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In this study, bio-composites were developed using polylactic acid (PLA) as the matrix and sisal fibers (SFs) derived from agave sisalana leaves as the reinforcement. The bio-composites were prepared through injection molding with the addition of tributyl 2-acetylcitrate (ATBC) plasticizer. The mechanical, thermal, and rheological properties of these bio-composites were investigated to understand the effects of fiber and plasticizer contents. The results showed that the addition of SFs improved the tensile and flexural moduli of the bio-composites but led to a decrease in tensile strength compared to neat PLA. The flexural strength initially decreased with low fiber content but recovered to the level of neat PLA as the fiber content increased. The impact strength increased with the incorporation of SFs and ATBC. However, the presence of ATBC had a negative impact on the tensile and flexural properties of the bio-composites. The thermal conductivity of the materials was influenced by the fiber content and processing temperature, increasing with SFs inclusion but decreasing with temperature. Differential scanning calorimetry analysis revealed increased crystallinity of PLA with the presence of SFs and ATBC. The specific heat capacity increased with ATBC but decreased with increasing SFs. Dynamic mechanical property testing showed variations in storage and loss moduli of the bio-composites at different temperatures. The storage modulus increased with higher fiber content and abruptly dropped around glass transition temperature. Rheological characterization demonstrated effective interactions between the fibers and matrix with good fiber dispersion, resulting in uniform shear viscosity versus shear rate for different capillary dimensions. The shear viscosity of the SFs/PLA mixture increased with increasing fiber content but decreased with the addition of plasticizer. Furthermore, the compounding and molding processes had a notable impact on the microstructure of the fibers, specifically resulting in fiber breakage and fiber separation during processing. [ABSTRACT FROM AUTHOR]

Natural fibers and nanomaterials are currently receiving more attention in the construction sector for two reasons. One reason is to use natural fibers instead of synthetic ones in fiber-reinforced concrete to create environmentally friendly products. In this study, sisal fiber (SF) and Cloisite 30B nanoclay particles were used to manufacture cement nano concrete. The cement nano concrete was reinforced with 3 wt% 10 mm sisal fiber and varying levels of Cloisite 30B nanoclay (0%, 0.5%, 1%, 1.5%, and 2%). Comprehensive research was conducted to evaluate the physical, mechanical, thermal, and water absorption properties of the concrete. The results indicate that the incorporation of nanoclay enhances these qualities. The results of the experiments indicated above demonstrate that the 3 wt% SF and 1.5% nanoclay concrete has superior mechanical qualities to other nanoclay concrete in terms of compressive strength (7.12 MPa) and flexural strength (9.6 MPa). Additionally, testing was performed on the concrete's morphology, physical properties, and water absorption. [ABSTRACT FROM AUTHOR]

In recent decades, in order to replace traditional synthetic polymer composites, engineering research has focused on the development of new alternatives such as green biocomposites constituted by an eco-sustainable matrix reinforced by natural fibers. Such innovative biocomposites are divided into two different typologies: random short fiber biocomposites characterized by low mechanical strength, used for non-structural applications such as covering panels, etc., and high-performance biocomposites reinforced by long fibers that can be used for semi-structural and structural applications by replacing traditional materials such as metal (carbon steel and aluminum) or synthetic composites such as fiberglass. The present research work focuses on the high-performance biocomposites reinforced by optimized sisal fibers. In detail, in order to contribute to the extension of their application under fatigue loading, a systematic experimental fatigue test campaign has been accomplished by considering four different lay-up configurations (unidirectional, cross-ply, angle-ply and quasi-isotropic) with volume fraction Vf = 70%. The results analysis found that such laminates exhibit good fatigue performance, with fatigue ratios close to 0.5 for unidirectional and angle-ply (±7.5°) laminates. However, by passing from isotropic to unidirectional lay-up, the fatigue strength increases significantly by about four times; higher increases are revealed in terms of fatigue life. In terms of damage, it has been observed that, thanks to the high quality of the proposed laminates, in any case, the fatigue failure involves the fiber failure, although secondary debonding and delamination can occur, especially in orthotropic and cross-ply lay-up. The comparison with classical synthetic composites and other similar biocomposite has shown that in terms of fatigue ratio, the examined biocomposites exhibit performance comparable with the biocomposites reinforced by the more expensive flax and with common fiberglass. Finally, appropriate models, that can be advantageously used at the design stage, have also been proposed to predict the fatigue behavior of the laminates analyzed. [ABSTRACT FROM AUTHOR]

Industrial development has led to an increase in demand for friction materials, resulting in increasingly prominent environmental issues throughout their entire life cycle, and developing green and eco‐friendly brake friction materials has become a focus in the braking field. This paper explores the mechanical and tribological properties of fly ash (industrial waste) and sisal fiber (natural fiber) as eco‐friendly components to enhance brake friction materials. Four samples containing different ratios of fly ash and sisal fiber were prepared and tested with a variable‐speed friction testing machine. The results show that the eco‐friendly alternative combination can effectively improve the friction coefficient, and reduce friction fluctuations and thermal degradation, but the wear rate will also increase accordingly. In addition, the worn morphology reveals the formation of the contact platform and wear mechanism. A hybrid integration of analytic hierarchy process (AHP) and multi‐objective optimization by ratio analysis (MOORA) was used to weigh various evaluation indicators objectively and rank the samples. The sample with 8% fly ash and 6% sisal fiber exhibited the best comprehensive tribological performance. Highlights: Development of eco‐friendly brake friction composites with natural and waste additives.Investigation of the effect of the natural wastes' ratio on prepared composites' physical, mechanical, and tribological properties.Evaluation of brake friction composites with AHP‐MOORA.Sample S6F8 exhibits the best comprehensive tribological performance. [ABSTRACT FROM AUTHOR]

In this research work, sisal fiber (agave sisalana) was converted into activated carbon through chemical activation technique (H3PO4 activation agent). Three different process parameters such as impregnation % on H3PO4, the temperature of the treatment, and treatment time have been modified through Box–Behnken design. Three process parameters with three different levels have been considered for investigation, such as impregnation % was kept as 25%, 50%, 75%; treatment temperature was kept as 300 °C, 400 °C, and 500 °C; and treatment time was kept as 30 min, 60 min, and 90 min. The adsorption of Reactive Red 120 (RR 120) dye from an aqueous solution onto sisal fiber activated carbon (SFAC) was examined. Three were 17 experiments conducted according to the pattern of Box–Behnken design. Batch adsorption efficiency was measured through the methylene blue (MB) number and the iodine number. The Design-Expert software tool was used to predict the optimal conditions of the process parameters. The optimal impregnation % was 25%, time was 76 min, and temperature was 434.5 °C for MB analysis. Similar results were reported for the optimal iodine number, where impregnation % was 25%, time was 64 min, and temperature was 441.5 °C. Two different polynomial models were derived, and it was validated through correlation analysis between the actual experimental results. [ABSTRACT FROM AUTHOR]

