Properties Of Fiber Reinforced Concrete Research Articles

A Comprehensive Review: Strength Optimization of Fibre Reinforced Concrete by Using Waste Plastic Bottles

Abstract: Fibre reinforced concrete (FRC) has gained considerable attention in the construction industry due to its enhanced mechanical properties and durability. In recent years, researchers have explored innovative methods to optimize the strength and sustainability of FRC by incorporating waste materials, particularly plastic bottles. This review paper critically examines the latest advancements, methodologies, and outcomes in the utilization of waste plastic bottles to enhance the strength of fibre reinforced concrete. Various parameters such as fibre type, aspect ratio, dosage, and curing conditions are analysed to understand their impact on the mechanical properties of FRC. Additionally, the environmental implications and economic feasibility of incorporating waste plastic bottles in FRC production are discussed. The findings of this review aim to provide insights for researchers, engineers, and policymakers in promoting sustainable practices in the construction industry

Fiber-reinforced concrete in high-temperature environments: In-depth survey on mechanical performance and rheological features

The successful automatic performance of fiber-reinforced concrete (FRC) has led to its widespread application; adding fibers affects its novel properties. It is anticipated that concrete's long-term qualities will be impacted by its workability. A comprehensive assessment of the mechanical performance and rheological properties of FRC is given in this study. It presents more detail on how the FRC behaves in searching temperatures and provides an analysis of several heating as well as cooling methods along with the way they affect test outcomes. The study explores how reinforcing fibers, aggregates and substitute materials affect FRC's fire resistance. In particular, the concept of workability, which is a crucial quality in concrete, is studied and rheological models that make use of several rheometers are developed to clarify the rheological behavior of FRC. Several techniques to improve rheological functionality and performance are revealed in this study. The findings highlight the conflicting characteristics of fibers that can enhance the mechanical aspects of cement while reducing its fresh and rheological qualities. A comparable set of benefits and drawbacks complement FRC's fluidity. The research examines feasible approaches to regulate the rheological characteristics of FRC, thereby simplifying and improving the mechanical performance and workability of FRC.

The Effect of Glass Flour on the Microstructure and Properties of Fiber-Reinforced Concrete: Experimental Studies

The introduced limits on carbon dioxide emissions by the European Union encourage experimental work on new-generation materials containing smaller amounts of clinker. Currently, silica fly ash from hard coal combustion is widely used in cement and concrete technology in Europe and Poland. Their wide application is determined mainly by the chemical and phase composition, and in particular by the activity of pozzolanic and its high fineness, like cement. The aim of this study was to assess the effect of glass flour and polypropylene fiber modifiers on the properties of concrete and its microstructure. To analyze the results, samples of reference ordinary concrete and samples with different amounts of glass flour (0–30%) and a constant number of polypropylene fibers (0.025 kg) were used. The obtained test results showed the possibility of producing ordinary concrete with the addition of glass flour. The average compressive strength for concrete containing 10% additive was set at 49.3 MPa, 51.2 MPa, and 53.1 MPa after 28, 56, and 90 days of maturation for a content of 20% of 44.6 MPa, 46.4 MPa, and 48.4 MPa, respectively, and for 30% of 41.5 MPa, 43.8 MPa, and 45.6 MPa, respectively. By modifying concrete with glass flour and polypropylene fibers, a composite resistant to negative temperatures can be obtained. Glass flour shows reactivity with the cement matrix, and in small amounts, it might cause the microstructure to seal and a slight increase in compressive strength.

Experimental Study on Flexural Performance of Precast Prestressed Concrete Beams with Fiber Reinforcement

Fiber-reinforced concrete (FRC) has good toughness and a gentle stress–strain softening section, which can improve the inherent defects of concrete material such as high brittleness, easy cracking, and poor fracture toughness. In this paper, carbon fiber, aramid fiber and mixed fiber are introduced to enhance the performance of precast prestressed concrete beams (PPCB). The effects of different fiber types and adding rate on mechanical properties of FRC were studied via axial compression test and four-point bending test. Based on the flexural performance test of precast FRC beams, the failure form and the improvement degree of flexural ability of the beams were analyzed. Moreover, the load–deflection curve and the quantified ductility index obtained by the test were discussed, and the law of the improvement effect of fiber type on flexural property was revealed. The results show that the optimal addition rate of fiber is 0.6%. In addition, the addition of fiber significantly increased the cracking load and ultimate bearing capacity of the test beam, whereby the average increase in cracking load and ultimate bearing capacity was 40% and 20%, respectively. At the same time, the ductility of the beam is obviously enhanced by the action of fibers, among which the hybrid fiber has the best effect. Specifically, the ductility coefficient analysis verifies that aramid fiber plays an important role in improving the ductility of the components.

