Barchip Fibers Research Articles

Performance Assessment of Hybrid Fibre-Reinforced Concrete (FRC) under Low-Speed Impact: Experimental Analysis and Optimized Mixture

Fibre-reinforced concrete (FRC) has gained tremendous attention in many disciplines due to its high initial strength, favorable mechanical properties, structural lightness, and energy-absorbing properties. In this research, Barchip fibres, Forta, and Basalt are utilized to reinforce concrete under penetration effect loading to examine the energy absorption and impact strength characteristics. To determine the parameters of the percentage of fibres on the impact resistance properties, the Box–Behnken method as a subset of the response surface method (RSM) was used. A diagram of RSM is adopted to determine the optimal percentage of fibres for higher initial strength and energy absorption. Results obtained using Design-Expert software revealed an initial strength of 886.127 N and an optimal energy absorption of 4.9865 J. In addition, the calculated R2 values and normal probability graphs showed a fairy accurate correlation between the results of the experimental and mathematical approaches. Finally, this study evaluated the fracture surface, adhesion of the fibres to the concrete, and degradation modes of the fibres to pave the way for optimal utilization of these hybrid FRCs.

Experimental investigation of single and hybrid-fiber reinforced concrete under drop weight test

The use of fiber-reinforced concrete in various industries is developing due to the desired mechanical properties, light weight of the structure, good energy absorption capacity, and high initial strength under impact loads. In this study, the energy absorption and initial strength of reinforced concrete with Forta, Basalt, and Barchip fibers under penetration impact loading were investigated. To investigate the effect of fiber percentage on impact properties, 16 specimens were subjected to experimental tests in single and hybrid groups. Also, the fracture surface and the adhesion of fibers to fiber-reinforced concrete with degradation modes were evaluated. The results showed that the initial strength and energy absorption in hybrid-fiber reinforced concrete increased by 45.3 and 49.7%, respectively, compared to single fiber reinforced concrete. Also, by examining the fracture surface of the specimens, it was found that the adhesion between the two Basalt and Forta fibers to the base concrete is very desirable. However, the separation between Barchip fibers and concrete is high and reduces the efficiency of these fibers in reinforcing concrete.

Assessing flexural and permeability performance of roller-compacted concrete pavement (RCCP) reinforcing with different types of synthetic fibres and crimped steel fibre

ABSTRACT The ever-increasing use of fibres in roller-compacted concrete pavement (RCCP) necessitates fully identifying the mechanical and permeability properties of RCCPs. Incorporating fibres in RCCP with different properties leads to a better comparative investigation that helps discover the unique effects of each fibre on the RCC characteristics. This aim was achieved via analyzing the test results of compressive and flexural strengths, flexural toughness, drying shrinkage, porosity, and water sorptivity. The reinforced RCCs were prepared by incorporating 0.5% and 1% of steel, Barchip, Kortta, and polypropylene fibres in a plain mixture. The plain mixture was chosen between nine mixtures, the differences of which were defined in w/c ratio, volume of cement content, and type of aggregate grading curve. The results indicated that increase in the volume of fibres from 0.5% to 1% could reduce the drying shrinkage rate and enhances the flexural toughness of FR-RCC. Furthermore, the water sorptivity and porosity were found to increase with the substitution of fibres in the RCC mixtures. Here, the water sorptivity of the specimens was highly dependent on the type and surface geometry of fibres. However, apart from other characteristics of fibres, the porosity was significantly increased, using fibres with a high aspect ratio.

Axial Stress-Strain Performance of Recycled Aggregate Concrete Reinforced with Macro-Polypropylene Fibres

