ABSTRACTAvailable as agricultural resources in many countries, natural fibers, such as flax, hemp, kenaf, exhibit mechanical properties comparable to those of synthetic fibers like glass. But they are lighter, biodegradable, and are often claimed to be less expensive. Composites with these natural fibers have the potential to be attractive alternative to synthetic fiber composites. The natural fibers, however, exhibit more scatter in their properties, are thermally less stable and are sensitive to moisture absorption. The choice of matrix to reinforce with these fibers therefore becomes critical.Currently, synthetic non-biodegradable polymers, such as polypropylene, polyester, etc., are being explored as matrix materials, for applications in sectors like automobiles and buildings. Biodegradable polymers, if made available in sufficient quantities at affordable prices, pave way for bio-composites in future. With both matrix and fibers being biodegradable, bio-composites become attractive candidates from the environment point of view.Extensive and reliable property data on natural fiber composites and/or on bio-composites, are still lacking, making product design with these materials rather tedious. Once the database is available, design & manufacture of products with natural fiber composites and biocomposites offer several opportunities and challenges.
External strengthening of concrete with natural and synthetic fiber composites