Study on Early-Age Elastic Modulus of FRC Using Electrical Resistivity and Resonance Frequency

The correlation between surface electrical resistivity and modulus of elasticity of fiber-reinforced concrete (FRC) was studied within early ages in this study as a novel nondestructive method for predicting the modulus of elasticity of FRC. In addition to the relationship of the two quantities, the influence of various discrete fibers such as glass, nylon, polypropylene, and steel on the early age properties of FRC was investigated. Twenty-one FRC mixes were designed and tested; including four fiber types, three different fiber volume fractions for each fiber type, and three different water-to-cement ratios for all the different mixes. The surface electrical resistivity meter and resonance testing gauge were used to measure each specimen’s surface electrical resistivity and modulus of elasticity. Early-age dynamic modulus of FRC may be predicted using the mechanical properties and dimension of the fiber, according to proposed mathematical calculations. Statistical analysis was performed on the experimental results and the results acquired by the proposed equations, to examine and proof the accuracy of the proposed equations. The acceptable coefficient of variation of 5–9 percent confirmed the good agreement between the measured and predicted values.

Experimental investigation on the mechanical properties and pore structure deterioration of fiber-reinforced concrete in different freeze-thaw media

• The mechanical properties and pore structure deterioration of FRCs in five freeze-thaw media (i.e. WF, NF, SSF, SCF, HSF) were studied. • The influence of the SCF on the mechanical properties of FRCs is the greatest, followed by the HSF, SSF, WF and NF. • There is an optimal fiber dosage for the FRCs to resist freeze-thaw cycle and salt erosion. • The porosities and salt corrosion degree of the FRCs exposed on the freeze-thaw cycles significantly increased. More engineering infrastructures have been built in cold regions and even permafrost area with salt-rich media, such as seawater, saline soil or groundwater. In such environment, the concrete is not only destroyed by freeze-thaw processes, but also damaged by corrosion. Therefore, this study investigated the mechanical properties and pore structure deterioration of fiber-reinforced concrete (FRC) in five types freeze-thaw media, i.e., water (WF), natural air (NF), 5 % sodium sulfate solution (SSF), 5 % sodium chloride solution (SCF), a mixture of the 5 % sodium sulfate and 5 % sodium chloride solution (HSF). A total of 180 freeze-thaw cycles were carried out on steel fiber-reinforced concrete (SFRC), polypropylene fiber-reinforced concrete (PPFRC), and basalt fiber-reinforced concrete (BFRC). The compressive strength and elastic modulus of FRCs after freeze-thaw cycles were measured to observe the influence of different media and fibers on the mechanical properties. The deterioration of the pore structure of the FRCs was observed by SEM (scanning electron microscope), XRD (X-ray diffraction), and MIP (mercury intrusion porosimetry) tests. The results show that the influence of the SCF on the mechanical properties of concrete is the greatest, followed by HSF, SSF, WF and NF. Moreover, there is an optimal fiber dosage for the FRCs to resist freeze-thaw cycles and salt erosion, the optimal fiber dosages for the SFRC, PPFRC and BFRC were 2 %, 2 ‰ and 0.5 ‰, respectively. Additionally, compared to the concrete not exposed to freeze-thaw cycles in the NF, the porosities of the FRCs exposed to the freeze-thaw cycles significantly increased. Under the same freeze-thaw media, the porosity of the BFRC is larger than that of the PPFRC. Furthermore, for the FRCs in the SSF, the proportions of gel micro-pores (<10 nm) decreased with the number of freeze-thaw cycles, whereas the proportions of capillary pores (10–5000 nm) and macro-pores (>5000 nm) increased.