The application of geopolymer composites in the construction of environmentally sustainable buildings and low-carbon structures has generated considerable interest, presenting an alternative and eco-friendly approach to composite materials. The purpose of this research is to develop a new composition of geopolymer concrete, dispersedly reinforced with sisal fiber, and investigate its structure and physical and mechanical properties. To evaluate the effectiveness of the proposed compositions, the fresh properties of the geopolymer concrete mixture—density and slump—and the properties of the hardened composite, namely, the compressive strength, flexural strength and water absorption, were studied. The most rational composition of the alkaline activator was established, and sisal fiber (SF) was protected from alkaline degradation by adding styrene-acrylic copolymer at an amount of 5% and microsilica at an amount of 3% to the concrete mixture. It was determined that the most optimal SF content was 1.0%. The compressive strength exhibited a maximum increase of 12.8%, the flexural strength showed a significant increase of 76.5%, and the water absorption displayed a decrease of 10.3%. The geopolymer fiber-reinforced concrete developed in this study is an environmentally friendly replacement for traditional types of concrete with cement binders and can be used for the manufacture of small architectural forms and landscaping elements. [ABSTRACT FROM AUTHOR]

Abstract The progressive increase in the rate of production of plastic bottles by the beverage and food industries in Nigeria has increased considerably over time, constituting large volume of waste generations from plastic waste bottles. Also, increasing demand for eco-friendly soil improvement materials and the growing desire to minimize waste generated daily, prompted the need for this study to look into ways to use such wastes and other sustainable materials in soil improvement. This study investigated the potential use of sisal fiber and plastic waste strips as partial replacement for cement to enhance the geotechnical characteristics of lateritic soils. Various laboratory experiments were conducted, encompassing specific gravity determination, grain size distribution, compaction assessment, Atterberg limit, unconfined compressive strength (UCS), and microscopic analysis. Sisal fiber and plastic waste strips were each varied at 0, 0.5, 1.0, 1.5, 2.0 and 2.5% while maintaining a constant 5% cement added to all the mix proportions. Results of investigation revealed an enhancement in plasticity of the soils with both treatment methods. Liquid limit shows a steady drop from 43% in its natural state to 42% and 41% at 1% sisal fiber and 1% plastic strips content respectively, while plasticity index showed a decline from 14.8% in its natural form to 12.69% and 10.8% at 2% sisal fiber and 1% plastic waste strips content respectively. Strength properties of the treated soil increased with increase in admixtures content. Microanalysis of the natural and optimally modified soils showed alteration in the fabric arrangement of the particles of soils. Based on the results of the study, optimally 1–1.5% sisal fiber/5%cement and 1–1.5% plastic waste strips/5%cement meaningfully improved the soil strength and can both be used as sub-base materials for light trafficked roads.

Mechanical, thermal, and water absorption properties of banana fiber and sisal fiber-reinforced epoxy biocomposites were evaluated with and without cashew nut shell (CNS) filler, either separately, or as hybrid biocomposites. Bidirectional woven mats were used to make composites by compression molding. The CNS filler content was 5% to 10%. Adding CNS filler of up to 5% improved the mechanical and thermal properties. Further increases in filler content above the threshold value diminished their mechanical properties due to poor dispersion and increased porosity. The maximum tensile and flexural strength were found as 43 and 92 MPa. The highest impact strength was obtained with the hybrid biocomposites with 5% filler. This was attributed to the toughening effect of phenolic compounds in the CNS. In addition, the thermal stability of the biocomposites was influenced by filler content. The biocomposites exhibited varying water absorption capacities as the filler content increased with the water uptake. Scanning electron microscopy (SEM) images showed the microsurface of the fractured samples and their interfacial bonding, fiber pull-out, and fracture. However, increasing filler content in the biocomposite reduced the filler pull-out and led to fiber breakage.

Studies are presently ongoing to advance the development of bio-composite materials through the exploration of the potential use of reinforcements of natural origin in polymer matrixes. In this particular investigation, hybrid reinforced composite was formulated for automotive application by utilizing epoxy as the matrix and sisal fiber-paper particles as the reinforcements. The sisal fiber was extracted employing soil retting method, subjected to surface treatment, and combined with paper particles. Following preparation of the reinforcements, predetermined compositions (3, 6, 9, 12 and 15 wt %) were mixed with epoxy resin before being poured into the moulds using hand layup process and were allow to cure. The study focused on the mechanical, wear, and water absorption properties, as well as the surface morphologies of the developed composites. The results of the study revealed that the optimal properties were achieved with the utilization of 9 wt. % and 12 wt. % sisal fiber-paper particles reinforced composite. Particulate paper was discovered to be a suitably surface compatibilizer in thermosets when used as fillers with fiber reinforcement. Thus, the epoxy based composite reinforced with hybrid sisal fiber-paper particles is suitable for automobile application in the fabrication of bumper and other epoxy based body parts.

