煤矸石混凝土轴心受压声发射特性与损伤模型研究

Acoustic Emission Characteristics and Damage Model of Coal Gangue Concrete under Axial Compression

对煤矸石粗集料取代率分别为0%,20%,40%,60%的4组煤矸石混凝土进行了轴心受压试验,并使用声发射(AE)技术对煤矸石混凝土受压破坏过程中的损伤演化规律进行动态分析.根据煤矸石混凝土受压损伤时所释放的声发射信号与能量,定性分析了材料的损伤程度,并以声发射参数为基础建立了煤矸石混凝土损伤演化方程与损伤本构模型.结果表明:煤矸石混凝土轴心受压应力应变全曲线形状与普通混凝土基本一致,随着煤矸石粗集料取代率的增大,煤矸石混凝土的峰值应力略有下降,但下降幅度不大;声发射参数可有效描述煤矸石混凝土损伤的演化规律,且随着煤矸石粗集料取代率的增大,煤矸石混凝土的耗能能力减弱;以声发射参数为基础建立的煤矸石混凝土轴心受压损伤本构模型与试验结果吻合较好,可以为煤矸石混凝土的理论研究与工程应用提供可靠的依据.

4 groups of coal gangue concrete with the substitution rate of aggregate of 0%,20%,40%,60% respectively were studied with axial compression testing. The damage evolution law of coal gangue concrete during the compression process was dynamically analyzed by acoustic emission(AE) technology,and the damage degree of coal gangue concrete was qualitatively analyzed by AE signals and AE energy released from coal gangue concrete under loading damage. The damage evolution equation and the constitutive model were established. The results show that the shape of stress-strain curve of coal gangue concrete under axial compression is basically the same as that of the ordinary concrete,and with increasing coal gangue replacement rate, the peak stress decreases slightly. The AE parameter can effectively describe the evolution law of coal gangue concrete damage,and with increase of coal gangue replacement rate,the materials ductility declines. The damage constitutive model of coal gangue concrete under axial compression based on AE parameters is in good agreement with the experimental results. The research results can provide reliable basis for the theoretical research and engineering application of coal gangue concrete in the future.