were still 4.5 times stronger than the undamaged, non-reinforced concrete.
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Hossain, Muhammad Monowar, Safat Al-Deen, Md Kamrul Hassan, Sukanta Kumer Shill, Md Abdul Kader e Wayne Hutchison. "Mechanical and Thermal Properties of Hybrid Fibre-Reinforced Concrete Exposed to Recurrent High Temperature and Aviation Oil". Materials 14, n. 11 (21 maggio 2021): 2725. http://dx.doi.org/10.3390/ma14112725.
Testo completoAbstract (sommario):
Over the years, leaked fluids from aircraft have caused severe deterioration of airfield pavement. The combined effect of hot exhaust from the auxiliary power unit of military aircraft and spilt aviation oils have caused rapid pavement spalling. If the disintegrated concreted pieces caused by spalling are sucked into the jet engine, they may cause catastrophic damage to the aircraft engine or physical injury to maintenance crews. This study investigates the effectiveness of incorporating hybrid fibres into ordinary concrete to improve the residual mechanical and thermal properties to prevent spalling damage of pavement. Three fibre-reinforced concrete samples were made with micro steel fibre and polyvinyl alcohol fibre with a fibre content of zero, 0.3%, 0.5% and 0.7% by volume fraction. These samples were exposed to recurring high temperatures and aviation oils. Tests were conducted to measure the effects of repeated exposure on the concrete’s mechanical, thermal and chemical characteristics. The results showed that polyvinyl alcohol fibre-, steel fibre- and hybrid fibre-reinforced concrete suffered a 52%, 40% and 26.23% of loss of initial the compressive strength after 60 cycles of exposure to the conditions. Moreover, due to the hybridisation of concrete, flexural strength and thermal conductivity was increased by 47% and 22%. Thus, hybrid fibre-reinforced concrete performed better in retaining higher residual properties and exhibited no spalling of concrete.
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Alberti, M. G., A. Enfedaque, J. C. Gálvez e A. Picazo. "Recent advances in structural fibre-reinforced concrete focused on polyolefin-based macro-synthetic fibres". Materiales de Construcción 70, n. 337 (18 febbraio 2020): 206. http://dx.doi.org/10.3989/mc.2020.12418.
Testo completoAbstract (sommario):
Fibre-reinforced concrete (FRC) allows reduction in, or substitution of, steel-bars to reinforce concrete and led to the commonly named structural FRC, with steel fibres being the most widespread. Macro-polymer fibres are an alternative to steel fibres, being the main benefits: chemical stability and lower weight for analogous residual strengths of polyolefin-fibre-reinforced concrete (PFRC). Furthermore, polyolefin fibres offer additional advantages such as safe-handling, low pump-wear, light weight in transport and storage, and an absence of corrosion. Other studies have also revealed environmental benefits. After 30 years of research and practice, there remains a need to review the opportunities that such a type of fibre may provide for structural FRC. This study seeks to show the advances and future challenges of use of these polyolefin fibres and summarise the main properties obtained in both fresh and hardened states of PFRC, focussing on the residual strengths obtained from flexural tensile tests.
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Banthia, N., e A. J. Boyd. "Sprayed fibre-reinforced polymers for repairs". Canadian Journal of Civil Engineering 27, n. 5 (1 ottobre 2000): 907–15. http://dx.doi.org/10.1139/l00-027.
Testo completoAbstract (sommario):
The use of fibre-reinforced polymers for repair and retrofit is growing at an unprecedented rate. This technique has been used for strengthening and rehabilitation of columns, beams, masonry, joints, etc. and has also found significant suitability for seismic applications. All research to date has focused, however, on wraps and jackets with continuous, unidirectional fibres. Within the auspices of Network of Centers of Excellence on Intelligent Sensing for Innovative Structures (ISIS) program, an entirely new method of fibre reinforced polymer coating is being developed. In this method, the composite with short, randomly distributed fibres is sprayed on the surface of concrete to be repaired. Composite gets pneumatically compacted on the application surface and develops a strong bond with concrete during the hardening process. In this paper, the effectiveness of the spray technique is compared with wraps carrying continuous fibres when applied to concrete cylinders under compression. To assess size effects, a companion test series involving larger cylinders was carried out. It was found that sprayed composites with randomly distributed short fibres performed equally well as or even better than wraps with continuous fibres. Within the continuous fibre wraps, those with a 0-90° fibre orientation are far more effective than those with a ±45° orientation.Key words: concrete, repair, glass fibre, polymer matrix, spray, wraps, deformability, size effects.
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Anandan, Sivakumar, Sounthararajan Vallarasu Manoharan e Thirumurugan Sengottian. "Corrosion Effects on the Strength Properties of Steel Fibre Reinforced Concrete Containing Slag and Corrosion Inhibitor". International Journal of Corrosion 2014 (2014): 1–7. http://dx.doi.org/10.1155/2014/595040.
