Influence Of Fiber Reinforcement Research Articles

Advances and perspectives in engineered cementitious composites: a comprehensive review

Engineered cementitious composites (ECCs) have garnered significant attention within the construction industry, owing to their exceptional mechanical properties and durability. This thorough review presents a meticulous analysis of the progress and prospects in ECC research. It begins by introducing the background and rationale for investigating ECCs, while outlining the objectives of the review. The review provides an encompassing overview of ECCs, encompassing their definition, characteristics, historical development, composition and constituent materials. Emphasis is placed on the examination of ECCs’ mechanical properties, specifically their flexural behaviour, tensile behaviour, compressive strength and resistance to environmental factors. Furthermore, the rheological properties of ECCs, including workability, flowability, self-healing, crack mitigation, viscosity and thixotropy, are discussed in detail. The review delves into the influence of fibre reinforcement on ECCs, encompassing the types of fibres utilised and their impact on mechanical and structural properties, as well as fibre dispersion and orientation. Additionally, it explores the diverse applications of ECCs across various fields, such as structural applications and sustainable building practices. The challenges and limitations associated with ECCs, such as cost and availability, are addressed, alongside an exploration of future trends and research directions.

Experimental study of relative humidity absorbed through capillarity of building material under isothermal conditions: Clay-Kaolin reinforced with Alfa fibers

The research article aims to investigate the hygroscopic behavior of water absorbed by capillarity in clay supplemented with Alfa fibers. This specific clay-fiber composite holds significant importance in Moroccan construction practices. The primary aim is to enhance comprehension and control over the material's hydrothermal behavior by investigating moisture absorption traits, responses to varying humidity and temperature conditions, and the influence of fiber reinforcement on moisture equilibrium and structural stability. As temperature levels rise, the equilibrium water content absorbed through capillarity demonstrates a downward trend. The introduction of Kaolin-Alfa fibers into the clay composite profoundly affects the pace at which equilibrium moisture content is lost. This attribute effectively mitigates the likelihood of cracks developing in earthen structures during the drying phase, as it uniformly disperses tensions resulting from shrinkage. The findings showed that by understanding its unique region, Predictions regarding the sorption tendencies of other building materials are possible because of the approximate estimation of Clay-Kaolin reinforced with Alfa fibers sorption behavior. Surface flaws arise on Clay-Kaolin reinforced with Alfa fibers as a result of rising average pore radius and spreading pressure brought on by rising temperature and relative humidity. Furthermore, the heightened average pore volume observed in regions characterized by elevated relative humidity levels precipitates various defects within building materials, a phenomenon that has a discernible impact on their durability.

Influence of Fiber Reinforcement on the Ultrasonic P-Wave Velocity and Unconfined Compressive Strength of Cemented Clay

Influence of Fiber Reinforcement on the Ultrasonic P-Wave Velocity and Unconfined Compressive Strength of Cemented Clay

A Numerical Simulation of Electrical Resistivity of Fiber-Reinforced Composites, Part 2: Flexible Bituminous Asphalt

Asphalt concrete pavements are vulnerable to freeze-thaw cycles. Consecutive cracking and penetration of corrosive agents can expedite the degradation of asphalt pavements and result in weight loss and reduced strength. Fiber reinforcement in flexible bituminous asphalt bridge cracks limits the crack width and enhances the toughness of the composite. Furthermore, steel fibers facilitate asphalt heating during maintenance and repair operations. Electrical resistivity is a vital parameter to measure the efficiency of these operations and to identify the state of degradation in fiber-reinforced asphalt concrete. The significant difference between conductivities of steel fibers and bituminous matrix warrants in-depth investigations of the influence of fiber reinforcement on the measured surface electrical resistivity of placed pavements. Numerical simulations endeavor to predict the resistivity and associated deviations due to randomly distributed fiber reinforcement. Results and discussions reveal the sources and magnitudes of fiber geometry and content adjustments. Outcomes investigate associated errors for practical applications.

