In this study,coal gangue is crushed and ground to prepare ultra fine powder.The effects of different dosages of coal gangue-based ultra fine powder on the slump,compressive-flexural strength,freeze-thaw resis-tance,and permeability of C50 concrete are investigated.Additionally,the mechanisms by which coal gangue-based ultra fine powder affects concrete are explored using methods such as heat of hydration and X-ray dif-fraction.The results indicate that coal gangue-based ultra fine powder reduces the slump of concrete,deterio-rating its workability.As the dosage of ultra fine powder increases,the mechanical strength and durability of the concrete exhibit a trend of first increasing and then decreasing,with an optimal dosage of 8%.Furthermore,ultra fine powder does not affect the types of hydration products but significantly enhances the hydration rate,accelerates the hydration process,refines the pore structure,densifies the matrix,and improves the freeze-thaw resistance and impermeability of the concrete.This research provides a new reference approach for the green and large-scale utilization of coal gangue.
关键词
煤矸石/超细粉/工作性能/力学性能/耐久性能/水化放热
Key words
coal gangue/ultra fine powder/workability/mechanical property/durability/heat of hydration
维普
万方数据