Increasing Fiber Content Research Articles

Experimental study on mechanical properties of recycled aggregate concrete with polypropylene fiber under combined compression‐shear loading

AbstractTo investigate the mechanical properties of polypropylene fiber recycled aggregate concrete (PPFRAC) under compression‐shear, 69 recycled aggregate concrete (RAC) specimens were tested with the parameters of polypropylene (PP) fiber volume content (0, 0.6, 0.9, and 1.2 kg/m3), recycled coarse aggregate (RCA) replacement rate (0%, 30%, 50%, 70%, and 100%), and normal stress (0, 3, and 6 MPa). In the tests, the failure pattern of the specimens was observed, and the effects of the polypropylene fiber content on the direct shear stress, compression‐shear stress, initial shear stiffness, and shear ductility coefficient of the PPFRAC were thoroughly investigated. The results show that as the polypropylene fiber content increases, the direct shear stress of concrete (Natural aggregate concrete and 100% recycled coarse aggregate concrete [100%RCA]) first increases and then decreases gradually. Meanwhile, the best PP fiber content is 0.9 kg/m3 in this study. Furthermore, the compression‐shear stress‐displacement curves of specimens were obtained. The compression‐shear strength under normal stress at 6 MPa is approximately 230% greater than at 0 MPa. However, the peak shear stress of concrete is almost not affected by the replacement rate of RCA. Finally, based on the Mohr circle theory, the compression‐shear calculation model of PPFRAC is verified, and the optimal calculation formula is given.

Shrinkage Behavior of Stabilized Earth Bricks Reinforced with Wheat and Barley Straw

Due to its ecological and financial benefits, earth building has gained global attention, with earth bricks being extensively used. Shrinkage and crack development have a considerable impact on the performance and quality of earth bricks. This study employs laboratory experiments to examine the shrinkage behavior of earth bricks reinforced with wheat and barley straw. In addition to this, the impact of cement and gypsum additives is examined. The obtained results indicate that increased fiber content reduces crack formation effectively. However, higher levels of cohesive soil have been shown to have a negative influence on shrinkage behavior. In general, higher fiber contents contribute to the improvement of earth brick performance. These findings offer useful insights for improving the composition and characteristics of reinforced earth bricks, resulting in enhanced performance and quality in sustainable construction practices.

Effects of fiber characteristics and specimen sizes on static and dynamic split-tensile failures of BFLAC: 3D mesoscopic simulations

In this study, a three-dimensional mesoscopic numerical model considering concrete heterogeneity and explicit modelling of basalt fibers was established to simulate the static and dynamic split-tensile failures of basalt fiber-reinforced lightweight aggregate concrete (BFLAC), with a special focus on the influences of structure sizes (D = 100, 200, 300 and 400 mm), basalt fiber contents (Vf = 0.1 %, 0.2 % and 0.3 %), fiber lengths (Lf = 6, 12, 18, 24 mm) and loading strain rates (ε̇ = 10-5/s ∼ 100/s) on split-tensile failure patterns, deformation characteristic and failure strengths. Simulation results indicate that as the fiber length increases, split-tensile strength of BFLAC enhances first and then remains unchanged. As the fiber content increases, both static and dynamic split-tensile strengths enhance, showing a fiber reinforcement effect which increases with the rising strain rate rise and reaches a threshold when the strain rate exceeds 1/s. Under static and low strain rates, the size effect on split-tensile strength of BFLAC is reduced by the addition of basalt fiber content; while there is a reverse size effect under high strain rates and it is strengthened with the increasing fiber content. Besides, the strain rate effect of BFLAC is stronger with the increasing basalt fiber content. A unified TDIF formula of BFLAC considering the influence of basalt fiber content was proposed, which can provide a valuable reference for the dynamic performance simulations and calculations.

