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1
Hasham, Md, V. Reddy Srinivasa, M. V. Seshagiri Rao, and 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.
Повний текст джерелаАнотація:
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.
2
Kahanji, C., F. Ali, and A. Nadjai. "Explosive spalling of ultra-high performance fibre reinforced concrete beams under fire." Journal of Structural Fire Engineering 7, no. 4 (December 12, 2016): 328–48. http://dx.doi.org/10.1108/jsfe-12-2016-023.
Повний текст джерелаАнотація:
Purpose The purpose of the study was to investigate the spalling phenomenon in ultra-high performance fibre reinforced concrete (UHPFRC) beams on exposure to a standard fire curve (ISO 834) under a sustained load. Design/methodology/approach The variables in this study were steel fibre dosage, polypropylene (PP) fibres and loading levels. The research investigated seven beams – three of which contained steel fibres with 2 vol.%, another three had steel fibres with 4 vol.% dosage and the seventh beam had a combination of steel fibres (2 vol.%) and PP fibres (4 kg/m3). The beams were tested for 1 h under three loading levels (20, 40 and 60 per cent) based on the ambient temperature ultimate flexural strength of the beam. Findings Spalling was affected by the loading levels; it exacerbated under the load level of 40 per cent, whereas under the 60 per cent load level, significantly less spalling was recorded. Under similar loading conditions, the beams containing steel fibres with a dosage of 4 vol.% spalled less than the beams with fibre contents of 2 vol.%. This was attributed to the additional tensile strength provided by the excess steel fibres. The presence of PP fibres eliminated spalling completely. Originality/value There is insufficient research into the performance of UHPFRC beams at elevated temperature, as most studies have largely focussed on columns, slabs and smaller elements such as cubes and cylinders. This study provides invaluable information and insights of the influence of parameters such as steel fibre dosage, PP fibres, loading levels on the spalling behaviour and fire endurance of UHPFRC beams.
3
Głodkowska, Wiesława, and Janusz Kobaka. "THE MODEL OF BRITTLE MATRIX COMPOSITES FOR DISTRIBUTION OF STEEL FIBRES / PLIENINIŲ FIBRŲ PASISKIRSTYMO KOMPOZITUOSE SU TRAPIOMIS MATRICOMIS MODELIS." Journal of Civil Engineering and Management 18, no. 1 (February 8, 2012): 145–50. http://dx.doi.org/10.3846/13923730.2012.657405.
Повний текст джерелаАнотація:
The paper deals with the distribution of steel fibres in the mineral composite of fine aggregate. The authors have proposed the distribution of steel fibres in a composite space model based on statistical grounds. The model provides for the randomness of fibre distribution in composite space in accordance with the adopted probability distribution. The developed model has been experimentally verified. The results concerning the distribution of steel fibres in mineral com- posite have been obtained from the statistical model and compared with those of the model frequently applied by other au- thors on the basis of geometric grounds. Good compatibility of steel fibre distribution for a description of both models has been ascertained. As the amount of fibres influences the strength of composite tensile, the relationship between the above introduced feature and the quantity of fibres in the cross-section located nearby tensile failure surface has been developed with reference to the experimental tests. Santrauka Straipsnyje analizuojamas plieninių fibrų pasiskirstymas kompozite su mineraliniais užpildais. Autoriai pasiūlė plieninių fibrų pasiskirstymo kompozite modelį, grįstą statistine analize. Fibrų pasiskirstymas matricoje nagrinėjamas kaip atsitiktinis dydis, pasiskirstęs pagal tikimybinį skirstinį. Modelis yra eksperimentiškai patikrintas: plieninių fibrų pasiskirstymas kompozito matricoje pagal siūlomą statistinį modelį buvo palygintas su kitų autorių tyrimų rezultatais, taikant modelius, grįstus geometriniais pagrindais. Gauti rezultatai sutampa gerai. Kadangi plieninių fibrų kiekis turi įtakos kompozito tempiamajam stipriui, pateikta eksperimentiniais tyrimais pagrįsta priklausomybė tarp fibrų kiekio ir kompozito tempiamojo stiprio.
4
Gribniak, Viktor, Pui-Lam Ng, Vytautas Tamulenas, Ieva Misiūnaitė, Arnoldas Norkus, and Antanas Šapalas. "Strengthening of Fibre Reinforced Concrete Elements: Synergy of the Fibres and External Sheet." Sustainability 11, no. 16 (August 17, 2019): 4456. http://dx.doi.org/10.3390/su11164456.
Повний текст джерелаАнотація:
In structural rehabilitation and strengthening, the structural members are often required to cope with larger design loading due to the upgrading of building services and design standard, while maintaining the member size to preserve the architectural dimensions and headroom. Moreover, durability enhancement by mitigating or eliminating the reinforcement corrosion problem is often desired. Concrete cracking is a major initiating and accelerating factor of the corrosion of steel reinforcement. The application of fibres is a prominent solution to the cracking problem. Furthermore, the fibres can increase the mechanical resistance of the strengthening systems. This study reveals the synergy effect of the combined application of steel fibres and external carbon fibre-reinforced polymer (CFRP) sheets. The investigation encompasses the use of fibre-reinforced polymer (FRP) reinforcing bars, discrete steel fibres, externally bonded and mechanically fastened FRP sheets in different combinations. It is discovered that the steel fibres can help to control concrete cracking and eventually alter the failure mode and enhance the flexural resistance. The FRP reinforcement system, together with the steel fibres, radically resolves the structural safety problem caused by corrosion of the steel bar reinforcement. Finally, the impact of the external sheet on the fire limit state performance needs to be resolved, such as by adopting fire protection rendering for the finishes layer.
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Lie, T. T., and V. K. R. Kodur. "Thermal and mechanical properties of steel-fibre-reinforced concrete at elevated temperatures." Canadian Journal of Civil Engineering 23, no. 2 (April 1, 1996): 511–17. http://dx.doi.org/10.1139/l96-055.
Повний текст джерелаАнотація:
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.
6
Krassowska, Julita, and 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.
Повний текст джерелаАнотація:
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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Abdullah, Muhd Afiq Hizami, Mohd Zulham Affandi Mohd Zahid, Badorul Hisham Abu Bakar, Fadzli Mohamed Nazri, and Afizah Ayob. "UHPFRC as Repair Material for Fire-Damaged Reinforced Concrete Structure – A Review." Applied Mechanics and Materials 802 (October 2015): 283–89. http://dx.doi.org/10.4028/www.scientific.net/amm.802.283.
Повний текст джерелаАнотація:
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.
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Al-Qutaifi, Sarah, and Ali Bagheri. "Evaluating Fresh and Hardened Properties of High-Strength Concrete Including Closed Steel Fibres." Open Civil Engineering Journal 15, no. 1 (May 4, 2021): 104–14. http://dx.doi.org/10.2174/1874149502115010104.
