碳酸钠和铝酸盐水泥复合制备速凝剂的研究

Study on the preparation of flash setting admixture with sodium carbonate and calcium aluminate cement

为配制速凝、早强、28 d抗压强度比大且碱含量低的速凝剂,开展了碳酸钠和铝酸盐水泥复合对硅酸盐水泥性能的影响。结果表明,1%碳酸钠与3%铝酸盐水泥复合,可以将硅酸盐水泥的初、终凝时间分别控制在5、10 min以内,且1 d抗压强度达10MPa、28 d抗压强度比达90%。XRD、DTA-TG和SEM测试分析表明,碳酸钠和铝酸盐水泥复合,促进了硅酸盐水泥的早期水化,尤其是促进钙矾石的生成,从而使其早期硬化结构更加致密。

To prepare the flash setting admixture with characteristics of flash setting and early strength,greater ratio of 28 d compressive strength,and lower alkali content,etc. the influences of sodium carbonate and calcium aluminate cement on the performances of Portland cement were studied. The results show that the initial setting time and final setting time can be shortened to no more than 5 and 10 min when 1% sodium carbonate was compounded with 3% upto aluminate cement,1 d compressive strength reaches 10 MPa,and compressive strength ratio at 28 d reaches 90%. The results with the test of XRD,DTA-TG and SEM show that the combination of sodium carbonate and calcium aluminate cement can accelerate the early hydration of Portland cement,especially for the formation of ettringite,which makes the early harden structure more compact.