Gaining an understanding of how chemical treatment affects the mechanical properties of natural fiber reinforced polymer composites is essential to enhance their performance and broaden their applicability across various engineering domains. The objective of this study was to develop bio-composites by combining polylactic acid with sisal fibers that have undergone chemical treatments and evaluating the mechanical properties at different temperatures to determine their suitability for high-temperature applications. For this purpose, sisal fibers were chemically treated using alkali, acetylation, and alkali/acetylation solution before composite processing. The results revealed that tensile strength slightly improved by alkali treatment, while both alkali/acetylation and acetylation treatments decreased the tensile strength and tensile modulus. Alkali treatment significantly enhanced flexural strength, while the effect of acetylation and alkali/acetylation treatments on flexural strength was less pronounced. All chemical treatments led to a slight increase in flexural strain at failure, but resulted in a decrease in tensile strain at failure and tensile modulus. Alkali treatment slightly increased flexural modulus, while acetylation and alkali/acetylation treatments significantly reduced it. The impact strength of the bio-composites was increased by alkali and acetylation treatments, but significantly reduced by alkali/acetylation treatment. Furthermore, the flexural strength of all bio-composites decreased as temperature increased, especially in plasticized bio-composites using tributyl 2-acetylcitrate plasticizer. The flexural strain at failure decreased with the addition of tributyl 2-acetylcitrate at room temperature. In plasticized bio-composites, the flexural strain at failure increased at 35°C, but decreased at 45°C. On the other hand, the flexural strain at failure of non-plasticized bio-composites remained constant up to 35°C, slightly increased up to 45°C, and then significantly increased at temperatures above 45°C. These bio-composites could be suitable for packaging industry as biodegradability is the criteria for such applications. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Railway Science & Engineering is the property of Journal of Railway Science & Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Epoxy-based hybrid composites are attention in various engineering domains. Distinctively, natural fiber-made epoxy composites are advantageous over synthetic fiber-made composites and attracted in automotive applications such as set frames, interior panels, dashboards, etc. Moreover, due to its high moisture absorption nature, the epoxy composite formed with natural fiber is suspected to have poor adhesive quality compared to synthetic fiber composite. It leads to lower adhesive performance and limits the behaviour of composite. The prime objective of the current work is to ensure the adhesive behaviour of NaOH-treated sisal fiber (SF) epoxy composite featured with silicon carbide nanoparticles (SiC). This composite is prepared with the constant percentage of SF as 15 wt% and varied wt% of SiC through compression mould technology. Influences of treated SF and SiC on pressing behaviour of surface morphology, tensile & flexural strength, microhardness, and fracture toughness of composites are experimentally investigated with ASTM D638, D790, D4762, and D6110 policy, and its outcomes are compared to 15wt% treated SF epoxy composite. The surface morphology study confirms that the SF and SiC appearances in the epoxy matrix are uniform and homogenous. The 5wt% SiC embedded with 15wt% treated SF facilitates higher tensile (65.2 ± 1.1 MPa) & flexural strength (69.1 ± 1.3 MPa), microhardness (35.5 ± 0.5 HV), and fracture toughness (1.56 ± 0.01 MPam0.5). The enriched epoxy hybrid composite sample will recommended for automobile interior parts application. [ABSTRACT FROM AUTHOR]

A novel process for manufacturing fiber-reinforced silica sol shells for investment casting is proposed. The influence of different fiber lengths and additions on the bending strength of the shell is investigated. Specifically, sisal fibers were suspended in a self-made fiber placement device under the influence of air fluidization and adhered to the surface of the backup slurry of shell. Both silica sol-immersed and untreated sisal fibers were employed as reinforcing agents for the investment shell. The results illustrate that fibers could be evenly placed on the surface of the shell with slurry by means of the air fluidization spread, thereby improving the strength of the fiber-reinforced shell. When the fiber length remained constant, the shell strength exhibited an initial increase followed by a decrease with an increase in fiber addition. At a fiber addition of 1.0%, the green strength of the shell reinforced with both treated and untreated fibers of length 4 mm reached its maximum values, which were 3.35 MPa and 3.14 MPa, respectively. When the fiber addition was 0.25%, the fired strength of the shell reinforced with the aforementioned two types of fibers reached their respective maximum values of 6.12 MPa and 5.86 MPa. [ABSTRACT FROM AUTHOR]

This research is focused on the physical, mechanical, morphological, elemental, and crystallographic properties of untreated, chemically treated, and emulsion-coated sisal fibers. Physical properties, such as diameter and water absorption, were investigated, while mechanical properties, including tensile strength, elongation at break, and modulus of elasticity, were assessed. The findings indicate a significant enhancement in tensile strength (up to 96.7%) and elastic modulus values (up to 214.43%) after chemical treatment, accompanied by a decrease in elongation at break (up to 56.8%). Interestingly, emulsion coating reduced the tensile strength and elastic modulus values, with a marginal increase in elongation at break for treated fibers. The fibers subjected to benzoylation exhibited the highest tensile strength and elastic modulus, followed by alkali-treated fibers. This trend was consistent for emulsion-coated fibers as well. The study outcomes were substantiated by examining the morphological, elemental, and crystallographic aspects of untreated and treated/coated fibers, indicating their suitability for diverse engineering applications. [ABSTRACT FROM AUTHOR]

The present paper is devoted to the proposal of appropriate numerical modelling able to provide a suitable description of the mechanical behavior of a composite geopolymer. Reference is made to a natural sisal-fiber-reinforced geopolymer. The study is based on the results of appropriate experimental investigations for compressive, flexural and splitting loadings, taking into account different weight percentages of fibers to evidence their role in the mechanical behavior. The main objective of the paper is to calibrate the microplane constitutive model, available in ANSYS software version 18.1, where the numerical analyses are performed. Therefore, the present study is structured in two different steps. Firstly, the mechanical behavior of geopolymers reinforced with sisal fibers is experimentally investigated, and subsequently, the gathered test data are interpreted and utilized to calibrate the relevant constitutive model to be used in the numerical stage. The obtained results are compared with experimental data, yielding good correlations. The paper's results supply the parameters required to obtain an affordable numerical model of the reinforced geopolymer for different percentages of fibers to be adopted for material design with assigned mechanical properties. [ABSTRACT FROM AUTHOR]

In the current research investigation, jute and sisal intra‐hybrid woven fabric were specifically tailored to maintain jute and sisal in weft and warp directions, respectively. Jute sisal intra‐hybrid composites were prepared with four layers of intra‐hybrid woven fibers using a compression molding technique. Physical, mechanical (static and dynamic), and thermal stability behavior were investigated, and their structure–property relationship has been established. The obtained results showed that jute‐sisal cross‐interplay‐based hybrid composites recorded maximum tensile and flexural modulus values with minimum anisotropy. It can be concluded from the current experimental investigation that weft/warp orientation and stacking sequence play a significant role in defining the mechanical performance and anisotropic nature of woven fiber‐reinforced laminated composites. Also, the anisotropic properties can be minimized by investigating the effect of fiber orientation and hybridization of natural fibers‐based laminated composites. Highlights: Woven mats were tailored to orient different fibers in warp and weft directions.The influence of the fiber's orientation and stacking sequence was analyzed.Fiber orientation and hybridization have influenced mechanical performance.The alternative stacking sequence has shown the highest mechanical properties. [ABSTRACT FROM AUTHOR]