Повний текст джерелаАнотація:
Background: The tensile strength of the plain concrete is weak. Thus, fibres are embedded in concrete to improve its ductility. However, pulling out steel fibres from concrete structures is one of the most encountered issues in the fiber-reinforced concrete, which hinders using their maximum capacities. Objectives: Thus, closed steel fibres (square shape) were incorporated into concrete mixes to evaluate their impacts against the pulling-out effects and assess the feasibility of applying Closed Steel Fibres (CSFs) on the fresh and hardened concrete properties. Hooked end and straight steel fibres were also investigated for comparison. Methods: The utilized steel fibres were incorporated with lengths of 20, 30, and 40 mm, and volume fractions of 0.25%, 0.50%, and 0.75%. Silica Fume (SF) was involved in the fibre-reinforced concrete mixtures at 7% of the cement weight. Results: Paper outcomes stated that the inclusion of steel fibres involved different impacts on the concrete compressive strength depending on the applied fibre geometries and content. Conclusion: CSFs exhibited better performance against the pulling-out effect from the surrounding concrete structure than those of hooked end and straight steel fibres. However, the addition of CSFs has increased the concrete permeability due to their poor space-filling capacity.
9
Kodur, VKR. "Performance of high strength concrete-filled steel columns exposed to fire." Canadian Journal of Civil Engineering 25, no. 6 (December 1, 1998): 975–81. http://dx.doi.org/10.1139/l98-023.
Повний текст джерелаАнотація:
Results from an experimental program on the behaviour of high strength concrete-filled steel hollow structural section (HSS) columns will be presented for three types of concrete filling. A comparison will be made of the fire-resistance performance of HSS columns filled with normal strength concrete, high strength concrete, and steel-fibre-reinforced high strength concrete. The various factors that influence the structural behaviour of high strength concrete-filled HSS columns under fire conditions are discussed. It is demonstrated that, in many cases, addition of steel fibres into high strength concrete improves the fire resistance and offers an economical solution for fire-safe construction.Key words: high strength concrete, steel columns, fire-resistance design, high-temperature behaviour, concrete-filled steel columns.
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Bošnjak, Josipa, Akanshu Sharma, and Kevin Grauf. "Mechanical Properties of Concrete with Steel and Polypropylene Fibres at Elevated Temperatures." Fibers 7, no. 2 (January 24, 2019): 9. http://dx.doi.org/10.3390/fib7020009.
Повний текст джерелаАнотація:
Addition of steel fibres to concrete is known to have a significant positive influence on the mechanical properties of concrete. Micro polypropylene (PP) fibres are added to concrete to improve its performance under thermal loads such as in case of fire by preventing the phenomena of explosive spalling. An optimum mixture of steel and micro PP fibres added to concrete may be utilized to enhance both the mechanical and thermal behaviour of concrete. In this work, systematic investigations were carried out to study the influence of elevated temperature on the mechanical properties and physical properties of high strength concrete without and with fibres. Three different mixtures for high strength concrete were used, namely normal concrete without fibres, Steel fibre reinforced concrete and Hybrid fibre reinforced concrete having a blend of hooked end steel fibres and micro PP fibres. The specimens were tested in ambient conditions as well as after exposure to a pre-defined elevated temperature and cooling down to room temperature. For all investigated concrete mixtures the thermal degradation of following properties were investigated: compressive strength, tensile splitting strength, bending strength, fracture energy and static modulus of elasticity. This paper summarizes the findings of the tests performed.
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Enfedaque, Alejandro, Marcos G. Alberti, Jaime C. Gálvez, and Pedro Cabanas. "Numerical Simulation of the Fracture Behavior of High-Performance Fiber-Reinforced Concrete by Using a Cohesive Crack-Based Inverse Analysis." Materials 15, no. 1 (December 23, 2021): 71. http://dx.doi.org/10.3390/ma15010071.
Повний текст джерелаАнотація:
Fiber-reinforced concrete (FRC) has become an alternative for structural applications due its outstanding mechanical properties. The appearance of new types of fibres and the fibre cocktails that can be configured by mixing them has created FRC that clearly exceeds the minimum mechanical properties required in the standards. Consequently, in order to take full advantage of the contribution of the fibres in construction projects, it is of interest to have constitutive models that simulate the behaviour of the materials. This study aimed to simulate the fracture behaviour of five types of FRC, three with steel fibres, one with a combination of two types of steel fibers, and one with a combination of polyolefin fibres and two types of steel fibres, by means of an inverse analysis based on the cohesive crack approach. The results of the numerical simulations defined the softening functions of each FRC formulation and have pointed out the synergies that are created through use of fibre cocktails. The information supplied can be of help to engineers in designing structures with high-performance FRC.
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Prabakaran, E., D. Vasanth Kumar, A. Jaganathan, P. Ashok Kumar, and M. Veeerapathran. "Analysis on Fiber Reinforced Epoxy Concrete Composite for Industrial Flooring – A Review." Journal of Physics: Conference Series 2272, no. 1 (July 1, 2022): 012026. http://dx.doi.org/10.1088/1742-6596/2272/1/012026.
Повний текст джерелаАнотація:
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
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More, Florence More Dattu Shanker, and Senthil Selvan Subramanian. "Impact of Fibres on the Mechanical and Durable Behaviour of Fibre-Reinforced Concrete." Buildings 12, no. 9 (September 13, 2022): 1436. http://dx.doi.org/10.3390/buildings12091436.
Повний текст джерелаАнотація:
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.
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Jothi Jayakumar, Vikram, and 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.
Повний текст джерелаАнотація:
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.
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Simon, Seena, Arun Prathap, Sharanya Balki, and R. G. Dhilip Kumar. "An Experimental Investigation on Concrete with Basalt Rock Fibers." Journal of Physics: Conference Series 2070, no. 1 (November 1, 2021): 012196. http://dx.doi.org/10.1088/1742-6596/2070/1/012196.
Повний текст джерелаАнотація:
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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Ding, Yi Ning, Yue Hua Wang, and Yu Lin Zhang. "Investigation on Toughness of Fibre Cocktail Reinforced Self Consolidating Concrete after High Temperature." Materials Science Forum 650 (May 2010): 67–77. http://dx.doi.org/10.4028/www.scientific.net/msf.650.67.
Повний текст джерелаАнотація:
The effect of different fibres on the residual load-bearing capacity and the failure pattern of high-performance self consolidating concrete (HPSCC) after exposure to high temperature hass been studied in this work. The polypropylene fibers mitigate the spalling of HPSCC element clearly, but did not show clear effect on the mechanic properties of concrete. The macro steel fiber reinforced HPSCC showed higher flexural toughness and ultimate load before and after high temperatures. The mechanical properties of hybrid fibre reinforced HPSCC (HFHPSCC) after heating were better than that of mono-fibre reinforced HPSCC. The failure mode changed from pull-out of steel fibers at lower temperature to broken down of steel fibers at higher temperature. The use of hybrid fibre can be effective in providing the residual strength and failure pattern, and improving the toughness of HPSCC after high temperature.
