Residual fracture energy of natural and recycled aggregate concrete after exposure to high temperatures. (30th April 2022)

• Record Type: Journal Article
• Authors: Chen, Wei; Peng, Linxin; Yang, Haifeng; He, Xingchuan
• Is Part Of: Structural concrete. Volume 24:Number 2(2023)
• Page Start: 1879
• Page End: 1892
• Publication Date: 2022-04-30
• Subjects: fracture energy -- high temperature -- recycled aggregate concrete -- stable fracture energy -- unstable fracture energy; Reinforced concrete -- Periodicals; 624.1834
• DOI: 10.1002/suco.202200037
• Languages: English
• ISSNs: 1464-4177

Abstract

Abstract: Fracture energy ( G F ) represents the average total energy consumed in the whole process of crack propagation. Using one parameter of G F, it is not sufficient to describe the fracture behavior during crack stable and unstable propagation periods. In this study, the G F, stable fracture energy ( G FS ) and unstable fracture energy ( G FU ) of natural and recycled aggregate concrete (RAC) were investigated by using three‐point bending tests. Totally, 128 cubic specimens (100 mm × 100 mm × 100 mm) and 64 notched beams with size of 510 mm × 100 mm × 100 mm were manufactured to test the compressive strength ( f cu ), splitting tensile strength ( f t ), load–deflection (P‐δ), and load‐cracking mouth opening displacement (P‐CMOD) curves, considering different replacement levels (0%, 30%, 70%, and 100%) of recycled coarse aggregate (RA) and high temperatures exposure (20, 100, 200, and 300°C). The effects of RA substitutions and temperatures on basic mechanical properties, G F, G FS, and G FU were analyzed. The results demonstrated that the f cu, f t, and elastic modulus ( E ) decreased with the incremental temperature. The G FS of concrete with different RA substitutions first decreased and then increased, and the minimum value appeared at 200°C. The G F and G FU of concrete with different RA substitutions increased with the elevated temperature, and the increase rate decreased with RA substitutions. When the temperature is less than 100°C, the G F and G FU of concrete remained mostly unchanged with the increase of RA substitutions, while the temperature reached 200 and 300°C, the G F and G FU of concrete increased and decreased with the increase of RA substitutions, respectively.