Drop-weight Impact Responses of Kenaf Fibre-Reinforced Composite-Metal Laminates: Effect of Chemical Treatment and Fibre Composition

Recently, fiber-metal laminates have gained high attention from material scientists and engineers, particularly when it comes to impact-critical applications. When compared to metallic alloys and composite materials, fiber-metal laminates offer several distinguishing advantages. This work intends to evaluate the low-velocity response of kenaf fiber-reinforced polypropylene metal-composite laminates with various fiber compositions, in line with the current trend of using natural fiber as possible reinforcement in composite materials. In addition, a comparison was made between the low-velocity impact response of non-treated and chemical-treated kenaf fiber-reinforced composite-metal laminates. A hot molding compression technique was employed to fabricate the laminates. Low-velocity impact tests were performed based on ASTM D7136 to determine the peak force, maximum displacement, and energy absorption of the materials. The results confirmed that NaOH treatment and increased fiber content resulted in a higher peak force of NaOH-treated kenaf-based metal laminates. For NaOH-treated laminates, the peak force of laminates with 70 wt% was found to be 11.20% higher than laminates with 50 wt% at the impact energy of 60 J. At fiber content of 70 wt%, the peak force of NaOH-treated laminates is 2.14% greater than that of untreated laminates when subjected to low-velocity impact with an energy level of 60 J. However, laminates with low fiber content and without NaOH treatment manifested higher maximum displacement and energy absorption due to the ductile behavior of such materials.

Mechanical properties and compressive constitutive model of steel fiber-reinforced geopolymer concrete

Geopolymer concrete is an environmentally friendly material, and the addition of steel fibers can overcome its brittleness and improve its performance, which has broad application prospects. However, there are currently few studies on the comparative analysis of mechanical properties between steel fiber-reinforced geopolymer concrete (SFGPC) and steel fiber-reinforced ordinary Portland concrete (SFOPC), as well as uniaxial compressive constitutive models for SFGPC. Therefore, 144 cubes and 36 prisms were tested for SFGPC and SFOPC. The main variables were the volume content of steel fibers (0 %, 0.5 %, 1 %, 1.5 %, and 2 %), curing age (7 and 28 days), and water-to-binder ratio (0.45, 0.5, and 0.55). The slump, failure pattern, compressive strength, splitting tensile strength, elastic modulus, peak strain, toughness index, and compressive stress−strain curves were obtained. The results indicate that with the increase of steel fiber content, the compressive strength, splitting tensile strength, peak strain, and toughness index of SFGPC increase, while the elastic modulus remains almost unchanged. Compared with the plain geopolymer concrete, the above corresponding indexes of SFGPC with 1 % steel fiber content can be increased by 9.9 %, 20.5 %, 23.3 %, and 52.2 %, respectively. The 7-day compressive and tensile strengths of SFGPC can reach about 80 % of the 28-day strengths. Under the same conditions, SFGPC exhibits higher strength, peak strain, and lower elastic modulus than SFOPC. The scanning electron microscope (SEM) test results show that the geopolymer matrix has a denser structure and a tighter bond with steel fibers than the cement matrix. Based on the plain geopolymer concrete, formulas for mechanical indexes and a uniaxial compressive stress−strain model of SFGPC were proposed.

Flexural Toughening of Hooked-End Steel Fibers Reinforced Mortars

This paper investigated the effect of hooked-end steel fiber at varying fiber content on the flexural toughening of fiber reinforced cement mortars (FRCM) by using three-point bending tests. In particular, to preserve the mortar workability, three low weight fractions (0.3%, 0.5% and 0.7%) and two cement matrices (M10 and M15) were investigated. The results showed that the mechanical bending behavior of the FRCM increases significantly at increasing fiber content and cement plaster matrix. An important aspect that has been addressed is how the flexural toughening is varied at varying fiber content and the type of matrix. Especially, all composite mortars exhibited a toughness index (TI) in the range of 10–45, indicating a suitable strengthening and toughening effect supplied by the hooked-end fiber addition. The best TI value, equal to 44, was experienced for the M10-D7 batch characterized by 0.7 wt.% of hooked-end steel fibers and an M10 cement matrix. Furthermore, unlike unreinforced concrete where brittle and unexpected failure occurs dominated by a sudden and catastrophic propagation of tensile cracks, the FRCM samples exhibited a ductile behavior with a marked residual post-crack resistance even for composites mortars with low metal fiber content.

Curly Kale (Brassica oleracea var. Sabellica L.) Biofortified with 5,7-Diiodo-8-quinolinol: The Influence of Heat Treatment on Iodine Level, Macronutrient Composition and Antioxidant Content.

