低温环境下碳酸锂对硫铝酸盐水泥水化和性能的影响

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。

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

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.