钢纤维增强粉煤灰基地质聚合物抗折过程声发射特性研究

Acoustic emission behavior of steel fiber reinforced geopolymer under three-point bending

制备钢纤维增强粉煤灰基地质聚合物,钢纤维的体积掺量不同,研究钢纤维体积掺量对地质聚合物抗折破坏行为及声发射特性的影响,通过研究声发射信号波形平均频率AF及RA(上升时间与幅值的比值)的变化趋势,得出地质聚合物基体的拉伸破坏及剪切破坏的规律。结果表明:镀铜钢纤维对地质聚合物的增韧效果明显;持续时间在40000μs以上,且所含能量很高的波形为诱发灾变破坏的波形;小RA值、大AF值对应着地质聚合物基体的拉伸破坏,大RA值、小AF值对应着纤维拔出过程中与基体的相对剪切破坏。

Geopolymer samples reinforced with different volume fractions of steel fibers were loaded under three- point bending process to investigate the relationship between the macroscopic mechanical behavior and mesoscopic damage evolution. The Acoustic emission（ AE） behaviors of steel fiber reinforced geopolymer（ SFRG） was measured to monitor the characteristics of damage evolution. Researching the acoustic emission signal waveform average frequency of AF and RA（ ratio of Riseing time and Amplitude）trends,the rule of macroscopic mechanical behavior and mesoscopic damage evolution can known. The results show that volume fractions of steel fibers can improve ductility; The disaster damage waveform duration is more than 40000 μs; Little RA value,big AF value corresponds to the tensile failure of geopolymer,and the big RA value,little AF value corresponds to the shear failure of geopolymer.