活化煤矸石掺量对水泥胶砂性能的影响OA

In order to explore the effect of activated coal gangue on the physical and mechanical properties of cement mortar,the activated coal gangue of a mine in Pingdingshan City,Henan Province was used as raw material to investi-gate the effect of its content on the basic physical properties,mechanical properties,drying shrinkage and softening co-efficient of cement mortar.The results show that the standard consistency of cement mortar increases slightly with the increase of activated coal gangue content(0-40％).The initial setting time was shortened by 79 min,and the final setting time was shortened by 75 min.The strength of the sample shows the change rule of'drop-rise-drop',and the comprehensive performance is relatively better when the content is 30％.The flexural strength of 28 d is 7.532 MPa,and the compressive strength is 47.6 MPa,which reaches 94.2％and 96.0％of the reference group,respectively.When the content of activated coal gangue is 10％,the 28 d drying shrinkage rate of the sample increases from 196×10-6 to 890×10-6,and then the growth rate slows down with the increase of coal gangue content.The improvement of activated coal gangue on the performance of cement mortar is mainly achieved through physical and chemical synergy:coal gangue particles as micro-aggregates fill the pores of cement mortar matrix,effectively optimi-zing the particle gradation of raw materials;after mechanical-chemical activation treatment,the active SiO2 and Al2O3 in coal gangue are more likely to react with the cement hydration product Ca(OH)2,which promotes the continuous formation of C-S-H and C-A-H gels,making the structure of hydration products more compact.