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American Society for Testing and Materials

Composites have been found to be the most promising and discerning material available in this century. Presently, composites reinforced with fibers of synthetic or natural materials are gaining more importance as demands for lightweight materials with high strength for specific applications are growing in the market. Fiber-reinforced polymer composite offers not only high strength to weight ratio, but also reveals exceptional properties such as high durability; stiffness; damping property; flexural strength; and resistance to corrosion, wear, impact, and fire. These wide ranges of diverse features have led composite materials to find applications in mechanical, construction, aerospace, automobile, biomedical, marine, and many other manufacturing industries. Performance of composite materials predominantly depends on their constituent elements and manufacturing techniques, therefore, functional properties of various fibers available worldwide, their classifications, and the manufacturing techniques used to fabricate the composite materials need to be studied in order to figure out the optimized characteristic of the material for the desired application. An overview of a diverse range of fibers, their properties, functionality, classification, and various fiber composite manufacturing techniques is presented to discover the optimized fiber-reinforced composite material for significant applications. Their exceptional performance in the numerous fields of applications have made fiber-reinforced composite materials a promising alternative over solitary metals or alloys.

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Fiber-Reinforced Polymer Composites: Manufacturing, Properties, and Applications.

Environmentally-friendly monofilament cellulosic fibres have been widely used as alternatives for conventional steel reinforcement within concrete. Recently, the use of cellulosic fibre fabrics and their fabric reinforced polymer composites as reinforcement materials within and/or outside of construction materials (e.g. concrete) has gained popularity due to their inexpensive cost and favourable specific mechanical properties compared with synthetic fibre fabrics (e.g. E-glass). This review presents a summary of recent development on cellulosic fibre Fabric Reinforced Cementitious (FRC) and Fabric Reinforced Geopolymer (FRG) composites, as well as their cellulosic Fabric Reinforced Polymer (FRP) composites as reinforcements of concrete, masonry and timber structures for civil engineering applications. This review covers: (1) properties (i.e. chemical composition, microstructure, mechanical properties and cost) of monofilament cellulosic fibres and their comparison with synthetic fibres, the relationship between fibre chemical composition and fibre mechanical properties, parameters affect fibre properties; (2) properties (e.g. fabrication of monofilament fibres to fabrics and structures) of cellulosic fibre fabrics, properties of polymer matrices, and properties (i.e. flexural, tensile, impact, insulation and fire properties) of cellulosic fabric FRP composites; and (3) properties (compressive, flexural and tensile and impact properties) of cellulosic FRC and FRG composites, and the properties of cellulosic FRP composites reinforced concrete, masonry and timber structures. In addition, the degradation mechanisms of cellulosic FRC and FRP are discussed. Furthermore, the durability of FRC, FRG and FRP composites are reviewed and the methods to improve the durability of FRC, FRG and FRP composites from the aspects of fibre modification and matrix modification are reviewed and summarized.

A review of recent research on the use of cellulosic fibres, their fibre fabric reinforced cementitious, geo-polymer and polymer composites in civil engineering

Since the last two decades, many researchers have refocused on using natural fibres, as reinforcements for cementitious and polymer based structural materials. The use of natural fibres for structural applications is not modern. Long before a century ago people in many small towns in China and Korea already mixed straws with mud to build walls in villages. However, at that time there was no systematic way to study the fundamental mechanism and interpret how natural fibres strengthen structures and what processes should be adopted to maximize the performance of natural materials. Currently, nevertheless natural fibre reinforced polymer (NFRP) composites have been widely used in automotive and building industries, it is still a room to promote them to high-level structural applications like primary structural components of aerospace and maritime structures. It is difficult to evaluate the quality of natural fibres, which generally extracted from the nature, and thus it is challenging to develop a generic formula to predict the structural and mechanical properties of NFRP composites. Hydrophilic and hydrophobic properties of natural fibres and polymers, respectively, cause poor bonding interaction at interface. Traditional shear-lag model was popularly used to study the stress transfer mechanism between fibre and matrix of advanced composites. However, such model is not applicable to NFRP composites due to the imperfect shape of nature fibres along their longitudinal direction and irregular shape of fibres' cross section. In this paper, analysis on different aspects in related to the use of natural fibres for real life engineering applications is given. Basic analytical models focusing on the stress transferability in composites are also discussed to provide an insight for researchers and engineers to understand the design and requirements of using natural fibres for structural applications in the future.

Properties of natural fibre composites for structural engineering applications

https://www.repository.cam.ac.uk/bitstream/1810/279810/1/Authors%20copy.pdf

Towards the design of high-performance plant fibre composites

In the present work the morphology of natural fibers was correlated with their mechanical properties via image analysis. Jute, sisal, curaua, coir and piassava fibers were tested under direct tension in a universal testing machine and the cross-sectional areas of the fibers were calculated using images obtained in a scanning electron microscopy. For the jute fiber the tests were performed for several gage lengths in order to investigate its influence on the tensile strength and to compute the machine compliance. For sisal, jute and curaua fibers the amount of fiber-cells, the size of the cell walls and the real area of the fibers were measured and their correlation with the tensile strength addressed. The curaua fiber presented the highest mechanical performance with tensile strength and Young’s modulus of 543 MPa and 63.7 GPa, respectively. Weibull statistical analysis was used to quantify the variability of fiber strength. The sisal fibers presented the highest Weibull modulus (3.70), whereas the curaua presented the lowest one (m = 2.2), which means that the sisal had the lowest variability and curaua the highest.

Thatiana Vitorino Castro Pereira

Papers

The effect of fiber morphology on the tensile strength of natural fibers