锌盐对水泥水化历程的影响

通过研究ZnCl2，ZnSO4对水泥凝结时间、水化热、电阻率及抗压强度的影响，探讨了锌盐对水泥水化历程的影响及其缓凝机理．结果表明：随着ZnCl2掺量的增加，水泥水化放热速率降低，水泥水化与硬化延缓，电阻率发展变慢，水泥早期强度明显降低，但对28d抗压强度影响较小；当ZnSO4掺量为0．10％时，水泥终凝时间约提前50min，当掺量大于0．10％时，水泥水化放热速率降低，电阻率发展变慢，水泥水化历程延缓，但不影响抗压强度的发展；同掺量下，ZnCl2延缓水化的作用大于ZnSO4；锌盐对水泥水化历程的影响规律不仅与其掺量有关，还与其所含阴离子有关。

Influence of Zinc Salts on Cement Hydration Process

In this paper the effects of ZnCl_2 and ZnSO_4 on setting time, heat of hydration, resistivity and compressive strength of cement were studied. Results show that with increasing amount of ZnCl_2, the hydration exothermic rate is lowered, hydration and hardening of cement is delayed, the resistivity development and the early strength are reduced, effect on 28 d compressive strength is slight. Moreover, with respect to ZnSO_4, when use level is 0.10%, cement final set was accelarated by 50 min. When use level is more than 0.10%, the hydration exothermic rate was lowered. And the resistivity is developed slowly. The cement hydration process is delayed. But strengths are not influenced. The retarding effect of ZnCl_2 is larger than that of ZnSO_4 with the same use level. The effect of zinc salts on cement hydration process not only has something to do with the mass of Zn~(2+), but also with their negative ion.