Interphase phenomena during humidification electrostatic fiber concrete

Objective. The targets of modern construction require the search and development of new efficient technologies. The main trend in building architecture is the creation of spectacular (buildings-symbols, objects of competitions of countries) objects and structures that attract the attention of people and add to the list of unique attractions. To implement such projects, it is necessary to introduce high-tech advanced techniques, which is the electrostatic method of manufacturing fiberreinforced concrete.Method. The paper considers a new method of forming products and structures from fiber-reinforced concrete using electrostatics. An important place in the method is occupied by the physics of interfacial phenomena, namely wetting and capillary effects. The electrostatic deposition of layers of dry concrete mixture on the shaping frame occurs with the help of electrostatic sprayers.Result. This method allows saving cement, due to the use of a water-cement ratio close to the theoretical value. The issue of compaction of applied layers of dry concrete mix due to wetting with water with surface-active additives is discussed. In this regard, the kinetics of filling through and dead-end capillaries with water and other aspects of the new technology are considered. A hydrophilic binder has been developed using calcium lignosulfonate additive, which makes it possible to demonstrate the effectiveness of the electrostatic method in the future.Conclusion. The processes of wetting and the kinetics of liquid filling capillaries and channels of various shapes between the particles of the dry concrete mixture, as well as the compaction of the powder system as a result of moisture, will make it possible to realize difficult and unique projects in reality. The developed hydrophilic cement based on the surface-active additive LST (0.25%) contributes to the effect of interfacial electrostatic adhesion, thereby improving the properties of fiber-reinforced concrete.

Effects of Low Temperatures on Flexural Strength of Macro-Synthetic Fiber Reinforced Concrete: Experimental and Numerical Investigation

Fiber-reinforced concrete (FRC) is an attractive alternative to traditional steel bar-reinforced concrete structures, as evidenced by the constantly increasing market consumption of structural fibers for this purpose. In spite of significant research dedicated to FRC, less attention has been given to the effects of low temperatures on the mechanical properties of FRC, which can be critical for a variety of structural typologies and regions. With this in mind, an experimental program was carried out to assess the flexural behavior of macro-synthetic fiber-reinforced concrete (MSFRC) at different temperatures (from 20 °C to −30 °C) by means of three-point bending notched beam tests. The tested MSFRCs were produced by varying the content of polypropylene fibers (4 and 8 kg/m3). The results proved that the flexural strength capacity of all MSFRCs improved with decreasing temperature. Finite element analyses were then used to calibrate constitutive models following fib Model Code 2010 guidelines and to formulate empirical adjustments for taking into account the effects of low temperatures. The outcomes of this research are the basis for future experimental and numerical efforts meant to improve the design of MSFRCs subjected to low temperatures during service conditions.

Influence of fibers on the mechanical properties of cementitious composites - a review

Concrete is one of the major construction materials and it will possess sufficient compressive strength if properly designed and prepared. However, due to lower tensile strength and brittle nature, plain cement concrete tends to show sudden failure. Under this context, the different methods to improve the tensile strength of concrete have gained importance. The addition of fibers to concrete is considered to be an effective method to prevent brittle failure and improve the desirable characteristics of concrete such as tensile strength, impact resistance, abrasion resistance, shatter resistance, post-cracking ductility and strain capacity. Some types of fibers are also used in concrete for the repair, rehabilitation and retrofitting of structural members. The amount of fibers added to a concrete mix is based on volume fraction and aspect ratio. The past studies carried out on Fiber Reinforced Concrete (FRC) led to the development of more effective fiber mixing methods and performance-enhancing strategies. Among the various fibers, steel fiber is the conventional and most popular material. Several other natural and synthetic fibers also have been subjected to extensive research across the globe. In addition to all these, the effectiveness of recycled fiber reinforced concrete (RFRC) and fiber reinforced geopolymer concrete have been checked by several researchers and advancements in these materials are considered to be crucial steps towards the achievement of sustainable construction. This paper reviews the performance of various natural and synthetic fibers such as steel fiber, glass fiber, basalt fiber, jute fiber, and polymer fiber as a reinforcing material in concrete. The study is based on various fresh and hardened properties of FRC and parameters such as relative fiber matrix stiffness, volume of fibers, aspect ratio of fibers, orientation of fibers, workability and compaction of concrete, size of coarse aggregate and mixing.

