Increasing Fiber Content Research Articles

Influence of Thermal Treatment and Granulometry on Physicochemical, Techno-Functional and Nutritional Properties of Lentil Flours.

Legume flours are an increasingly popular food ingredient. Thermal treatments applied prior to milling legumes and granulometry can modify flour properties, altering sensory, digestibility and functional attributes. Raw and treated (soaked and cooked) lentil flours of different granulometry were produced. The applied treatment resulted in an increase in fiber content (25.4 vs. 27.6% for raw and treated lentil flour, respectively) and water absorption capacity. It also led to a decrease in ash content (3.3 vs. 1.8% for raw and treated, respectively) and a darker flour. Treated lentil flour was mainly composed of fractions of high granulometry, which could be beneficial for products where a lower glycemic index is sought, as they demonstrated higher fiber and lower carbohydrate content than the finer fractions. Treated flour may be used as an ingredient in the development of raw products, including beverages and desserts, due to its reduced anti-nutritional compounds' content and enhanced organoleptic aspects. The obtained results allow an in-depth characterization of raw and treated lentils flour with different particle sizes to consider a formal and complete standardization of these flours and for understanding their utility and specific food applications.

Effect of moisture on breakdown strength and glass transition temperature of bio-polyamide reinforced with glass or basalt fiber

In this study we investigate the effect of moisture content on the dielectric breakdown strength and glass transition temperature (Tg) of bio-polyamide 4.10 reinforced with glass or basalt fiber (15, 30, 50 wt%). Moisture absorption decreased with increasing fiber content, regardless of fiber type. The reduction in breakdown voltage (BDV) was more pronounced in the composites with higher moisture content reinforced with basalt fiber. This may be due to weaker interactions at the interface. The presence of moisture decreased the glass transition temperature of the composites. PA 4.10, especially reinforced with glass fiber, is characterized by better performance properties than PA 6.6 reinforced with 50 wt% glass fiber in applications requiring both stability of mechanical properties and dielectric properties.

Mechanical properties and damage modeling of hybrid fiber reinforced concrete under freeze-thaw cycles

This study aimed to investigate the mechanical properties of steel-polyacrylonitrile hybrid fiber reinforced concrete and its durability under freeze-thaw damage. Firstly, the mechanical properties of hybrid fiber reinforced concrete were studied by compressive strength and flexural strength tests. Secondly, with the help of rapid freeze-thaw test, the variation rules of mass loss rate and relative dynamic elastic modulus were characterized. Based on the test results and freeze-thaw damage theory, the evolution equation of freeze-thaw damage of hybrid fiber reinforced concrete based on Weibull distribution was established. The results show that the enhancement effect of hybrid fiber on the mechanical strength of concrete is better than that of single mixed fiber, especially in the improvement of flexural strength; Accordingly, compared with the single mixing of steel fibers or single mixing of polyacrylonitrile fibers, hybrid fibers are more effective in improving the durability of concrete against freezing and this improvement effect increases with the increase of steel fiber content; The freeze-thaw damage model of Weibull distribution can better reflect the freeze-thaw damage process of hybrid fiber reinforced concrete .Through the freeze-thaw damage evolution curve, it can be found that after 500 freeze-thaw cycles, the freeze-thaw damage degree of the hybrid fiber reinforced concrete with different steel fiber content has been very close, which means that the influence of steel fiber content on the freeze-resistant performance of hybrid fiber reinforced concrete will be limited. This study provides a theoretical basis and technical basis for the design of concrete structures in alpine regions.

Strengthening and embrittlement effect of cryogenic temperature on fiber reinforced geopolymer composite

