The Research On Preparation Of Binding Material And Concrete With Waste Sludge Yellow Gypsum

With industrial development, yellow gypsum production increased year by year. These little efficient use yellow gypsum require substantial land for the needs of large stowage, not only which occupy land, but pollute the environment. Their economic and efficient use, not only that will help for changing from spent to usable, environmental protection, land conservation, reducing the consumption of non-renewable resources, but can mitigate the enormous economic burden for enterprises and promote their health and sustainable development.This paper is designed to prepare the binding material and concrete by waste sludge yellow gypsum, cement, stone, sand and admixture. The performances of binding material are studied in the paper. The experimental results showed that it is absolutely feasible to prepare binding material by using cement, yellow gypsum and superplasticizer after drying and grinding of yellow gypsum. The cement micellae compressive and bending strength of adding yellow gypsum(10percent)can meet the standard requirements of P.O4.5, which means the binding material’s set time and soundness are qualified. To prepare C30concrete, whose impermeability meet the requirements of P12,the yellow gypsum(30percent),cement(70percent),CJ-1 superplasticizer (1.2to2.0percent)are mixed. Through XRD analysis of variant age micellae and concrete samples, the results indicate that the hydration products of composite using yellow gypsum and cement are main tobermorite, ettringite and dihydrate gypsum. To form compact hardened material, the tobermorite, ettringite and dihydrate gypsum bind mutually, then strength is produced.