Behavior analysis of waste fiber-reinforced recycled concrete columns under axial and eccentric compression

This study was determined the impact of recycled coarse aggregate content (0%, 50%, and 100%), waste fiber length (12, 19, and 30 mm), volume fraction of waste fibers (0.08%, 0.12%, and 0.16%), slenderness ratio (2, 5, and 8), and eccentricity (0, 30, and 60 mm) on the bearing capacity of concrete columns. The results indicated that the cracking load and ultimate bearing capacity of waste fiber recycled concrete (WFRC) column decrease as the replacement rate of recycled aggregates increases, and initially increase before decreasing with the increase in both the length and content of waste fibers. The highest bearing capacity is achieved when the waste fiber length is 19 mm with a content of 0.12%. The waste fibers exhibit superior bond strength with the concrete matrix and effective load transfer, which inhibit the development the cracks during the loading process and improve the bearing capacity of the specimens. Additionally, the experimental results of WFRC were compared with the theoretical values calculated according to the "Code for Design of Concrete Structures" GB50010-2010, the ratios of the calculated value to the experimental value in the range of 0.81–1.10. The feasibility and safety of the related properties of the WFRC column according to the results calculated by the standard GB50010-2010. The standard GB50010-2010 can guide the application design of WFRC compression members in practical engineering.