Understanding the cryogenic behaviour of geopolymer composite (GPC) is essential to implement them in real structural elements at cryogenic temperatures. The paper presents a comprehensive investigation on the compressive strength, flexural behaviours, and energy absorption capability of both plain GPC and fiber-reinforced geopolymer composite (FRGPC) containing different fiber types and contents subjected to in-situ −170 °C. The results demonstrate that the compressive strength of plain GPC and FRGPC increases by 104.9 %–213.6 %, and the flexural strength increases by 73.4 %–212.5 %, exhibiting a significant cryogenic strengthening effect. Moreover, compared to flexural strength, compressive strength of GPCs displays a higher sensitivity to the cryogenic strengthening effect. The failure mode of FRGPCs changed from ductile failure to ductile-brittle failure at −170 °C, which is due to the decreased ductility induced by the cryogenic embrittlement effect. Additionally, cryogenic exposure has a greater impact on reducing the ductility of FRGPCs containing PP fibers than those with steel fibers. However, the negative effects of cryogenic embrittlement effect on ductility can be mitigated by incorporating steel fibers and increasing fiber content. The further analysis reveals that strengthening and embrittlement effect are associated with the increased cumulative energy and the sudden release of local energy, respectively. These findings contribute to the understanding of GPC performance at cryogenic temperature, which can guide the development of more resilient and durable GPC for cryogenic applications.

Study on the dynamic fracture mechanical properties of ultra high-performance concrete under the influence of steel fiber content

Ultra-high performance concrete (UHPC) is characterized by its ultra-high strength and durability, making it suitable for use in large-span bridges, super high-rise buildings, and other special structures. These types of structures often have high requirements for crack control, making the exploration of UHPC's fracture mechanics properties of significant importance. Therefore, this paper sets up four steel fiber contents (0 %, 0.6 %, 1.2 % and 1.8 %) and four strain rates (10−5/s, 10−4/s, 10−3/s and 10−2/s), totaling 16 working conditions. The hydraulic servo system combined with digital image correlation (DIC) technology was used to conduct fracture mechanics tests on UHPC three-point bending beams. The test results show that the unstable fracture load of UHPC increases with the increase of strain rate and steel fiber content, and increasing the steel fiber content can enhance the strain rate effect of UHPC to a certain extent. Additionally, combined with the J-criterion model, this study proposed a dynamic criterion for the unstable fracture load of UHPC considering the influence of steel fiber content. The initial fracture toughness, unstable fracture toughness, and fracture energy of UHPC are significantly more affected by steel fiber content than by strain rate. Through DIC technology, the analysis of UHPC crack propagation shows that UHPC without steel fibers experiences rapid crack expansion in the Pre-90 % to Peak stage, with less influence from the strain rate. However, UHPC with steel fibers exhibits a more uniform crack growth rate, with the crack emergence phase gradually lagging as the strain rate increases. For UHPC without steel fibers, the crack opening displacement (COD) at the unstable fracture load point surges suddenly, while the COD development in UHPC with steel fibers is slower. At lower strain rates, an increase in steel fiber content leads to an earlier sudden increase phase in UHPC's COD; at higher strain rates, the influence of steel fiber content on the sudden increase phase of UHPC's COD is more scattered. The research results of this paper provide a theoretical basis for the calculation and analysis of the dynamic response of UHPC structures under seismic loads.

Effects of Carbon Fiber Content on the Crystallization and Rheological Properties of Carbon Fiber-Reinforced Polyamide 6.

Carbon fiber (CF)-reinforced polyamide 6 (PA6) composites have an excellent performance, attributed to properties such as light quality, high strength, and vibration reduction, and they are widely used in fields such as aerospace and transportation. Four kinds of carbon fiber-reinforced polyamide 6 (CF/PA6) composite pellets with carbon fiber contents of 20, 30, 40, and 50 wt.% were prepared using twin screw extrusion. The results were characterized using a simultaneous thermal analyzer, capillary rheometer, electronic universal material testing machine, and scanning electron microscope (SEM); their crystallization, rheological behavior, mechanical properties, surface structure, etc., were studied. DSC results indicate that an increase in carbon fiber content enhances the thermal stability of CF/PA6 and narrows the crystallization window but has a minor effect on the molecular chain diffusion time. The crystallinity reaches its maximum at a carbon fiber content of 40 wt.%, reaching 55.16%. The steady-state rheological behavior reveals that CF/PA6 behaves as a pseudoplastic fluid, exhibiting shear-thinning behavior. When the carbon fiber content is 40 wt.%, the power law exponent (n) reaches its maximum, and the consistency coefficient (K) decreases by 300 Pa⋅sn compared to the 30 wt.% content. With increasing temperature, n increases while K decreases. SEM observations reveal that samples with carbon fiber contents of 20 wt.% and 40 wt.% exhibit better fiber dispersion and orientation. However, the interfacial bonding strength is superior in the 40 wt.% sample. When the carbon fiber content reaches 50 wt.%, significant injection molding defects occur at the clamping end, leading to extensive matrix tearing during tension testing.

