低温环境下碳酸锂对硫铝酸盐水泥水化和性能的影响

Effects of Li2CO3 on the hydration and properties of sulphoaluminate cement at low temperature environment

主要研究了在0、4、8、12℃养护温度下碳酸锂对硫铝酸盐水泥水化和性能的影响。结果表明,低温养护环境下,掺入少量的碳酸锂可以明显缩短硫铝酸盐水泥的凝结时间,当碳酸锂掺量大于0.10%时,硫铝酸盐水泥凝结时间基本上不再变化,0、4、8、12℃养护环境下,掺0.10%碳酸锂的硫铝酸盐水泥初、终凝时间分别为90、150min,57、74min,43、57min,23、38min。碳酸锂可以促进硫铝酸盐水泥中硫铝酸钙矿物在低温下的早期水化,从而提高低温养护下硫铝酸盐水泥净浆的12h、1d和3d抗压强度,但对硫铝酸钙28d的水化程度无影响,而且当碳酸锂掺量较高时,低温下养护的硫铝酸盐水泥净浆7d和28d抗压强度会降低。

In this paper,the effects of Li2CO3 on the hydration and properties of sulphoaluminate cement(CSA)at four curing temperatures(0,4,8,12℃)were investigated.Under low temperature curing environment,a small amount of Li2CO3 can significantly shorten the setting time of CSA.When the amount of Li2CO3 is more than 0.10%,the condensing time of CSA will not change basically.The initial setting time and final setting time of CSA doped with 0.10%Li2CO3 were 90 min and 150 min,57 min and 74 min,43 min and 57 min,23 min and 38 min,respectively,in a curing environment of 0,4,8,12℃.Li2CO3 can promote the early hydration of calcium sulphoaluminate in CSA at low temperature,thus improving the compressive strength of CSA slurry at low temperature for 12 h,1 d and 3 d,but it has no effect on the degree of hydration for calcium sulphoaluminate at 28 d.When the dosage of Li2CO3 is high,the 7 d and 28 d compressive strength of CSA paste cured at low temperature lowers down.