Testo completoAbstract (sommario):
Corrosion in steel can be detrimental in any steel rebar reinforced concrete as well as in the case of steel fibre reinforced concrete. The process of corrosion occurring in steel fibre incorporated concrete subjected to corrosive environment was systematically evaluated in this study. Concrete specimens were prepared with steel fibre inclusions at 1.5%Vf(volume fraction) of concrete and were added in slag based concrete (containing manufactured sand) and replaced with cement at 20%, 40%, and 60% of total binder. Accelerated corrosion studies were carried out using alternate wetting and drying cycle accompanied with initial stress at 40% and 60% of ultimate stress. Concrete specimens were then immersed in chloride-free water and sodium chloride solution (3.5%) after subjecting to initial stress. The alternate wetting and drying process of different concrete mixes was continued for longer exposure (6 months). Later, the strength degradation during the accelerated corrosion process was then assessed in compressive and flexural tests. Test results indicated that the strength degradation was marginal in the case of steel fibre reinforced concrete containing higher slag content and for the concretes containing corrosion inhibitors. The maximum strength reduction was noticed in the case of plain concrete containing steel fibres and, with the slag addition, a considerable reduction in corrosion potential was noticed. Also, with the increase in slag replacement up to 60%, a significant increase in strength was noticed in flexural test. Experimental test results also showed that the corrosion process in steel fibre reinforced concrete can be controlled with the incorporation of corrosion inhibitors in cementitious system.
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Ghaffar, Abdul, Amit S. Chavhan e Dr R. S. Tatwawadi. "Steel Fibre Reinforced Concrete". International Journal of Engineering Trends and Technology 9, n. 15 (25 marzo 2014): 791–97. http://dx.doi.org/10.14445/22315381/ijett-v9p349.
Testo completo
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Zheng, Z. "Synthetic fibre-reinforced concrete". Progress in Polymer Science 20, n. 2 (1995): 185–210. http://dx.doi.org/10.1016/0079-6700(94)00030-6.
Testo completo
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Abd Rahman, Norashidah, Siti Amirah Azra Khairuddin, Norwati Jamaluddin e Zainorizuan Mohd Jaini. "Strength of Reinforced Fibrous Foamed Concrete-Filled Hollow Section". Materials Science Forum 936 (ottobre 2018): 219–23. http://dx.doi.org/10.4028/www.scientific.net/msf.936.219.
Testo completoAbstract (sommario):
At present, research on concrete-filled sections extends to using lightweight concrete to reduce the total weight of such structures. However, research on concrete-filled hollow sections (CFHS) using foamed concrete remains ongoing. Therefore, this study was conducted to determine the strength of reinforced fibrous foamed CFHSs. Two types of fibre, namely, steel and polypropylene fibres, were used. A short-column specimen was prepared and tested under compression load. Result shows that adding steel fibre to foamed concrete indicates a higher strength than adding polypropylene fibre. The strength of the CFHS is increased by adding reinforced bar and fibre in foamed concrete.
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Kovács, I. "Structural performance of steel fibre reinforced concrete — Part III. Behaviour in tension". International Review of Applied Sciences and Engineering 5, n. 2 (1 dicembre 2014): 105–17. http://dx.doi.org/10.1556/irase.5.2014.2.2.
Testo completoAbstract (sommario):
The present paper of a series deals with the experimental characterisation of tensile splitting strength and compressive behaviour of different structural concrete containing different volume of steel fibre reinforcement (0 V%, 0.5 V%, 1.0 V%, 75 kg/m3, 150 kg/m3) and different configuration of steel fibres (crimped, hooked-end). Tensile splitting tests were carried out on standard cylinder (∅ = 150 mm, l = 300 mm) specimens (so-called Brazilian test) considering random fibre orientation. Since the fibre orientation may significantly affect the tensile behaviour test series were also performed on cross-section (100 mm × 100 mm) of steel fibre reinforced concrete beams (100 mm × 100 mm × 240 mm) sawn out of steel fibre reinforced slab elements. Taken as a whole behaviour of steel fibre reinforced concrete was examined in tension taking into consideration different experimental parameters such as fibre content, type of fibres, fibre configuration, fibre orientation, size of specimens (size effect) and concrete mixture.
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Konrád, Petr, e Radoslav Sovják. "Experimental procedure for determination of the energy dissipation capacity of ultra-high-performance fibre-reinforced concrete under localized impact loading". International Journal of Protective Structures 10, n. 2 (13 marzo 2019): 251–65. http://dx.doi.org/10.1177/2041419618819506.
