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Modern research is focused on the discovery of new compounds that meet the requirements of modern construction. An example of low energy consumption is that buildings consume between 20% and 40% of energy. In this research, the effect of fiber addition on the properties of compacted earth bricks composed of clay and sand and fixed with cement is studied. Fiberglass or palm are used in different proportions (0% and 0.4%). This is done by studying the change in mechanical and thermal properties. The study focuses on clarifying the role of fiber type and the amount of compressive force applied to the soil. To change the properties of bricks. This is studied using experimental methods and systematization criteria. The results showed a decrease in density by 9.1%, with a decrease in water absorption by 8%, an increase in brick hardness by 42.7%, and a decrease in thermal conductivity by 22.2%. These results show that the addition of fiber improves mechanical and thermal properties. Which reduces energy consumption. The results are important because they explain the changes that occur in the earth block when palm fibers and glass are added and how they are used to improve earthen buildings.

Fibers are widely used in construction because they have mechanical and thermal properties that improve the properties of structures added to them. This paper addresses the improvements made to the compressed earth block (CEB) when palm fibers and glass are added. This block is made up of soil and cement. The fiber ratio varies between 0% and 0.4%, and a compressive force of 2.5 MPa is applied to the samples. The physical, mechanical, and thermal properties of the CEB are studied according to systematic criteria using a numerical simulation program to find out how heat is transferred inside the samples. Preliminary results showed that the addition of fibers reduces the bulk density value between 1.88% and 11%, increases the compressive strength between 14.28% and 28.85%, decreases the thermal conductivity value between 1.38% and 22.22%, and decreases specific heat observed by 19.34% and 25.77%. These results give a clear view of the changes in the CEB when fibers are added and how to improve some properties.

Flame retardants are often developed for epoxy resins and then transferred into their fiber-reinforced composites with uncertain results. Understanding this transfer in detail represents a critical scientific challenge. This study systematically compares epoxy resins with their glass-fiber reinforced composites, focusing on bisphenol A diglycidyl ether with the hardener dicyandiamide, the flame retardants melamine polyphosphate, ammonium polyphosphate, and silane ammonium polyphosphate, along with inorganic silicate. The research investigates changes in pyrolysis (thermogravimetry), flammability (UL 94, limiting oxygen index), and fire behavior (cone calorimeter) while also examining the flame-retardant modes of action and overall fire performance. The findings reveal that alterations in the amount of fuel, thermal properties, melt flow, and protective layer significantly impact ignition, flammability, and fire load, with a critical reduction in carbonaceous char within the composites preventing intumescence. This study quantifies the effects and provides a fundamental scientific understanding of the complex transfer process of flame retardants from resins to composites, offering essential insights that are of major importance for developing more effective flame-retardant materials.

Polymer composite gears are under investigation as a promising solution to mitigate the performance gap between polymer and metal gears. The study presented in this paper evaluates the fatigue and wear performance of E-glass fiber reinforced polymer composite gears. The E-glass fibers are vacuum infused with bioepoxy, followed by autoclave curing. High-speed milling is utilized to fabricate the gears, which are then subjected to testing at torques ranging from 0.5 to 0.8 Nm. Gear failure modes predominantly include wear combined with tooth edge intra-bundle fiber delamination due to fatigue, followed by extensive inter-ply delamination just prior to failure. Gear tooth wear volume demonstrates a nearly linear correlation with the number of cycles, with accelerated wear rates observed at higher torques. E-glass fiber polymer composite gears exhibit a shorter service life and a higher wear coefficient compared to our previously developed carbon fiber reinforced polymer composite gears. However, their performance remains fair, with a service life between that of PA6 GF30 and PA66 GF30 glass fiber reinforced gears.

The effect of the addition of sustainable materials and alkali-resistant glass fibers on perlite concrete is studied in this paper. The research includes slump, density, flexural strength, split tensile strength, compressive strength, and thermal conductivity tests. This specimen was cast using Portland cement, metakaolin (which replaced 15% of the cement weight as pozzolanic materials), a combination of coarse and fine perlite aggregate, superplasticizer, and local ash (which was employed as a filler and replaced by cement weight in a ratio of 10%). The ratio of cement to perlite (volumetric ratio) was 1:2. The concrete reinforced 1% alkali resistance glass fibers by volume of concrete. The results show that adding sustainable materials to the concrete increased its cylinder compressive strength by a percentage of (57.75%, 41.76%, and 44.82%) for 7,28 and 60 days, respectively and both tensile and flexural strength increased at a ratio of (37.28%, 30.33% and 34.5%), (36.05%, 68.22% and 56.52%) respectively at (7,28 and 60 days). And including alkali-resistant glass fibers increases the compressive, tensile and flexural strength in a ratio of (61.5%, 43.58%, 47.45%), (61.54%, 44.08% and 52.71%) and (113.95%, 124.3% and 97.85%) respectively at (7,28 and 60 days), compared with reference mix. The density increased by adding sustainable materials and fibers but stayed within the limitations of structural lightweight concrete (ASTM C330). The thermal conductivity also increased after adding sustainable materials and glass fibers compared with the reference mix, but it was within the constraints of insulation concrete.

The present work investigates the mechanical properties of a composite material composed of multi-walled carbon nanotubes (MWCNTs), nano-aluminum powder (NAP), and glass fibers (GF) for five different compositions. The study further investigated how MWCNTs contribute to maintaining the mechanical properties of nanocomposites when exposed to elevated temperatures, up to 180 °C. The evaluation of impact strength revealed that the nanocomposite, composed of 2 % MWCNTs, 15 % NAP, and 10 % GF, demonstrated the greatest impact strength. At room temperature, the composite containing 2 % MWCNTs, 5 % NAP, and 20 % GF exhibited the highest ultimate tensile strength (UTS). Conversely, at elevated temperatures reaching up to 180 °C, the highest UTS was observed in the composition with 2 % MWCNTs, 10 % NAP, and 15 % GF. The hardness of the nanocomposite was influenced by its composition; at room temperature, the maximum hardness was observed in the mixture containing 2 % MWCNTs, 20 % NAP, and 5 % GF. In contrast, at elevated temperatures, the composition with 2 % MWCNTs, 5 % NAP, and 20 % GF exhibited the highest hardness. Overall, the study found that incorporating GF and NAP improved the mechanical properties of the composite. These results indicate that the composite's performance could be further optimized for specific applications through the addition of filler materials.

In this work, the properties of self-compacting concrete (SCC) and SCC containing 0.5 and 1% glass fibers (with lengths of 6 and 13 mm) were experimentally investigated, as well as their performance at high temperatures. With a heating rate of 5 °C/min, high-temperature experiments were conducted at 200, 400, 600, and 800 °C to examine mass loss, spalling, and the remaining mechanical properties of SCC with and without glass fibers. According to the results of the flowability and passing ability tests, adding glass fibers does not affect how workable and self-compacting SCCs were. These findings also demonstrated that the mechanical properties of samples with and without glass fibers rose up to 200 °C but then decreased at 400 °C, whereas the mixture containing 0.5% glass fibers of a length of 13 mm displayed better mechanical properties. Both SCC samples with and without glass fibers remained intact at 200 °C. Some SCC samples displayed some corner and edge spalling when the temperature reached about 400 °C. Above 400 °C, a significant number of microcracks started to form. SCC samples quickly spalled and were completely destroyed between 600 and 800 °C. According to the results, glass fibers cannot stop SCC from spalling during a fire. Between 200 and 400 °C, there was no discernible mass loss. At 600 °C, mass loss starts to accelerate quickly, and it increased more than ten times beyond 200 °C. The ultrasonic pulse velocity (UPV) of SCC samples with glass fibers increased between room temperature and 200 °C, and the mixture containing 0.5% glass fibers of a length of 13 mm showed a somewhat higher UPV than other SCC mixtures until it started to decline at about 400 °C.

