Recent advances in concrete-filled fiber-reinforced polymer tubes: a systematic review and future directions

This paper aims to consolidate and summarize the latest advancements in concrete-filled fiber-reinforced polymer (FRP) tubes. Through a systematic approach, the review paper presents the significant attention within civil engineering applications towards utilizing fiber-reinforced polymer (FRP) compounds, due to their lightweight properties, elevated strength, resistance to corrosion, fatigue endurance, and adaptability in design. The study aims to expand the added benefits of using FRP tubes as a mold during concrete casting, making them particularly suitable for structures exposed to harsh and corrosive environments, such as those near seawater with high chloride concentrations. The goals of this study are attained through an extensive exploration of academic databases, journals, conference proceedings, and pertinent literature. The paper undertook an analytical examination, discerning patterns, trends, and significant discoveries throughout the literature. It involved comparing and contrasting various studies, methodologies, and results to grasp the present state of research in the field. A critical assessment of the reviewed literature was conducted, evaluating both strengths and weaknesses encompassing methodological approaches, theoretical frameworks, and empirical evidence. Civil engineering has increasingly embraced fiber-reinforced polymer (FRP) materials for their lightweight nature, robust strength, corrosion resistance and fatigue durability. FRP products like sheets, panels, rods, wires, shapes, frameworks, and tubes find utility in various civil engineering applications. Among these, FRP tubes play a dual role as concrete molds and provide lateral support. This makes them ideal for structures in harsh environments, such as coastal areas with high chloride levels. Recent research focuses on traditional concrete-filled FRP tubes (CFFTs), exploring practical experiments and theoretical analyses, while also delving into innovative variations and advanced manufacturing techniques for FRP tubes. This paper extensively examines recent pioneering research on concrete structures reinforced with FRP tubes. It encompasses discussions on the geometric characteristics of FRP tubes, the materials employed, and diverse concrete compositions, which vary depending on the utilization of different aggregate types including sea sand, recycled aggregate, and lightweight aggregate. In summary, this review offers valuable insights into the latest advancements in FRP tube-reinforced concrete structures, serving as a reference for future research and practical applications.