Reliability-based assessment of the partial factor for shear design of fibre reinforced concrete members without shear reinforcement

Fibre reinforced concrete (FRC) is increasingly used for structural purposes owing to its many benefits, especially in terms of improved overall sustainability of FRC structures relative to traditional reinforced concrete (RC). Such increased structural use of FRC requires safe and reliable models for its design in ultimate limit states (ULS). Particularly important are models for shear strength of FRC members without shear resistance due to the potential of brittle failure. The fib Model Code 2010 contains a model for the shear strength of FRC members without shear reinforcement and the same partial factor accepted for RC structures is accepted for FRC elements. This approach, however, is potentially on the unsafe side since the uncertainties of some design-determining mechanical properties of FRC (i.e., residual flexural strength) are larger than those for RC. Therefore, in this study, a comprehensive reliability-based calibration of the partial factor γc for the shear design of FRC members without shear reinforcement according to the fib Model Code 2010 model is performed. As a first step, the model error δ is assessed on 332 experimental results. Then, a parametric analysis of 700 cases is performed and a relationship between the target failure probability βR and γc is established. The results demonstrate that the current model together with the prescribed value of γc = 1.50 does not comply with the failure probabilities accepted for the different consequences of failure of FRC members over a 50-year service life. Therefore, changes to the shear resistance model are proposed in order to achieve the target failure probabilities.

Fresh and rheological characteristics of fiber reinforced concrete——A review

Fiber reinforced concrete (FRC) has been widely used due to its perfect mechanical performance, but inclusion of fibers has a decisive influence on the fresh properties. Workability as a short-term property is expected to affect long-term properties of concrete. In this paper, the definition of workability, rheological models of FRC, measurement methods of workability and rheological properties, as well as the measure techniques of the fiber orientation and distribution were discussed in detail. This paper presents a complete and updated literature review on the effects of fiber, various constituent, mixing and temperature on the fresh and rheological characteristics. It also reveals the relationship between workability, rheological properties and mechanical performance of FRC. Most importantly, the paper discusses plausible strategies to control rheological properties of FRC, which makes workability and mechanical performance of FRC simpler and more predictable.

Effects of Coarse Aggregate Maximum Size on Synthetic/Steel Fiber Reinforced Concrete Performance with Different Fiber Parameters

Recently, fiber has been incorporated into concrete mixtures, where its distribution in the concrete matrix helps to improve and enhance the mechanical properties of fiber-reinforced concrete (FRC). The aim of this study is to investigate the influence of steel and synthetic fiber parameters, along with different coarse aggregate maximum sizes (CAMZs) on FRC performance. Additionally, in past research, the empirical relationships among the compressive, tensile, and flexural strengths of plain concrete and FRC were assessed, and correlations between these mechanical properties of FRC were examined. For each CAMZ, four fiber dosages for each fiber type were considered. The results demonstrate the mechanical properties of FRC enhanced as the fiber length increased from 13 mm to 60 mm, the CAMZ increased from 9.5 mm to 37.5 mm, and the ratio of the fiber length to the CAMZ was in the range of 0.35–5.68. All mixtures have been intended to exhibit similar compressive strengths; however, the synthetic/steel fiber advanced the brittleness ratio of specimens with G10, G19, and G38 to approximately 36.8%, 40.7%, and 47.4% greater than the contral specimens, respectively. In addition, from the regression analysis investigation, there are strong correlations from the regression analysis of the mechanical property results of FRC.

Fiber Foam Tuffcrete Structure and Properties Formation on the Basis of Volcanic Tuff Dusting Waste

The results of studies on the foam concrete and fiber concrete development based on volcanic tuff dusting waste are presented. The foam concrete compositions that can significantly reduce the Portland cement consumption and at the same time increase its strength properties are proposed. To study the dispersed reinforcement parameters’ effect on the properties of fiber-reinforced concrete, an experiment with a second-order composite rotatable plan such as a regular hexagon was conducted. The use of fosta nylon fibers in foam concrete increases their strength properties and positively affects the structure. Dispersed fibers not only reinforce the matrix, but also significantly change its structure indicators, in particular, porosity indicators (uniformity of pore diameter distribution, average pore size), which in turn affects the strength characteristics of the material.

