Fiber Concrete Research Articles

Laboratory study of metakaolin and microsilica effect on the performance of high-strength concrete containing Forta fibers

In the present study aims to produce high-strength fiber concrete containing microsilica and metakaolin. Eight concrete mixing samples have been defined. The samples include the control concrete with ordinary Portland cement, replacing 10 percent of the weight of cement with microsilica. The amount of microsilica was kept constant in the next six designs. Three samples with the addition of Forta fibers at the rate of 0.2, 0.5, and 0.8 percent. Finally three samples with 0.5% Forta fibers and 8, 10 and 12% metakaolin were subjected to compressive, tensile and elastic modulus tests at the ages of 7 and 28 days. The addition of Forta fibers and the replacement of microsilica and metakaolin in concrete reduced the slump of concrete up to 5 cm. The highest compressive strength, tensile strength and elastic modulus at the age of 28 days of design 8 (concrete containing 10% microsilica, 0.5% Forte fibers and 12% metakaolin) are respectively equal to 73.6 MPa, 5.55 MPa and 37.49 MPa with The increase was 19.43%, 32.77% and 15.21% compared to control concrete without pozzolan and additives. Also, the relationship between compressive and tensile strength were presented. In total, all samples containing microsilica and fibers had a favorable effect on the resistance properties of concrete compared to the control design. The constant concern of bridge engineers, especially concrete bridges, is the production of concrete with high-strength and very low permeability in the face of their surroundings. Therefore, the result of this research can be a significant contribution to improving the quality of concrete used in bridge constructions.

Evaluation of recycled gravel in the concrete mixture for the surface layer of rigid flooring

Paving with recycled aggregates has already been widely carried out in some countries where there is already consolidated knowledge on the subject. This work analyzes in the laboratory the physical and mechanical behavior aspects of recycled aggregate in concrete mixes for rigid pavements. After selective collection at a construction site, the waste undergoes a crushing process, subsequent to granulation and separation into fractions to be used again in the realization of a new mixture with 40 and 100% replacement of natural gravel for recycled with the addition of structural concrete fibers that decrease shrinkage and increase final strength. In the same mix, these mixtures were compared with a conventional mixture that obtained better performance and presented greater compressive strength. The study sought to analyze the technical feasibility of using recycled material, testing the thickness of several concrete slabs for application on the pavement. Thus, it is concluded that the analyzed recycled aggregate is of promising use in hard pavement coating, as it presents a compressive strength superior to 25 MPa.

Compressive Strength Dependency on the Effect of Temperature Variation on the Percentages of Steel Fiber in Concrete

Aims: The aim of this study is to check the effectiveness of steel fiber on the compressive strength of concrete. Background: Fibers have long been used as building materials to improve the ductility, tensile, compressive, and flexural strengths of concrete. Although fibers have been known as an effective reinforcement material for concrete structures, it is also acknowledged to be a suitable alternative to reinforcement steel bars. Objective: The objective of this research is to investigate some engineering properties, the compressive behavior of steel fiber reinforced concrete (SFRC), and the effect of elevated temperatures of up to 1000°C on concrete. Methods: Various tests which included the slump test, compressive strength test, as well as heating tests were done. The workability (slump) and thermal effects of M20 SFRC were evaluated. Results: Based on the results obtained, it could be observed that the workability of the M20 concrete reduced with the increase in steel fiber (SF) content from 0% to 1.6% as values obtained were 80mm, 73mm, 67mm, 61mm and 55mm for SF contents of 0%, 0.4%, 0.8%, 1.2%, and 1.6% respectively. These values showed medium workability of the concrete according to ASTM C-143/C-143 M-03. Also, the addition of SF to plain M20 concrete greatly improved the compressive strength (ƒc) with the concrete strength at 26.89N/mm2, 30.41N/mm2, 32.85N/mm2, 35.90N/mm2 and 39.66N/mm2 after 28 days of curing for steel fiber contents of 0%, 0.4%, 0.8%, 1.2%, and 1.6% respectively. The f_c after heating the concrete mix to 1,000°C showed improved thermal resistance with 4.2N/mm2, 8.23N/mm2, 11.63N/mm2, 15.60N/mm2 and 17.20N/mm2 for SF contents of 0%, 0.4%, 0.8%, 1.2% and 1.6% respectively. Conclusion: The incorporation of steel fibers in the concrete mix decreased the workability of SFRC but increased its compressive strength and balling tendencies.

