低氯低碱新型混凝土早强剂的研究

A New Type of Concrete Accelerator with Low Contents of Chloride and Alkali

针对现行氯化物系和硫酸盐系早强剂存在的缺陷,利用晶种、高价阳离子硫酸盐和羟基羧酸为组分制成一种新型早强剂。它可以显著提高混凝土的早期强度,降低其坍损和泌水,以及减少其收缩。此外,新型早强剂对水泥的适应性强,在低温下具有良好的早强效果,其混凝土的抗渗、抗冻性能高,耐久性好,Cl-和Na+含量低,无钢筋锈蚀和碱-骨料反应的潜在危害。工程应用表明,这种早强剂具有很好的市场开发前景。

Aimed at the shortcomings and the applied limitation of the existing accelerators of concrete, a new type of accelerator has been developed. It is composed of the crystal seed, the high valence cation sulfate and hydroxycarboxylic. When the new accelerator is added into concrete, it will increase the early strength of concrete, reduce the slump-loss and bleeding, and decrease the shrinkage. The new accelerator has a good compatibility with cement. The effect of early strengthen is obvious at low temperature. The concrete frost-resistance and impermeability are improved, and the durability becomes better. The new acceleratar has the low contents of Cl^- and Na^＋, so it can＇t cause the latent endangerment of steel corrosion and of alkali-aggregate reaction. The results of practical engineering application show that the new accelerator has a wide and broad market in future.