Experimental investigating the properties of fiber reinforced concrete by combining different fibers

Adding fibers improves concrete performance in respect of strength and plasticity. There are numerous fibers for use in concrete that have different mechanical properties, and their combination in concrete changes its behavior. So, to investigate the behavior of the fiber reinforced concrete, an in vitro study was conducted on concrete with different fiber compositions including different ratios of steel, polypropylene and glass fibers with the volume of 1%. Two forms of fibers including singlestranded and aggregated fibers have been used for testing, and the specimens were tested for compressive strength and dividable tensile strength (splitting tensile) to determine the optimal ratio of the composition of fibers in the concrete reinforced by hybrid fibers. The results show that the concrete with a composition of steel fibers has a better performance than other compounds. In addition, by adding glass and propylene fibers to the composition of steel fibers, the strength of the samples is reduced. Also, if using the combination of fibers is required, the use of a combination of glass fibers with steel fibers will provide a better compressive strength and tensile strength than the combination of steel fibers with propylene.

Effect of fiber types on the electrical properties of fiber reinforced concrete

Using fibers in concrete, has been recognized as a practical method to improve concrete properties such as reduction in crack development and higher resistance against impact and abrasion. Dry cementitious material exhibits very high electrical resistivity. However, fibers can significantly decrease the electrical resistivity of concrete which affects its insulating nature and has negative effects on concrete properties such as durability and also in special cases such as rail road ties production. In this paper the effect of steel, glass, and nylon fiber on the electrical properties of Fiber Reinforced Concrete (FRC) is investigated. Six different fiber volume fractions (Vf) (0.10% vol., 0.25% vol., 0.50% vol., 0.75% vol., 1.00% vol., 1.50% vol.) and several water-to-cement ratios (w/c) were considered as the main variables in the present study. In order to test the electrical properties of FRC, 100 mm × 200 mm cylinders were casted, cured and tested. The four point technique was used for measuring the surface electrical resistivity of concrete after curing in water for 3, 7, 28, and 44 days. Additionally, the compressive strength of each specimen was determined experimentally using the Compression Test Machine. The results revealed that the electrical resistivity of FRC decreases with an increase in fiber content but different types of fibers have different electrical effects on concrete. The effects of different volume fractions of three fiber types, together with different concrete mix proportions are presented and discussed.

Impact of waste fibers on the mechanical performance of concrete composites

Concrete composite reinforced with fibers enhances strength at the micro level, to reduce cracks and to make it lighter in weight. Previous researchers used metallic, vegetable as well as synthetic fibers for this purpose. In the current study, waste synthetic fibers (glass, polyester, and polypropylene) were added in three different proportions (2%, 4%, and 6%) by the weight of cement. The aim was to investigate their effect on the mechanical properties of fiber reinforced concrete (FRC) and fiber reinforced mortar (FRM). After curing of samples for 28 days different mechanical testing (compressive strength, impact strength, and three-point bending strength) were conducted to compare their performance. From the results obtained it was concluded that the mechanical properties were improved by adding the synthetic fibers with different proportions. Glass fiber has the highest effect on the compressive strength of FRC followed by polypropylene and polyester fibers. 4% proportions of the fibers had better performance in mechanical properties of FRC than 2% and 6% in all the samples tested. Also, in flexural strength, the same trend was observed while in impact strength the polyester performs better than polypropylene. From the results, it was concluded that the glass fiber reinforced concrete has given the best performance with 4% fiber ratio in all aspects.

Research on the Dynamic Mechanical Properties and Constitutive Models of Steel Fiber Reinforced Concrete and Polypropylene Fiber Reinforced Concrete

This paper presents the results of an experimental research designed to investigate the dynamic mechanical properties and constitutive model of fiber reinforced concrete (FRC), including steel fiber reinforced concrete (SFRC) and polypropylene fiber reinforced concrete (PFRC) under fast loading. Experimental results are achieved by using the electrohydraulic servo loading test method, implying that the dynamic mechanical properties of PFRC and SFRC, such as peak stress, peak strain, and toughness, are positively affected by strain rate. The experimental elastic modulus test results of FRC with different fiber contents indicate that the elastic modulus is positively affected by polypropylene or steel fibers and increases with the increment of fiber content. Finally, the experimental stress-strain curves obtained in the MTS electrohydraulic servo system test are fitted by a damage dynamic constitutive model of FRC. The good fitting with experimental results proves that the model could be appropriate to describe the dynamic mechanical properties of FRC.