The addition of macro-polypropylene fibres improves the stress-strain performance of natural aggregate concrete (NAC). However, limited studies focus on the stress-strain performance of macro-polypropylene fibre-reinforced recycled aggregate concrete (RAC). Considering the variability of coarse recycled aggregates (CRA), more studies are needed to investigate the stress-strain performance of macro-polypropylene fibre-reinforced RAC. In this study, a new type of 48 mm long BarChip macro-polypropylene fibre with a continuously embossed surface texture is used to produce BarChip fibre-reinforced NAC (BFNAC) and RAC (BFRAC). The stress-strain performance of BFNAC and BFRAC is studied for varying dosages of BarChip fibres. Results show that the increase in energy dissipation capacity (i.e., area under the curve), peak stress, and peak strain of samples is observed with an increase in fibre dosage, indicating the positive effect of fibre addition on the stress-strain performance of concrete. The strength enhancement due to the addition of fibres is higher for BFRAC samples than BFNAC samples. The reduction in peak stress, ultimate strain, toughness and specific toughness of concrete samples due to the utilisation of CRA also reduces with the addition of fibres. Hence, the negative effect of CRA on the properties of concrete samples can be minimised by adding BarChip macro-polypropylene fibres. The applicability of the stress-strain model previously developed for macro-synthetic and steel fibre-reinforced NAC and RAC to BFNAC and BFRAC is also examined.

Influence of Barchip fiber on early-age autogenous shrinkage of high-strength concrete internally cured with super absorbent polymers

High-strength concrete (HSC) usually suffers the high early-age autogenous shrinkage owing to the low water-binder (w/b) ratio. Barchip fiber and super absorbent polymers (SAPs) have been utilized to reduce the autogenous shrinkage of HSC at early age. The relationship between autogenous shrinkage and ultrasonic velocity of internally cured high-strength concrete (ICC) reinforced with Barchip fiber was studied utilizing the non-contact shrinkage test. Experimental study and corresponding analysis demonstrated that: (1) the autogenous shrinkage and ultrasonic velocity of concrete decreased with the volume percentage of Barchip fiber increasing, and decreased with the addition of SAPs; (2) models for predicting early-age autogenous shrinkage strain and ultrasonic velocity of ICC reinforced with Barchip fiber considering the fiber volume percentage and age were proposed; (3) the model of early-age autogenous shrinkage strain based on the results of ultrasonic velocity at different ages and at 28 d with no addition of Barchip fiber was proposed; (4) the prediction model of early-age autogenous shrinkage strain of ICC reinforced with Barchip fiber based on the age-dependent parameter on ultrasonic velocity was proposed.

Early-age stress relaxation and cracking potential of High-strength concrete reinforced with Barchip fiber

High-strength concrete (HSC) is vulnerable to early-age cracking due to the low water-to-cement (w/c) ratio. The polypropylene fiber, Barchip fiber, is utilized to improve the early-age behavior of HSC. Investigations on the influence of the proportion of Barchip fiber on early-age stress relaxation and cracking potential of HSC were conducted utilizing restrained ring test in this research. Experimental investigations and related analysis demonstrated that: (1) the free shrinkage of HSC decreased with increasing proportion of Barchip fiber; (2) the strain in steel ring decreased with increasing proportion of Barchip fiber; (3) the residual stress decreased with increasing proportion of Barchip fiber; (4) the relaxed stress of HSC decreased with increasing proportion of Barchip fiber; (5) the stress rate of HSC decreased with increasing proportion of Barchip fiber; (6) the cracking potential of HSC decreased with increasing proportion of Barchip fiber. The cracking potential parameter at the age of 10.58 d decreased by 15.2%, 31.9%, and 44.3% when the proportion of Barchip fiber increased from 0% to 0.3%, 0.6%, and 0.9%, respectively.

Influence of Barchip fiber on early-age autogenous shrinkage of high strength concrete

High strength concrete (HSC) is vulnerable to early-age cracking owing to a low water-to-cement (w/c) ratio. Barchip fibers have been utilized to reduce the autogenous shrinkage of concrete. The relationship between autogenous shrinkage and ultrasonic velocity of HSC reinforced with Barchip fibers was studied utilizing the non-contact shrinkage test. Results indicated that the autogenous shrinkage and ultrasonic velocity of concrete decreased with the volume percentage of Barchip fibers increasing. Besides, models for predicting early-age autogenous shrinkage strain were proposed considering the fiber volume percentage and age based on the results of ultrasonic velocity.

