Study on fatigue damage and fatigue crack propagation of rubber concrete

In order to study the crack propagation process and damage mechanism of rubber concrete under fatigue loading, the fatigue test of plain concrete beam and rubber concrete beam with precast cracks was carried out, and the loading process was monitored in real time by acoustic emission. The results show that after the addition of rubber, the maximum deformation of rubber concrete under fatigue load is about twice that of plain concrete, and the fatigue life and fracture energy increase. It is confirmed by AE signals that there is hysteresis between cracks and loads under fatigue load due to the lag of energy transfer. The incorporation of rubber particles also reduces the range of changes in stress strength factors. The b-value of AE reflects the damage state and crack development of the concrete. When the b-value is reduced to 0.8, it can be used as an early warning indicator of structural failure.

Automated summary

In order to understand the crack propagation process and damage mechanism of rubber concrete under fatigue loading, fatigue tests were conducted on plain concrete beams and rubber concrete beams with precast cracks, and the loading process was monitored in real time using acoustic emission. The results showed that the addition of rubber increased the maximum deformation of rubber concrete under fatigue load, resulting in increased fatigue life and fracture energy. Acoustic emission signals confirmed that there was a hysteresis effect between cracks and loads due to the lag in energy transfer. The incorporation of rubber particles also reduced variations in stress strength factors. The b-value of acoustic emission reflected the damage state and crack development of the concrete, and a reduction to 0.8 could be used as an early warning indicator of structural failure.