Influence of the Addition of Palm (Borassus Aethiopum Mart.) Fibers on the Durability of Compressed Earth Blocks

This study aims to determine the influence of the content and length of the palm (borassus aethiopum mart.) fibers on the physical, mechanical and thermal properties of Compressed Earth Blocks (CEB). Three fiber contents (0.2%, 0.4% and 0.8%) of different lengths (10 mm, 20 mm, or 40 mm) were used to make CEB. CEB with 0% fiber content were manufactured to serve as control samples. CEB specimens stabilized with palm fibers or not were subjected to various tests according to standard XP P 13-901 for the determination of the following properties: dry density, water absorption, dry compressive strength, abrasion resistance and thermal conductivity. The results show that the dry density of CEB decreases from 4% to 7% when the content and length of the fibers increase respectively from 0.2% and 10 mm in length to 0.8% and 40 mm in length. The water absorption of fiber-containing CEBs ranges from 14% to 22% with increasing fiber content and length. The results also indicate that the mechanical and thermal properties are improved for well-chosen fiber contents. Thus, the dry compressive strength of the fibers increases by more than 13% for a fiber content of 0.2% and a length of 10 mm compared to CEB with 0% fibers. On the other hand, the optimal abrasion resistance values are obtained for a fiber content of 0.4% and a length of 40 mm. For all CEBs, the thermal conductivity values vary from 0.51 W/mK to 0.38 W/mK when the fiber content varies from 0.2% to 0.8%. Overall, palm fiber content has a greater influence on the measured physical, mechanical and thermal characteristics than fiber length.

Experimental research on shear strength characteristics of cement-stabilized dredged silty clay reinforced with alginate fiber

In order to avoid uneven dispersion or agglomeration of traditional fibers after mechanical mixing, alginate fibers as natural fibers were selected in this study to reinforce the cement-stabilized dredged silty clay, forming alginate fiber-reinforced cement-stabilized dredged silty clay. The shear strength of cement-stabilized dredged silty clay reinforced with alginate fibers with the same cement content (9 % by wet weight) and cured for 7 and 28 days was investigated. Consolidated undrained (CU) triaxial compression tests were carried out on reinforced soil samples with varying fiber lengths (3 mm, 6 mm, and 9 mm) and fiber contents (0 %, 0.3 %, 0.6 %, and 0.9 % by weight of wet soil) to assess the shear strength characteristics. The results showed that, on average, the shear strength increased by 18.30 % and 18.56 % with the increasing content and length of alginate fibers, respectively. The variation in deviator stress and axial strain exhibited a shift from strain-softening to strain-hardening with increased confining pressure, alginate fiber content, and length. Hence, a double exponential curve model with different fiber content and length in three confined pressures was proposed, and the correlation coefficient of the fitting results was above 0.90. The secant modulus E50 increased and subsequently decreased with the length of fibers, with the largest secant modulus E50 observed for 6 mm fiber length. The strength parameters (cohesion c and internal friction angle φ) exhibited contrasting responses to variations in alginate fiber length and content. The cohesion of the fiber-reinforced soil specimens increased by 29.0 % and 13.1 %, respectively, for increased fiber content and length. Nevertheless, the angle of internal friction remained relatively unchanged. The findings of this study can serve as a reference guide for related engineering projects.