Effect of Barchip fiber on stress relaxation and cracking potential of concrete internally cured with super absorbent polymers

High-strength concrete (HSC) that has shown the outstanding performance is extensively utilized in construction. HSC usually suffers the high autogenous shrinkage when the water-to-cement (w/c) ratio is low. Internal curing (IC) is developed as reservoir in concrete to reduce HSC shrinkage at early age by introducing additional water. Meanwhile, Barchip fibers have been already utilized to improve material properties of HSC. Investigations on the effect of the proportion of Barchip fibers (0%, 0.3%, 0.6%, and 0.9% by volume fraction of concrete) on early-age stress relaxation of concrete internally cured with super absorbent polymers (SAPs) were conducted by restrained ring test. Results obtained from the test were as follows: (1) the free shrinkage in concrete deceased with the increase of the proportion of Barchip fibers; (2) the strain in steel ring decreased when the proportion of Barchip fibers increased; (3) the residual stress in concrete decreased with the increase of the proportion of Barchip fibers; (4) increasing the proportion of Barchip fibers caused the decrease of stress rate; (5) the relaxed stress increased with increase of Barchip fibers proportion; (6) when the proportion of Barchip fibers increased, the time to cracking of concrete was delayed, and the cracking potential of concrete decreased significantly; (7) SAPs utilized in IC improved the performance of concrete reinforced with Barchip fibers significantly.

Bacillus subtilis bacteria used in fiber reinforced concrete and their effects on concrete penetrability

Fiber-reinforced concrete has found wide applications in recent years as a remedy for compensating for the weak concrete tensile and flexural strengths. The use of fibers in concrete, however, increases its porosity. This drawback calls for remediation techniques to reduce concrete porosity and permeability in order to enhance its durability. Calcite sediments are capable of filling part of concrete pores to reduce its porosity. In the present study, use was made of bacteria as sediment producing agents in concrete specimens strengthened with different types of fiber. For this purpose, a strain of Bacillus subtilis was employed in its culture medium at a concentration of 107 cell/ml both as a replacement for the water in the concrete mixture and in a surface treatment gel. Moreover, polypropylene, steel, and barchip fibers were used at volume percentages of 0.3, 1, and 0.75%. The concrete specimens thus obtained were subsequently cured for 28, 56, and 90 days (depending on the type of experiment) in either plain water or the calcium lactate-urea solution. Measurements of water, CO2 and chloride ion penetration depths revealed that the use of bacteria in both curing environments led to reduced water, CO2, and chloride ion penetration depths in the bacteria-incorporated specimens, with the highest reductions of 64.75%, 39.77%, and 27.4% recorded for water, chloride ion, and carbonation depths, respectively. This is while the specimens subjected to surface treatment exhibited reductions of 57.75%, 24.94%, and 23.3% in their water, chloride ion, and carbon dioxide penetration depths, respectively, relative to those of the control specimens. Thus, the use of bacteria in the concrete mixture and its curing in the calcium lactate-urea solution were found capable of filling concrete pores to reduce porosity in fiber-reinforced specimens.

Influence of Barchip fiber length on early-age behavior and cracking resistance of concrete internally cured with super absorbent polymers

High performance concrete (HPC) has been applied in practical engineering for a wide range owing to its superior performances, including low permeability, high strength, high modulus, and other superior performance. However, with the high internal temperature and self-desiccation that induced by the low water-to-binder (w/b) ratio, HPC suffers high autogenous shrinkage, which leads to the premature cracking of HPC after peak stress at early age. For the purpose of increasing the cracking resistance of concrete effectively, Barchip fibers and the internal curing materials are used to improve the early-age properties of concrete. Although researches on the cracking resistance of HPC reinforced with different contents of Barchip fiber or internally cured with different kinds of internal curing materials have been conducted, studies on the effect of Barchip fiber length on the cracking resistance of internally cured HPC (ICHPC) with super absorbent polymers (SAPs) at early age are rather lacking. In present research, the effect of length of Barchip fibers (0, 42, 54, and 60 mm) on the early-age cracking resistance of ICHPC under the adiabatic condition was studied by Temperature Stress Test Machine. Results of the experimental research and related analysis indicated that (1) the splitting tensile strength and compressive strength of HPC increased as the Barchip fibers were applied; (2) the use of SAPs reduced autogenous shrinkage, restrained tensile stress rate, and tensile creep behavior, and increased temperature drop and the cracking resistance of HPC at early age; (3) the autogenous shrinkage decreased and the temperature drop, cracking age, cracking stress of ICHPC increased as the Barchip fiber length increased; (4) the tensile creep behavior of ICHPC increased as the Barchip fibers were applied, and decreased as the Barchip fiber length increased; (5) the cracking resistance of ICHPC increased first and then decreased as the Barchip fiber length increased, as obtained from the integrated criterion; (6) the poor dispersion of Barchip fibers may result in the decrease of the early age behavior and cracking resistance of ICHPC when the fiber length exceeded 54 mm.

