碱矿渣粉煤灰混凝土的冲击损伤特性

Impact Damage Characteristics of Alkali Activated Slag and Fly Ash Based Concrete

关键词:  碱矿渣粉煤灰基混凝土  损伤特性  冲击劈裂拉伸试验  冲击压缩试验  分离式霍普金森压杆

Key words:  alkali activated slag and fly ash based concrete(ASFC)  damage characteristics  dynamic splitting tensile test  dynamic compression test  split Hopkinson pressure bar(SHPB)

摘要:

以NaOH，Na2CO3为碱激发剂，制备了强度等级为C30的碱矿渣粉煤灰基混凝土（ASFC），运用改进后的100分离式霍普金森压杆（SHPB）试验装置开展了冲击劈裂拉伸和压缩试验，从能量角度分析了ASFC在冲击荷载下的损伤特性，并进行了对比研究.结果表明:ASFC的破坏形态均随着入射能量平均变化率的增加而趋于严重，ASFC的能量吸收量也随入射能量平均变化率的增大而增加，但增加速率逐渐变缓，总体规律可用二次多项式关系来表示；ASFC在冲击压缩状态下的破坏状况明显比冲击劈裂拉伸状态下严重，而且能量吸收量和增加速率均远大于冲击劈裂拉伸状态；ASFC的抗冲击损伤能力随着冲击力度的增大而增加，且与冲击作用形式有关，在压缩状态下的抗冲击损伤能力比劈裂拉伸状态更为优异.

Abstract:

High flowing C30 alkali activated slag and fly ash based concrete(ASFC) was prepared in which slag and fly ash were activated by NaOH(NH) and Na2CO3(NC). Dynamic splitting tensile and compression tests were made by the 100 split Hopkinson pressure bar(SHPB) apparatus improved by using the pulse shaper technique, and damage characteristics of ASFC under impact loading were measured. In addition, a comparative study was made. The results indicate that, fracture morphology of ASFC tends to be serious and energy absorbing capacity of ASFC increases with the increasing of incident energy average rate, however, increase rate gradually become slow, and general rule can be expressed by quadratic polynomial curve; fracture state of ASFC under the condition of impact compression is more significant than that under the condition of impact splitting tension, and energy absorbing capacity and increase rate under the condition of impact compression are greater than that under condition of impact splitting tension. Thus it can be seen that damage resistance of impact increase with increasing of impact strength; compared with the condition of impact splitting tension, damage resistance of impact of ASFC is better.