Many disorders are a result of an inadequate supply of macronutrients and micronutrients in the diet. One such element is iodine. This study used curly kale (Brassica oleracea var. Sabellica L.) biofortified with the 5,7-diiodo-8-quinolinol iodine compound. The effect of the heat treatment on the chemical composition of the curly kale was studied. In addition, iodine bioavailability was evaluated in in vivo studies. Our investigation showed that iodine loss depends on the type of heat treatment as well as on the variety of kale. Curly kale biofortified with iodoquinoline had significantly higher iodine levels after thermal processing (steaming, blanching, boiling) than the vegetable biofortified with KIO3. Generally, steaming was the best thermal processing method, as it contributed to the lowest iodine loss in curly kale. The red variety of kale, 'Redbor F1', showed a better iodine stability during the heat treatment than the green variety, 'Oldenbor F1'. The thermal treatment also significantly affected the dry matter content and the basic chemical composition of the tested varieties of the 5,7-diI-8-Q biofortified kale. The steaming process caused a significant increase in total carbohydrates, fiber, protein and crude fat content ('Oldenbor F1', 'Redbor F1'), and antioxidant activity ('Oldenbor F1'). On the other hand, boiling caused a significant decrease, while steaming caused a significant increase, in protein and dry matter content ('Oldenbor F1', 'Redbor F1'). The blanching process caused the smallest significant decrease in ash compared to the other thermal processes used ('Oldenbor F1'). A feeding experiment using Wistar rats showed that iodine from the 5,7-diI-8-Q biofortified kale has a higher bioavailability than that from the AIN-93G diet. A number of promising results have been obtained, which could form the basis for further research.

A Novel Banana Fiber Reinforced Green Composite from Maleated Castor Oil and Linseed Oil

In recent decades, the consumerist society has recognized the consequences of petrochemicals, hence the interest of scientists has been drawn toward renewable products obtained from biological sources. In this study a novel biocomposite with the use of the least chemicals was fabricated by crosslinking maleated castor oil (MACO) and linseed oil (LO) by free radical polymerization, using benzoyl peroxide (BPO) as the free radical initiator. The significance of this study is that the polymer matrix is derived entirely from vegetable oils with slight modifications. Banana fibers are one of the strongest natural fibers that may be taken from the banana pseudo-stem that is discarded after the fruit is harvested. To convert this post-harvest waste into a value-added product, NaOH-treated banana fibers were used as the reinforcement for the developed composite. The characterization of the fibers and the composites was carried out by performing Fourier-transform infrared spectroscopy (FT-IR), X-Ray diffraction analysis (XRD), Dynamic mechanical analysis, tensile and compressive stress analysis, Scanning electron microscopy (SEM), Thermogravimetric (TG)/derivative thermogravimetric (DTG) and thermal conductivity analysis. Composites were also analyzed for their water absorptivity and chemical resistivity. The influence of varying banana fiber weights on the composite’s mechanical strength was investigated using a dual cantilever flexural test. It revealed that the composite’s strength increased with increasing fiber content until 50% (w/w) and then dropped as the fiber content increased further. The maximum tensile strength of the optimum composite was 16.92 ± 4.70 Megapascal (MPa) and the composite was resistant against a compressive force of 4,500 kN without any fractures. The composites’ water absorptivity and chemical resistivity tests revealed that increasing the fiber content enhanced the composites'swelling. The composite was acidic and saline water resistant, but not alkaline solution resistant. Additionally, the thermal conductivity measurements of the composite showed that the composite is a thermal insulator. The composite with 50% (w/w) fiber load, 20% (w/w) BPO, 10% (w/w), LO and 20% (w/w) MACO exhibited the best overall performances.

Effect of steel fiber on the permeability of freeze-thaw damaged concrete under splitting tensile and compressive loads

This study investigated the effect of steel fibers on the permeability and mechanical properties of freeze-thaw damaged concrete under splitting tensile and compressive loads. A specially designed permeability apparatus is used to investigate the continuous permeability performance of steel fiber reinforced concrete (SFRC) subjected to loads. Results demonstrated that for the concrete without load, the addition of steel fibers exhibits a negative effect on the impermeability performance of the concrete matrix without freeze-thaw damage. The initial permeability of SFRC specimens is between 81.7 % and 180 % higher than that of NC specimens. The addition of steel fibers shows a positive effect on the impermeability of concrete subjected to freeze-thaw cycles. The permeability of SFRC under loads can be categorized into two stages. In the first stage, the concrete matrix is the main water channel. The addition of steel fiber can effectively increase the maximum radial deformation of the first stage and maintain low permeability of concrete in a large radial deformation range. In the second stage, concrete cracks are the main water channels. Both the addition of steel fibers and freeze-thaw cycles can reduce the permeability of the concrete in the second stage. Furthermore, under compressive load, with the increasing of stress level, the permeability of SFRC exhibits a slowly decreasing trend, this is followed by a significant increasing trend. The addition of steel fibers can maintain low permeability performance in a large stress level range, and as the steel fiber content increases, the permeability at peak load gradually decreases. The strain–permeability curves of SFRC under splitting tensile and compressive loads subjected to freeze-thaw cycles are investigated. The permeability of SFRC gradually increases with the increasing of the number of freeze-thaw cycles when the compressive strain exceeds 0.002. However, the opposite trend is observed under splitting tensile load. Notably, the reduction in concrete permeability due to the steel fibers is more significant under splitting tensile load than that under compressive load. Future work might integrate this research with stress-strain constitutive equations and finite element analysis. This will offer a foundational framework for engineering applications aimed at enhancing the permeability of steel fiber concrete under freeze-thaw conditions.

