Stress Avalanches of Polyethylene Terephthalate Fiber–Reinforced Concrete Beams during Flexure

Abstract

Stress–time avalanches of recycled polyethylene terephthalate (PET) fiber–reinforced concrete during flexure were investigated based on high temporal resolution signals in this study. Stress drops were extracted based on measurements collected at 100 kHz and modeled as avalanches using the mean field model. Two types of avalanches were observed during flexure of PET fiber beams, i.e., small avalanches collapsed on the scaling regime and large avalanches beyond the regime. The measured stress drop profiles of small avalanches in the scaling regime agreed with predictions from the mean field theory that has been used to model avalanches. When the peak stress was reached after the fracture of bottom concrete, the postpeak avalanche size could exceed the avalanche size at the bottom fracture. Findings from this study could provide essential clues to the understanding of fiber-reinforced concrete during bending.