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.

Strengthening of poor and improper soils, in order to be utilized in civil engineering projects, for fabricating a soil with ideal engineering properties, is called stabilization and REINFORCEMENT. Soil stabilization is used for various purposes such as prevention of surface erosion, improvement of poor subgrades, controlling of shifting soils, rehabilitation of base layers and retrieving of old paths. Today, because of weaknesses such as poor strength and long duration for curing with common stabilizers (lime and cement), the attitude for finding new materials which can improve these deficiencies has increased. In this research, a sandy soil, a petrochemical material called epoxy resin (as stabilizer), and also a FIBER (as soil reinforcing agent) were used to evaluate their effects on soil resistance-parameters. The behavior of stabilized soil in compression and shear was determined in this project. Results of the tests revealed that compression and tensile strengths of stabilized soil with epoxy resin were increased significantly; while the strengths of the sandy soil without epoxy were too weak. By addition of FIBER to the soil samples, the soil compression strength was not increased; whereas, it has profound effect to promote tensile strength. Also, soil samples containing FIBER showed more deformation. This means that they absorb more energy under loading to reach the rupture stage.

Background and Aim: The aim of this study was to evaluate the effect of glass-FIBER on the flexural strength of composite resins.Methods & Materials: The study was done experimentally in which flexural strength of glass - FIBER reinforced composite resins were assessed with a three-point load test on 22 samples. 11 samples of composite resin blocks and 11 samples of composite resins reinforced with glass- FIBER were prepared in a mold of 25x6x2mm and stored in 100% of moisture for one month, until they were ready for testing in an Instron Universal Testing Machine using a crosshead speed of 1 mm/min. Student t test was used for statistical analysis.Result: Flexural strength in the first group was 22.39±3.38 MPa and in second group was 29.74±2.36 MPa. According to t test analysis, the difference between the two groups was statistically significant. (P<0.01).Conclusion: The results of this study suggest that the flexural strength of the FIBER-reinforced composite made from glass - FIBERs was more than composite resin.

Background and Aim: REINFORCEMENT with FIBER is one of effective methods for improvement in flexural properties of indirect composite resin restorations. The composition of the overlying veneering composite plays a critical role in the flexural properties of the final FIBER reinforced restoration. The aim of this in-vitro study was to evaluate the effect of FIBER REINFORCEMENT on the flexural strength of three laboratory-processed FIBER-reinforced composite resins.Materials and Methods: In this experimental-laboratory study, 72 bar type specimens (3×2×25 mm) were constructed by using three types of FIBER-reinforced composite resins (Gradia, Signom, Bellglass) and one Plexiglas mold. In each type of composite resin, two groups (one with FIBER and one without FIBER) were constructed. These specimens were tested by the three-point bending method to measure flexural strength. Data were statistically analyzed with two way ANOVA, Tukey and T-test at 0.05 significance level.Results: The mean flexural strength of Gradia with FIBER was higher than the other groups (150.14 MPa) and the mean flexural strength of Signom without FIBER was the least (60.53 MPa). There was a significant difference between the mean primary fracture force in the three groups (P<0.001).Conclusion: Within the limitations of this study, it may be concluded that REINFORCEMENT with FIBER considerably increases the fracture resistance of composite specimens and the overlying veneering composite may play an important role in the transverse strength of FIBER reinforced composite specimens.

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...

The aim of this study was to investigate flexural strengthening of screwed Glulam made with poplar (Populus alba). Polyurethane adhesive and screw were used for joining layers and applying pressure for manufacturing of three-layer glulam. The variables of this study were types of reinforcing (galvanized steel, aluminum sheet and glass FIBER REINFORCEMENT polymer) and arrangements of reinforcing: No. 1 (bonded on the bottom (tension) side); No. 2 (bonded on the bottom and top (Tension and compression) side); No. 3 (bonded on the bottom, top and between two bottom layers); No. 4 (bonded on the bottom, top and among layers). Bending test was conducted by Instron according to ASTM D7341. The highest MOR (82. 96 MPa) and MOE (1066. 33 MPa) were both observed in Glulams reinforced by galvanized steel sheet with arrangement of No. 2 and the lowest MOR (57. 82 MPa) and MOE (4397. 33 MPa) were both related to Glulams reinforced by GFRP wrapped with arrangement of No. 1. MOR and MOE of control Glulams were 48. 1 and 4330 MPa. The increasing percentage of MOR due to reinforcing by galvanized steel, aluminum sheet and GFRP Wrapped were 72. 5, 57. 8 and 42. 6, respectively. The increasing percentages for MOE were 134. 2, 57. 6 and 28. 4, respectively. Failure modes of Glulams changed from brittle to ductile by reinforcing resulted in improving of flexural behavior. The independent effect of types and arrangements of reinforcing on MOR and MOE and also the interaction of types and arrangements of reinforcing on MOE were statistically significant.

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