Effect of hybridization on camphor soot-embedded palmyra fiber-reinforced nylon nanocomposites

In the present study, camphor soot-filled palmyra fiber-reinforced nylon-6 hybrid nanocomposites (CPFNnC) were prepared using a twin-screw extruder with different wt% of CPFNnC (0, 3, 6 or 9 wt%). These composites were characterized to study their thermal, mechanical and rheological properties. Thermogravimetric analysis showed a marginal increase in thermal stability with 6 wt% CPFNnC. Differential scanning calorimetry curves showed a slight increment in the melting point in CPFNnC, while degradation temperature decreased with fiber content. Dynamic mechanical analysis indicated a maximum storage modulus for 6 wt% CPFNnC at 803 MPa compared with fiber-free nylon-6 (696 MPa at 25 °C). Tan δ for 3 wt% CPFNnC showed a better damping effect due to the existence of palmyra fibers. Creep results indicated that CPFNnC containing 6 wt% fibers has a minimum depth impression of 0.124 mm compared with fiber-free nylon with 0.146 mm. Scanning electron microscopy revealed a uniform distribution of modified palmyra fibers in the matrix and brittle fracture was observed in the CPFNnC. Compared with fiber-free nylon-6, the tensile strength, flexural strength and density of the CPFNnC increased with increase in fiber content; however, the impact strength was reduced and a lower melt flow index was found.

Addition of soluble fiber to standard purified diets is important for gut morphology in mice

Purified diets (PD) increase standardization and repeatability in rodent studies but lead to differences in the phenotype of animals compared to grain-based “chow” diets. PD contain less fiber and are often devoid of soluble fiber, which can impact gut health. Thus, the aim of the present study was to modify the PD AIN93G by addition of soluble fiber, to promote more natural gut development as seen with chow diets. One hundred twenty male C57BL/6J mice were fed over 12 weeks either a chow diet, AIN93G or one of three modified AIN93G with increased fiber content and different ratios of soluble fiber to cellulose. Gut health was assessed through histological and immunohistochemical parameters and gut barrier gene expression. Gut microbiota composition was analyzed and its activity characterized through short chain fatty acid (SCFA) quantification. Feeding AIN93G led to tissue atrophy, a less diverse microbiota and a lower production of SCFA compared to chow diet. The addition of soluble fiber mitigated these effects, leading to intermediate colon and caecum crypt lengths and microbiota composition compared to both control diets. In conclusion, the addition of soluble fibers in PDs seems essential for gut morphology as well as a diverse and functional gut microbiome.

Strength and Stiffness Evaluation of a Fiber-Reinforced Cement-Stabilized Fly Ash Stone Dust Aggregate Mixture

The utilization of waste fly ash in road construction is primarily confined to its use in embankment filling or as a stabilizer when combined with lime and cement. Its application in structural pavement layers, such as the base and subbase, faces a challenge due to the high volume of fine particles, which renders it brittle when stabilized. In this study, fly ash was blended with stone dust and aggregated to enhance its gradation. Subsequently, it was stabilized with cement to bolster its strength, rendering it suitable for pavement use. Additionally, polypropylene (PP) fibers were introduced to mitigate the brittleness of the mixture. An extensive experimental investigation was conducted to assess the strength and stiffness properties, including compressive strength, indirect tensile strength, flexural strength, cyclic indirect tensile modulus, and flexural modulus of fiber-reinforced cement-stabilized mixtures of fly ash, stone dust, and aggregate. The experimental results reveal that the addition of PP fibers up to 0.25 wt.% enhances compressive strength, but any further increase in fiber content leads to a reduction in strength. However, indirect tensile strength and flexural strength show improvement, with an increase in fiber percentage up to 0.5 wt.%. It was observed that cement content plays a dominant role in stabilizing these materials. Appropriate relationships have been established between strength and modulus parameters for stabilized mixtures. Based on the strength and stiffness study, a combination of 70% fly ash and 30% stone dust aggregate with 6% cement can be considered for the base layer. Regarding the behavior of indirect tensile strength and flexural strength, an optimum fiber percentage of 0.35% is recommended.