Centrifuge model studies on desiccation cracking behaviour of fiber-reinforced expansive clay

In this study, randomly distributed fiber reinforcement on the desiccation cracking behavior of expansive clay was investigated. Modeling considerations for the desiccation cracking behavior of unreinforced and fiber-reinforced clay was established using dimensional analysis. A custom-designed setup consisting of a specimen container, heating assembly, and digital image acquisition system was designed, calibrated, and used in the present study. A series of desiccation cracking tests were performed on unreinforced and fiber-reinforced expansive clay in a balanced beam geotechnical centrifuge. The test setup performance was evaluated by conducting tests at varying gravity levels and performing modeling of models. Digital image analysis and particle image velocimetry techniques were used to obtain qualitative information about the cracking of clay under the influence of fiber reinforcement and the varying thickness of the clay layers. The specimens reinforced with fibers exhibited improved cracking resistance than unreinforced clay specimens. The results indicate that the desiccation cracking of clays can be successfully modeled in a geotechnical centrifuge, highlighting the fact that this study is the first-ever such study. This knowledge can be used to study the behavior of critical geotechnical structures, especially clay barriers of landfill cover subjected to desiccation cracking.

Determination of Single Parameter for Serviceability Requirements of Fibre Reinforced Concrete: Study of Fracture Characteristics

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.

INFLUENCE OF FIBER REINFORCEMENT ON CONCRETE SHRINKAGE FOR RIGID ROAD AND AIRFIELD PAVEMENT REPAIR

Abstract. The influence of fiber reinforcement with steel anchor fiber on the shrinkage of modified concrete for rigid airfield pavements repair has been determined. A 2-factor experiment was carried out, in which the following composition factors were varied: the amount of hardening accelerator Sika Rapid 3 from 0 to 2.4% of the cement content (0-9.6 kg/m3); the amount of steel anchor fiber with 1 mm diameter and 50 mm length, from 0 to 100 kg/m3. For the concrete batching were used: Portland cement CEM II / AS 42.5 in the amount of 400 kg/m3, granite crushed stone 5-20 mm, quartz sand, plasticizer admixture BASF MasterGlenium SKY 608 in the amount of 1.2% by cement content. The workability of the mixtures was S2 (6-8 cm); W/C ratio depended on the concrete composition. Due to the use of superplasticizers, the W/C of all investigated mixtures was in the range of 0.309-0.343. The shrinkage of the prism specimens was recorded after 3 hours, 6 hours, 1, 2, 3 and 7 days of being in air-dry conditions. The shrinkage process does not end after 7 days of concrete hardening, however, the general nature of the influence of variable factors on its value remains. It has been established that fiber-reinforced concretes, with a fiber amount of 50 kg/m3 and with a fiber amount of 100 kg/m3, have 10-15% less shrinkage compared to unreinforced concretes. Compositions with a fiber amount of 50 kg/m3 and 100 kg/m3 have practically the same shrinkage, which is explained by an increase in W/C ratio with an increase in the amount of fiber reinforcement. The amount of hardening accelerator has a less noticeable effect on the amount of concrete shrinkage. By adding Sika Rapid 3, concrete shrinkage at the age of 7 days is reduced by 2-9%. This effect can be explained by the fact that internal stresses arising in the process of structure formation and moisture loss in concrete are contained in a more durable cement-sand matrix. The concrete shrinkage without fiber and accelerator was also measured up to the age of 98 days. It was found that the limiting shrinkage for such concrete is 2.5×10-4. The analysis of the drawn experimental-statistical model showed that with the amount of metal fiber from 60 to 90 kg/m3 and the amount of the hardening accelerator from 0.9 to 2.4%, the shrinkage of the investigated concretes is minimal (7 = 1.3×10-4). Thus, the use of fiber reinforcement with anchor steel fiber and a hardening accelerator can significantly reduce the concrete shrinkage for the rigid airfield pavements repair is important for this material.

Electrical Resistivity of Steel Fibre-Reinforced Concrete-Influencing Parameters.