The observation of fibers in salvadora persica roots inspired us to consider the idea of using them as reinforcement to create an innovative composite. The current work focuses on the volumetric mass density, extraction, molding, and mechanical testing of composites and hybrid composites made from salvadora persica roots and glass fibers reinforced with two types of polyester matrix, chosen due their characteristics suitable for use in different orientations. Various extraction and combination methods have been used to identify an optimal approach for obtaining fibers from salvadora persica roots, considering its chemical composition (hemicellulose, pectin, and lignin). In this investigation, the hand lay-up method was used to mold specimens with different geometries. The composite and hybrid composite were combined with a polyester matrix and subjected to various mechanical tests namely; tensile, impact resistance, and water absorption. The results indicate that reinforcing polyester resins with SP fibers, whether long or short, enhances the overall mechanical properties of the composite. Additionally, improved adhesion between salvadora persica roots fibers and resin was observed.

Abstract Degradation of polymer composites is a significant problem in many engineering aspects. Due to the interaction of various degradation factors during the exploitation of composites, a synergistic effect of destruction is observed. The article describes the phenomena occurring in glass fiber reinforced polyester laminates under the influence of ultraviolet radiation (UV) in an aquatic environment. The laminates were exposed to UV-A, UV-B and UV-C radiation for 1000 h in free-air and underwater conditions. During the test, the materials were immersed at stable depth of 1 mm and 10 mm, respectively. The three-point bending tests performed on the samples after being exposed to UV showed an increase in the flexural strength of the composites. Simultaneously, degradation of the outer surface layer was observed. The degradation removed the thin resin film from the surface which resulted in a direct exposure of the reinforcing fibers to the environment. The transformations taking place in the deeper layers of the composite increased the mechanical strength due to the additional cross-linking reactions excited by the energy arising from the radiation. Moreover, the formation of polymer structures from free styrene remaining after the technological process and the occurrence of free radical reactions as a result of the cage effect was also observed.

The screw pine and E-glass fibers were hybridized in the vinyl ester resin matrix to prepare the hybrid composite laminates in the present communication. Hybrid composite laminates at the constant volume fraction of 35.12% has been fabricated using the hot press compression molding in two forms, namely dispersed and skin-core, to evaluate the mechanical properties. Mechanical properties of composite laminates were studied based on the various volume fraction of glass fiber content (0, 3.32, 8.15, 12.44 and 16.53 vol.%). The scanning electron microscopy (HITACHI S-3000N) was used to study the fracture surface of composite laminates. The results of hybrid composite laminates were compared with a neat resin sample and screw pine fiber (35.12 vol.%) alone composite. The results revealed that the mechanical properties of both the type of composite laminates increased as glass fiber addition was increased. The SPF18.59/GF16.53 hybrid composite laminate exhibits the highest level of mechanical properties because of the concentration and higher elongation percentage of glass fibers. Moreover, the skin-core type composites perform better than those of the dispersed type hybrid composites. Because of the stretching nature of screw pine fibers, they elongate when the load is transferred from glass fibers to screw pine fibers, resulting in an increase in mechanical properties. The property values were predicted using a theoretical model, and it was found that the two were in good agreement.

This article’s aim is to analyze physical, mechanical, and fracture properties as well as the thermal investigation of geopolymer composites reinforced with flax, glass fiber, and also the hybrid combination of fibers. Two types of matrices were considered as composites matrices. The first composition was based on fly ash and river sand. The second matrix composition contained fly ash and glass spheres. The content of reinforcement was 1% by mass. Compressive strength and three-point bending fracture tests were performed. The values of fracture toughness and fracture energy were determined. The resonance method was used to verify the dynamic characteristics, such as the dynamic modulus of elasticity and the dynamic Poisson ratio. The results show that single-type fibers in composites based on fly ash and glass spheres did not affect compressive strength. However, introducing hybrid reinforcement increased compressive strength by about 10% compared to the reference specimens. Flax fibers and hybrid reinforcement ensured higher fracture toughness and energy. The results also revealed great potential for glass sphere application to geopolymer materials in terms of fracture mechanics and thermal properties. Despite the lower strength properties in relation to geopolymers based on sand aggregate, applying reinforced fibers into the composite with glass spheres enhanced the compressive strength compared to other materials. Materials modified with glass spheres have a thermal conductivity twice as low as that of materials containing river sand.

Extensive research is being conducted globally on incorporating fibres into concrete to enhance its mechanical properties. This study aims to evaluate the strength characteristics of fibre-reinforced concrete (FRC) with varying mix proportions. 18 concrete samples of M-25 grade were prepared, incorporating different percentages of steel and glass fibers. Six samples contained glass fibres (GF) at 5%, 10%, and 15% by weight of cement, and six contained steel fibres (SF) at the same percentages. Additionally, two samples were prepared with a combination of 5% glass fibres and 10% steel fibres and two samples with 10% glass fibres and 5% steel fibres. These were compared to a control sample without fibre reinforcement. The compressive strength of the FRC was assessed at 7 and 28 days. The findings indicate that higher percentages of glass fibers had a notably negative impact on compressive strength, while the inclusion of steel fibers had a comparatively lesser effect. The maximum compressive strength was observed by including 5% steel fibres at 28 days. However, increasing the fiber content beyond this percentage resulted in a reduction in compressive strength. The lowest compressive strength was recorded in samples containing 15% glass fibers at 28 days.

Glass fibers (GFs) are commonly used as reinforcements for advanced polymer composites. To improve the interfacial shear properties and mechanical properties of GF-reinforced composites (GFRPs), carbon nanotubes (CNTs) are directly grafted onto GFs using chemical vapor deposition (CVD). However, this process requires high temperatures, which causes thermal degradation of GFs, deteriorating their mechanical properties. In this study, a low-temperature CNT-grafting process was investigated using a bimetallic catalyst introduced onto a GF fiber surface via precursor solutions. The mechanical properties of the CNT-grafted GFs fabricated at different CVD temperatures were evaluated; they consistently showed low tensile strengths at temperatures above 400 °C. Subsequently, various CNT-grafted GFRPs were manufactured, and their mechanical properties were characterized. Interestingly, the flexural strengths of the composites increased with maintained tensile strength, despite a deterioration of the CNT-grafted GF reinforcements due to the CVD process. This could be attributed to the improved interfacial shear strength (IFSS) of the CNT-grafted GFs at the fiber level, and the enhanced compressive strength and interlaminar shear strength (ILSS) of CNT-grafted GFRPs at the composite level. Considering the properties of GF through CVD processes, particularly in relation to temperature, and factors such as IFSS, ILSS, tensile, compressive and flexural properties of composite materials, grafting CNTs on GF via a CVD system demonstrated its highest optimality at 450 °C.

