毒重石作水泥混合材的研究

结合毒重石质量优、易加工、生产成本低及吸收X射线、γ射线等特点，制备了以普通硅酸盐水泥熟料为主要原料，毒重石作水泥混合材，辅以适量石膏的水硬性胶凝材料。考察了毒重石掺量对水泥标准稠度用水量、凝结时间、安定性、不同龄期机械强度以及辐射屏蔽能力的影响。结果表明：毒重石对普通硅酸盐水泥熟料具有一定的缓凝作用；毒重石本身参与水化的能力很差，在水泥中基本上是作为非活性掺和材料，主要起填料的作用；毒重石水泥具有一定的辐射屏蔽能力，且随着毒重石掺量的增加，水泥的屏蔽效果增强。

Study on witherite as admixture of cement

Combining witherite′s characteristics，such as high quality，easy-processing，low production cost，absorbing X ray and γ ray etc.，hydraulic cementing material was prepared by using ordinary portland cement clinker as main material， witherite as admixture，and proper amount of gypsum as excipients.Influences of different witherite doping contents on water requirement of normal consistency，setting time，soundness，mechanical strength，and radiation shield performance of the cement were investigated.Results showed that witherite had some retarding effect on the Portland cement clinker.However，the ability of witherite to participate in hydration of cement clinker was so poor that it was basically being an inactive admixture and played a role of filler in cement.Cement based materials with witherite as admixture had certain radiation shield ability， and the radiation shielding effect was more apparent as the content of witherite increased.