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Gailitis, Rihards, Andina Sprince, Tomass Kozlovksis, Leonids Pakrastins, and Viktorija Volkova. "Impact of Polypropylene, Steel, and PVA Fibre Reinforcement on Geopolymer Composite Creep and Shrinkage Deformations." Journal of Physics: Conference Series 2423, no. 1 (January 1, 2023): 012030. http://dx.doi.org/10.1088/1742-6596/2423/1/012030.
Повний текст джерелаАнотація:
Abstract For the last 40 years, there has been increased interest in geopolymer composite development and its mechanical properties. In the last decades, there have been cases when geopolymer composites have been used for civil engineering purposes, such as buildings and infrastructure projects. The main benefit of geopolymer binder usage is that it has a smaller impact on the environment than the Portland cement binder. Emissions caused by geopolymer manufacturing are at least two times less than emissions caused by Portland cement manufacturing. As geopolymer polymerization requires elevated temperature, it also has a significant moisture evaporation effect that further increases shrinkage. It can lead to increased cracking and reduced service life of the structures. Due to this concern, for long-term strain reduction, such as plastic and drying shrinkage and creep, fibre reinforcement is added to constrain the development of stresses in the material. This research aims to determine how different fibre reinforcements would impact geopolymer composites creep and shrinkage strains. Specimens for long-term property testing purposes were prepared with 1% of steel fibres, 1% polypropylene fibres (PP), 0.5% steel and 0.5% polyvinyl alcohol fibres, 5% PP fibres, and without fibres (plain geopolymer). The lowest creep strains are 5% PP fibre specimens, followed by 1% PP fibre, plain, 0.5% steel fibre and 0.5% PVA fibre, and 1% steel fibre specimens. The lowest specific creep is to 5% PP fibre reinforced specimens closely followed by 1% PP fibre followed by 0.5% steel and 0.5% PVA fibre, plain and 1% steel fibre reinforced composites. Specimens with 0.5% steel and 0.5 PVA fibre showed the highest compressive strength, followed by 1% PP fibre specimens, plain specimens, 1% steel fibre, and 5% PP fibre reinforced specimens. Only specimens with 1% PP fibre and 0.5% steel, and a 0.5% PVA fibre inclusion showed improved mechanical properties. Geopolymer concrete mix with 1% PP fibre inclusion and 0.5% steel and 0.5% PVA fibre inclusion have a 4.7% and 11.3% higher compressive strength. All the other fibre inclusion into mixes showed significant decreases in mechanical properties.
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Wani, Umar Islam. "Determination of Single Parameter for Serviceability Requirements of Fibre Reinforced Concrete: Study of Fracture Characteristics." International Journal for Research in Applied Science and Engineering Technology 9, no. 11 (November 30, 2021): 108–15. http://dx.doi.org/10.22214/ijraset.2021.38768.
Повний текст джерелаАнотація:
Abstract: This The influence of fibre reinforcement on crack propagation in concrete was studied . Thirty-five double torsion specimens, made with three types of fibres (fibre glass , straight steel fibres and deformed steel fibres ) were tested . The variables were the fibre volume and size of the fibres. The test results indicated that the resistance to rapid crack growth increased somewhat with increasing fibre content up to about 1.25% - 1.5% by volume. The degree of compaction had an enormous effect on the fracture properties .The fracture toughness increased with fibre content up to about 1.25% by volume, and then decreased , due to incomplete compaction. It was found that in this test geometry, fibres did not significantly restrain crack growth. It was also observed that once the crack had propagated down the full length of the specimen, the system changed from a continuous system to a discontinuous system, consisting of two separate plates held together by the fibre reinforcement. Different types of fibres did not significantly affect the fracture toughness. Keywords: Fibre glass, straight steel fibers, deformed steel fibers, fracture toughness.
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Sabariman, Bambang. "KUAT TEKAN AKSIAL KOLOM PENDEK TERKEKANG PENAMPANG PERSEGI DIPERKUAT SERAT BAJA." INERSIA: lNformasi dan Ekspose hasil Riset teknik SIpil dan Arsitektur 14, no. 1 (April 30, 2018): 1–12. http://dx.doi.org/10.21831/inersia.v14i1.19499.
Повний текст джерелаАнотація:
ABSTRACTConfinement in concrete can increase ductility and compressive strength of the column (P0). While the use of steel fibre can also increase the ductility of concrete. In this study, the steel fibres as an additive in concrete short columns confined, and short columns were given concentric axial loads until they reach collapse. The results showed that the use of steel fibres in concrete can increase P0. The compressive strength (P0) of a confined short column without steel fibre was 52.06 ton to 63 ton, while on a short column with steel fibre was 57.68 ton to 69.28 ton. Those indicated that concrete short columns with steel fibres can increase the compressive strength, but in this study, the effect of the Ast (column longitudinal reinforcement area) has not yet. Keywords: Compressive strength, Confined, Short column, Steel fiber.ABSTRAKKekangan pada beton dapat meningkatkan daktilitas dan kuat tekan kolom (P0), sedangkan pemakaian serat baja (steel fiber) juga dapat meningkatkan daktilitas beton. Dalam penelitian ini serat baja sebagai bahan tambah pada beton kolom pendek terkekang, dan kolom pendek dibebani gaya aksial konsentris sampai mencapai runtuh. Hasilnya menunjukkan bahwa pemakaian serat baja pada beton terkekang dapat lebih meningkatkan P0. Kuat tekan P0 pada kolom pendek terkekang tanpa serat baja didapat 52.06 ton sampai dengan 63 ton, sedang pada kolom pendek terkekang memakai serat baja didapat 57.68 ton sampai dengan 69.28 ton. Hal ini menunjukkan bahwa kolom pendek beton terkekang dan diperkuat serat baja dapat meningkatkan kuat tekan kolom pendek, tetapi dalam penelitian ini kuat tekan kolom pendek belum mengamati pengaruh pemakaian Ast (luas tulangan longitudinal kolom). Kata kunci: Kuat tekan, Pengekangan, Kolom pendek, Serat baja
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Tadiboina, Naga Venkata Vamsi Krishna, and U. V. Narayana Rao. "Investigation of Mechanical Properties of M-sand concrete with Polypropylene and Steel fibers." IOP Conference Series: Earth and Environmental Science 1130, no. 1 (January 1, 2023): 012047. http://dx.doi.org/10.1088/1755-1315/1130/1/012047.