Mechanical and Durability Properties of Fibre Reinforced Concrete made with OPC, GGBS and Metakaolin

Concrete is a globally utilized material in the construction field. In the last few decades, Concrete consumption has become multifold and usage has enhanced in massive scale due to the rapid growth of infra sector. Generally, Concrete consists of cement, aggregate, and water; these ingredients become more expensive day by day and additionally hard to please and is increasing widely. During the process of making Ordinary Portland Cement(OPC) produces a large amount of greenhouse gases and the environment being polluted. To minimize the cement utilization and environmental issues is essential to switch the cement by another alternate materials such as pozzolanas. The various number of pozzolanic materials comes from industrial wastes are Groundz Granulatedz Blastz furnacez Slagz (GGBS), xFlyqAsh (FA), zSilicazFume (SF), Metakaolin (MK) etc are utilized in concrete. Similarly, the availability of river sand is getting drained furthermore it turns out troublesome. In order to avoid this problem river sand is alter by zManufacturedkSand (M Sand). An attempt is made in the present investigation to study on properties of fiber reinforced concrete (qsteelu fibers @ 1% of binder) of M40 grade made with OPC, GGBS, MK and manufactured sand. In this study, OPC is replaced by GGBS and MK in different proportions. By casting requisite number of cubes, cylinders then zMechanical properties are determined such as fCompressivekstrength,sSplitdtensile strength tests and durability properties are determined by conducting Water absorption and Sorptivity tests. Test results are compared between controlled concrete and innovative concrete of M40 grade.It is observed that 30%(15%GGBS,15%MK) replacement is optimum for strength and durability criteria.

Mixture design of self-levelling ultra-high performance FRC

Fibre reinforced concrete (FRC) generally has low workability, especially when the water/cementitious materials (W/CM) ratio is low and the fibre content is high. Hence, the production of self-levelling ultra-high performance FRC is rather difficult. Adding more superplasticizer (SP) may be one solution, but there could be the problem of over-dosage. In this research, the fresh and hardened properties of FRC containing different amounts of steel fibres were studied. To achieve ultra-high performance, the W/CM ratio was lowered to 0.17 and the fibre volume was increased to 2%. The workability was evaluated in terms of slump, flow, flow rate and a newly defined measure called degree of levelling, whereas the strength was evaluated in terms of cube strength. It was found that there is an optimum SP dosage for maximum degree of levelling. Moreover, by correlating the strength of the FRC to the plain matrix strength and fibre volume, design equations were derived from which it can be seen that the matrix strength and fibre volume are the key factors governing the strength of FRC and that they together exert certain synergistic effect.

Impact resistance of fiber-reinforced concrete – A review

This paper reviews the state of the art of the impact resistance of ordinary fiber-reinforced concretes (FRCs) containing various fibers. First, various types of impact test methods that are current available are addressed as well as some concerns about them based on extensive literature reviews and our perspective. Then, common properties of FRCs under impact loading regardless of fiber type, such as the reasons for their enhanced strength under impact, the effect of size on impact resistance, and several factors (i.e., matrix strength, loading conditions, and fiber existence) that influence strain-rate sensitivity, are discussed. Furthermore, the comprehensive impact resistances of FRCs with various fibers (i.e., steel, polymeric, carbon, basalt, natural, and hybrid fibers) are investigated under different loading conditions. After summarizing the impact properties of FRCs with various fibers, the comparative impact resistance of FRCs according to the fiber type is evaluated to determine which type gives the best improvement of impact resistance. Lastly, the effect of supplementary cementitious materials (SCMs), i.e., fly ash, silica fume, and slag, on the impact resistance of FRCs is examined, and some combinations of SCM and fiber types that lead to enhanced impact resistance are suggested.