Abstract The preparation of basalt and S‐glass fiber‐reinforced poly(dicyclopentadiene) via ring‐opening metathesis polymerization using a thermally latent pre‐catalyst, that is, Mo(N‐3,5‐Me2‐C6H3)(= CH‐(2‐MeO‐C6H4))(IMes)(OTf)2 (1, IMes = 1,3‐dimesitylimidazol‐2‐ylidene; OTf = SO3CF3) is reported. Complementarily, the non‐latent first‐generation Grubbs initiator RuCl2(PPh3)2(CHPh) (2) is used. 2 can be rendered latent by the addition of ppm amounts of triphenylphosphine (PPh3). Both 1 and 2/PPh3 allow the realization of thermally latent single‐component systems with sufficient pot life that do not require pre‐mixing of the individual components shortly before use. The prepared fiber matrix composites are characterized in terms of mechanical, thermal, and chemical stability.

Abstract Currently, hybridization of natural-synthetic fibers within a polymeric matrix has received wide attention owing to its promising properties. This study investigated the mechanical properties of interply and intraply hybrid jute (J)-glass (G) fiber/epoxy composites. The mechanical properties (i.e., tensile, flexural, and impact) of the pure jute, pure glass, and their hybrid composites were evaluated. The prepared composite samples consisted of five plies of woven fabrics. Interply hybrid composites comprised three layering sequences: G3JG, GJGJG, and 2GJ2G. Intraply hybrid composites of similar co-woven plies were fabricated by either the alternative replacement of a single glass yarn with a single jute yarn (G1J1) or two jute yarns (G1J2). The results showed that increasing the glass fraction in the interply hybrid composites improved their tensile properties. The two intraply hybrid composites provided almost similar tensile moduli, while the tensile strength of the G1J1 samples was approximately 41% higher than that of the G1J2 counterparts. The maximum flexural properties were provided by 2GJ2G composites, followed by GJGJG, and they were interestingly higher than those of pure glass composites. The G1J1 intraply hybrid composites offered a higher flexural strength and a lower flexural modulus than those provided by the pure glass composites. Compared to the pure glass composites, the impact strengths of the 2GJ2G and GJGJG samples decreased by 4% and 16%, respectively. In summary, the GJGJG hybrid composites exhibited the highest specific tensile, flexural, and impact properties compared to the other hybrid composites.

Cracks in asphalt mixtures compromise the structural integrity of roads, increase maintenance costs, and shorten pavement lifespan. These cracks allow for water infiltration, accelerating pavement deterioration and jeopardizing vehicle safety. This research aims to evaluate the impact of synthetic fibers, specifically glass fiber (GF) and polypropylene fiber (PPF), on the crack resistance of Hot-Mix Asphalt (HMA). An optimal asphalt binder content of 5% was used in all sample designs. Using the dry mixing technique, GFs and PPFs were incorporated into the HMA at dosages of 0.50%, 1.00%, and 1.50% by weight of the aggregate. The effects of these fibers on the mechanical fracture properties of the HMA were assessed using Semi-Circular Bending (SCB), Indirect Tensile Asphalt Cracking Tests (IDEAL-CTs), and Three-Point Bending (3-PB) tests. This study focused on fracture parameters such as fracture work, peak load, fracture energy, and crack indices, including the Flexibility Index (FI) and Crack Resistance Index (CRI). The results from the SCB and IDEAL-CT tests showed that increasing GF content from 0.5% to 1.5% significantly enhances the flexibility and crack resistance of HMA, with FI, CRI, and CT Index values increasing by 247.5%, 55%, and 101.35%, respectively. Conversely, increasing PPF content increases the mixture’s stiffness and reduces its crack resistance. The PP-1 mixture exhibited higher FI and CT Index values, with increases of 31.1% and 10%, respectively, compared to the PP-0.5 mixture, based on SCB and IDEAL-CT test results. The SCB, IDEAL-CT, and 3-PB test results concluded that fibers significantly influence the fracture properties of bituminous mixtures, with a 1% reinforcement dosage of both PPFs and GFs being optimal for enhancing performance across various applications.

Objective: to investigate and compare the reinforcing effects of glass fibers (GFs) and ZrO2 nanoparticles at different ratios on the Flexural Strength (FS), Microhardness (MH), and Surface Roughness (SR) of autopolymerizing provisional PMMA. Methods: A total of one hundred and twenty specimens of autopolymerizing PMMA were prepared for FS, MH, and SR tests and grouped as follows: no additives (control group), for the tested groups, different ratios of GFs and ZrO2 at 5% of autopolymerizing PMMA were incorporated. The ratios of GFs/ZrO2 nanoparticles were 0%-5%, 1%-4%, 2%-3%, 2.5%-2.5%, 3%-2%, 4%-1% and 5%-0% (n = 5). The FS was evaluated using the three-point bending test, MH was evaluated using the Vickers microhardness tester and SR was evaluated using a contact-type profilometer. Data were analyzed using ANOVA, Tukey’s test, and Person correlation at 0.05 level of significance. Results: The unreinforced group had the lowest FS, MH, and SR mean values followed by (0%GFs + 5% ZrO2), (1% GFs + 4% ZrO2), (2% GFs + 3% ZrO2), (2.5% GFs + 2.5% ZrO2), (3% GFs + 2% ZrO2), (4% GFs + 1% ZrO2) and (5% GFs + 0% ZrO2) which had the highest values. Conclusion: Hybrid reinforcement with GFs, ZrO2 nanoparticles, or a combination of them effectively improved flexural strength and microhardness of autopolymerizing provisional PMMA that would create provisional restorations with extended clinical service. GFs demonstrated superior reinforcing effects compared to ZrO2 nanoparticles. However, reinforcement with 2.5–5% GFs increased the surface roughness for provisional restoration.

In this work, woven jute and glass fabrics were used as natural fiber and synthetic fiber reinforcements, respectively, and unsaturated polyester resin was used as a thermoset polymer matrix to fabricate jute/polyester and glass/polyester composites via compression molding. As expected, glass/polyester exhibited superior performance than jute/polyester composites in terms of mechanical properties and moisture uptake behavior. Further, both composite laminates were exposed to gamma (γ) irradiation at a dose of 5 kGy to enhance their performance. After γ-irradiation, it was revealed that tensile strength, bending strength, tensile modulus, bending modulus, and impact strength increased by approximately 14, 28, 20, 21, and 13%, respectively, for the case of jute/polyester composites while glass/polyester composites demonstrated 13, 27, 15, 14, and 22% increase of the values, respectively. Further characterization of the composite samples was performed via moisture uptake in water and salt solutions, Scanning Electron Microscopy (SEM), and Energy Dispersive Spectrum (EDS) analysis.

Agave fiber/polymer matrix composites have recently been used in automotive, aerospace, and construction field, where they will be secure for shape-made applications. Hand lay-up is used to make Agave and Glass fiber-reinforced polyester composites (A/GFRP), Agave fiber-reinforced polyester composites (AFRP), and Glass fiber-reinforced polyester composites (GFRP). The impact energy absorbed and tensile strength for A/GFRP material are higher than those for AFRP material. Drilling of GFRP, AFRP, and A/GFRP composites is carried out by using carbide twist drill D 5407060 of 6 mm diameter. Process parameters include two distinct speeds (800 rpm and 1200 rpm) and two distinct feeds (0.02 mm/rev and 0.04 mm/rev). The influences of processing parameters on thrust force and delamination while drilling GFRP, AFRP, and A/GFRP materials are investigated. For the optimum process parameter (feed = 0.02 mm/rev and 800 rpm) for GFRP, AFRP, and A/GFRP, the thrust force and delamination factor are limited at these feed rate conditions. In comparison to AFRP, delamination is minimum for A/GFRP drilled with carbide tools at lower feed rates as per microstructural examination. The Taguchi technique is used to determine the best feed and speed parameters for machining responses, and it demonstrates that acceptable values are achievable with A/GFRP.