Mechanical properties and flexural behaviour of fibrous cementitious composites containing hybrid, kenaf and barchip fibres in cyclic exposure

In this study, the mechanical properties and flexural behaviour of the fibrous cementitious composites containing hybrid, kenaf and barchip fibres cured in cyclic exposure were investigated. Waste or by-product materials such as pulverized fuel ash (PFA) and ground granulated blast-furnace slag (GGBS) were used as a binder or supplementary cementitious to replace cement. Barchip and kenaf fibre were added to enhance the mechanical properties and flexural behaviour of the composites. A seven mix design of the composites containing hybrid, kenaf and barchip fibre mortar were fabricated with PFA-GGBS at 50% with hybridization of barchip and kenaf fibre between 0.5% and 2.0% by total volume weight. The composites were fabricated using 50 × 50 × 50 mm, 40 × 40 × 160 mm and 350 × 125 × 30 mm steel mould. The flexural behaviour and mechanical performance of the PFA-GGBS mortar specimens were assessed in terms of load-deflection response, load compressive response, and crack development, compressive and flexural strength after cyclic exposure for 28 days. The results showed that specimen HBK 1 (0.5% kenaf fibre and 2.0% barchip fibre) and HBK 2 (1.0% kenaf fibre and 1.5% barchip fibre) possessed good mechanical performance and flexural behaviour. As conclusion, the effect of fibres was proven to enhance the characteristics of concrete or mortar by reducing shrinkage, micro crack and additional C-S-H gel precipitated from the pozzolanic reaction acted to fill pores of the cement paste matrix and cement paste aggregate interface zone between mortar matrix and fibre bonding.

Influence of Barchip fiber on early-age cracking potential of high performance concrete under restrained condition

High performance concrete (HPC), which is a new-tech concrete, has been widely applied for its good workability, lasting durability, low permeability, and high strength. However, the high temperature rise and high autogenous shrinkage induced by the low water-to-cement (w/c) ratio would increase the early-age cracking potential in HPC. In order to reduce the cracking potential of HPC, Barchip fibers are applied to strengthen the early-age properties. Although the influence of Barchip fibers on the mechanical properties of concrete has been studied, investigations on the influence of Barchip fibers on the early-age cracking potential of HPC under adiabatic condition at uniaxial constant restraint degree are still lacking. The early-age cracking potential of HPC reinforced with different amounts of Barchip fibers (0, 4, 8, and 12 kg/m3) was tested by Temperature Stress Test Machine under adiabatic condition at full restraint degree in present study. Test results and corresponding analysis indicated that (1) the compressive strength and splitting tensile strength were enhanced by the addition of Barchip fibers in HPC; (2) Barchip fibers reduced autogenous shrinkage, restrained tensile stress rate and increased cracking age, specific tensile creep of early-age HPC; (3) the integrated criterion utilized to evaluate the cracking potential decreased first and then increased with increasing amount of Barchip fibers; (4) the optimal Barchip fiber amount of 8 kg/m3 was recommended for that poor dispersion and fiber clumping may occur in HPC with excessive addition of Barchip fibers.

Properties of hybrid cementitious composite with metakaolin, nanosilica and epoxy

The compressive strength and durability potentials of hybrid cementitious composites (HCC) that contain metakaolin (MK), produced in the laboratory using raw kaolin, nanosilica and epoxy resin was the main focus of this research study. The HCC specimens contain 10% metakaolin (MK), 1% colloidal nanosilica (CNS) and 1% epoxy resins and the specimens were examined for early ages of 7, 28, and 90days of exposure in both water and seawater. The durability properties investigated in this research study comprise of water absorption, intrinsic air permeability, chloride penetration and porosity. All tests were conducted to assess the influence of MK, CNS and epoxy on the compressive strength and the durability properties of the HCC specimens. The result showed that HCC specimens with 10% MK, 1% CNS was durable relative to all the properties. Nevertheless, the addition of both natural fibers (coconut and oil palm fruit bunch fibers) and synthetic fiber (bar chip fiber) has a slight negative impact on the durability properties of HCC specimens. Conclusively, the results showed that the menace of water, liquid and gas transportation by water absorption, capillary suction, porosity, chloride penetration, and intrinsic air permeability of HCC were lesser than that of control specimen.