Influence of basalt fiber on pore structure, mechanical performance and damage evolution of cemented tailings backfill

To study the influence of the addition of basalt fibers on the mechanical properties, pore structure, and damage evolution characteristics of the cemented tailings backfill (CTB), the uniaxial compression tests, nuclear magnetic resonance tests and scanning electron microscopy analysis were conducted on the CTB with four different content and lengths of basalt fibers. Test results show the following. (1) An increase in the content of basalt fibers will lead to an increase in the proportion of micropores and secondary pores in the CTB, while a decrease in the proportion of macropores. The influence of basalt fiber length on pore structure is not as significant as the content. (2) With the increase of basalt fiber content and length, the peak stress and peak strain of the CTB increase, but the elastic modulus decreases. Basalt fiber can significantly improve the ductility and bearing time of the CTB, with a length of 12 mm and a content of 1.5 % having the best effect. The length of basalt fibers affects macroscopic mechanics more than content. (3) The CTB without fiber have fewer cracks and faster crack propagation speed, while the CTB with fiber have more cracks and slower crack propagation speed. Basalt fibers mainly play a bridging role between hydration products, delaying the failure process of the sample. (4) A damage constitutive model was constructed. The rationality and reliability of the model were verified, and the damage evolution law of CTB was analyzed. The content and length of basalt fibers have a positive impact on damage evolution.

Mechanical and morphological properties of unsaturated polyester resin composites reinforced with recycled PET fibers of varying lengths

Purpose This study aims to deal with both the development and mechanical investigations of unsaturated polyester matrix (UPR) composites containing recycled polyethylene terephthalate (PET) fibers as new fillers. Design/methodology/approach UPR/PET fibers composites have been developed as mats by incorporating 5, 8, 13 and 18 parts per hundred of rubber (phr) of 6-, 10- and 15-mm length PET fibers from the recycling of postconsumer bottles. The mechanical and physical properties of the composites were investigated as a function of fiber content and length. A significant increase in stress at break and in ultimate stress (sr) were observed for composites reinforced with 5 and 8 phr of 15-mm length PET fibers. The Izod impact strength of UPR/mat PET fiber composites as a function of fiber rate and length showed that the 5 and 8 phr composites for the 15-mm length PET fiber have the optimal mechanical properties 13.55 and 10.50 Kj/m2, respectively. The morphological study showed that the strong adhesion resulting from the affinity of the PET fiber for the UPR matrix. The ductile fracture of materials reinforced with 5 and 8 phr is confirmed by the fiber deformation and fracture surface roughness. Findings This study concluded that the PET fiber enhances the properties of composites, a good correlation was observed between the results of the mechanical tests and the structural analysis revealing that for the lower concentrations, the PET fibers are well dispersed into the resin, but entanglements are evidenced when the fiber content increases. Originality/value It can be shown from scanning electron microscopy micrographs that the fabrication technique produced composites with good interfacial adhesion between PET fibers and UPR matrix.

Mechanical properties and microstructure of SWGA-BF improved rock muck discharged from slurry shield tunnels