A comprehensive review on the use of natural fibers in cement/geopolymer concrete: A step towards sustainability

The construction industry is shifting towards environmentally friendly products due to the rising demand for non-renewable raw materials, their high energy consumption, and, most importantly, their detrimental environmental effects. High levels of solid waste produced by raw materials release dangerous gases like nitrous and Sulphur oxides, which are very harmful to the environment. In recent years, the usage of fibers has tremendously increased to make significantly robust structures. For sustainable, waste-free development, manufactured fibers can be replaced with natural fibers without compromising on the requirements. This study considers various natural fibers like basalt, coconut/coir, banana, sugarcane bagasse, hemp, kenaf, bamboo, jute, sisal, abaca, and cotton, and their effects on fresh and hardened concrete have been discussed. This article also reviews the composition, preparation, and processing procedures of various natural fibers, and their potential applications in building materials are highlighted. Future research avenues are identified, and possible negative impacts and limitations are discussed. Our findings confirm the feasibility of standard concrete using natural fibers in cement or geopolymer concrete. Lastly, this review compiles insights from numerous sources to aid academia and the construction industry in developing eco-friendly materials.

Mechanical and Durability Performance of Macro Polypropylene Fibrous Concrete

Mechanical and Durability Performance of Macro Polypropylene Fibrous Concrete

Using genetic algorithms for optimal beam design in high-strength fibrous concrete

Using genetic algorithms for optimal beam design in high-strength fibrous concrete

Study on the Compressive Stress–Strain Curve and Performance of Low-Slump Polypropylene Fiber Concrete after High Temperature

This study aims to investigate the effect of high temperature on the mechanical properties of low-slump polypropylene fiber (PPF) concrete, and tests the tensile and compressive properties of 204 groups of low-slump PPF concrete with eight different dosages and four different lengths at normal temperature and after high temperature. The results of the compressive test showed that PPF can significantly improve the mechanical properties of concrete after high temperature when the fiber content is small, and the compressive strength of low collapse polypropylene fiber concrete after high temperature showed a tendency to rise and then fall at the same temperature with an increase of the fiber admixture. When the fiber content was 0.5 kg/m3, the compressive strengths of 3 mm, 9 mm, 15 mm and 19 mm reached their maxima, which were 9.65%, 11.33%, 7.90% and 2.87% higher than that of ordinary concrete, respectively. With an increase in fiber length, the effect of PPF on the compressive strength of concrete is not obvious. PPF at high admixture further increases the pore and air content in concrete, which decreases the compactness of the concrete, thus leading to a decrease in the compressive strength of the concrete. When the temperature was 800 °C and the fiber admixture was 5.0 kg/m3, the compressive strength of PPF concrete with different lengths reduced by 17.83%, 17.27%, 22.59% and 23.92%, respectively, compared to normal concrete. In addition, according to the results, the optimal combinations of strength at room temperature and after high temperature were 3 mm fiber length and 1.0 kg/m3 dosing and 9 mm fiber length and 0.5 kg/m3 dosing, respectively, which increased the compressive and tensile strengths by 17.15% and 25.72% at room temperature and by at least 6% and 20% after high temperature, compared to the concrete without fiber dosing. Moreover, the stress–strain constitutive equations of PPF concrete at normal temperature and after high temperature were established, which can be used for finite element simulation and related mechanical analysis of PPF after high temperature.

Compression behavior of GFRP reinforced hybrid fibre reinforced concrete short columns subjected to eccentric loading

