Experimental Study of Using Industrial by-Products Gypsum as Cement Retarder

The present thesis conducts experiment that uses three industrial by-products gypsum,including citric acid slag,titanium gypsum and flue gas desulfurization gypsum,as cement retarder and examines the cement physical and mechanical performance after mixing with the three cement retarders when the admixing quantity of SO3 is from 2% to 3%,then the author compares it with that of cement mixed with natural gypsum.The experiment shows that the physical performance indexes of cement when mixed with industrial by-products gypsum meet the corresponding national standards;cement mixed with citric acid slag needs increased water,but its setting time is suitable and of high strength in early and late stage;physical performance of cement mixed with flue gas desulfurization gypsum is similar to that of cement mixed with natural gypsum.And the delayed coagulation of titanium gypsum is slightly less effusive.