Evaluating Mechanical Properties of Macro-Synthetic Fiber-Reinforced Concrete with Various Types and Contents

Concrete, as one of the most widely used construction materials, has a brittle behavior. Adding fibers with different types and contents would affect the ductility behavior and mechanical properties of concrete. Hence, an experimental study was conducted to investigate effects of type and content of polymer fibers on mechanical properties of fiber-reinforced concrete such as flexural strength, compressive strength, indirect tensile strength, and elastic modulus. In the present research, the concrete samples were made and, then, evaluated, using three different types of polymer fibers, including twisted, barchip, and fibrillated, with the contents of 0.2, 0.4, and 0.6 volume percentages, respectively. The results showed that by adding fibers to the concrete samples, the flexural and tensile strength was increased by 19.6–81.69% and 0.84–34.29%, respectively; besides, the addition of the fibers to concrete reduced the compressive strength and elasticity modulus by 4.57–26.32% and 12.48–37.08%, respectively. The concrete containing twisted and barchip fibers, despite the different types of fibers, had similar flexural performance.

Characterization of metakaolin and study on early age mechanical strength of hybrid cementitious composites

In this study, the potency of using laboratory produced metakaolin as partial replacement of cement in the evolution of a hybrid cementitious composites (HCC) was investigated. Some chemical composition and phases of metakaolin were appraised with the aid of X-ray fluorescence (XRF) and X-ray diffraction. Particle size analyzer was used to study the physical properties of metakaolin produced in the laboratory from purified Kaolin. Early age mechanical strength and shrinkage properties of structural grade HCC developed by replacing fly ash in the original ECC M45 design with metakaolin (MK), colloidal nanosilica (CNS) and epoxy were examined. The designed mixtures consist of five mixtures with the control and base mix exposed to water and seawater. The control mix consists of only the fine aggregate and cement while the base mix consists of cement, fine aggregate, 10% MK and CNS with epoxy resin at 1% each by weight of the binder. Synthetic barchip fibres and some natural fibres namely, oil palm fruit bunch and coconut fibres were incorporated. The water cement ratio was designed as 0.30 for all mix ratios. The result reveals that the inclusion of MK, CNS and epoxy have a significant effect on the fresh properties of the HCC and at early age of 7, 28 and 90days. The mechanical strengths were better improved than the standardized M45 ECC at these early ages.

The Properties of Fiber Reinforced Gypsum Plaster

Aims: Investigations were conducted on the development of gypsum plaster used naturally by adding 1% of admixture (Superplasticizer) and reinforcing it with Barchip fibers. Methodology: Different percentages of Barchip as 0, 0.5, 0.75, 1, 1.25 and 1.5% were used. The compressive and flexural strength of such gypsum plaster are discussed Results:The results show that the use of 1% superplasticizer with 1% of Barchip fiber increased the c ompressive and flexural strength by about 44 and 62%, respectively. Conclusion: The use of superplasticizer with Barchip fibers would significantly enhance the mechanical properties of gypsum plaster.

The effect of using high strength flowable system as repair material

The maintenance and the repair of concrete structures have become more needed in the field of Civil Engineering. The selection of repair materials for concrete structures requires an understanding of the material behavior. Therefore, this research is conducted to provide a clear indication and understanding of the behavior and structural performance in engineering construction. The combined system of substrate concrete with different mix proportions of flowable high strength system reinforced by hybrid fibers was used to study its mechanical properties. The experimental tests are: compressive strength, splitting tensile strength, flexural strength and pull-out test. It was found that the high strength flowing concrete (HSFC) provides the best performance when the compressive strength of the repaired system is needed, whereas the high strength flowable mortar (HSFM) has the best performance when the tensile strength of repaired system is required. The best value of pull out test was obtained from using the flowable high strength mortar reinforced with 1.5% steel fiber +0.25% palm fiber +0.25% Barchip fiber as the repair material, whereas, the least value of pull-out test was obtained from samples using epoxy.

