基于分形维数的饱水地质聚合物混凝土冲击毁伤效应评估

Impact Damage Assessment of GC in Water Environment Based on Fractal Dimension

利用霍普金森压杆系统对饱水环境下的地聚物混凝土(GC)进行了冲击试验,在筛分试验的基础上利用分形维数对GC的冲击毁伤效应进行了评估。结果表明:地聚物混凝土干燥试件(DGC)及饱水试件(WGC)的冲击破碎产物是一种统计意义上的分形;在饱水环境下,由于试件内部水分产生的粘阻效应,WGC在相同破坏程度时承受的冲击速率更大、冲压强度更高、吸能效果也越好。GC材料的冲击压缩强度、冲击韧度与分形维数间均具有一定的正相关性,利用冲击破碎分维能较好的对建筑在冲击作用下的毁伤效应进行有效评估。

A split Hopkinson pressure bar(SHPB)apparatus was adopted to investigate the behaviour of geopolymer concrete(GC)in water environment.And the damage effect was assessed based on fractal dimension through analysis of broken concrete.The results indicate that the fragment-size distribution of GC fragments statistically has fractal property subjected to impact loading both in water and dry environment.In water environment,WGC perform higher strain rate,impact strength and better property of energy absorption at same damage degree due to crack stopping effect of water.At the same time,there existed close connection between fractal dimension and the behaviour of GC under impact loading,which can be used to assess the damage effect effectively.