Sprayed Concrete Under The Shock Load Of Dynamic Mechanical Properties

In underground rock or excavation blasting engineering(including mine engineering,tunnel engineering,civil air defense engineering cavern,the size of the underground space engineering,etc.),the blasting vibration effect affects the stability of surrounding rock and supporting structure.Study injection coagulation layer response to blasting dynamic effect and dynamic mechanical properties of its own,to reduce the influence of blasting vibration,improve the integrity and stability of the sprayed concrete structure and carrying capacity is important.In view of the present research,the study is mainly statical and less dynamic.Therefore,it is necessary to study the mechanical properties of shotcrete.Paper using split hopkinson pressure bar(SHPB)system,the different ratio of hardener,different age,different impact speed of sprayed concrete dynamic mechanics performance.Under the effect of shock load,the stress strain curve of the four kinds of accelerator is different.At the time of the day,the peak of the curve is quite high,and the peak part is more perturbation.Then,as the age of age increased,the amount of the accelerator was inversely proportional to the peak stress,and the peak partial perturbation decreased.The curve presents two elastic changes during the period of 7 days and 14 days.The early low-pressure pre-shock of the shotcrete was similar to the viscoelastic phase of the day and three days,and the intensity of the 28 days increased.The later strength of the spray concrete in the period of 2%was obviously increased.The prediction of the velocity of the jet concrete is indicated by the prediction of the pre-shock of different ages,and the velocity of the wave velocity of the jet concrete is significantly lower than that of the first and third days.The impact of the concrete wave velocity after three days of age is small;On the whole,the later the impact age is,the smaller influence of the concrete wave velocity will have...