This paper presents a systematic study of the electrical resistivity of different steel fibre-reinforced concretes with fibre contents from 0 kg/m3 to 80 kg/m3 in order to identify possible effects of interactions among concrete composition and fibre type and content regarding electrical resistivity. Based on a literature review, four parameters, w/c ratio, binder content, ground granulated blast-furnace slag (GGBS) and fineness of cement, which show a significant influence on the electrical resistivity of plain concrete, were identified, and their influence on the electrical resistivity as well as interaction effects were investigated. The results of the experiments highlight that the addition of fibres leads to a significant decrease in electrical resistivity, independent of all additional parameters of the concrete composition. Additionally, it was shown that a higher porosity of the concrete, e.g., due to a higher w/c ratio, also results in a lower electrical resistivity. These results are in agreement with the literature review on plain concrete, while the influence of the concrete composition on the electrical resistivity is weaker with the increase in fibre content. The influence of fibre reinforcement is thus not affected by changes in the concrete composition. In general, a higher fibre dosage leads to a decrease in electrical resistivity, but the impact on the electrical resistivity varies slightly with different types of steel fibres. Based on this study, the potential of determining the fibre content using electrical resistivity measurements could be clearly presented.

Influence of fiber reinforcement towards the physical characteristics of low density polyethylene laminated composites

Influence of fiber reinforcement towards the physical characteristics of low density polyethylene laminated composites

The Influence of Fiber Reinforcement on the Properties of the Self-Compacting Concrete Mix and Concrete

The paper considers the influence of fiberglass on the rheological and stress-strain properties of self-compacting concretes. The use of fiberglass in self-compacting concrete compositions makes it possible to achieve a sufficient coefficient of grain separation in coarse and fine fillers, which significantly influences the mobility and technological effectiveness of self-compacting mixes. Optimum compositions of self-compacting concretes are obtained, rational volumes of the hyper-plasticizing additive and of fiberglass are determined. The components were selected experimentally, in order to optimize the composition according to rheological characteristics. It is established that the use of fiberglass positively influences the stress-strain characteristics of concrete: it raises the compressive strength, as well as the bending tensile strength without deteriorating the workability and spreadabilityof the self-compacting concrete mix.

Influence of fiber reinforcement on mechanical behavior and microstructural properties of cemented tailings backfill

Abstract Fibers are accountable for an increase of compressive and shear strengths, particularly at the post-peak and post-cracking stages. The level of the strength improvement is primarily based on several factors: fiber type and content; fiber geometry, fiber distribution within the matrix; and the fiber-matrix interaction. An experimental campaign consisting of uniaxial compression and scanning electron microscopy tests were carried out to realize the effect of fiber reinforcement on mechanical behavior and microstructural properties of cemented tailings backfill (CTB) prepared with different fiber types (e.g., polypropylene, polyacrylonitrile and glass fibers) and contents (0%-control sample, 0.3, 0.6%, and 0.9%). Experimental results exhibit that polypropylene fiber exhibited the strongest reinforcing effect, followed by polyacrylonitrile and glass fiber. The rate of strength increase of the three fiber-reinforced fills after curing of 28 days reached 39.6%, 34.8% and 23.1%, respectively. A fiber content of 0.6% in the mixture is considered as a critical point, and the compressive strength of fiber-reinforced CTB samples first increases and then decreases, the peak strain and the post-peak ductility properties are positively correlated with fiber content. The failure process of fiber-reinforced CTB samples is mainly divided into four stages: pore compaction, linear elasticity, strain softening and crack propagation. It has the feature of ‘cracking without breaking’. Besides, fiber-reinforced CTB samples have a dense microstructure and good adhesion, improved interface between the fiber and the CTB matrix, and suppressed crack propagation. Lastly, an empirical equation was developed to forecast the peak strength and elastic modulus of CTB samples with different curing times.