The waste muck discharged during shield tunneling has become the main source of urban construction waste. The modification of discharged muck from shield tunnels into roadbed materials can significantly improve resource utilization efficiency, but freeze–thaw environments can pose safety hazards. In this study, solid waste gelling agents (SWGAs) (50 % cement, 36 % blast furnace slag, 6 % calcium aluminate, 5 % semihydrate gypsum, 2 % calcium oxide, and 1 % alum) and basalt fiber (BF) were used as reinforcing materials for the waste muck discharged from the construction of slurry shield tunnels in rock formations. By conducting freeze–thaw cycle tests, unconfined compression tests, scanning electron microscopy (SEM) analysis, and image analysis by the ImageJ software, the effect of the freeze–thaw environment on the mechanical properties and microstructure of the improved tunnel muck by SWGA-BF composite was studied. The results show that the damage to the unconfined compressive strength (UCS) of the SWGA-BF improved tunnel muck caused by freeze–thaw cycling can be divided into three stages: rapid damage stage, slow damage stage, and basically stable stage, corresponding to N = 0 ∼ 3, N = 3 ∼ 9 and N > 9, and the damage degree generated by freeze–thaw cycle in each stage is 33.9 %, 16.7 %, and 5.0 %, respectively. The first freeze–thaw cycle causes the greatest damage. The variation characteristics of the elastic modulus of improved tunnel muck were similar to those of UCS, and the value of elastic modulus is linearly related to the UCS. The optimal content of BF is 0.5 %. As the fiber content increases, the yield strain and failure strain increase in a wavy manner. SEM tests reveal that the freeze–thaw environment increases the pore area, the size, and the number of fissures of the improved tunnel muck. However, after 12 freeze–thaw cycles, the particle diameter and abundance decreased by 20.46 % and 4.89 %, indicating that the freeze–thaw cycle effect has a greater impact on particle diameter than particle abundance. The deterioration of the microstructure eventually decreased the macro tunnel muck strength. These results have important reference values for the reutilization of waste muck discharged from shield tunneling for roadbed backfill materials in seasonally frozen areas.

Mechanical, Chloride Permeation, and Freeze–Thaw Resistance of Recycled Micronized Powder Polypropylene-Fiber-Engineered Cementitious Composites

Research on engineered cementitious composites was carried out using recycled micronized powder from waste construction waste as a substitute for cement. Consequently, this paper focuses on the investigation of recycled micronized powder (RMP) as the subject of study. Using RMP-PP-ECCA0 as the control group, we explored the impact of polypropylene fiber content (0.5%, 1%, 1.5%, 2%) and the substitution rate of RMP (10%, 20%, 30%, 40%) on the mechanical properties, resistance to chloride ion penetration, and freeze–thaw durability of recycled micronized powder polypropylene-fiber-engineered cementitious composites (RMP-PP-ECCs). It was found that, with the increase in RMP substitution rate and fiber content, the mechanical, chloride ion permeation, and freeze–thaw resistance of recycled micronized powder polypropylene-fiber-engineered cementitious composites showed a trend of increasing and then decreasing when the RMP substitution rate was 10%, and the fiber content was 1.5%; the compressive, tensile, chloride ion permeation, and freeze–thaw resistance of recycled micronized powder polypropylene-fiber-engineered cementitious composites were most obviously improved. Compressive strength performance increased by 18.8%, tensile strength performance increased by 80.8%, maximum tensile strain increased by 314%, and electrical flux decreased by 56.3%. Meanwhile, when the recycled micronized powder substitution rate was 10%, the fiber content was 1%, with the most obvious improvement in flexural and freeze–thaw cycle resistance, compared with the control group 28 d flexural strength increased by 22%, after 150 freeze–thaw cycles, the mass-loss rate was reduced by 26%, and the relative dynamic elastic modulus was improved by 4%. In addition, the chemical composition of the regenerated microfractions and the defects in the matrix of the fracture surface of the tensile specimens, the distribution of polypropylene fibers, the surface morphology, and the failure mode were analyzed by X-ray diffraction and scanning electron microscopy.

Increasing fibre in white flour and bread: Implications for health and processing.

Dietary fibre is beneficial for human health, but dietary intakes are below recommended levels in most countries. Cereals are the major source of dietary fibre in Western diets, with bread providing about 20% of the daily intake in the United Kingdom. Despite the promotion of fibre-rich wholegrain products, white bread (which has a lower fibre content) remains dominant in many countries due to cultural preferences. Increasing the fibre content of white bread and other products made from white flour is therefore an attractive strategy for increasing fibre intake. This can be achieved by exploiting genetic variation in wheat without major effects on the processing quality or the consumer acceptability of products. Modelling data for food consumption in the United Kingdom shows that increasing the fibre content of white flour by 50% (from about 4% to 6% dry weight) and in wholegrain by 20% will increase total fibre intake by 1.04 g/day and 1.41 g/day in adult females and males, respectively. Furthermore, invitro studies indicate that the increased fibre content of white bread should reduce the rate of starch digestion and glucose release in the human gastrointestinal tract.