3D printed fiber reinforced composites are replacing metals and thermosetting polymers due to their lightweight structure and mechanical performance. Fused deposition modeling (FDM) is an additive manufacturing technology that can produce complicated functioning parts. Samples of Nylforce composite materials were manufactured at three different raster orientations (0°, 45°, and 90°) with the help of a 3D printer. In order to evaluate the mechanical properties of the nylon composites with carbon fibers (CF) and glass fiber (GF); 3-point flexural tests were carried out. The highest stiffness (modulus) was found for nylon + GF composite at room temperature, indicating that the material can better resist bending forces. On the other hand, the nylon + CF composite exhibited elastic behavior, lower flexural strength, and higher deflection. Overall, the flexural strength of composites was improved because the interface between the nylon matrix and fibers provided good stress transfer. Dynamic mechanical analysis (DMA) also clearly indicated that the nylon + GF composite material had maximum storage modulus, loss modulus and complex modulus with low tan δ, indicating improved fiber/matrix interfacial interaction and limitation of polymer chain mobility. Moreover, scanning electron microscope (SEM) images revealed that the main drawbacks for nylon composite material were void formation, fiber pull-out, and fiber breakage. Generally, the results of this research provide a unique knowledge base regarding the structural behaviors and the mechanical properties of nylon composites built with 3D printing technology. Finally, the findings of the current research will be beneficial in the application of these composite materials in their end-use.

Abstract Lightweighting of automotives is crucial for the decrease of fuel and energy consumption, as well as CO2 emission and environmental pollution. Polymer composites, especially the high strength glass fiber/polyamide (GF/PA) composites, have great potential in lightweight; however, they have not been universally accepted due to their insufficient performance. Here, a stearate‐ended hyperbranched polyester (HBP‐12‐n) is designed and high‐performance GF/PA6 composites with high GF content are prepared. The flowability of the composites can be further increased by combining carboxyl‐ended hyperbranched polymer (HyPer C181) with HBP‐12‐n. Compared with unmodified GF/PA6 composites, the melt flow index (MFI) can be increased remarkably to 587% by adding a 0.7 wt% mixture of HBP‐12‐75 and HyPer C181, and the strength and toughness remain competitive. The simultaneous improvement in MFI and impact strength of GF/PA6 composites is the first discovery of this kind, and a synergistic mechanism of amphiphilic bridging‐deformation slipping‐interfacial strengthening of hyperbranched polymers is proposed to account for this phenomenon. This work provides a simple strategy to fabricate GF/PA6 composites with the extensive application for automotive parts and has great prospects in making automotives lightweight and reduction of CO2 emissions.

Marine soft clays are prevalent in coastal regions of China, giving rise to engineering challenges such as salt swelling, corrosion, and load bearing in foundations with soft soil. This study is dedicated to enhancing the mechanical properties of fiber-reinforced cement-stabilized soft clay (FCSSC) and revealing its strengthening mechanism. Uniaxial compression tests are performed to explore the impact of fiber length, fiber amount, and curing ages on mechanical behavior. The stabilization mechanisms of cement and glass fibers are explored through damage analyses and microscopy. Based on the experimental results, a damage constitutive model is formulated for FCSSC, and its validity is established by comparing fitting curves with testing curves. The results demonstrate a significant improvement in the mechanical properties of the stabilized soil, attributed to the synergistic effects of the cement and glass fibers. The growth rate of the unconfined compressive strength decreased with increasing curing ages. Notably, the fiber length significantly impacted the strength index, with short-chopped fibers playing a crucial role in strength enhancement. The compressive strength exhibited an initial increase followed by a decrease with rising fiber content, reaching a maximum between 0.3% and 0.4%. The bridging effect of the glass fibers proved effective in inhibiting compression crack expansion and mitigating structural damage of the soil sample. However, excessive fiber content or length led to improved local porosity, resulting in the deterioration of strength and deformation properties. The stress–strain curves fitted using the proposed damage constitutive model accurately reflected the stress–strain relationship and deformation characteristics of the FCSSC.

Electronic waste (e-waste) is one of the fastest-growing waste streams in the world and Europe is classified as the first producer in terms of per capita amount. To reduce the environmental impact of e-waste, it is important to recycle it. This work shows the possibility of reusing glassy substrates, derived from the MW-assisted acidic leaching of Waste Printed Circuit Boards (WPCBs), as an adsorbent material. The results revealed an excellent adsorption capability against methylene blue (MB; aqueous solutions in the concentration range 10−5 M–2 × 10−5 M, at pH = 7.5). Comparisons were performed with reference samples such as activated carbons (ACs), the adsorbent mostly used at the industrial level; untreated PCB samples; and ground glass slides. The obtained results show that MW-treated WPCB powder outperformed both ground glass and ground untreated PCBs in MB adsorption, almost matching AC adsorption. The use of this new adsorbent obtained through the valorization of e-waste offers advantages not only in terms of cost but also in terms of environmental sustainability.

The problem of lack of sustainability for public garden furniture in special weather conditions such as heat and rain, and the damage of these furniture as a result of continuous use and exposure to stress, pressure and land. The research aimed to provide local qualities of overlapping materials suitable to serve as furniture for public parks and by using filler materials reinforced with banana and glass fibers. Hybrid composite materials based on polymeric materials were prepared by manual epoxy casting supported by banana fibers in the form of filaments and glass fibers.Four samples were produced:• The first sample: 50 grams banana fibers bristles, 100 grams glass fibers, 1 kg epoxies.• The second sample: 50 grams banana fibers bristles, 200 grams glass fibers, 1 kg epoxies.• The third sample: 100 grams fiberglass (1) woven layer, 1 kg epoxy.• Fourth sample: 200 grams of fiberglass (2) woven layer, 1 kg epoxy.• The fourth sample is the ideal sample, due to its high tensile strength; high elongation, very high tensile stress and high pressure resistance although it is one of the highest samples in terms of weight loss and ground resistance. They are very suitable qualities for making garden and garden furniture, which allows for a higher use life and resistance to use conditions, and not affected by conditions of weather conditions .• As for the first sample, it is an economic sample. It appears to us in the case of wanting to obtain the lowest cost of raw materials, high tensile strength, high elongation, relatively high flexural stress, with high pressure stress and very little weight loss. It is a very ideal economic sample .• As it becomes clear the important economic aspect in producing this type of furniture in a simple way and in a pure Egyptian style, as the material of banana fibers and glass fibers was used instead of burning them. Also, glass fibers are used for reinforcement, which gives a large part of the continuity of the furniture with some maintenance

Recently, glass fiber reinforced polypropylene is commonly used in scientific and industrial applications such as marine, aerospace, automotive, and construction industries among other materials because of their low cost, lightweight, easy processing, and high reliability. For those promising characteristics, researches have been undertaken for understanding the thermal and mechanical behaviors of polypropylene. The main objective of this study is to investigate the mechanical properties of polypropylene (PP) and glass fiber reinforced polypropylene (GFPP) pipes, which are used in water distribution networks and compressed air systems. Tensile tests were performed at different cross-head speeds at room temperature while, flexural tests were conducted at different cross-head speeds with five distinct temperatures 23, 35, 50, 70, and 90 °C. The experimental results show that both materials are sensitive to cross-head speed, temperature, and holding time. Additionally, the percentage of elongation at break and toughness of GFPP are lower than that of PP. However, the elastic modulus and yield stress of GFPP are higher than that of PP at the same cross-head speed. On the other hand, the bending energy and the dissipated energy of GFPP are higher than that of PP under all cross-head speeds and testing temperatures. PP gains 20.4% and GFPP gains 15.2% bending energy with raising cross-head speed from 5 to 50 mm/min. Also, a decrease in flexural modulus for both materials occurs with raising temperature from 23 to 50 °C.

