In this work, we studied stress variations occurring during flexure of early-age steel fiber reinforced concrete beams. By preparing beams with different fiber volume ratios, four-point bending tests were performed to evaluate the specimens at different loading rates. A new experimental system was created to collect the stress-time curves collected at 100 kHz sampling rate so that temporal profiles of stress drops were analyzed in high resolution. Meanwhile, stress drops were modeled as avalanches due to interactions between steel fibers and cement matrices during flexure. Good agreement on avalanche statistics and dynamics was obtained between measurements and the predicted power law exponents and scaling functions from the mean field model. The observations of different avalanche types also illustrated the essential failure features evolved during flexure of steel fiber reinforced beams.

中文翻译：

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早期钢纤维混凝土梁弯曲过程中的雪崩

在这项工作中，我们研究了早期钢纤维混凝土梁弯曲过程中发生的应力变化。通过制备具有不同纤维体积比的梁，进行四点弯曲试验以评估不同加载速率下的试样。创建了一个新的实验系统来收集以 100 kHz 采样率收集的应力-时间曲线，以便以高分辨率分析应力下降的时间曲线。同时，由于钢纤维和水泥基体在弯曲过程中的相互作用，应力下降被模拟为雪崩。在测量值与来自平均场模型的预测幂律指数和标度函数之间获得了关于雪崩统计和动力学的良好一致性。