Bio-based materials are becoming increasingly important as demand for conventional wood-based products raises environmental issues, potentially leading to deforestation. As a result, environmentally acceptable, cost-effective, and easily available alternative natural biomass materials for these intended utilizes are highly required. In this work, a waste wheat straw cellulose polymer matrix composite reinforced with sisal fiber through physical and chemical treatment methods for fiberboard application was synthesized and characterized. The composite materials were developed using the polymer solution casting method. Waste wheat straw composites with 0, 5, 10, 15, 20, 25, and 30 wt% of sisal fiber with respect to the matrix were prepared. Qualitative and quantitative approaches, as well as exploratory and experimental research methods, were employed. Fourier transform infrared (FTIR) spectroscopy was used to investigate the functional group of wheat straw cellulose, while scanning electron microscopy (SEM) was used to examine the sisal fiber morphology. Flexural strength was tested by using a universal testing machine, and impact strengths were measured by a V-notch Charpy tester based on medium-density fiberboard (MDF) and low-density fiberboard (LDF) as control samples. The water absorption of the samples was also studied. The work complied with ANSI A208.2–2002's general test standards for general usage. The results showed that the maximum flexural strength attained at 20 wt% of reinforcement was (56.83 MPa) and the impact strength at 20 wt% sisal fiber was (30.33 J), while the MDF and LDF control samples' flexural strengths were 35.5 MPa and 41.5 MPa, respectively, and the impact strengths were (20.16 J and 25 J), respectively. The lowest water absorption value was achieved at 5 wt% of sisal fiber, and the value was (2.09%). However, water absorption of (74.04%) for MDF and (106.98%) for LDF was measured. Thus, it was discovered that using waste biomass such as wheat straw instead of raw wood may provide a composite material with superior flexural strength, impact strength, and reduced water absorption for fiberboard applications. [ABSTRACT FROM AUTHOR]

Copyright of International Journal of Engineering Research & Development (IJERAD) is the property of International Journal of Engineering Research & Development and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As one of the world’s most fragile and sensitive ecological regions, Xizang risks significant environmental damage from using traditional materials, including cement and lime, to improve and reinforce loose accumulated sandy soil slopes. To address this issue, this study utilized a low-concentration biodegradable polyvinyl alcohol (PVA) solution combined with sisal fibers (SFs) to stabilize loose accumulated sand in southeastern Xizang. A series of physical, mechanical, and microscopic analyses was conducted to evaluate the properties of the treated sand. The results indicated the following. 1) The stress-strain curves of the improved samples exhibited an elastic-plastic relationship. Failure was observed in two stages. At a strain of 3% or less, the samples demonstrated elastic deformation with a linear increase in stress, whereas the deviator stress increased rapidly and linearly with an increase in axial strain. Once the strain exceeded 3%, the deformation became plastic with a nonlinear increase in the stress-strain relationship, and the growth rate of the deviator stress gradually decreased and leveled off. 2) Under varying confining pressure conditions, the relationship curve between the maximum (σ1-σ3)max∼σ3 for both untreated loose accumulated sandy soil and soil improved with the PVA solution, and the sisal fiber was approximately linear. 3) The SFs created a skeletal-like network that encased the soil particles, and the hydroxyl functional groups in the PVA molecules bonded with both the soil particles and the fiber surface, thereby enhancing the interfacial properties. This interaction resulted in a tighter connection between the soil particles and SFs, which improved the stability of the structure. 4) The incorporation of a PVA solution and SFs significantly enhanced the mechanical strength and deformation resistance of the loose accumulated sandy soil. The optimal ratio for the improved soil was SP = 3% and SL = 15 mm, which increased the cohesion from 24.54 kPa in untreated loose accumulated sandy soil to 196.03 kPa. These findings could be applied in engineering practices to improve and reinforce loose accumulated sandy soil slopes in southeastern Xizang and provide a theoretical basis for such applications.

Environmentally, biodegradable natural fiber plays a vital role in polymer composite fabrication due to its cost-effectiveness, reduced specific weight, and specific stiffness behavior. Besides, the research gap spotted on processing challenges, including lack of adhesive behavior, results in lower mechanical behavior of composite. The main objective of the present research is synthesizing of epoxy-based poly composite enclosures with 5% sodium hydroxide processed natural sisal fiber (SF) as 20 vol% via thermally assisted injection mold route, which functional behavior is enriched by the accumulations of 3, 6, and 9 vol% of nanosilicon carbide particles (SiC). The impacts of processing accumulations of nano-SiC/SF on metallurgical (scanning electron microscope (SEM)) and mechanical functional properties including tensile strength, elongation percentage, flexural strength, and fracture toughness of epoxy/NaOH-treated natural SF and its composites embedded with nano-SiC are studied. The novel research is recorded with the exposure of SEM metallurgical analysis results, and better SF distribution along the epoxy matrix with a coarse grain of nano-SiC is identified on hybrid compositions. Amid the various compositions mentioned above, the epoxy/20 vol% SF (NaOH treated)/6 vol% nano-SiC composite has superior tensile strength, better elongation percentage, improved flexural strength, and good fracture toughness of 54 ± 1.5 MPa, 18 ± 1%, 76 ± 2 MPa, and 1.61 ± 0.04 MPam0.5, which is greater than the value of epoxy/20 vol% SF (NaOH treated) composite sample. [ABSTRACT FROM AUTHOR]

Natural fiber-reinforced polymer matrix composites have great potential in various engineering applications due to their lightweight, bio-degradable, non-toxic, and easy availability. However, natural fibers have low inherent behaviour during the preparation of composite. The present investigation is an attempt to enhance an inherent performance of epoxy hybrid nanocomposite with the inclusion of 30 wt% NaOH treated sisal (Agave sisalana) fiber, varied (5, 10, and 15 wt%) weight percentages of nano silicon carbide (SiC) and blended with 5 wt% graphite particles. Compression mould synthesized epoxy composite samples are subjected to surface morphology, flexural strength, toughness, and abrasion studies. The scanning electron microscope results showed the homogenous particle distribution and composite sample 4 (epoxy/30 wt% sisal fiber/15 wt% SiC/5 wt% Gr) is found to have a superior flexural strength of 73.5±0.5 MPa, high fracture toughness of 1.62 MPa m0.5, enhanced wear resistance (0.023 mg/m), and good frictional coefficient. [ABSTRACT FROM AUTHOR]

Increased use of synthetic non-biodegradable polymeric matrices for composite manufacturing, poses a serious threat to the environment. This necessitates the development of 100 % biodegradable green composites using natural plant-based fibers and biodegradable natural polymers. This study focuses on the biodegradability and mechanical characteristics of biodegradable green hybrid composites fabricated with particles of agricultural waste cashew shell, sisal fibers, and corn starch resin using hand layup followed by compression molding. Mechanical characteristics such as tensile, flexural, impact strength, shore D hardness, and soil burial biodegradation characteristics were studied experimentally. The microstructures of the fractured surfaces were also analyzed through SEM images. Composite sample fabricated with an optimum cashew shell particle proportion of 10 wt %, three sisal fiber mat layers and corn starch resin has recorded the highest mechanical strengths such as 11.4 MPa, 10.9 MPa and 310.15 J/m in tensile, flexural and impact strengths respectively. Thus, the green hybrid composite made with agricultural waste cashew shell particles, sisal fibers, and corn starch resin is a potential and eco-friendly modern material for light load and short-life applications. [ABSTRACT FROM AUTHOR]