Comparison of the mechanical characteristics of engineered and waste steel fiber used as reinforcement for concrete

Engineered steel fiber has been used for reinforcing concrete since the mid-nineteenth century. The influence of fiber reinforcement on the mechanical characteristics of concrete is commonly known and thoroughly described in literature. The fast growing and vibrant market of engineered steel fiber is increasingly disrupted by waste steel fiber obtained during recycling of tires. The lack of knowledge about properties of the waste steel fiber significantly limits its technically viable use. The main aim of the conducted research program was to test waste steel fiber and to compare its properties with most popular engineered steel fiber. Such properties as tensile strength estimated according to EN ISO 6892-1:2009, ductility tested according to EN 10218-1:1994, and tensile strength after ductility test were considered. Waste steel fiber proved to be characterized by much higher tensile strength and ductility than engineered steel fiber. Stress–strain characteristics of both the types of fiber also differ significantly. Conducted bends influence the tensile strength and modulus of elasticity of all tested waste and engineered steel fiber. The achieved knowledge would allow to create sustainable steel fiber-reinforced concretes in a much more efficient way.

Influence of fibre reinforcement on the post-cracking behaviour of a cement-stabilised sandy-clay subjected to indirect tensile stress

An experimental campaign was carried out to determine the influence of polypropylene fibre content and length on the post-cracking response of a sandy-clay stabilised with different cement contents. Three main sets of specimens were prepared: cement-stabilised specimens with two cement contents (5% and 10%); fibre-reinforced specimens with three fibre contents (0.1%, 0.2% and 0.3%) and cement-fibre-reinforced specimens combining the mentioned fibre and cement contents. Tensile tests on the fibres and indirect tensile tests and triaxial compression tests on the prepared specimens were conducted. Results show that the post-cracking behaviour is strongly affected by the combination of fibre and cement content as well as fibre length. Pull-out was the governing failure mode. Post-peak tension loss rate increased with fibre content, as a result of the loss of influence of the fibres on the post-peak behaviour. On the contrary, an increase in fibre content resulted in higher pre-peak strength gain rates and higher peak stresses.

Influence of fibre reinforcement on selected mechanical properties of dental composites.

For splinting or designing adhesive bridges, reconstructive composite structures with increased mechanical properties owing to embedded reinforcement fibres are used. The aim of this article was to determine the influence of glass and aramid fibres on the mechanical strength of composites reinforced with these fibres. Two polymer-ceramic microhybrid materials: Boston and Herculite were tested. Three types of reinforcement fibres were used: aramid (Podwiązka) with a single layer weave, a single layer weave glass fibre (FSO) and triple layer weave glass fibre (FSO evo). Tests were conducted in accordance with the requirements of ISO 4049:2009. The following material types were chosen for research: Boston, Boston + Podwiązka, Herculite, Herculite + Podwiązka, Herculite + FSO and Herculite + FSO evo. The scope of research included: flexural strength B, bending modulus of elasticity εB and work to failure of the reinforced composite Wfb. Additionally, microscopic observations of fracture occurring in samples were made. In comparison: the Herculite (97.7 MPa) type with the Herculite + FSO evo (177.5 MPa) type was characterized by the highest strength. Fibre reinforcement resulted in decreasing the elasticity modulus: Herculite + reinforcement (6.86 GPa; 6.33 GPa; 6.11 GPa) in comparison with the Herculite (9.84 GPa) and respectively Boston + reinforcement (10.08 GPa) as compared with the Boston (11.81 GPa). Using glass fibres increases flexural strength of the test composites. Using aramid fibres does not change their strength. The elasticity modulus of the reinforced reconstructive structures decreases after application of either type of fibres. However, their resistance to the crack initiation increases.

Influence of Fiber Reinforcement and Abrasive Particle Size on Three-Body Abrasive Wear of Hybrid Friction Composites

In the present study, enhancement of abrasion resistance of phenol formaldehyde (PF) resin based hybrid friction composites with different ingredients viz. binder, micron sized fibers and fillers have been synergistically investigated. Hybrid friction composites based on basalt and recycled aramid fibers were prepared using compression moulding. Three-body abrasive wear tests were conducted according to ASTM G-65 standard by dry sand/rubber wheel abrasion tester using two different size of angular silica sand abrasives (212 and 425 μm) at a constant load of 40 N. The results indicated that the wear volume loss increases with increasing abrading distance and abrasive particle size. However, the specific wear rate decreased with increasing abrading distance and increases with increase in abrasive particle size. Addition of fiber content has a significant influence on the abrasive wear performance of these composites. Further, the worn surfaces were examined by scanning electron microscopy to identify the involved wear mechanisms.

