The Study of the Phosphorus Slag Used as Premixed Pumping Concrete Admixture

摘要

The physical and chemical properties of the phosphorus slag are similar to slag, but some compositions of the phosphorus slag and their fluctuations retards the cement setting time and its activity, which limits the application of phosphorus slag in concrete. In this paper, major chemical components of phosphorus slag were analyzed by chemical analysis method, and the content of vitreous body was studied by X-ray diffraction. The retard setting time and its influence factors were analyzed by associating with initial and final setting time with normal consistency water consumption while 50% cement be replaced by phosphorus slag, The activity and its influence factors were studied by associating with standard mortar strength while 30% cement be replaced by phosphorus slag. Additive for premixed pumping concrete with 10-20% cement be replaced by phosphorus slag, were prepared from water reducer, air-entraining agent and water retention agent. The mechanism of hydration and hardening were studied by differential thermal analysis and scanning electron microscope. C30 premixed pumping concrete with 10-20% cement replaced by phosphorus slag, had great workability, the compression strength after hardened for one day reached lOMPa and was better than S75 slag after 28days. The results indicated that, take the advantage of the activity and the retarding effect, premixed pumping concrete with 10-20% cement could be replaced by phosphorus slag, retention agent could be reduced as well.