Flexural performance and damage evaluation on basalt fiber reinforced polymer (BFRP) sheet reinforced concrete

Basalt fiber reinforced polymer (BFRP) is a promising composite material for concrete restoration as an external sheet reinforcement. This work aims to propose a methodology that can effectively monitor and evaluate the damage of external BFRP sheet reinforced concrete during its industrial service life. For better understanding of flexural performance and damage evaluation on BFRP sheet reinforced concrete, four-point bending tests were conducted on specimens produced with different bonding conditions (bonding BFRP sheet at 0%, 80%, 90%, and 95% of failure load) to explore suitable repair strategies for engineering. Multi-view digital image correlation technique is used to analyze the deformation on concrete part and BFRP sheet simultaneously. Such a noncontact measurement makes it possible to observe crack development and evaluate damage degree of concrete beams during loading process and could be applied in industrial measurement. In addition, crack development could be characterized by length and width, which is calculated by strain distribution of both concrete part and BFRP sheet. Results reveal that BFRP sheet could improve about 78.56% of flexural strength and 304.38% of ductility. Besides, it is found that the growth of damage degree is steadier in BFRP reinforced specimens. According to the early warning levels proposed in this work, it is suggested that BFRP reinforcement should be adopted before concrete is loaded to 90% of failure load to allow for timely repair and facilitate subsequent health monitoring.