The aim of this study was to synthesize glass ionomer-silk Fiber composite and examining the effect of adding natural degummed silk Fiber on the mechanical properties of glass ionomer cement (GIC). For this purpose, natural degummed silk Fibers with 1 mm length and 13-16 mm diameter were added to the ceramic component of a commercial glass ionomer cement in 1, 3, and 5 wt. %.Compressive strength (CS), three-point flexural strength (FS) and diametral tensile strength (DTS) of the prepared glass ionomer-silk Fiber were measured. Analysis of variance (ANOVA) was used to compare the obtained results. Moreover, SEM technique was used for the investigation of the surface morphology of the as-prepared composite and the fractured area. The results showed that the highest compressive strength, flexural strength and diametral tensile strength were obtained using 3, 3, and 5 wt. % of silk Fiber, respectively. However, at 3 wt. % of silk Fiber, all three measures of strength exhibited a significant increase compared to the commercial GIC. Therefore, it can be suggested that the addition of 3 wt. % silk Fiber to the ceramic component of GIC is desired for dental restorations and orthopedic implant applications, where the maximum strength in all three modes of loading would be beneficial.

Plant Fiber composites are currently experiencing strong development, particularly due to the growing interest in them in the automotive industry. These Fibers are an excellent alternative to glass Fibers from the environmental point of view due to their biodegradability and their much more neutral combustibility in terms of the release of harmful gases or solid residues. However, the incorporation of cellulosic materials into the thermoplastic matrix affects a large number of properties. Many factors, such as the nature and rate of the incorporated filler, can influence the properties of the composites. The present work involves studying the effect of the particle size of a natural Fiber on the properties of a polymer matrix. The plant Fibers used are DISS Fibers ground into a powder with a particle size of less than 63µm. Different formulations based on HDPE/Diss were prepared with different amounts of the filler (10%, 20% and 30%). The HDPE/Diss composites were first processed using a calender, then molded into samples of various shapes with a thickness of 3 mm by compression at 190 °C. These were characterized by various techniques: physical tests, mechanical tests, rheological and morphological tests.

Objective: Introduction of Fiber-reinforced composites (FRC) greatly enhanced the restoration of fractured anterior teeth. The purpose of this study was to assess the effect of Fiber Reinforcement on fracture resistance of incisal edge composite restorations of variable thicknesses.Methods: Forty extracted sound human maxillary incisors were divided into four groups of 10. Incisal reduction was done by 3mm in groups 1 and 3 and by 4mm in groups 2 and 4. Incisal edge was restored with hybrid composite in groups 1 and 2 and hybrid composite reinforced by two Ribbond Fibers in the palatal surface in groups 3 and 4. All specimens were mounted in acrylic blocks, stored in saline solution and thermocycled. The teeth were then subjected to static load by universal testing machine until fracture. The load was applied at 135° angle relative to the tooth surface to an area2mm apical tothe incisal edge at a crosshead speed of 1mm/min. Data were analyzed using Tukey’s test andp≤0.05 was considered significant.Results: The mean fracture resistance was 436 (242) N, 492 (195) N, 992 (275) N and 1080 (236) N in groups 1 to 4, respectively and the difference in this regard among the 4 groups was statistically significant (p=0.000). The mean fracture resistance in group 3 (Fiber-reinforced, 3mm thickness) was higher than that in group 1 (no Fiber, 3mm thickness). This value in group 4 (Fiber-reinforced, 4 mm thickness) was also higher than in group 2 (no Fiber, 4mm thickness). The highest fracture resistance was seen in group 4.Thickness of composite had no significant effect on fracture resistance (p=0.347).Conclusion: Application of two Ribbond Fibers can significantly increase the fracture resistance of incisal edge composite restorations.

1. Introduction: The utilization of steel Fiber Reinforcement concrete (SFRC) in practical applications is gained considerable attention owing to its acceptable strength (Nili & Afroughsabet, 2010; El-Dieb, 2009) and durability. Taking to account, SFRC in constructions may inevitably subjected to short duration dynamic loading, the impact resistance of SFRC which cured under different curing conditions must be well documented. To evaluate the resistance of SFRC under impact loadings, a variety of test procedures have been suggested (ACI Committee 544, 1996). In this study, the drop-weight test as recommended by ACI committee 544 (ACI Committee 544, 1996) were utilized...

In general, shear Reinforcement in reinforced concrete beams typically involves the use of stirrups. However, substituting stirrups with continuous rectangular spiral Reinforcement can enhance construction efficiency and lower costs. Meanwhile, the adoption of Fiber-reinforced concrete in concrete structures is on the rise due to its distinctive properties. To address the tensile and shear vulnerabilities of concrete, reinforcing it with Fibers is a viable solution. This study explores the experimental replacement of stirrups with continuous rectangular spiral Reinforcements in both traditional concrete and steel Fiber-reinforced concrete (SFRC) beams. Three beams were subjected to static loading tests: the first beam, referred to as ST-NC, featured stirrups and normal concrete as a reference; the other two beams incorporated continuous rectangular spiral Reinforcements with normal concrete (SP-NC) and steel Fiber-reinforced concrete at a 0.75% volume fraction (SP-F0.75). The experimental findings indicate that the beam reinforced with continuous rectangular spiral Reinforcements and Fiber concrete exhibits improved shear resistance, energy absorption, and ductility compared to the normal concrete beam and the reference beam. The beams with continuous rectangular spiral Reinforcements, using normal concrete and steel Fiber-reinforced concrete, demonstrated a 23.8 and 46.5% increase in shear capacity, respectively, compared to the reference beam. Additionally, energy absorption in SP-NC and SP-F0.75 beams increased by 69 and 158%, respectively, compared to the reference beam. The ductility of the continuous rectangular spiral Reinforcement beam with normal concrete and steel Fiber-reinforced concrete is 0.87 and 1.17 times that of the reference beam, respectively. Notably, the results reveal a reduction in the ductility of the SP-NC beam compared to the reference beam, and the addition of 0.75% by volume of Fibers to the concrete resolves this ductility weakness in the SP-NC beam. These findings underscore the advantages of employing continuous rectangular spiral Reinforcements in beams constructed with steel Fiber-reinforced concrete, as proposed in this study