Study on short fiber reinforcement mechanism for mechanical performance improvement of 3D‐printed short‐continuous carbon fiber reinforced thermoplastic composites

Abstract3D printing of continuous carbon fiber reinforced thermoplastic (C‐CFRTP) composites is a promising fabricating process to achieve complex lightweight structures within a short time; nevertheless, low mechanical performance between printed layers is always a limitation. Adding short carbon fibers during C‐CFRTP fabrication could achieve short‐continuous carbon fiber reinforced thermoplastic (S/C‐CFRTP) composites with enhanced mechanical properties. However, the underlying reinforcement mechanism is not well understood, which hinders the optimization of 3D printing process for S/C‐CFRTP. This paper investigates reinforcing behavior of short carbon fibers and impregnation behavior of the matrix (short carbon fiber reinforced PA6) under various 3D printing conditions. The results indicate that promoting both reinforcing and impregnation behaviors during S/C‐CFRTP 3D printing can improve mechanical performance. As short carbon fiber content increases, the mechanical performance initially experiences enhancement caused by the reinforcing behavior of short fibers, followed by a decline attributed to the insufficient impregnation of the molten matrix. Higher nozzle temperatures facilitate the impregnation behavior of the molten matrix, resulting in superior mechanical performance. Moreover, by leveraging the reinforcement mechanism, the optimal parameter combination is proposed to improve tensile, flexural, and interlaminar shear strengths of the 3D‐printed S/C‐CFRTP to approximately 368.27, 319.80, and 20.09 MPa, respectively.Highlights Reinforcement mechanism is revealed by reinforcing and impregnation behaviors. Short carbon fiber content affects both reinforcing and impregnation behaviors. Beyond 15 wt%, short carbon fiber content shows adverse effects on performance. High nozzle temperature promotes impregnation behavior to improve performance. Optimal parameters raise 19.8% tensile, 39.9% flexural and 161.2% shear strength.

Experimental Study on the Mechanical Properties of Steel Fiber Ferronickel Slag Powder Concrete

The use of ferronickel slag powder (FNSP) as a cementitious additional material has been supported by numerous reports. FNSP concrete has the same shortcomings as ordinary concrete, including low hardness. In this study, in order to make FNSP concrete more durable, end-hooked type steel fibers were incorporated. To understand how various elements affect the mechanical properties of steel fibers, an experiment was carried out on the mechanical properties of steel FNSP concrete (SFNSPC). FNSP’s principal ingredients, with a particle size distribution ranging from 0.5 to 100 μm and a sheet-like powder shape, are CaO, SiO2, Al2O3, MgO, and others, according to tests conducted on the material’s microstructure and composition. Then, eighteen mix proportions were developed, comprising six distinct FNSP replacement rate types and three distinct steel fiber content types. Crucial metrics were evaluated and analyzed, including the relationship among the toughness, tensile strength, and compressive strength as well as slump, splitting tensile strength, compressive strength, and uniaxial compressive stress–strain curve of SFNSPC. The results showed that the slump of SFNSPC under different FNSP replacement rates decreased with increasing steel fiber volume. Steel fibers have a small but positive effect on SFNSPC’s compressive strength; nonetheless, as FNSP replacement rates increased, SFNSPC’s slump gradually decreased, though not by much. These results show that FNSP is a viable alternative cementitious material in terms of strength. Specifically, the splitting tensile strength of SFNSPC improves with an increase in steel fiber content, and the pace at which SFNSPC strength drops with an increase in the FNSP replacement rate. With varying mix proportions, the stress–strain curve trend of SFNSPC remains mostly constant, and steel fibers improve the compressive toughness of SFNSPC. After adding 0.5% and 1.0% steel fibers, the toughness index of concrete with different FNSP replacement rates increased by 8–30% and 12–43%, respectively.

Study on flexural and self-repairing properties of shape memory alloy concrete beams

The generation and expansion of cracks in concrete materials have always been a problem that needs to be solved, and an increasing number of scholars are beginning to hope that structures will have bionic functions of self-diagnosis and self-repairing of damage. In this study, shape memory alloy (SMA) concrete beams are prepared. The flexural and self-repairing properties of SMA concrete beams were investigated by a four-point bending test. The effects of various factors on the bearing capacity, ductility, and crack width before and after repair were analyzed. The experimental results indicate that the increase of SMA fiber content and the complexity of the SMA bar end shape can significantly enhance the flexural bearing capacity and repair performance of the beam. The increase in the bond length of SMA bars can enhance the bending resistance of the beam, but it will reduce its self-repairing performance. The repair rate of SMA on concrete cracks is 45.7 %-76.5 %, and the load recovery rate is between 49.4 % and 80.6 %. The flexural load capacity calculation formula is proposed, and the calculation results closely match the test values, providing a reference for the application of SMA.

