冻融后煤矸石混凝土受压损伤声发射特性

摘要

为了研究冻融循环作用后煤矸石混凝土的受压损伤特性,基于声发射技术,对冻融循环作用0,25,35,45次后的煤矸石混凝土进行单轴抗压试验,对煤矸石混凝土受压破坏全过程中的损伤特性进行动态分析;依据冻融循环后煤矸石混凝土受压破坏过程中所释放的声发射能量,对其内部损伤程度进行定性分析,并依据声发射事件累计计数建立了煤矸石混凝土损伤演化模型.研究表明:随着冻融循环次数的增加,煤矸石混凝土的初始损伤程度增大,峰值应力减小,脆性表现明显;依据声发射事件累计计数建立的损伤演化模型与试验结果符合较好,为研究冻融环境下的煤矸石混凝土损伤演化规律提供了参考.%Based on the acoustic emission technology of coal gangue concrete under freeze-thaw cycles of 0,25,35,45 times,the compression damage characteristics of coal gangue concrete during the whole failure process were measured.Related to the acoustic emission energy released from the failure of coal gangue concrete,the damage evolution rule of coal gangue concrete was established according to the cumulative counting of acoustic emission events.The results show that with the increase of the number of freeze-thaw cycles,the initial damage value of coal gangue concrete becomes larger,the peak stress becomes smaller,the brittleness turns more obvious.The damage evolution model based on the cumulative counting of acoustic emission events is in good agreement with the experimental results,which provides the basis for studying the damage evolution rule of coal gangue concrete under freeze-thaw environment.