In this investigation, the influence of various plasma powers 80 W and 120 W for 30 min on mechanical as well as surface characteristics of unidirectional sisal fibers surface treated using cold glow discharge argon plasma had been explored. Agave sisalana is a rosette-forming succulent plant farmed primarily for its fibers, which have been extracted from the leaves. Sisal fibers possess low in compactness, ubiquitous, and environmentally friendly, although they typically exhibit problems such as hydrophilicity and performance. Per our observations, the cold glow discharge argon plasma modification provided the sisal fiber-reinforced epoxy composite (SFREC) with nearly 50.32% significantly greater interlaminar shear strength, 48.66% significantly greater flexural strength, 48.74% elongation at break, and 30.919% significantly greater tensile strength compared to the untreated sisal fiber-reinforced epoxy laminate. Overall morphological features for cold glow discharge argon plasma-treated sisal fibers had been compared to the untreated sisal fibers using Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD), revealing an improvement in fiber surface structure. FTIR particularly revealed the influence of oxidation of basic constituents of the sisal fiber and/or a reduction of both phenolic and secondary alcohol groups leading hydrophobicity after the surface modification. Furthermore, XRD analysis reveals the cold glow discharge plasma Ar alteration increased crystallite size and crystallinity by eradicating some undesirable elements of the sisal fiber and rearranging the crystalline zones. Hence, sisal fibers might well be exploited for industrial application after becoming surface treated to accomplish the aim of fostering self-sustaining biodegradable natural resources. [ABSTRACT FROM AUTHOR]

Studies are presently ongoing to advance the development of bio-composite materials through the exploration of the potential use of reinforcements of natural origin in polymer matrixes. In this particular investigation, hybrid reinforced composite was formulated for automotive application by utilizing epoxy as the matrix and sisal fiber-paper particles as the reinforcements. The sisal fiber was extracted employing soil retting method, subjected to surface treatment, and combined with paper particles. Following preparation of the reinforcements, predetermined compositions (3, 6, 9, 12 and 15 wt %) were mixed with epoxy resin before being poured into the moulds using hand layup process and were allow to cure. The study focused on the mechanical, wear, and water absorption properties, as well as the surface morphologies of the developed composites. The results of the study revealed that the optimal properties were achieved with the utilization of 9 wt. % and 12 wt. % sisal fiber-paper particles reinforced composite. Particulate paper was discovered to be a suitably surface compatibilizer in thermosets when used as fillers with fiber reinforcement. Thus, the epoxy based composite reinforced with hybrid sisal fiber-paper particles is suitable for automobile application in the fabrication of bumper and other epoxy based body parts. [ABSTRACT FROM AUTHOR]

The present work aims to analyze the deformation and stresses of lap joints made of sisal fiber-reinforced composite joined with epoxy adhesive under a transverse load. Finite element models were created with varying numbers of layers in the adherent (two, four), and the response of each layer was identified in terms of deformations, normal stresses, and shear stresses. Additionally, the lap joint was modeled with Buckminster fullerene reinforcement, and the composite was prepared with sisal fiber composite and epoxy adhesive (S/E), sisal fiber-reinforced composite with Buckminster fullerene mixed epoxy adhesive composite (S/FMA), and sisal fiber reinforced with fullerene mixed epoxy and fullerene mixed epoxy adhesive (S/F/F/E). Comparative studies were performed to investigate the effectiveness of fullerene on the adhesive and the adherent by studying the deformations and stresses generated on each layer. The addition of fullerene to the adhesive and sisal fiber-reinforced composite reduced transverse deformation by 27.4%. Adding two more layers to the lap joint without increasing the total laminate thickness reduces stress in both the pure epoxy adhesive and fullerene mixed adhesive. This research is useful for designing lap joints reinforced with natural fibers and nano-reinforcements, while considering the influence of the number of layers in an adherend. [ABSTRACT FROM AUTHOR]

In the process of research and development of self-healing concrete, it is observed that there are three main factors controlling the self-healing effect of concrete: first, the bacteria with repair ability and strong vitality; Second, the carrying capacity of the carrier and the matching degree with concrete; The third is the concentration of bacteria. This paper focuses on the mechanical properties of Bacillus subtilis self-healing concrete with sisal fiber, PVA, and expanded perlite as the carrier. To better study the mechanical properties of self-healing concrete caused by the carrier, the experiment adopts the design parameters of C30 concrete and conducts experiments on compressive resistance, flexural resistance, freeze-thaw cycle, and sulfate corrosion resistance to analyze the influence of different carriers on the mechanical properties of self-healing concrete, and obtains the best carrier. The concentration gradients of three groups of bacterial solution were set as 2od, 2.5od, and 3od, respectively, for comparison to avoid the influence of bacterial concentration. It compared the impact of bacterial solution concentrations on the specimen's mechanical properties, and the effect of carriers was also analyzed. The experimental results show that the mechanical properties of the specimen using 2.5od bacterial liquid concentration with PVA as the carrier have peaked. With the increase in bacterial solution concentration, the specimens' comprehensive mechanical properties increased first and then decreased. The compression resistance of the specimen with PVA is higher than that of the specimen with sisal fiber and expanded perlite. At the same time, the frost resistance and corrosion resistance of the PVA carrier specimen is also higher than that of the specimen with sisal fiber and expanded perlite carrier.

In recent decades, in order to replace traditional synthetic polymer composites, engineering research has focused on the development of new alternatives such as green biocomposites constituted by an eco-sustainable matrix reinforced by natural fibers. Such innovative biocomposites are divided into two different typologies: random short fiber biocomposites characterized by low mechanical strength, used for non-structural applications such as covering panels, etc., and high-performance biocomposites reinforced by long fibers that can be used for semi-structural and structural applications by replacing traditional materials such as metal (carbon steel and aluminum) or synthetic composites such as fiberglass. The present research work focuses on the high-performance biocomposites reinforced by optimized sisal fibers. In detail, in order to contribute to the extension of their application under fatigue loading, a systematic experimental fatigue test campaign has been accomplished by considering four different lay-up configurations (unidirectional, cross-ply, angle-ply and quasi-isotropic) with volume fraction Vf = 70%. The results analysis found that such laminates exhibit good fatigue performance, with fatigue ratios close to 0.5 for unidirectional and angle-ply (±7.5°) laminates. However, by passing from isotropic to unidirectional lay-up, the fatigue strength increases significantly by about four times; higher increases are revealed in terms of fatigue life. In terms of damage, it has been observed that, thanks to the high quality of the proposed laminates, in any case, the fatigue failure involves the fiber failure, although secondary debonding and delamination can occur, especially in orthotropic and cross-ply lay-up. The comparison with classical synthetic composites and other similar biocomposite has shown that in terms of fatigue ratio, the examined biocomposites exhibit performance comparable with the biocomposites reinforced by the more expensive flax and with common fiberglass. Finally, appropriate models, that can be advantageously used at the design stage, have also been proposed to predict the fatigue behavior of the laminates analyzed.

