| Paste filling is the effective way to solve coal buried under buildings,railways,and water bodies and control surface subsidence at present,which is also an important technical measures to avoid environmental pollution.Otherwise,this technology could manage the environmental pollution because of the Wind-blown sand and fly ash from source,realizes the rational utilization of paste waste,changes the current situation of the administration after the contamination,and promotes the development of technology from exploration to environmental management.The property of filling materials is the key of paste filling technology,and decides the effect of the filling.There into the content of fly ash.cement,fine fraction of Wind-blown sand and concentration of paste are the important factor.This thesis studies the factor of influencing the property of filling paste through mineral component analysis,operational characteristics experiment and so on.The property of paste filling is studied on the basis of the technological process of paste filling and control theory of overlying rock.There are two aspect to the paste.First,the paste must have better liquidity.Plasticity and stability.Second,the filling paste must have suitable early strength and long-term strength to insure the supporting role under the goaf.This thesis measure th,e index of paste property through slump,slump flow,bleeding rate and compressive strength.At last,the best mixture proportion is chosed.The thesis studies the slump,slump flow and bleeding rate experiment in the differ,ent of fly ash content,cement content,fine particle Wind-blown sand and concentration.The result show that the slump,slump flow,and bleeding rate reduced with the increase of fly ash,cement and concentration.But slump and slump flow increased at first and reduced at later,the bleeding rate reduced with the increased of fine particle Wind-blown sand.The thesis studied the different age compressive strength of paste in the different of fly ash content,cement content,fine particle Wind-blown sand and concentration.The result show that the content of fly ash has no on the early strength,the concentration has significant impact,the cement is the second andthe last is fine particleWind-blown sand.The concentration has significant impact on the seven days compressive strength,others has no significant effect.The content of fly ash has significant impact on the long-term strength,the second is cement,the third is fine particle Wind-blown sand,the last is concentration.The content of fly ash has significant impact on the long-term strength,the concentration has significant impact on the early strength,and the fine particle Wind-blown sand has long influence to the strength,The microscopic images of the paste materials under different age conditions were obtained by scanning electron microscopy.The microscopic changes of the paste materials at different ages were discussed.The microscopic changes of the paste materials under different age conditions were qualitatively analyzed.The microscopic changes of different proportions of paste materials under different age conditions were quantitatively analyzed. |