Повний текст джерелаАнотація:
Abstract This study looks into the impact of the adding of polypropylene(pp) and Hooked-end steel (HES) fibre on the mechanical characteristics of M-sand concrete (MSC). HES fibres with a 30-mm length were used at 1% to the weight of the cement for every mix and Polypropylene(pp) fibers with length 12-mm were used at the content of 0.25%, 0.50%, and 0.75% and 1%. All the mixes were produced with the mixing of HES and pp fibers. All the mixes with fiber-reinforced concretes (FRC) contained 60% M-sand as fine aggregate (FA) replacement. For increment of workability, the super plasticizer is also added. The compressive strength, splitting tensile strength, flexural strength of the concrete mixes was examined for M30 Concrete. Results of this work indicated that the adding of the M-sand improves compression characteristics of plain concrete mix. The outcomes also show that the mechanical characteristics of MSC were amplified by the addition of steel (HES) and polypropylene (pp) fibers at each weight fraction taken into account in this investigation. Additionally, it was found that adding 1% steel fiber considerably increased the concrete’s split tensile test values and also flexural test values. The blend with the highest performance out of all the varied steel and polypropylene(pp) fibre combinations tested had 1% HES and 0.5% pp fiber. Finally, the findings demonstrated that adding fibres to concrete led to reduction in compressive strength and increase in the value of split tensile strength and also flexural strength.
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Almojil, Marwan, and Pete S. Bate. "Cold Rolling and Annealing Microstructures and Textures of Low Carbon Steels." Materials Science Forum 654-656 (June 2010): 214–17. http://dx.doi.org/10.4028/www.scientific.net/msf.654-656.214.
Повний текст джерелаАнотація:
The development of crystallographic textures of IF and HSLA steels after 20, 50, 70 and 90% cold rolling reductions and subsequent recrystallisation have been investigated using Electron Backscattered Diffraction (EBSD). The HSLA steel was initially processed to give a volume fraction of about 0.2 of fine pearlite colonies, which acted as mechanically hard particles. Both cold rolling and recrystallisation textures are shown to be largely dependent on the rolling reduction for both steels. With increasing rolling reduction, the texture shows gradual intensification of α and γ fibre components. Although PSN was the dominant nucleation site in the HSLA steel during annealing, the α and γ fibres also exist in the recrystallisation textures, but with lower density.
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Klyuev, Sergey, Alexander Klyuev, and Nikolai Vatin. "Fine-grained concrete with combined reinforcement by different types of fibers." MATEC Web of Conferences 245 (2018): 03006. http://dx.doi.org/10.1051/matecconf/201824503006.
Повний текст джерелаАнотація:
The article deals with the application of combined reinforcement of fi-ne-grained concrete with steel wave and polypropylene fibers. High-density packaging of the mixture components was used to improve the strength and deformation characteristics. In order to reduce the cost of fibre concrete, composite binders were developed. Rational selection of filler and the use of a steel wave fiber gave the opportunity to get the fibre concrete with tensile compressive strength – 84.8 MPa, the tensile strength in bending – 19.8 MPa on technogenic sands of the Kursk Magnetic Anomaly. With combined reinforcement by steel and polypropylene fiber on technogenic sands of the Kursk magnetic anomaly fibre concrete with a tensile compressive strength – 82.8 MPa, in bending – 19.1 MPa was developed. With the same strength charac-teristics the developed mixture of fibre concrete based on combined re-inforcement due to reducing the amount of steel fiber at cost is lower by 25% compared to the composition on steel fiber and the same com-posite binder.
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Naraganti, Srinivasa Rao, Rama Mohan Rao Pannem, and Jagadeesh Putta. "Influence of Hybrid Fibres on Bond Strength of Concrete." International Journal of Mathematical, Engineering and Management Sciences 5, no. 2 (April 1, 2020): 353–62. http://dx.doi.org/10.33889/ijmems.2020.5.2.029.
Повний текст джерелаАнотація:
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.
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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, no. 2 (December 1, 2014): 105–17. http://dx.doi.org/10.1556/irase.5.2014.2.2.
Повний текст джерелаАнотація:
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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Hao, Yifei, Xin Huang, and Hong Hao. "Mesoscale modelling of concrete reinforced with spiral steel fibres under dynamic splitting tension." Advances in Structural Engineering 21, no. 8 (October 10, 2017): 1197–210. http://dx.doi.org/10.1177/1369433217734654.
Повний текст джерелаАнотація:
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.
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Li, Fang-Yuan, Liu-Yang Li, Yan Dang, and 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.
Повний текст джерелаАнотація:
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.
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Bista, Sagar, Sagar Airee, Shikshya Dhital, Srijan Poudel, and Sujan Neupane. "Comparison of Mechanical Properties of Normal and Fibre Reinforced Concrete (Grade M15)." Journal of Advanced College of Engineering and Management 5 (December 18, 2019): 153–64. http://dx.doi.org/10.3126/jacem.v5i0.26764.
Повний текст джерелаАнотація:
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.
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Li, Fang-Yuan, Cheng-Yuan Cao, Yun-Xuan Cui, and Pei-Feng Wu. "Experimental Study of the Basic Mechanical Properties of Directionally Distributed Steel Fibre-Reinforced Concrete." Advances in Materials Science and Engineering 2018 (June 20, 2018): 1–11. http://dx.doi.org/10.1155/2018/3578182.
Повний текст джерелаАнотація:
Directionally distributed steel fibre-reinforced concrete (SFRC) cannot be widely applied due to the limitations of current construction technology, which hinders research on its mechanical properties. With the development of new construction technologies, such as self-compacting concrete or 3D printing, directionally distributed SFRC has found new developmental opportunities. This study tested, compared, and analysed the basic mechanical properties of ordinary concrete, randomly distributed SFRC, and directionally distributed SFRC. The differences between the damage patterns parallel and perpendicular to the direction of the steel fibres were evaluated in directionally distributed SFRC. When the fibre volume fraction is high and the compression is applied perpendicular to the fibre direction, as the loading increases, the transverse deformation of the specimen is constrained by the fibres. When the compression is applied parallel to the fibre direction, the fibre cannot effectively constrain the transverse deformation of the specimens. When the volume fraction of directionally distributed steel fibres was 1.6%, the elastic modulus of the directionally distributed steel fibres was 39% higher than that of ordinary concrete. Comparison of the experimental values of the elastic modulus with those estimated by existing calculation methods revealed that a modification of the current calculation theories may be required to calculate the changes in the elastic modulus of directionally distributed SFRC with a high volume fraction of steel fibres.
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Yan, Cheng, and Sidney Mindess. "Bond between epoxy-coated reinforcing bars and concrete under impact loading." Canadian Journal of Civil Engineering 21, no. 1 (February 1, 1994): 89–100. http://dx.doi.org/10.1139/l94-009.