The application of geopolymer composites in the construction of environmentally sustainable buildings and low-carbon structures has generated considerable interest, presenting an alternative and eco-friendly approach to composite materials. The purpose of this research is to develop a new composition of geopolymer concrete, dispersedly reinforced with sisal fiber, and investigate its structure and physical and mechanical properties. To evaluate the effectiveness of the proposed compositions, the fresh properties of the geopolymer concrete mixture—density and slump—and the properties of the hardened composite, namely, the compressive strength, flexural strength and water absorption, were studied. The most rational composition of the alkaline activator was established, and sisal fiber (SF) was protected from alkaline degradation by adding styrene-acrylic copolymer at an amount of 5% and microsilica at an amount of 3% to the concrete mixture. It was determined that the most optimal SF content was 1.0%. The compressive strength exhibited a maximum increase of 12.8%, the flexural strength showed a significant increase of 76.5%, and the water absorption displayed a decrease of 10.3%. The geopolymer fiber-reinforced concrete developed in this study is an environmentally friendly replacement for traditional types of concrete with cement binders and can be used for the manufacture of small architectural forms and landscaping elements.

The use of industrial waste red mud in polymer composites promotes environmental sustainability by mitigating the environmental impacts associated with landfill disposal. Previous research by the authors on red mud sisal fiber composites resulted in increased strength; it is expected that the strength can be increased further through fiber treatment. As a result, the current study sought to examine the effects of chemical‐treated sisal fiber reinforcement on the mechanical properties of red mud composites. Alkaline treatment and silane treatment were both used as chemical treatment methods. Red mud was added in three different weight percentages, and composites were built using the compression molding method and tested for hardness, tensile strength, flexural strength, and impact strength. The findings indicate that the strength of the composite increases with the incorporation of treated fibers, silane‐treated 30% red mud composites showed a maximum hardness of around 92 shore D. The tensile strength of the composites containing 20% red mud and treated with silane was the highest, reaching ca. 63 MPa. This significant increase in strength was attributed to the formation of strong interfacial bonding between the red mud, fiber, and matrix. Furthermore, the silane‐treated 20 wt% red mud composites have the highest flexural strength (ca. 244 MPa) and impact strength (ca. 26 J/m). However, increasing the red mud content above 20 wt% resulted in decreased tensile, flexural, and impact strength due to poor bond development, and red mud agglomeration. The findings of this study are beneficial for the design and development of composites based on red mud, as well as for promoting sustainable waste management practices. Highlights: Red mud composites achieve superior mechanical strength.Chemical treatment enhances sisal fiber reinforcement.Sustainable waste management promoted through composite utilization.Strong interfacial bonding improves composite performance. [ABSTRACT FROM AUTHOR]

Styrene butadiene thermoplastic elastomer (SBS)/polystyrene (PS)/sisal fiber (SF) composites were prepared by melt-blending method. The tensile creep behavior of SBS/PS/SF composites was studied and fitted by four viscoelastic models including Findley, Burger, generalized Kelvin-Voigt and Maxwell models. The effects of content and surface properties of SF treated by alkali and silane coupling agent on the creep behavior, structures and thermal properties of the composites under the action of tensile stress were investigated. The results indicated that the generalized Kelvin-Voigt model and generalized Maxwell model could best fit the tensile creep behavior of SBS/PS/SF composites. The creep resistance and thermal stability of the composites improved with the increases of SF content and tensile stress. The interfacial properties of fiber and matrix were enhanced after SF treated by silane, which would be beneficial to the improvements of the creep resistance and thermal stability. The glass transition temperature of the composite increased with the increase of SF content, but decreased after the action of the tensile stress. [ABSTRACT FROM AUTHOR]

Sisal fiber exhibits a fibrous and porous structure with significant surface roughness, making it highly suitable for storing phase change materials (PCMs). Its intricate morphology further aids in mitigating the risk of PCM leakage. This research successfully employs vacuum adsorption to encapsulate paraffin within sisal fiber, yielding a potentially cost-effective, durable, and environmentally friendly phase change energy storage medium. A systematic investigation was carried out to evaluate the effects of sisal-to-paraffin mass ratio, fiber length, vacuum level, and negative pressure duration on the loading rate of paraffin. The experimental results demonstrate that a paraffin loading rate of 8 wt% can be achieved by subjecting a 3 mm sisal fiber to vacuum adsorption with 16 wt% paraffin for 1 h at −0.1 MPa. Through the utilization of nano-CT imaging enhancement technology, along with petrographic microscopy, this study elucidates the mechanism underlying paraffin storage within sisal fiber during vacuum adsorption. The observations reveal that a substantial portion of paraffin is primarily stored within the pores of the fiber, while a smaller quantity is firmly adsorbed onto its surface, thus yielding a durable phase change energy storage medium. The research findings contribute to both the theoretical foundations and the available practical guidance for the fabrication and implementation of paraffin/sisal fiber composite phase change energy storage mediums. [ABSTRACT FROM AUTHOR]

Hydrothermal aging is a matter of considerable concern for natural fiber-reinforced polymers; it can alter dimensional stability and induce microcracks and macro strain on the composite structure. This study applied a sorption kinetic model and examined the effects of water on the damping factor of sisal mat-reinforced polyester composites. The experimental data were fitted well using a Boltzmann sigmoid function, suggesting a promising first step toward kinetic water sorption modeling. Additionally, a damping test was carried out using the impulse excitation technique, highlighting the composite material's dynamic response under varying water absorption conditions. The result showed that damping exhibited sensitivity to water absorption, increasing significantly during the first 24 h of immersion in water, then remained steady over time, inferring a critical time interval. An empirical model proved satisfactory with the correlation coefficient for sorption rates and damping of sisal mat polymeric composites. [ABSTRACT FROM AUTHOR]

In recent years, the use of natural fibers in concrete has gained considerable attention due to their potential as a sustainable alternative to conventional steel reinforcements. This paper investigates the strength performance of natural fiber-reinforced recycled aggregate concrete using copper slag as a replacement for fine aggregate. The natural fibers used in this study were extracted from sisal and coconut coir. The experimental program involved casting and testing cube, cylinder, and prism specimens to study the strength performance on various proportions of concrete mix design. The specimens were tested for compressive, tensile, and flexural strength at 28 days of maturity. The results showed that the addition of natural fibers significantly improved the strength performance of the recycled aggregate concrete. Furthermore, the replacement of fine aggregate with copper slag improved the microstructure in terms of effective bonding and formation of a denser mix. [ABSTRACT FROM AUTHOR]

