利用福建某铅锌尾矿和矿渣粉制备高强混凝土试验

通过正交试验来探讨影响铅锌尾矿和矿渣粉制备高强混凝土的因素,并利用XRD、SEM来分析水化产物及微观形貌。试验结果表明:1当矿渣粉磨60 min(比表面积为625.6 m2/kg)、铅锌尾矿和矿渣粉以1∶1的质量比混磨60 min(比表面积为719.1 m2/kg)、石膏掺量为胶凝材料总量的2%时可以制备出28 d抗压强度达到93.75 MPa的高强混凝土;XRD图谱和SEM图片显示,混凝土试件的早期强度主要来源于钙钒石的形成,养护期间体系中C-S-H凝胶生成量的增加,以及C-S-H凝胶与钙钒石紧密穿插在一起是后期强度增长的主要来源。2石膏过量会使体系不断生成钙钒石,钙钒石表面的电性能会发生吸水肿胀现象导致体系破裂,从而使混凝土的抗压强度降低。

Preparation of High Strength Concrete Using Fujian Lead-zinc Tailings and Slag Powder

Influence factors of high strength concrete made from lead-zinc tailings and slag powder were discussed by orthogonal tests.Hydration products and their microstructure were analyzed by XRD and SEM.The results showed that:①high strength concrete with the compressive strength of 93.75 MPa at 28 d were prepared when the slag was milled for 60 min（the specific surface 625.6 m²/kg)，and the mass ratio of the lead-zinc tailings to slag is 1 to 1 milling for 60 min（the specific surface 719.1 m²/kg)，and the gypsum accounts for 2% of the cementitious materials.The XRD spectrum and the SEM photograph indicated that the early strength of the concrete is derived from the AFt and the C-S-H gel generated increasingly during the curing time.Meanwhile the AFt closely surrounded by C-S-H gel contributed to the main strength increasing in later stage.②AFt will be constantly generated in the system when the dosage of gypsum is excessive，AFt surface will burst owing to absorbing to much water，and then the compressive strength of concrete is decreased.