Повний текст джерелаАнотація:
The bond between epoxy-coated reinforcing bars and concrete under static, high strain rate, and impact loading was studied for plain concrete, polypropylene fibre reinforced concrete, and steel fibre reinforced concrete. The bond stress, slip, crack development, the bond stress–slip relationship, and the fracture energy during the bond-slip process were investigated experimentally. The results were compared with those for uncoated reinforcing bars. It was found that for epoxy-coated rebars, the bond resistance decreased, in terms of the maximum local bond stress and the average bond stress; wider cracks developed during the bond process; and the fracture energy during bond failure decreased. It was also found that the influence of epoxy coating on the bond behaviour for push-in loading was much more significant than for pull-out loading. However, steel fibre additions at a sufficient content, and higher concrete strength, can mitigate the above effects to a considerable degree. Polypropylene fibres were much less effective in this regard than steel fibres. Key words: epoxy-coated rebars, bond, fibre concrete, strain rate, impact steel fibres, polypropylene fibres, concrete, high strength concrete.
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Makara, ’Nyane, Riaan Combrinck, and Humaira Fataar. "Behaviour of Steel Fibre Reinforced Concrete Pavements on A Single Fibre Level." MATEC Web of Conferences 364 (2022): 05018. http://dx.doi.org/10.1051/matecconf/202236405018.
Повний текст джерелаАнотація:
Concrete is a popular construction material used all around the globe. It is strong in compression and weak in tension. To mitigate this tensile weakness, various reinforcement methods have been used over the years, of these, fibre reinforced concrete (FRC) has gained popularity. Fibres not only improve the tensile strength of the concrete matrix, but also control crack propagation through crack bridging action. The goal of this study is to investigate the long-term behaviour of FRC pavements through conduction of static and fatigue meso-scale level tests using different steel fibres. To achieve this goal, the influence of different fibre geometries and embedment angles on the pull-out behaviour of fibres in FRC was investigated first. This was carried out by examining 60mm Dramix 3D steel and 5D steel fibres at single fibre level. The embedment depth was kept constant at half the fibre length, and the fibre embedment angles were tested at 0°, 15° and 30°. The average maximum pull-out load, Amax, was determined first through static tests then fatigue tests were carried out using 85% of the Amax value on pre-damaged samples. These tests indicated that an increase in fibre embedment angle and number of hooks leads to additional anchorage of the fibre. Fibre pull-out was found to be the dominant fibre failure mechanism for the static single fibre pull-out tests (SFPTs).
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Aslani, Farhad, and Shami Nejadi. "Bond characteristics of steel fibre reinforced self-compacting concrete." Canadian Journal of Civil Engineering 39, no. 7 (July 2012): 834–48. http://dx.doi.org/10.1139/l2012-069.
Повний текст джерелаАнотація:
Steel fibre reinforced self-compacting concrete (SFRSCC) is a relatively new composite material that combines the benefits of the self-compacting concrete (SCC) technology with the advantages derived from the fibre addition to a brittle cementitious matrix. Steel fibres improve many of the properties of SCC elements including tensile strength, ductility, toughness, energy absorption capacity, fracture toughness and cracking. Although the available research regarding the influence of steel fibres on the properties of SFRSCC is limited, this paper investigates the bond characteristics between steel fibre and SCC. Based on the available experimental results, the current analytical steel fibre pullout model is modified by considering the different SCC properties and different fibre types (smooth, hooked) and fibre inclination. To take into account the effect of fibre inclination in the pullout model, apparent shear strengths (τ(app)) and slip coefficient (β) are incorporated to express the variation of pullout peak load and the augmentation of peak slip as the inclined angle increases. These variables are expressed as functions of the inclined angle (ϕ).
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Kovács, I. "Structural performance of steel fibre reinforced concrete — Part II. Compressive behaviour and stress-strain relationship." International Review of Applied Sciences and Engineering 5, no. 1 (June 1, 2014): 21–33. http://dx.doi.org/10.1556/irase.5.2014.1.3.
Повний текст джерелаАнотація:
Abstract The present paper of a series deals with the experimental characterisation of compressive strength and compressive behaviour (stress-strain relationship) of different structural concrete containing different volume of steel fibre reinforcement (0 V%, 0.5V%, 1.0V%, 75 kg/m3, 150 kg/m3) and different configuration of steel fibres (crimped, hooked-end). Compressive tests were carried out on standard cube (150 mm × 150 mm × 150 mm) and cylinder (Ø = 150 mm, l = 300 mm) specimens considering random fibre orientation. Since the fibre orientation may significantly affect the compressive behaviour, test series were also performed on cylinders (Ø = 70 mm, l = 100 mm) drilled out of fibre reinforced concrete beams and prisms (100 mm × 100 mm × 240 mm) sawn out of steel fibre reinforced deep beams. Throughout the tests stress-strain relationships were registered on the standard cube and cylinder specimens as well. In conclusion, behaviour of steel fibre reinforced concrete was examined in compression 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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Gupta, Vivek, and Gokulnath Venkadachalam. "A Review on Effect of Elevate Temperature on Properties of Self-Compacting Concrete Containing Steel Fiber, Glass Fiber and Polypropylene Fiber." International Journal of Research in Engineering, Science and Management 3, no. 10 (October 10, 2020): 9–15. http://dx.doi.org/10.47607/ijresm.2020.326.
Повний текст джерелаАнотація:
This paper presents an investigation into the efficiency of temperature-sensitive self-compacting concrete. Reviewing on self-compacted concrete, steel fibre, glass fibre, Polypropylene fibre. To this end, adding fibres (steel fibre, glass fibre, Polypropylene) content 1.2% for mixture of concrete material. When the cube samples were 28 days old. They have been heated to high temperatures. Each samples were heated to different temperatures for each concrete mixture (0ºC,100C, 200ºC). Then, Tests for weight loss and compressive strength were performed. The Observations of surface cracks were made after exposure to high temperatures. A significant loss of strength up to 30-40% for all concretes after 300ºC was observed, especially for concrete containing Polypropylene fibre, glass fibre, steel fibre. The fibres reduced the risk of explosive spalling and prevented it. Based on the results of the study, the output of fine aggregate concrete can be inferred.
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Hao, Yi Fei, Hong Hao, and Gang Chen. "Experimental Tests of Steel Fibre Reinforced Concrete Beams under Drop-Weight Impacts." Key Engineering Materials 626 (August 2014): 311–16. http://dx.doi.org/10.4028/www.scientific.net/kem.626.311.
Повний текст джерелаАнотація:
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.