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Sisal fibers (SF) are able to enhance the mechanical properties of cementitious materials. However, the rheology of fiber-reinforced cementitious materials is a complex subject due to the significant flow perturbations caused by the fibers in the cement matrix. The effect of SF on the flowability and rheological properties of the cement paste were evaluated in this study. SF of three lengths (3, 6, and 12 mm) were added to the cement paste at different dosages. The results showed that the flowability of the cement paste containing SF decreased with the fiber length and dosage. The rheological curves agreed well with the Bingham model. With the presence of the same dosage of longer SF, the yield stress increased by about 20 times compared to the reference sample. With increase in SF dosage, the plastic viscosity also increased; however, the influence of SF length on the plastic viscosity has less influence than that of yield stress. The results of this study could provide a technological reference for the design and deployment of SF-reinforced cementitious materials in practice. The rheology of fiber-reinforced cementitious materials is known to be a complex subject. The introduction of sisal fibers (SF) can significantly affect the workability of cementitious materials. This study focuses on the effect of different dosages of SF of three lengths (3, 6, and 12 mm) on the flowability and rheological properties of cement paste. The results show that the flowability of the cement paste decreases with increasing SF length and dosage. The introduction of SF still shows a shear thinning behavior and the rheological profile is found to be consistent with the Bingham model. The yield stress is more sensitive to the length of SF. The SF dosage plays a major role in the evolution of viscosity. To obtain insights that will be beneficial for practical applications, relationships between variable parameters and rheological properties were determined. This paper attempts to refine the qualitative control of cost-effective cementitious materials with respect to the dispersion of SF in the cement matrix to enable life-cycle evaluation. In addition, examining the rheological properties of cementitious materials enables the design of building materials on demand, including fiber-reinforced cement-based materials. [ABSTRACT FROM AUTHOR]

This research investigates the mechanical characteristics of a novel hybrid composite material, which combines bio-epoxy reinforced with sisal fiber and integrated with fly ash nano-fillers. The study focuses on exploiting the environmentally friendly attributes of natural fiber composites and reducing reliance on synthetic materials. In this study, sisal fiber serves as the reinforcement, and a bio-epoxy matrix is utilized to create the composite. To further enhance its properties, fly ash, a byproduct of coal-fired power plants, is incorporated as a nano-filler. The experimental findings reveal significant improvements in the mechanical properties of the composite due to the inclusion of fly ash nano-fillers. The tensile strength shows a notable enhancement of up to 6.3%, flexural strength experiences an impressive increase of 68%, impact strength demonstrates a remarkable boost of 28%, and scratch hardness elevates by 17% which were all achieved at 20% fiber weight fraction and 5% fly ash weight fraction. The considerable potential of this hybrid sisal fiber reinforced bio-epoxy composite, integrated with fly ash nano-fillers, as an eco-friendly alternative to traditional synthetic composites is evident from these results. Such enhancements make the composite suitable for a wide range of engineering applications, including the manufacturing of automotive components, construction materials, and consumer goods. By adopting this bio-composite, industries can actively contribute to sustainable practices while maintaining optimal performance in their products. This research offers valuable insights into a promising solution for eco-conscious engineering applications, with both quantitative and qualitative evidence demonstrating the achievement of superior mechanical properties in this innovative hybrid material. [ABSTRACT FROM AUTHOR]

The landfill liner is the last line of defense to protect the soil from damage, but it is difficult to satisfy both impermeability and crack resistance requirements with conventionally compacted clay. This paper proposes a new composite material to enhance the anti-seepage and anti-cracking properties of clay as a solution to this problem. In this Study, the effects of two single amendment materials, Nano-SiO2 (6 dopings) and sisal fiber (SF) (4 dopings), and a composite amendment material (Nano-SiO2+SF), on the permeability and cracking resistance of the improved clay were investigated by infiltration tests and dry-wet cycle tests, respectively. The nuclear magnetic resonance test (NMR) test reveals the microscopic pore changes of soil and explore the reinforcement mechanism. The findings of penetration experiments demonstrate that Nano-SiO2 and SF, both single and composite components, can increase the modified clay's impermeability. The optimum content of Nano-SiO2 is 3%, and its permeability coefficient is 5.09 × 10−8 cm·s−1, which is two orders of magnitude lesser than that of virgin soil. The results of three dry and wet cycle tests showed that the overall trend of fracture length and cracking factor (CIF) increased with the increase of the number of de-wetting. After the third de-wetting of the modified clay, 0.75% Nano-SiO2 + 0.3% SF is the optimal dose, which reduces the fissure length by 19.94 times and CIF by 27.25 times compared with the three de-wetting of the plain clay. As a whole, the data demonstrates that the composite Nano-SiO2 and SF are able to make up for the shortcomings of each component. It can simultaneously improve the anti-seepage and anti-cracking properties of the enhanced clay. The test results provide a certain benchmark for the impermeability and anti-cracking of landfill liners. [ABSTRACT FROM AUTHOR]

Bituminous substantial blends are the essential layer used commonly in Versatile pavements. The property of bituminous mixes can be improved by extension of fibers like coir strands. Fiber lengths were saved for instance 10mm, 15mm and 20mm and used at the speed of 0.3%, 0.5% and 0.7% by weight of mix. This paper gives a review of including Sisal fiber and Coir fiber as added substances in bituminous mix concrete. The utilization of sisal fiber moreover, coir fiber animates better, strength and impedes from channel down of the blend. The wire of fiber in the mix work on the mechanical properties. In India around 8 lakh heaps of coir fiber being made and used various outcomes, the extra waste fiber dumped in open land causing serious normal pollution. Along these lines, a survey has been embraced to involve the waste fiber as help in bituminous concrete. Sisal Fiber with low upkeep and irrelevantly extreme and recyclable mileage. The external forefront removes the sisal fiber that disposes of the crush from inside the plaid herringbone and fine fibers are open. Sisal is against static and will not easily ingest water or suddenness and doesn't attract dust particles or trap them. This paper shows the impact of sisal fiber with loop fiber on bituminous substantial blend. [ABSTRACT FROM AUTHOR]

The present paper is devoted to the proposal of appropriate numerical modelling able to provide a suitable description of the mechanical behavior of a composite geopolymer. Reference is made to a natural sisal-fiber-reinforced geopolymer. The study is based on the results of appropriate experimental investigations for compressive, flexural and splitting loadings, taking into account different weight percentages of fibers to evidence their role in the mechanical behavior. The main objective of the paper is to calibrate the microplane constitutive model, available in ANSYS software version 18.1, where the numerical analyses are performed. Therefore, the present study is structured in two different steps. Firstly, the mechanical behavior of geopolymers reinforced with sisal fibers is experimentally investigated, and subsequently, the gathered test data are interpreted and utilized to calibrate the relevant constitutive model to be used in the numerical stage. The obtained results are compared with experimental data, yielding good correlations. The paper’s results supply the parameters required to obtain an affordable numerical model of the reinforced geopolymer for different percentages of fibers to be adopted for material design with assigned mechanical properties.