High performance Csf/SiC ceramic matrix composites fabricated by material extrusion 3D printing and precursor infiltration and pyrolysis

Material extrusion (ME) 3D printing is an emerging technology to fabricate short carbon fiber reinforced SiC ceramic matrix composites (Csf/SiC CMCs) with highly oriented short carbon fibers. In this study, the Csf/SiC CMCs were fabricated by ME 3D printing combined with the following precursor infiltration and pyrolysis (PIP). The short carbon fibers could be well kept after the PIP process. The effects of solid loading and fiber content on the microstructure and mechanical properties of the Csf/SiC CMCs were also investigated. Higher solid loading was beneficial for obtaining the denser Csf/SiC CMCs with more oriented fibers. The introduction of short carbon fibers brought more pores. The bending strength and fracture toughness of Csf/SiC CMCs first increased and then decreased with the increase in fiber content. The pulling-out and breakage of short carbon fibers contributed to the improvement of mechanical properties. High performance Csf/SiC CMCs with a bending strength of 212.74 MPa and fracture toughness of 5.84 MPa m1/2 were simultaneously achieved when the solid content was 50 vol% and the fiber content was 20 vol%. It is believed that this study can provide some understanding of the 3D printing of fiber reinforced CMCs.

Mechanical and tribological characterization of vacuum pressurized impregnation (VPI) treated bamboo fiber-reinforced polymer (FRP) composites with jute mat layer under fretting wear conditions

ABSTRACT The study explored the performance of VPI-treated bamboo fiber reinforced FRP laminated composites, focusing on fretting wear and mechanical behavior with various chemical treatments. FTIR analysis revealed that NaOH treatment effectively removed hemicelluloses and lignin, with peak shifts at 3330, 2918, and 1420 cm−1, while tannic acid induced peak shifts at 1640 and 1500 cm−1, indicating cellulose interactions. Phosphoric acid treatment reduced intensity at 3340 and 2890 cm−1, suggesting cellulose depolymerization. TGA showed varied weight loss profiles, reflecting thermal property modifications. XRD analysis indicated changes in crystalline structure, and SEM revealed structural alterations. Tensile strengths at 0.5% weight were 216 ± 3.0 MPa for alkaline-treated bamboo fiber composite (A-BFC), 256 ± 0.01 MPa for tannic acid-treated bamboo fiber composite (T-BFC), and 281 ± 3.0 MPa for phosphoric acid-treated bamboo fiber composite (P-BFC). Fretting wear analysis demonstrated that P-BFC withstood loads up to 45N, with wear resistance improving with increased fiber content. dynamic mechanical analysis (DMA) highlighted that P-BFC exhibited the highest initial storage modulus and a tan δ peak of 69°C, compared to T-BFC and A-BFC, both at 68°C. The wear rate decreased with higher bamboo fiber content and load, showcasing the potential of VPI-treated bamboo fiber composites for applications requiring enhanced strength and wear resistance.

Development of Dusun Traditional Fermented Fish (Bosou Ikan) Using Different Concentrations of Tuhau (Etlingera coccinea)

This study aimed to determine the best formulation of Dusun traditional fermented fish (Bosou ikan) through sensory evaluation employing a 9-point hedonic test. Various concentrations of Etlingera coccinea, ranging from 0% to 8% w/w, were incorporated into fermented fish samples. Results revealed that the formulation containing 2% E. coccinea (F1) consistently exhibited superior sensory attributes, maintaining the traditional appearance while enhancing aroma, taste, and overall acceptability. Statistical analysis using the Friedman test confirmed F1's superiority, showing the lowest mean rank among alternatives (p<0.05). Proximate analysis of F1 demonstrated notable increases in ash, crude fat, crude fiber, and crude protein content compared to Control Bosou ikan formulations, indicating enhanced nutritional profiles. Shelf-life analysis demonstrated a more controlled trend in reducing total viable count and total yeast and mold counts for the F1 formulation compared to the control, suggesting a potential influence of E. coccinea in inhibiting excessive microbial proliferation. Comparison of microbial loads between raw and cooked samples revealed that cooking effectively eliminated microbial counts, reaching safety consumption levels of 4 log10 CFU/g (total yeast and mold) and 6 log10 CFU/g (total viable count). The decrease in pH of raw and cooked samples over one month was attributed to increased acidity resulting from the activities of Lactobacillus sp., which utilizes carbohydrates in the medium to produce lactic acid. The study highlights that the F1 formulation with 2% Etlingera coccinea offers the most favourable sensory characteristics, proximate analysis, and microbial quality, providing valuable insights for product development in Bosou ikan production.