This paper presents the results of an experimental study carried out on the GFRP reinforced hybrid fibre concrete short columns subjected to eccentric compression. In this study, hybrid fiber-reinforced concrete was prepared in different volume ratios of hybrid fibers and the cooperative effect of the GFRP reinforcement and the steel-PVA hybrid fibre concrete with different fibre ratios under eccentric loading was explored. 10 GFRP reinforced hybrid fibre concrete short columns and 2 plain reinforced concrete short columns were tested to investigated their eccentric compressive properties. The tests results are presented in terms of failure modes, longitudinal reinforcement strain, concrete compressive strain and compressive load capacity of GFRP reinforced hybrid fibre concrete eccentrically compressed short columns. The results show that the concrete on the compressed side was crushed when the specimen under both the initial eccentricity of 50 mm and 100 mm the reinforcement were pulled on the tension side of specimen under a larger initial eccentricity of 100 mm. The addition of fibres can effectively prevent the crack generation and development and improve the bonding property between reinforcement and concrete. Besides, the addition of steel fibre contributes a better performance on the ultimate compressive capacity of specimen under a lager initial eccentricity with an optimal ratio of steel fibre at 1.4 %. PVA fibre effectively improve the ductility of the concrete, so that the hybrid fibre concrete elements remain relatively its integrity after failure. Finally, considering the effect of GFRP reinforcement and different ratios of steel fibre and PVA fibre on the compressive capacity of short concrete columns, the equation for the calculation of the ultimate compressive capacity of partial sections of eccentric columns is proposed, and a good agreement was observed between the tested and calculated value.

Effect of different fiber sizing on basalt fiber-reinforced cement-based materials at low temperature: From macro mechanical properties to microscopic mechanism

The interfacial bonding performance between basalt fiber bundles with three type of sizing agent and cement-based materials at different curing environment was studied through analyses on pull-out tests and scanning electron microscope (SEM) results. The mechanical development law of three type of basalt fiber reinforced concrete (BFRC) was studied through analyses on mechanical property tests and computed tomography (CT) results and theoretical analysis of molecular structure. It is concluded that: (1) The low-temperature environment significantly deteriorates the bonding properties of the basalt fiber and the cement mortar. The effect of bonding strength of basalt fiber cement mortar (BFCM) specimens with different fiber sizing agents differs significantly: dispersed type > flexible type > cluster type; (2) The SEM micro-morphology and CT scanning analysis show that the type of sizing agent affects the optimal volume dose of basalt fiber in concrete. Besides, the type of sizing agent affects the formation and development of the interface transition zone between the fiber and the cement matrix. (3) The differences in the molecular structure of the sizing agents have a significant effect on the interfacial properties of the basalt fiber-cement matrix, in which sizing agent containing KH560 component is better for the interface improvement between fiber and cement matrix. Large molecular weight epoxy resins may reduce the surface roughness of the basalt fiber sizing agents.

Utilization of Palm Fiber and Sikacim Concrete Additive as Additional Materials in Concrete Mixtures Viewed From the Strength of Pulling

Concrete is an important material used in regional construction. The purpose of this study was to utilize palm fiber as an additive to increase the split tensile strength of concrete. In addition, the sicacim concrete additive is used as a chemical additive in concrete mixtures to produce higher-quality concrete. This study used sicacim concrete additives (0.08% cement) and palm fiber (4%, 5%, and 6% by weight) as cement substitutes. The components of the test object used in this study were vessels with a size of 15 x 30 cm, aged 28 years, and rut values of 60-180 cm—alloy configuration using SNI 03-2834-2000 technique. There are a total of 12 specimens, three for each variation. The finished test is a substantial elasticity test. Based on the research results, the split tensile strength of standard concrete is 3.52 MPa; the split tensile strength of concrete with a mixture of 4% palm fiber and 0.8% sicacim concrete additive is 3.69 MPa; the splitting tensile strength of concrete using a mixture of 5% palm fiber and 0.8% sicacim concrete additive is 4.09 MPa; then the tensile strength of the concrete uses a mixture of 6% palm fiber and 0.8%.ABSTRAKBeton merupakan bahan penting yang digunakan dalam pembangunan daerah. Tujuan penelitian ini adalah memanfaatkan ijuk sebagai bahan tambahan untuk imeningkatkan ikuat itarik ibelah ibeton. iSelain iitu, aditif betonisicacim digunakanisebagaiibahanikimia itambahan idalam campuran betonidalam upaya menghasilkan ibeton iyang ilebih iberkualitas. Dalam penelitian iini, iaditif ibeton isicacim i(0,08% isemen) idan iijuk (4%, 5%, dan 6% berat) digunakan sebagai pengganti semen. Komponen benda uji yang dimanfaatkan pada penelitian ini adalah bejana dengan ukuran yaitu 15 x 30 cm dengan umur 28 tahun, dan nilai rut 60-180 cm. Konfigurasi paduan menggunakan teknik SNI 03-2834-2000. Total ada 12 spesimen, tiga untuk setiap variasi. Uji selesai adalah uji elastisitas substansial. Berdasarkan hasil penelitian, daya tarik belah pada beton normal adalah diangka 3,52 MPa kuat tarik belah beton dengan campuran 4% ijuk dan 0,8% aditif beton sicacim adalah 3,69 MPa; daya tarik belah beton menggunakan bahan campuran 5% ijuk dan 0,8% aditif beton sicacim adalah 4,09 MPa; kemudian daya tarik belah beton menggunakan campuran sebesar 6% ijuk dan 0,8%.