Influence of fibre-reinforcement on light-transmittance and microhardness of bulk-fill resin-composites

Influence of fibre-reinforcement on light-transmittance and microhardness of bulk-fill resin-composites

Influence of fiber reinforcement on strength and toughness of all-lightweight concrete

The effect of fiber reinforcement on all-lightweight concrete in which both fine and coarse aggregates are artificially lightweight was investigated experimentally. Three different fibers (i.e., steel, vinylon and polyethylene) were compared for their effects on the compressive strength, splitting tensile strength, flexural strength, shear strength, and toughness. Normal concrete with the same compressive strength as the all-lightweight concrete was prepared as a reference. Using 1.5% vinylon fibers significantly improved the flexural strength of the all-lightweight concrete 234% higher than that of normal concrete. Using 1.2% steel fiber increased the fracture toughness of the all-lightweight concrete more than twelve times.

Influence of Fiber Reinforcement on the Properties of Denture Base Resins

Advances in the medical sciences along with rapid increase in the specialized and better treatment modalities, certainly prolonged the human life with a drastic increase in the number of elderly in the past few decades. Tooth loss is one of the manifestations of aging. Dentures and dental implants are the major prosthetic devices given to restore physiological and esthetic functions of oral tissues of edentulous or partially edentulous patients. Complete and partial dentures based on polymeric compositions are the most popular devices since the cost of dental implants and metal-base dentures are much higher. Among the polymers, poly (methyl methacrylate) (PMMA) is the most commonly used material for this purpose. Although, this material is not ideal in every respect, it is the combination of qualities rather than one single desirable property that accounts for its popularity and usage. One of the main drawbacks of this material is considered to be its poor mechanical performance. There have been several attempts in the recent past to address the problem of inferior mechanical properties of these materials. Generally, there are three ways which have been investigated to improve the mechanical properties of denture bases; search for or development of an alternative material to PMMA; chemical modification of PMMA; and the reinforcement of PMMA. Present article is a review of types of fibres reinforced in denture prosthesis and their effects on mechanical properties of denture prosthesis.

Steel fibre and transverse reinforcement effects on the behaviour of high strength concrete beams

An experimental program was carried out to investigate the influence of fibre reinforcement on the mechanical behaviour of high strength reinforced concrete beams. Eighteen beams, loaded in four-point bending tests, were examined by applying monotonically increasing controlled displacements and recording the response in terms of load-deflection curves up to failure. The major test variables were the volume fraction of steel fibres and the transverse steel amount for two different values of shear span. The contribution of the stirrups to the shear strength was derived from the deformations of their vertical legs, measured by means of strain gauges. The structural response of the tested beams was analyzed to evaluate strength, stiffness, energy absorption capacity and failure mode. The experimental results and observed behaviour are in good agreement with those obtained by other authors, confirming that an adequate amount of steel fibres in the concrete can be an alternative solution for minimizing the density of transverse reinforcement. However, the paper shows that the use of different theoretical or semi-empirical models, available in literature, leads to different predictions of the ultimate load in the case of dominant shear failure mode.

Three-dimensional finite element analysis of posterior fiber-reinforced composite fixed partial denture Part 2: influence of fiber reinforcement on mesial and distal connectors

The aim of this study was to evaluate the influence of connectors under two different loading conditions on displacement and stress distribution generated in isotropic hybrid composite fixed partial denture (C-FPD) and partially anisotropic fiber-reinforced hybrid composite fixed partial denture (FRC-FPD). To this end, two three-dimensional finite element (FE) models of three-unit FPD from mandibular second premolar to mandibular second molar - intended to replace the mandibular first molar - were developed. The two loading conditions employed were a vertical load of 629 N (applied to eight points on the occlusal surface) and a lateral load of 250 N (applied to three points of the pontic). The results suggested that the reinforcing fibers in FRC framework significantly improved the rigidity of the connectors against any twisting and bending moments induced by loading. Consequently, maximum principal stress and displacement generated in the connectors of FRC-FPD were significantly reduced because stresses generated by vertical and lateral loading were transferred to the reinforcing fibers.