Abstract Background Enormous improvements in dental materials’ manufacturing for the aim of producing durable dental materials without compromising the aesthetic properties were developed. One of the approaches that fulfill this aim is the use of reinforcing glass fibers as fillers into dental materials, typically resin polymers, in order to obtain glass fiber-reinforced composites. Glass fiber-reinforced composite offered many advantages to the dental materials though some limitations were recorded in many literature. Methods In this review, a study of the glass fibers’ types, factors affecting the properties and the properties of glass fibers reinforced materials was carried out; in addition, research papers that experimentally studied their applications in dentistry were presented. Conclusion The success of glass fibers reinforced composites in dentistry depends on glass fibers’ composition, orientation, distribution, amount, length and adhesion; these factors once employed according to the required clinical situation would provide the essential reinforcement to the dental restorations and appliances.

Continuous lattice fabrication is a newly introduced method for additive manufacturing of fiber-reinforced thermoplastic composites that allows to deposit material where it is needed. The success of this technology lies in a printing head in which unconsolidated continuous fiber-reinforced composite is pulled through a pultrusion die before the material is extruded and deposited out of plane without the use of supporting structures. However, state-of-the-art composite feedstock like commingled yarns shows limits in achievable material quality and part dimensions due to the underlying fiber architecture where thermoplastic fibers are mingled with reinforcement filaments. Hybrid bicomponent fibers overcome these constraints because each individual reinforcement filament is clad in a thermoplastic sheath. This results in absence of time-consuming fiber impregnation steps that would negatively effect void content and material quality.This study compares the material quality of pultrudates made from hybrid bicomponent fibers to that of commercially available commingled yarns at various processing conditions. Experiments are reported in which polycarbonate composite profiles with a diameter of 5 mm containing 50 vol% to 60 vol% E-glass fibers are pultruded at different die filling degrees, mold temperatures and pultrusion speeds. The results show that the pultrudates obtained from hybrid bicomponent fibers have lower void content than those manufactured under the same conditions from commingled yarns. We assess this to be caused by the difference in consolidation mechanism which in the case of the hybrid bicomponent fibers is dominated by coalescing of the thermoplastic sheaths compared to the Darcian flow-dominated consolidation of commingled yarns.

Adding fibers is an effective way to enhance the printability and mechanical performance of 3D printable cementitious materials. Glass fibers are commonly used owing to their sound mechanical properties, high durability and affordable price. However, there is still a lack of systematic and in-depth research on the effects of adding glass fibers to cementitious materials. In this study, a series of 3D printable mortars with varying glass fiber content and water/cement (W/C) ratio were produced to evaluate their printability, flexural strength and compressive strength. The results showed that decreasing the W/C ratio generally has positive effects on printability and mechanical performance, whereas increasing the glass fiber content from 0% to 1% would substantially improve the extrudability, dimensional stability and buildability; increase the flexural strength by up to 82%; but decrease the compressive strength by up to 35%. Such large differences in the effects of glass fibers on the flexural and compressive strengths indicate significant material anisotropy. In fact, comparison of the strength results of printed specimens to those of un-printed specimens reveals that the printing process could increase the flexural strength by 98% but decrease the compressive strength by 47%.

The demand for sustainable construction materials has driven the exploration of various innovative approaches to enhance the properties of concrete for reducing its environmental impact. The present study examines the effects of incorporating recycled concrete aggregate (RCA), slag cement, alccofine, and glass fibers into concrete mixtures. In the present study, it has been observed that recycled concrete aggregate (RCA) exhibits inferior properties, including higher water absorption and poorer performance, when compared to natural coarse aggregate. Various replacement levels of RCA were utilized in this study to assess its impact on concrete performance. Alccofine, a supplementary cementitious material, is used to partially replace the binding material. Additionally, glass fibers were added to enhance the flexural and tensile behavior of the concrete. The concrete mixtures were designed to meet the required strength and durability specifications. A comprehensive testing program was conducted to evaluate the fresh and hardened properties of the concrete. A slump cone test was performed for assessing the workability of fresh concrete. For hardened concrete, compressive strength, flexural strength, and split tensile strength are evaluated. The results demonstrated that incorporating RCA, slag cement, alccofine, and glass fibers into the concrete mixtures improved mechanical properties. The use of RCA led to a reduction in natural resource consumption, namely natural coarse aggregate in concrete. On the other hand, the generated construction and demolition (C&D) waste is used effectively. Portland slag cement (PSC) and alccofine (A) improved the long-term strength of concrete. The addition of glass fibers significantly enhanced the tensile and flexural performance of the concrete, resulting in improved crack resistance and overall performance. This study introduces a novel concept by exploring the potential utilization of recycled concrete aggregate, slag cement, alccofine, and glass fibers in combination as sustainable and high-performance components in concrete mixtures. Previous research has not extensively studied this combination of materials, making it a unique and innovative approach. These findings contribute to the development of eco-friendly construction practices and provide insights for engineers, researchers, and practitioners aiming to incorporate recycled materials and supplementary cementitious materials into concrete construction.

The issue of upgrading and strengthening the reinforced concrete (RC) infrastructure has become of great importance. Recently, textile-reinforced mortar (TRM) was used in the field of structural strengthening. In the current study, using of TRM for flexural retrofitting of one-way reinforced concrete (RC) slabs was experimentally and theoretically investigated. The parameters examined included; the number of TRM layers (1, 3, 5 layers) and the strengthening configuration fully and partially). For this purpose, eight specimens were prepared and tested under three points- loading up to failure. The result showed that the TRM increases substantially the flexural capacity of RC slabs. The highest flexural capacity increase recorded was 103 %. It was also noted that increasing the number of retrofitting layers resulted in different increases in the flexural capacity. It was also shown that the strengthening configuration plays an important role in the effectiveness of the technique. The fully covered approach showed higher loading capacity than the partial cover technique provided that the same TRM layer is applied. Finally, the ultimate moment of the strengthened specimens was calculated theoretically and compared with that obtained experimentally. The results of calculations showed a good agreement between the theoretical and experimental results.

The paper presents and describes the procedure of testing the materials that were available for the production of a multifunctional protective helmet. The procedure was carried out at the company Šestan-Busch d.o.o. as part of the EU project for the development and production of a multifunctional protective helmet. The test results showed that carbon fibers polymers as a composite material have the best impact absorption properties which was a key criterion for material selection. Other materials; glass fibers polymers, aramid fibers polymers and combinations in the test procedure showed worse results compared to the selected criterion.

