The Study Of Influencing Factors Of Paste Filling Performance

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 coal gangue 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、cemen、fine fraction of coal gangue 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、mechanical characteristics experiment and deformation 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 three 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. Third, the filling paste must have lower systolic rate. This thesis measure the index of paste property through slump、slump flow、bleeding rate、compressive strength of different instars cube specimens and paste shrinks of different instars cube specimens. At last, the best mixture proportion is chosed.The mineral compositions of coal gangue and fly ash are analyzed by XRD, the coal gangue is from Xinyang coal mine and the fly ash if from Fenxi mine. The coal gangue should be broken before matching because there are more particle that is more than300mm. the coal gangue belongs to sandstone and argillaceous. So, the property of coal gangue is stable and is suitable to be the coarse aggregate of paste materials. The fly ash contain lower calcium oxide, and have pozzolanic activity. The pozzolanic activity is played at the later stage.The thesis studies the slump、slump flow and bleeding rate experiment in the different of fly ash content、cement content、fine particle coal gangue 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 coal gangue.The thesis studied the different age compressive strength of paste in the different of fly ash content、cement content、fine particle coal gangue 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 and the last is fine particle coal gangue. 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 coal gangue, 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 coal gangue has long influence to the strength.The shrinkage of different age paste is studied in the different of fly ash content、cement content、fine particle coal gangue and concentration. The result show that the shrinkage is smallest when the fine particle coal gangue is40%; the more cement is used in the materials, the shrinkage is larger, the concentration is opposite. Otherwise, the fly ash has better inhibitory effect on the shrinkage.