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Pathan, Mohd Gulfam, Rajan L. Wankhade, A. M. Shende, Ajay Swaroop, and Nuha Mashaan. "Experimental Analysis for Performance of Concrete with Addition of Steel Fibres, SBR and Polypropylene Fibres." Jurnal Kejuruteraan 34, no. 3 (May 30, 2022): 429–45. http://dx.doi.org/10.17576/jkukm-2022-34(3)-10.
Повний текст джерелаАнотація:
Sufficient experimentation is observed in literature to examine the brittle behaviour of concrete. Presently, addition of different modified polymer and fibres can be treated as an effective way for improving the behaviour of concrete. Steel fibres are now generally mixed with concrete as because of such fibres sufficient strengths are gained. Fibre Reinforced Concrete acquires high stiffness, strength and durability subjected to different environment. In this experimental investigation it is mixed steel fibres with concrete with various percentages (0.35% to 0.85%) with addition of Polypropylene fibre. The primary objective is first to check whether the employment of steel fibres allows the improvement in strength. Next objective is to verify the effect of a mixing of steel fibres and modified polymer namely SBR. The third objective of the present study deals with the combination of steel fibres with synthetic polypropylene fibres in varying percentages. Preparation of specimen is performed in lab for different contents% of styrene butadiene rubber polymer with the hooked end SF. The experimental program includes cube, cylinder and beam specimens with fabricated in 1% to 10% steel fibres. Further 15% modified polymer-SBR is added in the different mixes. After this 0.15% to 0.25% polypropylene is mixed to M30 and M40 grade of concrete. The volume fraction for fibre having 100 kg/m3 of steel fibres (1.27% Vf) may be effectively employed. It is seen that by varying the %contents of SF’s and SBR; strong bond is developed leading to bridge of micro cracks by the polypropylene in RC members.
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Miller, Hugh D., Ali Akbarnezhad, Sara Mesgari, and Stephen J. Foster. "Effects of silane treatment on the bond between steel fibres and mortar." Magazine of Concrete Research 74, no. 10 (May 2022): 528–40. http://dx.doi.org/10.1680/jmacr.20.00366.
Повний текст джерелаАнотація:
The ability of fibres to resist crack growth in fibre-reinforced concrete can be significantly influenced by the fibre–matrix bond. This investigation reveals surface treatment of fibres as a viable technique for developing a uniform bond along the fibre–cement interface to resist growth of microcracks and thereby complement the physical restraint against pull-out provided by fibres’ shape and friction. Previous reports have shown effective chemical treatment of glass, carbon and polypropylene fibres. However, research into chemical surface treatment processes for steel fibres, the most common in concrete, is scarce and focused on corrosion and dispersion, rather than the fibre–matrix bond. Here, a silane treatment technique is proposed to strengthen the steel fibre–cementitious matrix bond. Surface energy measurements and X-ray photoelectron spectroscopy demonstrate the effectiveness of this treatment. Fibre pull-out tests conducted on silane-treated fibres show an apparent increase in pull-out energy, accompanied by a delay in reaching the peak load, compared with untreated fibres, suggesting increased resistance to crack initiation and growth. Furthermore, the results indicate improved flexural strength and direct tensile strength of mortar reinforced with silane-treated fibres compared with untreated fibres. The improvements are further corroborated by results from restrained drying shrinkage and volume of permeable voids.
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Lanwer, Jan-Paul, and Martin Empelmann. "Performance-Based Fibre Design for Ultra-High Performance Concrete (UHPC)." Applied Sciences 12, no. 17 (August 26, 2022): 8559. http://dx.doi.org/10.3390/app12178559.
Повний текст джерелаАнотація:
The paper presents a method to establish a performance-based fibre design of high-strength micro steel fibres for ultra-high-performance concrete (UHPC). The performance-based fibre design considers effects of fibre layout, fibre orientation, and type of loading (quasi-static and cyclic) and expands the current approach using experiences and suitability testing results. The performance-based fibre design is based on a so-called utilization rate, which is determined via pullout tests of high-strength micro steel fibres in UHPC under quasi-static as well as high cyclic loading with varying orientations and embedment depths. The utilization rate for a straight fibre pullout is 0.27 on average considering the measured tensile strength of the fibre and 0.50 considering the manufacturers specifications. For inclined fibres, additional bending stresses occur at the exit point of the fibre channels, leading to a significant increase in local tensile stress. Therefore, the utilization rate of inclined fibres under quasi-static loading is approximately 60–70% higher than in the case of straight embedded fibres (comparing it to the measured tensile strength). Comparing the utilization rate to the manufacturer’s specification, it increases to approximately 1.00. Under cyclic loading, the additional bending stresses in inclined fibres result in a local increase of the load amplitude, leading to a reduced fatigue resistance and premature fibre rupture, underlining the feasibility of a performance-based fibre design.
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Wetzel, Alexander, Daniela Göbel, Maximilian Schleiting, Niels Wiemer, and Bernhard Middendorf. "Bonding Behaviour of Steel Fibres in UHPFRC Based on Alkali-Activated Slag." Materials 15, no. 5 (March 4, 2022): 1930. http://dx.doi.org/10.3390/ma15051930.
Повний текст джерелаАнотація:
The mechanical performance of fibre-reinforced ultra-high-performance concrete based on alkali-activated slag was investigated, concentrating on the use of steel fibres. The flexural strength is slightly higher compared to the UHPC based on Ordinary Portland Cement (OPC) as the binder. Correlating the flexural strength test with multiple fibre-pullout tests, an increase in the bonding behaviour at the interfacial-transition zone of the AAM-UHPC was found compared to the OPC-UHPC. Microstructural investigations on the fibres after storage in an artificial pore solution and a potassium waterglass indicated a dissolution of the metallic surface. This occurred more strongly with the potassium waterglass, which was used as an activator solution in the case of the AAM-UHPC. From this, it can be assumed that the stronger bond results from this initial etching for steel fibres in the AAM-UHPC compared to the OPC-UHPC. The difference in the bond strength of both fibre types, the brass-coated steel fibres and the stainless-steel fibres, was rather low for the AAM-UHPC compared to the OPC-UHPC.
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Zhang, Jin Yi, Xin Tang Wang, Ping Xin Sun, and Hong Liang Sun. "Experimental Study of Post-Fire Behavior of Steel Fiber Reinforced Ceramsite Concrete Filled Steel Tubes." Applied Mechanics and Materials 204-208 (October 2012): 3401–4. http://dx.doi.org/10.4028/www.scientific.net/amm.204-208.3401.