Development and performance evaluation of alkali-activated multiple solid waste-based building foam insulation materials

To reduce building environmental pollution and energy consumption has become the mainstream development trend of today’s society. The building foam insulation materials (SWFIM) was developed by using blast furnace slag (BSF), waste photovoltaic glass (WPG), rice husk ash (RHA), and plant ash (PA), and the corresponding preparation technologies were proposed. The dry density, thermal conductivity, compressive strength, volumetric water absorption and pore structure parameters of SWFIM were measured. The effects of the amount of hydrogen peroxide solution (HPS), foam stabilizer (FS) and polyethylene (PE) fiber on the basic properties of SWFIM were discussed. The microscopic morphology of SWFIM was characterized by SEM (Scanning electron microscope) technology, and the mechanism of three influencing factors were revealed. The relationship between the basic properties of SWFIM was discussed and the corresponding prediction models were established. The test results showed that the effects of HPS and FS on the basic properties of SWFIM were complementary. When the amount of HPS and FS was 10 % and 1 %, respectively, SWFIM have achieved encouraging performance. PE fiber had different degrees of negative effects on the thermal properties of SWFIM, and the negative effects gradually increased with the increase of PE fiber content. The improvement effect of PE fiber on the compressive strength of SWFIM changes from positive influence to negative influence with the fiber content. When the fiber content increased to 0.6 %, the improvement effect was most obvious, increased by about 12.20 %. Statistics showed that the thermal conductivity and compressive strength of SWFIM were 0.0497 ∼ 0.0581 W/(m·K) and 0.33 ∼ 0.52 MPa, respectively. This showed that SWFIM was expected to become a potentially competitive building insulation material.

Evaluation of compression self-healing performance of a smart cementitious composite SMA-ECC

A two-stage compressive test was adopted to study the self-healing performance of a smart cementitious composite SMA-ECC under compression. The ultrasonic pulse and sorptivity tests were used to track self-healing ability and resistance to internal damage, respectively. A total of 32 groups of specimens, including 28 groups of SMA-ECC specimens and 4 groups of ordinary ECC specimens, were tested with various fiber contents and preloading levels. The strength recovery rate, relative dynamic elastic modulus recovery rate before and after self-healing, and cumulative water absorption were measured during the tests. It was found that the strength recovery rate of the SMA-ECC increased by 29.2% to 37.2% compared to the ordinary ECC. The elastic modulus recovery rate after self-healing of the SMA-ECC is approximately 3 to 10 times that of the ordinary ECC, and SMA-ECC with a 0.9% fiber content exhibits the best healing effect, with a remarkable 194% increase in elastic modulus recovery rate compared to ECC. As for internal damage, an increase in fiber content corresponds to a decrease in relative sorptivity coefficient (η) in most cases. Notably, for SMA-ECC specimens featuring a 0.9% fiber content, η reaches its nadir, hovering around 0.7. The situation takes an unexpected turn when fiber content hits 1%, as the relative sorptivity coefficient experiences a 14.9% increment compared to the SMA-ECC with 0.9% fiber content. Based on the test results, it is concluded that the SMA-ECC has excellent compressive recovery performance and the ability to resist internal damage. The optimal SMA fiber content for the self-healing performance of the SMA-ECC is determined to be 0.7% to 0.9%.

Environmental Properties of Coconut Fiber/Reinforced Thermoplastic Starch/Beeswax Hybrid Composites

The creation of degradable biocomposites is anticipated to alleviate the challenges of worldwide environmental contamination and resource exhaustion. The study investigates the effect of coconut fiber on the environmental properties and water affinity behavior of thermoplastic starch/beeswax composite. The biocomposites were fabricated by incorporating the coconut husk fiber range from 10 to 50 wt%. The thermoplastic starch contains cassava starch, glycerol, and beeswax. The modification of the mixture became efficient when the mixing was determined to be stronger when used as a high-pace blender to aid the mixing process. The mixture then underwent a hot compression molding method to form the mixture into the desired sample form. We can conclude from the results that samples with high fiber content absorb less water than those with no fiber content. For moisture absorption, when the fiber content increases, the ability of the fiber to moisture absorption is decreased. The thickness swelling results show that the sample shows less swelling as the fiber percentage increases. For the soil burial test, incorporating 50 wt% coconut fiber decreases the weight reduction for 4 weeks. For the water solubility test, the solubility of 50 wt% is the best. Based on the findings, integrating coconut fiber into the modified thermoplastic cassava starch increases the composite properties relative to the non-reinforcement matrix material starch.