Indicative performance of fiber reinforced polymer (FRP) encased beam in flexure

Fiber reinforced polymer (FRP) is an ideal reinforcing material for marine structures because of its chemical stability. It is normally used in rod form to substitute the conventional steel bars in marine structures. However, the FRP bar reinforced concrete structure tends to fail with limited ductility. Thus, the safety of its application is greatly affected. This study aimed to enhance the ductility of FRP reinforced structure by proposing a novel FRP encased beam design. Structural behaviors of different encased beams were studied under four point flexural loading. Four types of encased beams were tested, namely, the plain FRP I-beam, the FRP I-beam with studs, the FRP I-beam with links and studs, and the FRP I-beam with studs and Barchip fiber. The results suggested that the FRP in the I-beam form could enhance the ductility performance of the FRP reinforced concrete beam, to a level that satisfies the ductility requirements as stated in the Canadian Highway Bridge Design Code, i.e. ductility index should exceed 4.0. However, shear studs should have to install on the FRP I-beam and this is also useful in preventing bond slip problem. Addition of Barchip fibers in the mixing concrete could further enhance the first crack load by 25.4%, while addition of stirrups enhanced the ultimate load carrying capacity by another 18.2%. However, both of these methods were not recommended since they would reduce the ductility of the beam, as opposed to the primary objective of the proposed design.

Application of non-corrosive barchip fibres for high strength concrete enhancements in aggressive environments

The trouble of sea water attacks in marine structures has suffered the engineers for decades. Until present, the most popular approach used to minimize the detrimental effects resulted by the sea water is the applications of high strength high performance concrete. The binary or ternary blended cement system is applied to improve the impermeability properties of the resulting concrete. Nonetheless, the sulphate attacks and the expansions and shrinkages caused by the environments would induce cracks at the structures. Once the cracks are initiated, it allows the penetration of harmful substances and ultimately reduces the durability of the structure in a substantial manner. In this experiment, a mechanical approach is employed to improvise the concrete in the aspects of strength and durability properties. The barchip fibre that is non-corrosive, short and discrete is introduced into high strength concrete so as to provide localize reinforcing effects to restrain the cracks development in the matrix. The specimens were exposed to three types of aggressive environments; namely tropical climate (A-series), alternate air and sea water in a 14-day cycle (4days in sea water+10days in air) (N-series) and continuous immersion in the sea water (W-series). Parameters like the compressive strength, permeability, porosity, chloride penetration were examined. The mineralogical and microstructures were studied by the means of X-ray diffraction (XRD) and scanning electron microscope (SEM) examination, respectively. The findings in these studies solidify the justifications provided in the discussions. The results verify that 1.8% would be the optimum dosage of barchip fibre that could provide greatest enhancements to the concrete. When the exposure period is prolonged, the increments in the compressive strength were above 12% and the permeability was also reduced. Together with other improvements, it could be concluded that the incorporation of barchip fibre has successfully suppressed the damaging effects that arise from the aggressive environments.

Evolution of Durable High-Strength Flowable Mortar Reinforced with Hybrid Fibers

The production and use of durable materials in construction are considered as one of the most challenging things for the professional engineers. Therefore, this research was conducted to investigate the mechanical properties and the durability by using of different percentages of steel fiber with high-strength flowable mortar (HSFM) and also the use of the hybridization of steel fibers, palm fibers, and synthetic fiber (Barchip). Different experimental tests (compressive strength, splitting tensile strength, flexural strength, and static modulus of elasticity among others) were determined after 90 days of normal water curing and 180 days of seawater exposure. The results indicate that hybrid fibers of 1.5% steel fibers + 0.25% palm fibers + 0.25% Barchip fibers provide significant improvement in the different mechanical properties of HSFM. Besides, the hybridization of fibers was found to be effective in the terms of durability (exposure to seawater). Therefore, the minimum reduction in static modulus of elasticity, compressive, splitting and flexural strength was obtained for the HSFM mixes of hybrid fibers using steel fibers with palm fibers and also for the use of steel, palm, and Barchip fibers.