The focus of this study is the development of innovative and sustainable geopolymer composites with improved elevated temperatures performances. To minimize production related costs and support a circular economy model, phosphate sludge and MK are chosen as precursors for alkaline activation, and glass fibers as reinforcement material. The geopolymer composites were prepared by incorporating glass fibers in a geopolymer matrix based on a mixture of metakaolin and PS in a ratio of 50% and with amounts ranging from 0.25% to 1% of fibers. The developed composites were assessed in terms of physical characteristics, microstructural properties and flexural strength prior to and after introduction to higher temperatures. The findings demonstrated that PS based geopolymer matrix flexural strength decreased in the region of temperature between 25 and 600 °C, but increased progressively at higher temperatures, achieving a gain of 3.2% at 1000 °C. The same trend was followed after glass fiber incorporation, leading to a more significant gain of about 16.5% with a 1% fiber content up to 1000 °C. This behavior was assigned to the decomposition of carbonate content of PS at 600 °C as well as to the crystallization of the geopolymer matrix at higher temperatures.

La Directiva sobre eficiencia energética de los edificios 2010/31/EU (EPBD) fue modificada por la Directiva 2018/844 del Parlamento Europeo para, entre otras cosas, acelerar la renovación profunda de los edificios en la Unión Europea (UE). Según esta actualización, los Estados miembros deberían crear un camino claro hacia el logro de un parque de edificios con cero emisiones en la UE para 2050, respaldado por hojas de ruta nacionales con hitos e indicadores de progreso nacionales, y por financiación e inversión públicas y privadas. Queda patente que la prioridad de la Comisión Europea para conseguir la verdadera descarbonización de las ciudades, debe ser, además de limitar las emisiones de los edificios nuevos, rehabilitar energéticamente los edificios existentes. España cuenta con una Estrategia a largo plazo para la rehabilitación energética en el sector de la edificación en España que ha sido valorada como la mejor estrategia de toda la Unión Europea. Esta estrategia tiene un carácter cualitativo y resulta de interés otorgarle datos cuantificables basados en los objetivos ya conseguidos que permitan articular políticas claras y eficaces. Está comunicación tiene como objetivo presentar los resultados del Informe de evaluación sobre políticas públicas de rehabilitación residencial en España (2013-2017) resultado del Proyecto de Investigación “utilización sostenible de recursos naturales” financiado por Ministerio para la Transición Ecológica (MITECO) en la convocatoria 2018. Este informe ha permitido dotar de valores cuantificables los ahorros energéticos y emisiones conseguidos en el periodo estudiado. Para ello se ha elaborado una metodología de investigación para el seguimiento y evaluación de las políticas públicas y las iniciativas privadas acerca de la regeneración y rehabilitación urbanas, se han desarrollado indicadores y se han realizado recomendaciones futuras que ayuden a medir los objetivos y resultados, singularmente en lo relativo al ahorro energético. Los resultados ponen en evidencia la falta de medida por parte de las administraciones públicas, y muestran que estamos lejos de los objetivos. Este estudio ha sido realizado por el Observatorio Ciudad 3R –Rehabilitación. Renovación. Regeneración-, el cual surge en 2017 enmarcado en la línea estratégica de trabajo de la Fundación Ecología y Desarrollo (ECODES), e intenta dar respuesta a uno de los Objetivos de Desarrollo Sostenible (ODS), relativo a las “Ciudades y comunidades sostenibles” (objetivo 11). Abstract The Directive on Energy Efficiency of Buildings 2010/31 / EU (EPBD) was amended by Directive 2018/844 of the European Parliament to, among other things, accelerate the deep renovation of buildings in the European Union (EU). According to this update, Member States should create a clear path towards achieving a zero-emission building stock in the EU by 2050 supported by national roadmaps with national milestones and indicators of progress, and by public funding and investment and private. It is clear t the European Commission's priority to achieve the true decarbonisation of cities must be, in addition to limiting emissions from new buildings, to energetically renovation of existing buildings. Spain has a long-term Strategy for energy rehabilitation in the building sector in Spain that has been valued as the best strategy in the entire European Union. This strategy is qualitative in nature, and it is interesting to provide it with quantifiable data based on the objectives already achieved that allow the articulation of clear and effective policies. This communication aims to present the results of the Evaluation Report on public policies for residential renovation in Spain (2013-2017) resulting from the Research Project "sustainable use of natural resources" funded by the Ministry for Ecological Transition (MITECO) in the call 2018. This report has made it possible to provide quantifiable values for the energy savings and emissions achieved in the period studied. A research methodology has been developed for the monitoring and evaluation of public policies and private initiatives about urban regeneration and renovation, indicators have been developed and future recommendations have been made to help measure the objectives and results, particularly regarding energy saving. The results show the lack of measure by public administrations and show that we are far from the objectives. This study has been carried out by the Observatorio Ciudad 3R –Renovation. Renewal. Regeneration-, which arises in 2017 framed in the strategic line of work of the Ecology and Development Foundation (ECODES) and tries to respond to one of the Sustainable Development Goals (ODS), related to "Sustainable Cities and Communities" (objective 11).

This paper experimentally investigates the effect of steel and glass fibers on the engineering properties of concrete. To achieve this, 0.3%, 0.6%, and 0.9% by volume fraction of steel and glass fibers are added in concrete mixtures with water-to-cement (W/C) ratios 0.35 and 0.45. For each ratio of water to cement, 21 cubic samples for compressive strength tests, 14 cylindrical samples for tension strength tests, and also 14 prismatic samples for three-point flexural strength tests were prepared. The experimental results show that adding 0.3% to 0.9% % steel fibers for concrete increases simultaneously the compressive, tension, and also flexural strengths in comparison with plain concrete. Adding glass fibers only between 0.3% to 0.6% increases the compressive strength. The results reveal that the best range for reinforcing concrete with steel fiber is 0.3% to 0.9 %, and glass fiber is 0.3% to 0.6 % by volume fraction of fiber to improve the engineering strengths concrete. As a rule of thumb, the tension and flexural strengths of concrete could be explained as 8% and 13% of the compressive strength, respectively.

The construction sector is responsible for relevant environmental impacts and one of its most crucial points is the use of concrete. Geopolymers represent the most promising green and ecological alternative for common Portland cement and cementitious materials, due to its proven durability, mechanical and thermal properties. This work presents an experimental and comparative study of adhesion at the fiber-matrix interface between glass fibers and carbon fibers added to the geopolymer matrix. This analysis was performed by pull-out test, whereby it was found that the greatest efficiency was obtained by reinforcing with the glass fibers, incorporated at 2 mm in the geopolymer matrix. As results, the adhesion between the fibers and the geopolymer structure can be assessed, as well as the optimum length of application.

This recent work presents the results of dissolution of glass fibers in corrosion medium. The main objective of this research was to obtain the information about long-term dissolution of three types commercially produced glass fibers (E-fibers, fibers Promaglaf HTI 1200 and Promaglaf HTI 1250), which are commonly used as thermal insulation. The long-term dissolution of fibers was investigated at the temperature of 37°C by dynamic flow-through tests in simulated lung fluid (SLF). The flow rate of SLF was 120 ml/day. In solutions, the pH values and changes in weight loss of fibers were measured and changes in corrosion medium were evaluated by AAS. Also the values of the time dependence of the normalized leach amount of glass components (NLi) were computed and were compared with the data of NLi obtained from kinetic model of UCT Prague. The changes in appearance and composition of the fibers were evaluated with SEM-EDS techniques. This research confirmed that all fibers were dissolving in SLF, but each type differently. E-fibers dissolved nearly congruently, compared to fibers Promaglaf HTI 1200 and 1250 which were less soluble than E-fibers and dissolved incongruently. That was caused by production of precipitates - calcium phosphorous and silica layers.

