A review of recent developments in application of plant fibers as reinforcements in concrete

Owing to growing environmental awareness, significant attention is being focused on plant fibers as inexpensive alternatives to polymeric fibers. Plant fibers used in concrete are eco-friendly, recyclable, and biodegradable. Therefore, the application of plant fibers as reinforcement in concrete has received considerable attention. This review covers recent research on the use of plant fibers in concrete. A bibliometric analysis was conducted to identify significant research achievements. Subsequently, the characteristics of plant fibers, including micromorphology, predominant components, physical and mechanical properties, the correlation between predominant chemical components and properties, thermal properties, and degradation mechanisms in cement composites, are introduced. Details of the effects of plant fibers on the properties (static, dynamic mechanical, durability, thermal, and self-healing) of concrete are discussed. After stating the basic issues on the application of plant fibers in concrete, various modification methods and mechanisms to improve the durability of plant-fiberreinforced concrete, including matrix (i.e., the addition of pozzolans and carbonation) and fiber modifications (i. e., physical and chemical modifications), are summarized. Subsequently, the hybrid use of plant fibers and other types of fibers are described, followed by a detailed presentation of evaluation indexes and mechanisms. This review provides fundamental knowledge on plant-fiber-reinforced concrete, discusses the main challenges in the development of plant-fiber-reinforced concrete, and proposes future research scopes.