Sustainable Electrically Conductive Bio-Based Composites via Radical-Induced Cationic Frontal Photopolymerization.

Diglycidylether of vanillyl alcohol (DGEVA), in combination with mechanically recycled carbon fibers (RCFs), was used to make, via Radical-Induced Cationic Frontal Photopolymerization (RICFP), fully sustainable and bio-based conductive composites with good electrical conductivity and consequent Joule effect proprieties. Three different fiber lengths, using three different sieve sizes during the mechanical recycling process (0.2, 0.5, and 2.0 mm), were used in five different amounts (ranging from 1 to 25 phr). The samples were first characterized by dynamic mechanical thermal analysis (DMTA), followed byelectrical conductivity and Joule heating tests. More specifically, the mechanical properties of the composites increased when increasing fiber content. Furthermore, the composites obtained with the longest fibers showed the highest electrical conductivity, reaching a maximum of 11 S/m, due to their higher aspect ratio. In this context, the temperature reached by Joule effect was directly related to the electrical conductivity, and was able to reach an average and maximum temperatures of 80 °C and 120 °C, respectively, just by applying 6 V.

Basalt Fibers versus Plant Fibers: The Effect of Fiber-Reinforced Red Clay on Shear Strength and Thermophysical Properties under Freeze–Thaw Conditions

Freeze–thaw cycling has a significant impact on the energy utilization and stability of roadbed fill. Given the good performance of basalt fiber (BF) and plant fiber (PF), a series of indoor tests are conducted on fiber-reinforced red clay (RC) specimens to analyze the shear strength, thermophysical, and microstructural changes and damage mechanisms of the RC under the freeze–thaw cycle–BF coupling, meanwhile, comparing the improvement effect of PF. The results indicate that the RC cohesion (c) first increases and then decreases with the increasing fiber content under BF improvement, reaching the maximum value at the content of 2%, and the change in the internal friction angle (φ) is relatively small. As the number of freeze–thaw cycles increases, cohesion (c) first decreases and then gradually stabilizes. The thermal conductivity increases with increasing moisture content, and the thermal effusivity increases and then decreases with increasing moisture content and fiber content. The heat storage capacity reaches the optimum level at a moisture content of 22.5% and a fiber content of 1%. Microanalysis reveals that at 2% fiber content, a fiber network structure is initially formed, and the gripping effect is optimal. The shear strength of PF-improved soil is higher than that of BF at a fiber content of 4–6%, and the thermal conductivity is better than that of BF. At the same fiber content, the heat storage and insulation capacity of BF-improved soil is significantly higher than that of PF.

Study on the Effects of Pasture Fiber on Thermal Properties of Slag Bricks.

In the context of ecological sustainability, this study focuses on the effect of variables of pasture fibers on the thermal properties of slag bricks made from a green recyclable material. This experiment uses slag as the binder, sand as the aggregate, and pasture fiber as an additive. The experimental variables include the additive content ratio of the pasture fiber, the size of the pasture fiber, and the type of pasture fiber. Significance analysis of the experimental results of the thermal performance tests is carried out using Minitab 18.1.0 software, and the optimal ratios for the thermal performance of the composite samples are derived from the response optimizer and conformity analysis. The results of the experiment's test analysis using Minitab 18 software indicate that, with an increase in pasture fiber content, the thermal performance of the composite samples initially decreases before increasing. Additionally, the lower the thermal conductivity of the composite sample, the lower the apparent density and the higher the porosity. Incorporating pasture fibers into slag bricks, as revealed in this study, reduces the waste of pasture resources in pastoral areas and promotes the development of sustainable building materials with favorable thermal properties.

