多次冲击荷载下玄武岩纤维高强混凝土孔隙结构及力学特性试验研究  

Experimental study on pore structure and mechanical properties of basalt fiber high strength concrete under multiple impact loads

作　　者：谢亮 XIE Liang(ZCCC Road and Bridge Construction Co.,Ltd.,Hangzhou 310000,China)

机构地区：[1]浙江交工路桥建设有限公司,杭州310000

出　　处：《复合材料科学与工程》2023年第12期112-118,共7页Composites Science and Engineering

摘　　要：为探究玄武岩纤维高强混凝土在多次冲击荷载作用下的安全性,采用非金属超声波分析仪及核磁共振试验装置测量不同应变率及冲击次数下试件纵波波速及内部孔隙结构,利用直径为74 mm分离式霍普金森压杆装置对试件开展动态压缩试验,分析试件纵波波速、损伤因子、T_2图谱、孔隙结构及应力应变随冲击气压及冲击次数间的变化规律。试验结果表明:试件纵波波速随冲击次数增加而降低,损伤因子随冲击次数的增加而增大,两者间呈良好的二次线性正相关;试件T_2图谱主要呈三峰型,冲击次数的增大会使图谱向右偏移且峰值增加;冲击次数的增加使孔隙直径增大且孔隙数目增多,试件孔隙率增大,且后续冲击作用更有利于裂隙的扩展;试件内部微孔、中孔含量占试件总孔隙率的95%以上,冲击荷载作用使试件内部微孔、中孔占比减小,大孔、裂隙占比增加;多次冲击荷载作用会使试件峰值应力降低,应变量增大,冲击次数与峰值应力间呈良好的二次函数负相关。In order to explore the safety of basalt fiber high strength concrete under multiple impact loads,the longitudinal wave velocity and internal pore structure of the specimen under different strain rates and impact times are measured by non-metallic ultrasonic analyzer and nuclear magnetic resonance test device.The dynamic compression test of the specimen was carried out by using the separated Hopkinson compression bar device with a diameter of 74 mm.The changes of longitudinal wave velocity,damage factor,T2 spectrum,pore structure and stressstrain with impact pressure and impact times are analyzed.The test results show that the longitudinal wave velocity decreases with the increase of impact times,and the damage factor increases with the increase of impact times,and there is a good quadratic linear positive correlation between them.The T2 spectrum of the specimen is mainly three peak type,and the increase of impact times will shift the spectrum to the right and increase the peak value.With the increase of impact times,the pore diameter and the number of pores increase,the porosity of the specimen increases,and the subsequent impact is more conducive to the expansion of cracks.The contents of micropores and mesopores in the specimen account for more than 95%of the total porosity.The impact load reduces the proportion of micropores and mesopores in the specimen,and increases the proportion of macropores and cracks.Under the action of multiple impact loads,the peak stress of the specimen will be reduced and the stress variable will be increased.There is a good quadratic function negative correlation between the impact times and the peak stress.

关 键 词：多次冲击荷载 玄武岩纤维高强混凝土 纵波波速 损伤因子 孔隙结构 峰值应力 复合材料 

分 类 号：TB332[一般工业技术—材料科学与工程]