Impact of elevated temperatures on the mechanical properties and microstructure of waste rubber powder modified polypropylene fiber reinforced concrete

To investigate the impact of elevated temperature on the residual mechanical properties and microstructure of waste rubber powder modified polypropylene fiber concrete (RPFC). A total of 20 mix proportions were designed, considering the effects of waste rubber powder (WPR) dosage, polypropylene fiber (PP fiber) dosage and different ambient temperatures on the mechanical properties and microstructure of RPFC. Surface color change, weight loss, residual compressive strength of RPFC were evaluated after exposure to 100C, 200C, 400C and 600C. Meanwhile, the digital image correlation (DIC) technique was adopted to monitor the surface crack development of prism specimens at different loading stages. By X-ray diffraction (X-RD) analysis and scanning electron microscope (SEM) observation, the chemical and physical changes of RPFC were explored comprehensively. The results showed that the weight loss of RPFC increased after high temperature and the microcracks on the surface of the specimen increased significantly with the WRP content increase at 600 °C. Below 200 °C, the strength loss rate of RPFC is lower than that of PP fiber concrete; it is significantly higher in 400C than that of PP fiber concrete. RPFC exhibits lower intensity in the X-RD curve than that of PP fiber concrete. The needle-like channels and pores formed thanks to fibers and WRP melting helps to release the vapor pressure and improve the concrete resistance to bursting. Finally, the relationship between ambient temperature and compressive strength was established.

Enhanced fracture and durability resilience using bio-intriggered sisal fibers in concrete

Biomimetic agents and natural fibers are the promising combo to enhance the strength and self-healing efficacy of concrete infrastructures. However, their contribution in durability and fracture attributes of the host concrete matrix is still questionable. This study explores the use of sisal fiber reinforcement and Bacillus Subtilis to modify the fracture, shrinkage, and durability performance of concrete. Fracture response was analyzed in compression, tension and flexural followed by durability tests conducted for chloride penetration, water absorption, and acid resistance. Results revealed that the addition of Bacillus Subtilis increases stiffness, while sisal fiber imparts ductility to the concrete. The resulting mixture exhibited significant improvements in compressive strength (14.0%), split tensile strength (36.8%), flexural strength (30.9%), and bi-surface shear strength (25.4%) as compared to the control mixture. Additionally, the toughness indices of the resulting concrete improved under compressive, split tensile, and flexural loadings. Incorporating sisal fiber and Bacillus Subtilis into concrete mixtures also led to a notable reduction in linear shrinkage (58.9%), attributed primarily to the fiber-reinforcing effect. When sisal fiber and Bacillus Subtilis are combined in the concrete mix, there is a net improvement in the concrete's durability. The resulting blend exhibited an increase of 18.3%, 24%, and 14.1% in resistance to water absorption, chloride ion penetration depth, and acid attack, respectively, as compared to the control mixture. Micro-forensics endorsed the signatures of microbially-induced calcite precipitation in the concrete mixture, which contributed to add in the durability of the resulting matrix. The study demonstrated that the conjunctive use of Bacillus Subtilis and sisal fiber can yield durable and ductile concrete. The findings provide valuable insights into the use of biomimetic agents and natural fibers to enhance concrete fracture and durability attributes, with significant potential for practical applications in the construction industry.