Mechanical Behavior of Low-Strength Hydraulic Lime Concrete Reinforced with Flexible Fibers under Quasi-Static and Dynamic Conditions

We investigate the effect of flexible fiber reinforcement on low-strength hydraulic lime concrete. This type of concrete is occasionally necessary to ensure compatibility with the substrate, particularly in the conservation and rehabilitation of historical heritage. For this purpose, we designed a matrix of hydraulic lime concrete based on a mix design method we proposed previously and added different amounts of polyvinyl alcohol fiber (volumetric contents of 0.3%, 0.6%, 0.9%, and 1.2%). We then conducted three-point bending tests on prismatic specimens with a central notch under quasi-static (displacement rate of 4 × 10−4 mm/s) and dynamic (4 mm/s) conditions, using a servo-hydraulic machine. The results indicate that, in both quasi-static and dynamic regimes, the flexural strength, the residual flexural strengths for different crack openings, and the work of fracture increase as the fiber content increases. Furthermore, transitioning from one regime to another (by increasing the strain rate or velocity) leads to a significant increase in these mechanical parameters.

High-fiber and low-glycemic index egg-roll cookies made from non-itchy taro (Colocasia esculenta var. Febi521)

Indigenous taro is a notable carbohydrate-rich food ingredient with significant dietary fiber. However, its natural itchiness has limited its widespread use. A new non-itchy variant, Febi521, was developed through in-vitro soma-clonal induction. This study aimed to create a high-fiber snack, specifically egg-roll cookies, using non-itchy taro (Colocasia esculenta var. Febi521). The cookies underwent comprehensive evaluation for their physical, chemical, and nutritional characteristics, including polyphenol content, glycemic index (GI), and glycemic load (GL). By fully substituting taro Febi521 flour in the recipe, we produced egg-roll cookies that were sensorially preferred, high in fiber (19.2 % wet basis), and had a low GI (39) and low GL (3). This formulation also met nutritional requirements for claims related to total fat, saturated fat, sodium, and cholesterol. Substituting taro flour increased fiber content threefold compared to wheat flour-based egg-roll cookies. This research highlights the potential of indigenous taro for diverse product development aimed at enhancing fiber intake among the population.

An Experimental Study on the Influence of Different Cooling Methods on the Mechanical Properties of PVA Fiber-Reinforced High-Strength Concrete after High-Temperature Action.

High-strength concrete (HSC) has a high compressive strength, high density, excellent durability, and seepage resistance, but its deformation ability is weak. Adding fibers can improve the physical and mechanical properties of HSC. Additionally, the HSC structure may face the threat of fire. In the process of fire extinguishing, the damage mechanism of high-temperature-resistant concrete is complicated due to the different contact conditions with water at different locations. Hence, it is essential to conduct pertinent research on the behavior of fiber-reinforced HSC with different cooling methods after high-temperature action. In this paper, polyvinyl alcohol fiber (PVA fiber) was selected to be added into the HSC to carry out high-temperature experimental research, so as to explore the apparent changes, failure pattern, and mass loss rate of the fiber-reinforced HSC using different cooling methods and analyze the influence of its residual compressive strength and flexural strength. The test results suggest that, with the increase in heating temperature, the color of the specimen's surface transitions from dark blue-gray to white, and the quantity of surface cracks on the specimen gradually rises. The mechanical strength gradually decreases as the heating temperature increases. At a consistent heating temperature, the mechanical strength initially rises, and then falls with an increase in fiber content. The maximum compressive strength and flexural strength were achieved at PVA fiber contents of 0.2% and 0.3%, respectively. For different temperatures and fiber contents, the mechanical strength after natural cooling is generally higher than that after immersion cooling. In addition, X-ray polycrystalline diffractometry (XRD) and scanning electron microscopy (SEM) tests were conducted to analyze the compositional alterations and microstructure of the fiber-reinforced HSC following high-temperature exposure, accompanied by an explanation of the factors influencing the alterations in the physical and mechanical properties. Therefore, the findings of this study can serve as a valuable reference for the utilization of HSC in engineering structures and contribute to the advancement of HSC technology.