Testo completoAbstract (sommario):
Research presented in this article is aimed to investigate the ability of ultra-high-performance fibre-reinforced concrete to absorb and dissipate mechanical energy at elevated strain rate loading. Specimens made of ultra-high-performance fibre-reinforced concrete were subjected to the low-velocity impact using the new testing procedure where no fixed supports that hold the sample during the impact were applied. The fibre volume fraction of the ultra-high-performance fibre-reinforced concrete was set as the main test variable in the framework of this study and the volumetric fraction of fibres was ranging from 0.125% to 2%. A high-speed camera was used to measure velocities of the impactor and the ultra-high-performance fibre-reinforced concrete specimen before and after the impact. Consequently, the energy dissipated by the ultra-high-performance fibre-reinforced concrete specimen during the impact was calculated using a simple energy balance equation. To determine the basic material properties of ultra-high-performance fibre-reinforced concrete, quasi-static loading rate was applied and conventional methods were used. A significant difference between the values of dissipated energies for different loading rates and various fibre volumetric fractions was observed. It can be noted that the new procedure shows a reasonable approach for testing the fibre-reinforced cementitious composites under localized impact loading and is worthy of further optimization.
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Jahandari, Soheil, Masoud Mohammadi, Aida Rahmani, Masoumeh Abolhasani, Hania Miraki, Leili Mohammadifar, Mostafa Kazemi, Mohammad Saberian e Maria Rashidi. "Mechanical Properties of Recycled Aggregate Concretes Containing Silica Fume and Steel Fibres". Materials 14, n. 22 (21 novembre 2021): 7065. http://dx.doi.org/10.3390/ma14227065.
Testo completoAbstract (sommario):
In this study, the impact of steel fibres and Silica Fume (SF) on the mechanical properties of recycled aggregate concretes made of two different types of Recycled Coarse Aggregates (RCA) sourced from both low- and high-strength concretes were evaluated through conducting 60 compressive strength tests. The RCAs were used as replacement levels of 50% and 100% of Natural Coarse Aggregates (NCA). Hook-end steel fibres and SF were also used in the mixtures at the optimised replacement levels of 1% and 8%, respectively. The results showed that the addition of both types of RCA adversely affected the compressive strength of concrete. However, the incorporation of SF led to compressive strength development in both types of concretes. The most significant improvement in terms of comparable concrete strength and peak strain with ordinary concrete at 28 days was observed in the case of using a combination of steel fibres and SF in both recycled aggregate concretes, especially with RCA sourced from high strength concrete. Although using SF slightly increased the elastic modulus of both recycled aggregate concretes, a substantial improvement in strength was observed due to the reinforcement with steel fibre and the coexistence of steel fibre and SF. Moreover, existing models to predict the elastic modulus of both non-fibrous and fibrous concretes are found to underestimate the elastic modulus values. The incorporation of SF changed the compressive stress-strain curves for both types of RCA. The addition of steel fibre and SF remarkably improved the post-peak ductility of recycled aggregates concretes of both types, with the most significant improvement observed in the case of RCA sourced from a low-strength parent concrete. The existing model to estimate the compressive stress-strain curve for steel fibre-reinforced concrete with natural aggregates was found to reasonably predict the compressive stress-strain behaviour for steel fibres-reinforced concrete with recycled aggregate.
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Singh, Niraj Kumar, e Baboo Rai. "A Review of Fiber Synergy in Hybrid Fiber Reinforced Concrete". Journal of Applied Engineering Sciences 8, n. 2 (1 dicembre 2018): 41–50. http://dx.doi.org/10.2478/jaes-2018-0017.
Testo completoAbstract (sommario):
Abstract Fibre reinforced concrete (FRC) presently utilized as a part of special structures subjected to dynamic loads for example airport pavements, expressways overlays, bridge decks and machine foundations. In most cases, FRC contains just a single kind of fibre. The utilization of at least two kinds of fibres in an appropriate mix can possibly improve the mechanical properties of concrete and result in performance synergy. The audit demonstrates that the blend of fibre allows a more powerful control of the dynamic crack development. This review analyses the components for synergistic impacts that gives direction on the fiber and matrix choice.
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Bajad, Mohankumar Namdeorao. "Basalt Fibre Reinforced Concrete Unprotected to Chemical Attack". Civil and Environmental Engineering 16, n. 1 (1 giugno 2020): 131–37. http://dx.doi.org/10.2478/cee-2020-0013.
Testo completoAbstract (sommario):
AbstractThis paper depends on a test examination on basalt fibres which started from volcanic shakes and were dissolved at high temperatures. These stones were accessible from the world’s profound hull. M30 evaluation of concrete was structured according to is 10262:2009 with basalt fibres. The fibres alongside mineral admixtures were utilized in three distinct extents, that is 0 %, 1 %, 2 %, 3 % by heaviness of cement. The goal was to decide the characteristics of fibre reinforced concrete with various fibre extents. The strength properties, for example, compressive strength, split tensile strength, flexural strength, shear strength and the impact on strength of concrete when it was unprotected to sulphate attack after stipulated extended ages of curing were contemplated and thought about. From the examination, it was discovered that the basalt fibre expanded the strength of concrete notwithstanding when unprotected to sulphate attack bit by bit when compared with consistent concrete. The ideal strength of concrete was accomplished with an enlargement of 2 % basalt fibre.