Повний текст джерелаАнотація:
The axial compressive mechanical behavior of steel fiber reinforced ceramsite concrete filled steel tubes (noted as SFR-CCST) after exposure to fire are experimentally studied. Effect of furnace temperature, dosage of steel fiber in specimens on the post-fire mechanical performance of the specimens after exposure to fire was especially discussed. The results show that all the specimens of SFR-CCST have higher post-fire bearing capacity and better plastic deformation, and there was no obvious descending segment in the load-strain curves of the most specimens after exposure to fire. It was concluded that the furnace temperature applied to the specimens and dosage of steel fiber in the specimens of SFR-CCST has some effect on the post-fire mechanical performance of the ceramsite concrete-filled steel tubes after exposure to fire, and the dosage of steel fiber of 0.5% has the most effect on the post-fire performance of lightweight aggregate concrete filled steel tubes after exposure to fire.
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Alberti, M. G., A. Enfedaque, J. C. Gálvez, and A. Picazo. "Recent advances in structural fibre-reinforced concrete focused on polyolefin-based macro-synthetic fibres." Materiales de Construcción 70, no. 337 (February 18, 2020): 206. http://dx.doi.org/10.3989/mc.2020.12418.
Повний текст джерелаАнотація:
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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Xu, Zhuo, Hong Hao, and Hong Nan Li. "Influence of Fibre Shapes on Dynamic Compressive Behaviour of Fibre Reinforced Concrete." Applied Mechanics and Materials 82 (July 2011): 112–17. http://dx.doi.org/10.4028/www.scientific.net/amm.82.112.
Повний текст джерелаАнотація:
In this paper results are reported of impact tests performed to study the influence of different fibre types on dynamic compressive properties of fibre reinforced concrete (FRC). FRC specimens are prepared with the same concrete and 1% of fibres of different types. The compressive impact tests are conducted with an instrumented drop weight impact system consisting of a hard steel drop weight, two 180t fast response loadcells, a high speed video camera, and a fast response data acquisition system. In this study, six fibre types with different shapes and material properties are considered. They are synthetic fibres, undulated, cold rolled, flattened, hooked end and a new spiral shape steel fibres. The dynamic stress-strain relationship is obtained by fitting the load history from the bottom loadcell to the average strain history captured by the strain gages. The energy absorption capabilities are defined as the area under the stress-strain curve of FRC specimens. The performance of the new spiral shape steel fibre is discussed by comparing the test results with those obtained from specimens reinforced with other types of fibres. The influence of the fibre shapes on the failure modes, ductility and energy absorbing capacity of FRC is discussed.
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Aslani, Farhad, Yinong Liu, and 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, no. 1 (October 5, 2019): 3–16. http://dx.doi.org/10.1177/1045389x19880613.
Повний текст джерелаАнотація:
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.
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Wiemer, Niels, Alexander Wetzel, Maximilian Schleiting, Philipp Krooß, Malte Vollmer, Thomas Niendorf, Stefan Böhm, and Bernhard Middendorf. "Effect of Fibre Material and Fibre Roughness on the Pullout Behaviour of Metallic Micro Fibres Embedded in UHPC." Materials 13, no. 14 (July 14, 2020): 3128. http://dx.doi.org/10.3390/ma13143128.
Повний текст джерелаАнотація:
The use of micro fibres in Ultra-High-Performance Concrete (UHPC) as reinforcement increases tensile strength and especially improves the post-cracking behaviour. Without using fibres, the dense structure of the concrete matrix results in a brittle failure upon loading. To counteract this behaviour by fibre reinforcement, an optimal bond between fibre and cementitious matrix is essential. For the composite properties not only the initial surfaces of the materials are important, but also the bonding characteristics at the interfacial transition zone (ITZ), which changes upon the joining of both materials. These changes are mainly induced by the bond of cementitious phases on the fibre. In the present work, three fibre types were used: steel fibres with brass coating, stainless-steel fibres as well as nickel-titanium shape memory alloys (SMA). SMA fibres have the ability of “remembering” an imprinted shape (referred to as shape memory effect), triggered by thermal activation or stress, principally providing for superior performance of the fibre-reinforced UHPC. However, previous studies have shown that NiTi-fibres have a much lower bond strength to the concrete matrix than steel fibres, eventually leading to a deterioration of the mechanical properties of the composite. Accordingly, the bond between both materials has to be improved. A possible strategy is to roughen the fibre surfaces to varying degrees by laser treatment. As a result, it can be shown that laser treated fibres are characterised by improved bonding behaviour. In order to determine the bond strength of straight, smooth fibres of different metal alloy compositions, the present study characterized multiple fibres in series with a Compact-Tension-Shear (CTS) device. For critical evaluation, results obtained by these tests are compared with the results of conventional testing procedures, i.e., bending tests employing concrete prisms with fibre reinforcements. The bond behaviour is compared with the results of the flexural strength of prisms (4 × 4 × 16 cm3) with fibre reinforcements.
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Wasilewski, Piotr. "Full-Scale Dynamometer Test of Composite Railway Brake Shoes – Study on the Effect of the Reinforcing Fibre Type." Acta Mechanica et Automatica 12, no. 3 (September 1, 2018): 204–8. http://dx.doi.org/10.2478/ama-2018-0031.
Повний текст джерелаАнотація:
Abstract When designing or developing friction materials, it is crucial to predict how the modification of the formulation will affect their properties. Fibres are introduced in the composition of the phenolic-based brake friction materials to improve their mechanical strength. Apart from reinforcing the composite, fibres can also affect its tribological and thermophysical properties. In this study two composite friction materials are compared. The difference between the materials was the type of reinforcing fibre used in the formulation – in one case it was glass fibre, in the other steel fibre. Thermal diffusivity of both materials was measured and thermal conductivity was calculated. Frictional characteristics determined by means of full-scale dynamometer tests are analysed and discussed. Substitution of glass fibre with steel fibre led to increase in the friction coefficient. Maximum average temperature below wheel surface, observed during the test of the material containing steel fibre, was lower as compared to the test results of the material with glass fibre in its formulation, despite higher heat flux in the course of brake applications. Thermal conductivity of the friction material was enhanced by including steel fibre in the formulation.
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Lakusic, Stjepan. "Mechanical flexural properties of concrete with melt-extract stainless steel fibres." Journal of the Croatian Association of Civil Engineers 72, no. 12 (January 2021): 1155–64. http://dx.doi.org/10.14256/jce.2992.2020.
Повний текст джерелаАнотація:
An experimental study is performed to evaluate the effect of melt-extract stainless steel fibres on mechanical and flexural properties of concrete. A total of seventy-two specimens are used to determine an optimum fibre dosage and mechanical properties of plain and steel fibre reinforced concrete. Twelve full-scale beam specimens are then exposed to four-point bending tests. The effect of melt-extract stainless steel fibres on flexural behaviour of beams is quantified in this testing. A beam specimen is exposed to four-point bending, after being subjected to 15000 cycles of fatigue load. Pre- and post-fatigue flexural properties of beams with melt-extract steel fibres are compared and discussed.
