C-S-H-PCE协同Al_(2)(SO_(4))_(3)对锂渣复合水泥水化性能影响

Synergistic Effect of C-S-H-PCE and Al_(2)(SO_(4))_(3) on the Hydration Properties of Lithium Slag-Cement Composite Binder

为了提升锂渣复合水泥浆体早期强度发展,研究了水化硅酸钙晶核与聚羧酸减水剂复合物(C-S-H-PCE)及Al_(2)(SO_(4))_(3)对锂渣复合水泥水化性能的协同效应。结果表明,C-S-H-PCE与Al_(2)(SO_(4))_(3)协同促进锂渣复合水泥浆体凝结硬化。2%C-S-H-PCE复配6%Al_(2)(SO_(4))_(3)使得复合水泥初凝时间和终凝时间分别缩短71.2%和68.1%,复合水泥砂浆1 d、3 d和28 d抗压强度分别增长37.6%,33.1%和9.9%。C-S-H-PCE通过提供成核位点促进硅酸盐矿物早期水化及锂渣后期火山灰反应,使得水化诱导期缩短,水化第二放热峰逐渐前移,水化放热总量和CH生成量增加。Al_(2)(SO_(4))_(3)溶解出Al3+促进钙矾石(AFt)生成,且可促进锂渣矿物相溶解并参与火山灰反应,使得硬化体系密实性提高。

In order to improve the early strength development of lithium slag(LS)composite binder,synergistic effect of synthetic calcium silicate hydrates(C-S-H)/polycarboxylate water-reducer(PCE)and Al_(2)(SO_(4))_(3) on the hydration properties of lithium slag-cement composite binder was investigated.The results showed that C-S-H-PCE and Al_(2)(SO_(4))_(3) synergistically promoted the solidification and hardening of lithium slag composite binder.The combination of 2%C-S-H-PCE and 6%Al_(2)(SO_(4))_(3) reduced the initial setting time and final setting time by 71.2%and 68.1%,respectively,and the compressive strength of the composite cement mortar at 1 d,3 d and 28 d increased by 37.6%,33.1%and 9.9%,respectively.By providing nucleation sites,C-S-H-PCE promoted the early hydration of silicates and the pozzolanic reaction of lithium slag,leading to shortened induction period,advanced heat release peak,increased total hydration heat release and production of CH.Al_(2)(SO_(4))_(3) dissolved Al3+to promote ettringite(AFt)formation,and promoted the dissolution of LS mineral phase and participates in the reaction of pozzolanic reaction,which generated the compactness of the hardened binder.