摘要
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。
Influence factors of high strength concrete made from lead-zinc tailings and slag powder were discussed by or-thogonal 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 m^2/kg),and the mass ratio of the lead-zinc tailings to slag is 1 to 1 milling for 60 min(the specific sur-face 719. 1 m^2/kg),and the gypsum accounts for 2% of the cementitious materials. The XRD spectrum and the SEM photo-graph 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 ab-sorbing to much water,and then the compressive strength of concrete is decreased.
出处
《金属矿山》
CAS
北大核心
2015年第1期176-180,共5页
Metal Mine
关键词
铅锌尾矿
高强混凝土
正交试验
钙钒石
XRD
SEM
Lead-zinc tailings
High strength concrete
Orthogonal test
XRD
SEM
Ettringite