In this paper, compression, flexural, tensile and abrasion tests are instituted by the addition of Bacillus megaterium MTCC with glass and steel fibers. The fundamental goal regarding this examination assignment is by segregate than apprehend calcite encouraging microscopic organisms yet in conformity with appearing at the reasonableness over these microorganisms because of utilizes among cement in conformity with enhancing its multiplication yet strength. Microorganisms in imitation of remain fused of cement duly after remaining soluble inferior proof by undergoing the high pH on cement and endospore-shaping after standing up to the mechanical anxieties actuated into cement during blending. They must show excessive urease work in conformity with inspiring calcium carbonate as calcite. Bacterial traces had been separated beyond soluble base exams on an embodied manufacturing range yet have been tried for urease movement, the dynamic in conformity with body endospores or precipitation over calcium carbonate. Considering its outcomes, she has been identified so Bacillus megaterium BSKAU, Bacillus licheniformis BSKNAU or Bacillus flexus BSKNAU. The effects have been contrasted Bacillus megaterium yet MTCC 1684 obtained from Microbial Type Culture Collection or bio life LTD, Hyderabad, India. In that trial with the aid of utilizing Bacillus megaterium MTCC1964 (105 cells/ml over blending water) or calcium lactate (5 g/lit) is utilized. The metal filaments 0 %, 0.5 %, 1.0 %, or 1.5 % yet glass strands 0 %, 0.5 %, 1.0 %, 1.5 % and 2.0 % added in accordance with the sure and reckon the stress esteems because 7, 14 and 28 days. In this effect, we watched high-pressure multiplication within glass filaments at 1% than steel strands at 1.5 %. These stage regarding glass strands then steel strands added according to the bacterial strong at to that amount factor discern the strain exorcism because blocks, pliancy because court of justice yet flexural attribute because bars at 7, 14, 28, 60 years old days. we either count the UPV take a look at for shapes and cantrobro take a look at because courthouse at 28 days historic and 60 days. SEM trial is done after discovering the propinquity concerning caco3 among Bacterial cement.

Composite materials are used for improving the parameters of common materials because of their high properties. Because of these properties and their variety they can be used for different types of common materials such as steel, concrete, wood. In this paper is about composite materials based on glass fibers and carbon fibers used as reinforcement which is applied on wood elements such as beams and then tested for bending.

In-plane and out-of-plane waviness are inevitable defects in parts that have curved sections made of continuous fiber-reinforced composites. These defects can be located in the micro, meso (ply level) and macro-scale (part level). In this study, an artificial out-of-plane fiber waviness was generated on the outer surface of the curved section of the L-shaped laminates. The fiber waviness generated was characterized experimentally using micrographs taken from the samples. The effect of fiber waviness on curved beam strength and delamination of the samples were determined through bending tests. Also, the effect of fiber waviness on the strain distribution on the curved section was quantified using Digital Image Correlation (DIC) technique.

Hypothesis: Using glass fiber in acrylonitrile-butadiene-styrene (ABS) composites has its limitations by increasing the final price (cost) of the product, abrasions in processing machines, the environmental and health problems during recycling as well as the reduction in impact strength of the composite. This study was carried out to evaluate the effect of silane-treated wollastonite, with a needle structure similar to glass fiber, as an alternative to glass fiber in order to eliminate the drawbacks of ABS/glass fiber composites, on the mechanical properties of ABS/wollastonite composites and compared with ABS/glass fiber composites.Methods: The ABS composites were produced using two types of wollastonite with different geometrical specifications. Dispersion of wollastonite in ABS matrix was evaluated using the SEM micrographs, and the mechanical properties of the composites were determined based on tensile and Izod impact testes. Then, the suitable wollastonite was selected and the ABS/wollastonite composites properties such as tensile, impact strength, thermal and dynamic-mechanical properties were compared with the ABS/glass fiber composites properties at similar percentage of reinforcement phase.Findings: The experimental results showed that the geometrical specification, especially the length/diameter ratio of wollastonite has a significant effect on the impact strength of the ABS composite as a result of good interfacial interaction between the filler and polymer matrix. The results showed significant improvement in the impact strength of ABS/wollastonite composites compared with that of ABS/glass fibers, while the modulus and strength as well as the Vicat softening temperature were acceptable compared with those of ABS/glass fibers composites. According to the results, ABS/wollastonite composites can be a good alternative to ABS/glass fiber composites in many applications.

Düzlem içi ve düzlem dışı dalgalanma, sürekli fiber takviyeli kompozitlerden yapılmış kavisli bölgelere sahip parçalarda kaçınılmaz kusurlardır. Bu kusurlar mikro, mezo (katman seviyesi) ve makro ölçekli (parça seviyesi) olabilir. Bu çalışmada, L şekilli laminatların kavisli bölümünün dış yüzeyinde yapay bir düzlem dışı fiber dalgası oluşturulmuştur. Elde edilen fiber dalgalanmaları, numunelerden alınan mikrogörüntüler kullanılarak deneysel olarak karakterize edilmiştir. Fiber dalgalanmaların kavisli kiriş mukavemeti ve numunelerin delaminasyonuna etkisi eğme testleri ile belirlenmiştir. Ayrıca, fiber dalgalanmasının eğri kesitteki birim şekil değiştirme dağılımına etkisi Sayısal Görüntü Korelasyonu (SGK) tekniği kullanılarak ölçülmüştür.

Introduction: Polymethyl methacrylate (PMMA) has been widely accepted and used in dentistry owing to its working characteristics, aesthetics and stability in the oral environment, ease in manipulation, and inexpensive processing methods and equipment. Aim and Objectives: The aim of this study was to evaluate the flexural strength of a high-impact PMMA denture base resin material and flexural strength of a commonly available heat cure PMMA denture base material with Kevlar, glass, and nylon fibers. Materials and Methods: The test samples were studied under two groups. The Group I (control group) comprised pre-reinforced PMMA (Lucitone 199; Dentsply Sirona Prosthetics, York, Pennsylvania, USA) consisting of 12 samples and second group comprised regular PMMA (DPI, Mumbai, India) reinforced with different fibers. The second test group was further divided into three subgroups as Group 2, Group 3, and Group 4 comprising 12 samples each designated by the letters a–l. All the samples were marked on both ends. A total of 48 samples were tested. Results were analyzed and any P value ≤0.05 was considered as statistically significant (t test). Results: All the 48 specimens were subjected to a 3-point bending test on a universal testing machine (MultiTest 10-i, Sterling, VA, USA) at a cross-head rate of 2 mm/min. A load was applied on each specimen by a centrally located rod until fracture occurred; span length taken was 50 mm. Flexural strength was then calculated. Conclusion: Reinforcement of conventional denture base resin with nylon and glass fibers showed statistical significance in the flexural strength values when compared to unreinforced high impact of denture base resin.

A Q‐switched all‐fiber Er‐doped laser operated at a wavelength up to 1625 nm is proposed and demonstrated. A self‐developed, element hybridization (Al, Ge, La, P, and Er in the core, Si and P in the cladding region) glass fiber with gain extended to U‐band is employed as gain medium. The compact laser cavity contains a fiber Bragg grating which was manufactured by means of point‐by‐point femtosecond laser inscription technique. Stable Q‐switched laser pulse train is successfully achieved using a semiconductor saturable absorber mirror at a low pump threshold of 29 mW. The laser has a maximum single pulse energy of 746 nJ and a minimum pulse duration of 26.8 μs. The pulse repetition rate can be gradually tuned from 6.47 to 11.87 kHz by increasing the pump power. In particular, the laser wavelength of the Q‐switched all‐fiber laser can be as long as 1625 nm. This is, to the best of our knowledge, the longest wavelength for the Q‐switched Er‐doped fiber lasers at this waveband.

