基于SHPB试验的高速铁路CRTSⅡ型CA砂浆动态性能

Dynamic mechanical properties of CRTS Ⅱ type CA mortar for high-speed railway based on SHPB test

采用分离式霍普金森压杆(Split Hopkinson Pressure Bar,SHPB)试验研究了高速铁路CRTS II型水泥乳化沥青砂浆(CA砂浆)的动态力学性能,并建立了CRTS II型CA砂浆的动态本构关系模型.结果表明:随着应变率的增大,CRTS II型CA砂浆峰值强度逐渐增加,但增加速率随应变率的增大而减小,当应变率从44.17增加至54.79 s-1和从54.79增加至108.47 s-1时,峰值强度分别增加了初始峰值强度的52.28%和7.5%,弹性模量随应变率的变化规律性较差;应变率越大,破坏时的贯通裂纹越多,碎裂程度越大;CRTS II型CA砂浆的比能量吸收随着应变率的增大而增大.所建立的动态本构模型拟合曲线与试验曲线具有较好的一致性.

Dynamic mechanical properties of CRTS Ⅱ type cement and asphalt mortar （CA mortar） for high-speed railway was studied by split Hopkinson pressure bar （SHPB）, and the corresponding dynamic constitutive model was established in present paper. The experimental results show that the peak strength of CA mortar increases gradually with the increasing of strain-rate. However, the increasing rate of peak strength of CA mortar deceases with the further increasing of strain-rate. The increasing rate of peak strength is 52.28% for the strain-rate ranging from 44.17 s-1 to 54.79 s-1 and 7.5% for the strain-rate from 54.79 s-1 up to 108.47 s-1, respectively. The dynamic Young＇s modulus of CA mortar increases by 3-25 times of initial value in this investigated strain-rate. The larger the strain rate is, the more serious the cracking is when CA mortar specimen damaged. The specific energy absorption of CA mortar increases with the increase of strain rate. The fitting curves of the established dynamic constitutive model agree well the experimental curves.