胶结剂性质对全尾砂胶结充填材料抗压强度的影响

Influence of the Properties of Binders on Unconfined Compressive Strength of Total Tailings Cemented Backfill Material

针对胶凝材料性质对全尾砂胶结充填材料抗压强度的影响进行了试验研究,采用压汞测孔仪(AutoporeⅣ9500)测定了固化体的总孔隙率和孔径分布。试验结果表明:当料浆固体浓度分别为70%、78%和86%并且胶凝材料掺量10%(以总固体质量计)时,掺矿渣水泥比掺水泥的固化体抗压强度分别提高了151%、127%和90%;当料浆固体浓度为86%并且胶凝材料掺量5%、养护龄期分别为7、14和28 d时,掺矿渣水泥比掺水泥的固化体抗压强度分别提高了68%、97%和141%;当料浆固体浓度为86%并且胶凝材料掺量分别为5%、10%、20%、30%和40%时,掺矿渣水泥比掺水泥的28 d固化体抗压强度分别提高了127%、89%、10%、-12%和-21%。结合压汞测孔数据和固化体抗压强度结果,得出结论:在高水胶比材料(即水胶比大于0.65)中,掺矿渣水泥比掺水泥的固化体中孔径更细(即水化产物更多或更分散),导致固化体中骨料(包括填料)的黏结面积增加而增加固化体抗压强度;在低水胶比材料中,掺矿渣水泥比掺水泥的固化体中总孔隙率大幅度增加,导致固化体中骨料的黏结强度降低而降低固化体抗压强度。

Influence of the properties of binders on unconfined compressive strength （UCS） of total tailings cemented backfill （TTCB） was investigated. The total porosity and pore size distribution of the samples were measured by using a mercury intrusion porosimeter （Autopore IV9500） （MIP）. The results showed that when the solid concentration of TFCB slurry was re- spectively 70% ,78% and 86% with the binder content of 10% （by total mass of solid） , the UCS of samples with slag cement was respectively 151%, 127 % and 90% higher than that of samples with 100% portland cement. When the solid concentration of TTCB slurry was 86% and the binder content was 5% , the 7 d, 14 d ,28 d UCS of samples with slag cement were respective- ly 68% ,97% and 141% higher than that of samples with 100% portland cement. When the solid concentration of TTCB slurry was 86% and the binder content was respectively 5% ,10% ,20% ,30% and 40% ,the 28 d UCS of samples with slag cement was respectively 127% ,89% ,10% , - 12% and -21% higher than that of samples with 100% portland cement. Based on MIP data and UCS results ,the conclusion was that under the condition of high water-binder ratio（ w（ W）/w（ B ） 〉 0.65 ）, the pore size of the sample with slag cement was finer（ i. e. hydration product was more or more dispersing） than that of the sample with 100% portland cement so that the increasing bonding area among aggregates （including powder fill） with slag cement in- creases the UCS of the sample. Under the condition of low water-binder ratio, the total porosity of the sample with slag cement was greatly higher than that of the sample with 100% portland cement so that the decreasing bonding strength of aggregates （including powder fill） in sample with slag cement lowers the 28 d UCS.