Abstract The strategy of combining the traditional reinforcement of glass fibers (GF) with lighter hollow glass microspheres (HGM) can afford to fulfill the need for potential light-weight and high-strength modern materials required in various sectors, such as automotive and aerospace industry applications. This work fabricated composites of PA6/GF/HGM by melting blending in a co-rotating twin-screw extruder, and subsequently, injection molded. The effects of HGM content on the density, morphological and mechanical properties were investigated and the PA6/GF/HGM composites properties were compared to the properties of the traditional PA6/GF (70/30) wt% composite, widely used today in automotive industries. With the increase of HGM amount in the formulations, a reduction of between 3 and 12% in density was achieved with a slight reduction in its mechanical properties, showing that this new strategy can be applied to replace the PA6/GF (70/30) wt% composite, providing a considerable weight reduction for these materials.

In this work, basalt fibers (BF) have been investigated as possible natural and sustainable replacements for the common synthetic mineral filler—glass fibers (GF)—used in polyamide 66 matrix (PA66). Composites have been prepared at two different fiber concentrations (15 and 25 wt.%, respectively) by melt blending. The developed systems have been mainly characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), capillary rheology, and scanning electron microscopy (SEM). The kinetic parameters to thermal degradation through the Coats–Redfern method allowed us to attest a negligible effect of fiber type on thermal stability of the developed systems. Composites incorporating 15 wt.% of fiber content possessed the highest activation energy (≥230 kJ/mol). The introduction of BF and GF in PA 66 polymer, regardless of content, always led to an increase in crystallization and melting temperatures, and to a similar reduction in crystallinity degree and glass transition temperature. The shear viscosity of the basic polymer increased by the addition of fillers, particularly at low shear rate, with a pronounced effect in the case of basal fibers. A slightly higher shear thinning behavior of BF/PA66 with respect to GF/PA66 composites was confirmed by fitting the flow curves through the power law model. Finally, a worsening in fiber dispersion, by increasing the content in the matrix, and a weak compatibility between the two phases constituting the materials were highlighted through SEM micrographs.

The issue of upgrading and strengthening the reinforced concrete (RC) infrastructure has become of great importance. Recently, textile-reinforced mortar (TRM) was used in the field of structural strengthening. In the current study, using of TRM for flexural retrofitting of one-way reinforced concrete (RC) slabs was experimentally and theoretically investigated. The parameters examined included; the number of TRM layers (1, 3, 5 layers) and the strengthening configuration fully and partially). For this purpose, eight specimens were prepared and tested under three points- loading up to failure. The result showed that the TRM increases substantially the flexural capacity of RC slabs. The highest flexural capacity increase recorded was 103 %. It was also noted that increasing the number of retrofitting layers resulted in different increases in the flexural capacity. It was also shown that the strengthening configuration plays an important role in the effectiveness of the technique. The fully covered approach showed higher loading capacity than the partial cover technique provided that the same TRM layer is applied. Finally, the ultimate moment of the strengthened specimens was calculated theoretically and compared with that obtained experimentally. The results of calculations showed a good agreement between the theoretical and experimental results.

Geopolymer concrete is typically characterized by a brittle behavior and limited crack resistance. This study evaluates the performance of ambient-cured slag-fly ash blended geopolymer concrete reinforced with glass fibers. Two types of glass fibers were used exclusively or as a hybrid combination. The workability of glass fiber-reinforced geopolymer concrete was assessed using the slump, compaction factor, and vebe time. The compressive strength, splitting tensile strength, and modulus of elasticity were used to characterize the mechanical properties, while water absorption, sorptivity, abrasion resistance, and ultrasonic pulse velocity were employed in evaluating the durability. Experimental results showed that the slump and compaction factor decreased by up to 75% and 18%, respectively, with glass fiber addition but less significantly in mixes reinforced with hybrid fiber combinations. Meanwhile, the vebe time increased by up to 43%. Hybrid glass fibers led to superior mechanical and durability properties compared to plain mixes and those reinforced with a single type of glass fiber, even at higher volume fractions. The compressive strength, splitting tensile strength, and modulus of elasticity increased by up to 77%, 60%, and 85%, respectively. While the water absorption decreased by up to 42%, the sorptivity, abrasion resistance, and ultrasonic pulse velocity increased by up to 67%, 38%, and 280%, respectively. Analytical regression models were established to predict the mechanical and durability characteristics of glass fiber-reinforced slag-fly ash blended geopolymer concrete and were compared to those of design codes.

Combining two types of reinforcement fiber in a common matrix may lead to different failure modes such as micro-cracks between the layers when the structure is subjected to lower stress levels. Real-time damage detection should be integrated into the hybrid composite structure to provide structural integrity and mitigate this problem. This paper outlines the working mechanisms and the fabrication of an integrated capacitive sensor in an intra-ply hybrid composite (2 × 2 twill weave). Uniaxial tensile and flexural tests were conducted to characterize the proposed sensor and provide self-sensing functionality (smart structure). The sensitivity and repeatability of the capacitive sensor were measured to be around 1.3 and 185 µΔC/Co, respectively. The results illustrate that onset of damage between layers can be detected by in situ monitoring. It can be seen that the initial damage was detected at the turning point where the relative change in capacitance begins to reduce while the load increases. Finite element modeling was also constructed to analyze the test results and explain the reasons behind the turning point. It was shown that the carbon yarns experienced high transverse shear stress (τxz) in the crimp region, leading to inter-fiber cracks.

Corrosion study of conventional reinforcement in concrete has been accorded wider importance in the last few decades based on the losses occurring in monitoring concrete structures. It is well known that the presence of chloride ions is one of the most significant factors contributing to the corrosion of reinforcing steel. Practically, it is observed that in the marine environment, the activating substances such as chlorides that penetrate the steel can counteract the passivity locally when the electrolyte is highly alkaline. The concrete cover is changed chemically when chloride ionspenetrate into the material, whereupon the pore solution is neutralized. Based on numerous studies, it is evident that steel fibers and glass fibers have less impact on cracked sections in a chloride environment and can oppose chloride infiltration. Glass fibers, when exposed to repeated freeze and thaw conditions, protect the passive layer. This review article highlights the corrosion behavior of reinforced concrete involving various factors such as cracking behavior, transportation, electric conductivity, resistivity, and diffusion of chloride ions in the presence of steel and glass fibers.

This paper experimentally investigates the effect of steel and glass fibers on the engineering properties of concrete. To achieve this, 0.3%, 0.6%, and 0.9% by volume fraction of steel and glass fibers are added in concrete mixtures with water-to-cement (W/C) ratios 0.35 and 0.45. For each ratio of water to cement, 21 cubic samples for compressive strength tests, 14 cylindrical samples for tension strength tests, and also 14 prismatic samples for three-point flexural strength tests were prepared. The experimental results show that adding 0.3% to 0.9% % steel fibers for concrete increases simultaneously the compressive, tension, and also flexural strengths in comparison with plain concrete. Adding glass fibers only between 0.3% to 0.6% increases the compressive strength. The results reveal that the best range for reinforcing concrete with steel fiber is 0.3% to 0.9 % and glass fiber is 0.3% to 0.6 % by volume fraction of fiber to improve the engineering strengths concrete. As a rule of thumb, the tension and flexural strengths of concrete could be explained as 8% and 13% of the compressive strength, respectively.