尾矿微粉掺量对红黏土无侧限抗压强度的影响

The Influence of the Tailings Powder Content on the Uniaxial Compressive Strength of Red Clay

为探讨铅锌尾矿微粉掺量对红黏土无侧限抗压强度的影响规律,对取样后的福建坡积红黏土进行振动筛筛分,保留0.63~1.25、0.315~0.63、0.16~0.315 mm和小于0.16 mm的颗粒,分别掺加土样质量15%、18%、21%和24%的微粉和水泥,以及微粉质量5%的氢氧化钠,试验研究尾矿微粉及其碱激发胶凝材料掺量对红黏土无侧限抗压强度的影响规律。结果表明:(1)42.5标号水泥加固红黏土试验的无侧限抗压强度最高,比对照土样的增加4~6倍,其中18%的42.5标号水泥掺量为较佳比例;(2)在铅锌尾矿微粉中掺加适量的氢氧化钠等激发剂,能有效激发尾矿微粉的活性,生成地聚物加固红黏土;(3)仅烘干和磨细的尾矿微粉、尾矿微粉M10抹灰砂浆、掺加活化剂和5%氢氧化钠的尾矿微粉,对红黏土体试件的加固效果一般。以上结论可为类似研究及工程应用提供参考借鉴。

In order to explore the influence of the amount of micro powder in lead-zinc tailing on the uniaxial compressive strength of red clay, one of Fujian slope red clay was sam pled and screened by vibrating screen, and particles of0.63-1.25, 0.315-0.63, 0.16-0.315 mm and less than 0.16mm were retained. 15%, 18%, 21% and 24% soil samples mass ratio tailing powder or cement and 5% tailing powder mass ratio solid sodium hydroxide were added respectively, The effect of tailing powder and its alkali activated cementitious material content on the uniaxial compressive strength of red clay was studied. The results show that:(1) The unconfined compressive strength of 42.5 cement reinforced red clay is the highest,which is 4-6 times higher than that of the comparison soil sample, of which 18% mass ration of 42.5 cement is the best proportion;(2) Adding an appropriate amount of activator such as sodium hydroxide into the lead-zinc tailing micro powder can effectively stimulate the activity of tailing micro powder and form geopolymer to strengthen red clay;(3) Only dried and ground tailing powder, tailing powder M10 plastering mortar, tailing powder mixed with activator and 5% sodium hydroxide have average reinforcement effect on red clay samples. The above conclusions can provide reference for similar research and engineering application.