Acoustic emissions evaluation of the dynamic splitting tensile properties of steel fiber reinforced concrete under freeze–thaw cycling.

Zhang, Hua; Liu, Xinyue; Bai, Lingyu; Ji, Shanshan; Pan, Luoyu; Li, Xuechen

This study empirically investigated the influence of freeze–thaw cycling on the dynamic splitting tensile properties of steel fiber reinforced concrete (SFRC). Brazilian disc splitting tests were conducted using four loading rates (0.002, 0.02, 0.2, and 2 mm/s) on specimens with four steel fiber contents (0%, 0.6%, 1.2%, and 1.8%) subjected to 0 and 50 freeze–thaw cycles. The dynamic splitting tensile damage characteristics were evaluated using acoustic emission (AE) parameter analysis and Fourier transform spectral analysis. The results quantified using the freeze–thaw damage factor defined in this paper indicate that the degree of damage to SFRC caused by freeze–thaw cycling was aggravated with increasing loading rate but mitigated by increasing fiber content. The percentage of low-frequency AE signals produced by the SFRC specimens during loading decreased with increasing loading rate, whereas that of high-frequency AE signals increased. Freeze–thaw action had little effect on the crack types observed during the early and middle stages of the loading process; however, the primary crack type observed during the later stage of loading changed from shear to tensile after the SFRC specimens were subjected to freeze–thaw cycling. Notably, the results of this study indicate that the freeze–thaw damage to SFRC reduces AE signal activity at low frequencies.

FIBER-reinforced concrete; FREEZE-thaw cycles; ACOUSTIC emission; STEEL; FOURIER analysis; FOURIER transforms

Frontiers of Structural & Civil Engineering, 2024, Vol 17, Issue 9, p1341

2095-2430

Academic Journal

10.1007/s11709-023-0988-4