Study on Strength and Conductivity of Graphite and Carbon Fiber Concrete

In order to study the effects of graphite and carbon fiber on the strength and conductivity of concrete, the compressive strength and conductivity of three types of composite concrete with different mixing ratios of graphite, glueless fiber and rubberized carbon fiber were tested. The results show that the strength of 5000 mesh graphite is weakened, but the ability to reduce resistivity is improved, and the resistivity can be stabilized at about 10 Ω·m. The performance of glue-free carbon fiber in concrete is better than rubberized carbon fiber. Carbon fiber can significantly change the electrical conductivity of concrete without significantly affecting the compressive strength of concrete. In the experiment, the best mixing ratio of concrete was cement 600 kg/m3, water-binder ratio 0.56, and 12mm glue-free carbon fiber content 0.89%. The 28d compressive strength is 36.4 MPa and the resistivity is 12.8 Ω·m.

Flexural Behavior of Slurry Infiltrated Waste Plastic Fiber Concrete

Flexural Behavior of Slurry Infiltrated Waste Plastic Fiber Concrete

Strengthening of AR Glass Fibre Concrete by Using Dunite Powder

Abstract: In the contemporary era. Concrete, the most significant and frequently used material, frequently needs to have a very high strength and acceptable workability. Research on glass fibre reinforced concrete led to the development of alkali resistant fibres with a high capacity for dispersion, increasing long-term durability. When dunite is utilised as a cement alternative rather of regular cement, concrete is discovered to become up to 40% stronger. Studies based on periodic cement rate data show that, on average, dunite powder is less expensive than cement. Future cement usage will be dominated by the replacement of dunite powder. In the current experimental investigation, alkali resistant glass fibres have been employed to investigate the effect on compressive and split tensile strength on M30 grade of concrete can be determined for 28,56 and 90 days

Mechanical Properties AR Glass Fibre Concrete by Using Dunite Powder

Abstract: In the modern world. The most significant and commonly utilised material, concrete, must frequently have a very high strength and appropriate workability.Alkali resistant fibres with a high capacity for dispersion were created as a consequence of research in glass fibre reinforced concrete, which increased long-term durability.Alkali resistant glass fibres have been used in the current experimental examination to explore the impact on compressive and split tensile strength on M30 grade of concrete.Concrete is found to become up to 40% stronger when dunite is used as a cement substitute rather than conventional cement.Test can be carried for 7 and 28 days. Studies based on periodic cement rate records indicate that the dunite powder is less expensive than cement, on average. The substitution of dunite powder will predominate in cement consumption in the future. It enhances, among other things, Split tensile strength, compressive strength.

Fiber incorporation and crack control: A synergistic approach to improving serviceability of RC concrete

This research elaborates on how cracking affects RC fiber concrete serviceability. It describes the different forms of fibrous concrete and how they function under cracking impact, enhancing concrete structure serviceability. Practical mechanical behavior language is often used to assess materials' performance. Historical assessment should help create experiences using RC fiber concrete, which reduces cracking and enhances concrete structures' serviceability. The issue is chronologically linked through early and modern author references. However, fibrous concrete's construction path is desirable worldwide. Fibrous concrete is employed in many building applications, from rehabilitation to new construction, due to its advantages over conventional construction materials. Lightness, high mechanical performance, the ability to manufacture in any form, ease of assembly, and a reduced need for supporting structures, controlled anisotropy, high specific strength, and specific stiffness all improve the serviceability of concrete structures. Fibrous concrete's many properties are opening new construction industry pathways. Thus, this research reviews the present use of fibrous concrete on cracks to improve concrete structure serviceability.

Experimental Study on Mechanical Performance and Microstructure of Polypropylene Fiber Recycled Concrete

Recycled concrete reinforced by polypropylene fibers boosts an alternative sustainable solution to address the need of reusing waste concrete. This paper reports experimental and analytical studies of static and dynamic comprehensive behavior on recycled concrete specimens reinforced with different contents of polypropylene fiber (PPF). Electro-hydraulic pressure testing was used to obtain static compressive strength, whereas 74 mm diameter Split Hopkinson Pressure Bar (SHPB) was applied for dynamic impact compression tests at four strain rates. In addition, the reinforcing mechanism of polypropylene fiber on recycled concrete was analyzed of the micro-structure through Scanning Electron Microscope (SEM). Finally, ANSYS/LS-DYNA was applied for the simulation of the SHPB test, which was validated by good agreements of the stress waveform and failure modes of the fiber-reinforced recycled concrete specimen during the impact test. It appears that polypropylene fiber can optimize the microscopic pore structure inside the concrete, thus effectively improving the mechanical properties of recycled concrete which were originally defected by recycled aggregate. Also, higher strain rates significantly increase dynamic compressive strength as well as impact toughness. This study shows that the optimal content of polypropylene fiber in recycled concrete is 0.1% – 0.2%. The numerical simulation by ANSYS/LS-DYNA further proved that the HOLMQUIST-JOHNSON-COOK (HJC) constitutive model can better reflect the dynamic performance of concrete.