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Lakusic, Stjepan. "Mechanical flexural properties of concrete with melt-extract stainless steel fibres." Journal of the Croatian Association of Civil Engineers 72, no. 12 (January 2021): 1155–64. http://dx.doi.org/10.14256/jce.2992.2020.
Повний текст джерелаАнотація:
An experimental study is performed to evaluate the effect of melt-extract stainless steel fibres on mechanical and flexural properties of concrete. A total of seventy-two specimens are used to determine an optimum fibre dosage and mechanical properties of plain and steel fibre reinforced concrete. Twelve full-scale beam specimens are then exposed to four-point bending tests. The effect of melt-extract stainless steel fibres on flexural behaviour of beams is quantified in this testing. A beam specimen is exposed to four-point bending, after being subjected to 15000 cycles of fatigue load. Pre- and post-fatigue flexural properties of beams with melt-extract steel fibres are compared and discussed.
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Shoaib, Mohd. "A Review: “Experimental Study on Steel Fiber Reinforced Concrete Using flat Crimped & Round Crimped Type Steel Fiber.”." International Journal for Research in Applied Science and Engineering Technology 10, no. 6 (June 30, 2022): 2813–16. http://dx.doi.org/10.22214/ijraset.2022.44472.
Повний текст джерелаАнотація:
Abstract: Steel Fibre Reinforced Concretes are characterized by high tensile and flexural strengths and high ductility, as well as by a high compressive strength and a very good workability. Ductility and strength of concrete can be improved at lower fiber contents, where fibers are used in combination rather than reinforcement with a single type of fiber. Durability problems concerning one type of fiber may be offset with the presence of a second type of fiber. Steel Fiber is added by 1% volume of concrete. The different concrete mixesalong with control mix proportions as 100% round crimped type fiber, 50% round crimped type fiber -50% flat crimped type fiber and 100% flat crimped type fiber. Two types of crimped steel fiber i.e. round crimped type steel fiber and flat crimped steel fiber are used of length having 50mm. An extensive experimental investigation consisting of 12 specimen of size 50 x 10 x 10cm for determining flexural strength, 12 specimen for compressive strength and 12 specimen for split end test are used.In the experiment, an combination of steel fibre with concrete is used, which improved various mechanical properties and the strength. This review study is a trial of givingsome highlights for inclusion of steel fibers especially in terms of using them with new mix ratio combinations with concrete.
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Drdlová, Martina, Oldřich Sviták, Petr Bibora, Miloslav Popovič, and René Čechmánek. "Blast Resistance of Slurry Infiltrated Fibre Concrete with Waste Steel Fibres from Tires." MATEC Web of Conferences 149 (2018): 01060. http://dx.doi.org/10.1051/matecconf/201814901060.
Повний текст джерелаАнотація:
The utilization of waste steel fibres (coming from the recycling process of the old tires) in production of blast resistant cement based panels was assessed. Waste fibres were incorporated in slurry infiltrated fibre concrete (SIFCON), which is a special type of ultra-highperformance fibre reinforced concrete with high fibre content. The technological feasibility (i.e. suitability of the waste fibres for SIFCON technology) was assessed using homogeneity test. Test specimens were prepared with three volume fractions (5; 7.5 and 10 % by vol.) of waste unclassified fibres. SIFCON with industrial steel fibres (10% by vol.) and ultra-highperformance fibre concrete with industrial fibres were also cast and tested for comparison purposes. Quasi-static mechanical properties were determined. Real blast tests were performed on the slab specimens (500x500x40 mm) according to the modified methodology M-T0-VTU0 10/09. Damage of the slab, the change of the ultrasound wave velocity propagation in the slab specimen before and after the blast load in certain measurement points, the weight of fragments and their damage potential were evaluated and compared. Realized tests confirmed the possibility of using the waste fibres for SIFCON technology. The obtained results indicate, that the usage of waste fibres does not significantly reduce the values of SIFCON flexural and compressive strength at quasi-static load - the values were comparable to the specimens with industrially produced fibres. With increasing fibre content, the mechanical parameters are increasing as well. Using of the waste fibres reduces fragmentation of SIFCON at blast load due to the fibre size parameters. Using of low diameter fibres means more fibres in the matrix and thus better homogeneity of the whole composite with less unreinforced areas. Regarding the blast tests, the specimen with waste steel fibres showed the best resistance and outperformed also the specimen with commercial fibres. Using of waste fibres in SIFCON technology can reduce the price of this composite by 70 % by keeping the original SIFCON extraordinary properties, which makes it very competitive material in the concrete area.
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De Melo Vieira, Mylene, Sergio Henrique P Cavalaro, and Antonio Aguado. "Analysis of the influence of chlorides in the mechanical behaviour of high-performance steel fibre reinforced cementitious composites." Journal of Urban Technology and Sustainability 4, no. 1 (June 7, 2021): e29. http://dx.doi.org/10.47842/juts.v4i1.29.
Повний текст джерелаАнотація:
Steel fibres are used in high amounts in high-performance steel fibre reinforced cementitious composite (HPSFRCCs) and ultra-high-performance steel fibre reinforced cementitious composite (UHPSFRCCs) to enhance its structural performance. Due to the amount and randomly distribution of steel fibres in the cementitious matrix a level of damage in the aesthetic and mechanical response of fibres may be expected for structures under chloride exposition. This work aims to assess the structural behaviour of uncracked HPSFRCCs subjected to chlorides. Eight mixes of HPSFRCCs with different fibre content (40, 80, 120 and 160 kg/m3), with and without chlorides added to the mixes were designed. Prismatic specimens were cast and exposed to two curing conditions: initially in wet room and then in climatic room. The mechanical properties were obtained by means of the 3-point bending tests. The presence of corrosion in cross-section of the specimens were also analysed after mechanical tests by means of visual inspection. The results showed that the chloride added to the mixes has little influence on the post-cracking response of fibres.
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Ouyang, Dong, Lin Jie Kong, Hao Fu, Liu Li Lu, Long Liao, and Chen Wu Huang. "Experimental Investigations on Mechanical Properties and Fire Resistance of Steel-Polypropylene Hybrid Fiber Reinforced Concrete." Advanced Materials Research 772 (September 2013): 182–87. http://dx.doi.org/10.4028/www.scientific.net/amr.772.182.
Повний текст джерелаАнотація:
This paper investigates the mechanical properties and the fire resistance of steel-polypropylene hybrid fiber-reinforced concrete. The type of the polypropylene fibers are polypropylene monofilament fiber, polypropylene fibrillated fiber, and macro polypropylene fiber, and the type of the steel fibers is hooked steel fiber. The experimental results show that the compressive strength, splitting tensile strength and flexural properties of steel-macro polypropylene hybrid fiber reinforced concrete are better than any others. And the fire resistance of steel-monofilament polypropylene hybrid fiber reinforced concrete is the best.