To enhance the adaptability of foam concrete in roadbed engineering, there is also a consideration to satisfy the increasing demand for sustainable and green building materials. This research examines the augmenting of the durability and mechanical properties of lightweight roadbed foam concrete (Basalt and Sisal fiber Lightweight Roadbed Foam Concrete - BSLRFC), through the incorporation of basalt and sisal fibers. A meticulous experimental investigation was executed on BSLRFC specimens, which comprised varying volume fractions (0.15%, 0.30%, and 0.45%) and disparate mixing ratios (2:1, 1:1, 1:2), to evaluate their mechanical, durability, and microscopic characteristics. The consequential observations indicate that the performance of the specimens manifests a pattern of initial improvement followed by a subsequent decline with the increasing volume fraction of the mixed fibers. Optimal mechanical attributes and durability performance were realized when the hybrid fibers volume fraction was calibrated at 0.3%, and an appropriate mixing ratio design was incorporated (with a basalt fiber to sisal fiber ratio of 1:2). The comprehensive microstructural analysis revealed the reinforced mechanism for the mechanical characteristics and longevity of the BSLRFC specimens. This provides strong data support for the wider application of BSLRFC in roadbed engineering.

Weight reduction should be accompanied by maintaining the strength and quality of materials utilized in construction. One of the comprehensive solutions to this problem can be the utilization of dispersed fiber reinforcement of concrete with plant fibers of various origins, which led to the sustainable production of concrete. Knowledge regarding the behavior of lightweight concrete with plant fibers is currently rather limited. Therefore, the primary aim of this article was to study the possibility of creating lightweight expanded-clay fiber concrete (ECFC) with improved characteristics, considering the dispersed reinforcement of this concrete with coconut (CF) and sisal (SF) fibers. Test methods and scanning electron microscopy (SEM) analyses were used for the structural study. Dispersed reinforcement of lightweight expanded clay concrete with fibers of organic origin has a positive effect on its mechanical characteristics. The optimal content of expanded clay in lightweight concrete was obtained in terms of the ratio of strength and density. The content of CF and SF, which provides the highest increases in compressive and flexural strength, was 2% of the mass of cement. It was found that SF in lightweight ECFC performs better and provides greater strength gains than CF. The compressive strength of ECFC with CF increased by 8.9%, the bending strength by 16.1%, and with SF by 10.1% and 18.3%, respectively, compared to the fiber-free composite. The coefficient of the constructive quality values of lightweight ECFC is up to 16% higher with CF and up to 18% with SF than a concrete composite without fibers. Moreover, formulas were derived to predict the compressive of ECFC with and without CF and SF.

Significant efforts have been made to improve concrete mix design for shrinkage reduction and crack control, including reduction of cement content and selection of cement type with less heat of hydration, maximizing aggregate contents, and introduction of discrete fibers in concrete to increase internal restraint. Although high-performance concrete (HPC) mixes including fibers [e.g., steel fibers, polypropylene fibers, or polyvinyl alcohol (PVA) fibers] have reduced the level of shrinkage cracking, they have not eliminated it. Thus, understanding the level of tensile strain the fibers take in the concrete could provide valuable information to aid engineers to make an informed decision on the need for fibers in tension demand in the concrete and determine the appropriate fiber detailing and concrete mix additives. As such, this study aimed to explore a multiscale, hierarchical fiber gradation through a combination of nanoscale nanofabrillated cellulose (NFC) with microscale sisal fibers and macroscale steel fibers in concrete to mitigate the causes of concrete shrinkage cracking at an early age. A total of 22 mixtures were designed and tested. The results show that nanofabrillated cellulose, sisal fiber, and steel fiber can play an excellent synergistic effect to inhibit the early-age shrinkage of concrete. The test data reveal that, when steel fiber is partially replaced by sisal fiber, the early shrinkage of steel fiber concrete is significantly reduced by 26.91% at maximum. Meanwhile, when the NFC content reached 0.15%, the 7-day shrinkage value of concrete reinforced by steel fiber, sisal fiber, and NFC was the lowest, and the shrinkage strain value decreased by 25.03% compared with N0. Compared with the experimental group in which sisal fiber partially replaced steel fiber, the 7-day shrinkage value of the experimental group in which sisal fiber mixed with NFC, sisal fiber mixed with NFC and steel fiber decreased to a certain extent, among which SF1.1FF0.4NFC0.15 showed the best shrinkage inhibition performance, and the shrinkage strain value decreased by 82.56% and 45.39% compared with N0 and SF1.1FF0.4, respectively. [ABSTRACT FROM AUTHOR]

As a part of the mission to create materials that are more environmentally friendly, we present the following proposal, in which a study of the mechanical properties of composite materials comprising a polyester resin with sisal fiber and bentonite particles was conducted. Sisal fiber was added to a matrix in percentages ranging from 5% to 45% in relation to the polyester resin weight, while bentonite remained fixed at 7% in relation to the polyester resin weight. The specimens were manufactured by compression molding. The mechanical properties were analyzed by tensile, bending, impact, stepped creep, and relaxation tests. In addition, energy-dispersive X-ray spectroscopy and scanning electron microscopy analyses were carried out to analyze the composition and heterogeneity of the structure of the composite material. The results obtained showed that 7% of bentonite added to the matrix affects the tensile strength. Flexural strength increased by up to 21% in the specimens with a 20% addition of sisal fiber, while the elastic modulus increased by up to 43% in the case of a 20% addition of sisal fiber. The viscoelastic behavior was improved, while the relaxation stress was affected. [ABSTRACT FROM AUTHOR]

Split Hopkinson pressure bar (SHPB) was used to investigate the dynamic compressive properties of sisal fiber reinforced coral aggregate concrete (SFCAC). The results showed that, with the increase of strain rate, the dynamic compressive strength, peak strain and toughness index of SFCAC are all greater than its static properties, indicating that SFCAC is a kind of rate-sensitive material. When the sisal fiber was blended, the failure mode showed obvious ductility. At high strain rates, the SFCAC without sisal fiber specimen was comminuted, and the SFCAC showed a "cracked without breaking" state. The results indicated that the sisal fiber played a significant role in reinforcing and strengthening the properties of concrete. The finite element software LS-DYNA was used to simulate two working conditions with strain rates of 78 and 101 s−1. The stressstrain curves and failure patterns obtained were in good agreement with the experimental results. [ABSTRACT FROM AUTHOR]