Prospects of the use of high-tension fiber concrete as the basis for the formation of protective shelters and fortification structures during the russian-ukrainian war

This article analyzes the current state of protective shelters and fortification structures, foresees the modern possibilities of using fastening and basalt-type structures to increase the stability of concrete fortifications both during the construction of buildings for the protection of the civilian population, and for the creation of dugouts, fortifications and fire structures for the protection of personnel in accordance.
 Studies of the physical and mechanical properties of fiber concrete modified with plasticizers and active mineral additives using basalt and polypropylene fibers have shown that their introduction has a positive effect on the strength characteristics of concrete. The compressive strength of fiber concrete at day 28 increases from 61.4 to 77.0 and 96.2 MPa, respectively, and the flexural strength from 7.4 to 12.7 and 13.8 MPa, respectively.
 For the production of reinforced concrete protective materials, it is more effective to create hybrid high-strength concrete using fibers of different nature, followed by the formation of a reinforced concrete slab of the appropriate size. At the same time, the standard provides for the manufacture of prefabricated reinforced concrete elements of fortification structures and platoon support points of wall panels of the SP-1, SP-2 type and floor slabs PP-1 with a thickness of at least 300 mm from heavy concrete of strength class C32/40 with the use of plasticizers and active chemical additives.
 However, when using the obtained hybrid fiber concrete with strength class C50/60 and using a reinforcing mesh according to the calculated data, it is possible to reduce the effective thickness of the fiber concrete slab to 27.5 cm installation of fortification.
 The use of a reinforcing mesh in a complex with basalt fiber provides increased resistance of fiber concrete to the action of a high-speed impact due to an increase in the density of the cementing matrix as a result of a decrease in water consumption, as well as due to spatial three-dimensional reinforcement with dispersed basalt fiber. As a result of the mutual combination of the strength characteristics of the concrete matrix at the micro- and macro-levels in hybrid fiber concrete, it is possible to reduce the thickness of reinforced concrete elements and reduce the weight of the protective structure while meeting the requirements of the standards for such fortifications. An increase in the strength of cement stone occurs due to a decrease in the concentration of stresses in places of local stresses and a redistribution of energy throughout the volume of the material.
 The conducted studies of modern hybrid high-strength concrete with basalt fiber create new opportunities for the creation of protective concrete fortifications and fortification structures.

Dynamic mechanical properties, interface structure evolution and deformation behaviors of PVA-carbon fiber reinforced concrete with negative Poisson’s ratio design

Based on the advantages of negative Poisson's ratio (NPR) materials in controlling deformation and absorbing energy, this paper combines NPR design with the preparation of fiber reinforced concrete (FRC) to optimize the anti-dynamic load performance of FRC. In this paper, a helical auxetic yarn (Hay) with NPR effect is obtained by wrapping carbon fiber (CF) on polyvinyl alcohol fiber (PVAF) at a certain angle, and it is mixed into concrete in different forms to obtain auxetic fiber concrete. In order to explore the influence of auxetic fiber on the anti-dynamic load performance of concrete, split Hopkinson pressure bar (SHPB) test and dropping ball impact test are carried out on different FRC. The impact resistance of FRC under different impact velocities is tested, and the impact resistance behavior of FRC is analyzed by digital speckle correlation method (DSCM). The results show that in SHPB test, the anti-impact strength of the layered auxetic fiber concrete is 19.1 % higher than that of the plain concrete (PC), and its fracture energy is increased by 25.8 %. In the dropping ball impact test, its fracture energy is 5 ∼ 9 times that of PC. In addition, the results of scanning electron microscopy (SEM) and DSCM test show that the incorporation of auxetic fiber has a positive effect on improving the generation and development of internal cracks in concrete, which is expected to provide a reference for the application of NPR materials in explosion resistance, penetration resistance and impact resistance of building structures.