纳米C—S—H/PCE对硅酸盐硫铝酸盐复合水泥凝结硬化的影响

胡建伟　谢永江　刘子科　郑新国　曾志　王月华　翁智财　蒋睿

摘 要：研究了纳米C—S—H/PCE对硅酸盐硫铝酸盐复合水泥凝结时间、早期水化历程及抗压强度的影响，采用XRD、TG、pH计和SEM等分析测试手段对早龄期水化产物和液相碱度等进行表征，探讨了纳米C—S—H/PCE对硅酸盐硫铝酸盐复合水泥的增强机理。结果表明：掺加纳米C—S—H/PCE能有效缩短硅酸盐硫铝酸盐复合水泥浆体初凝及终凝时间，当C—S—H掺量≥1.0%时，硅酸盐硫铝酸盐复合水泥的初、终凝时间差明显缩短。纳米C—S—H/PCE加快了硅酸盐硫铝酸盐复合水泥水化放热速率，提高了总的水化放热量，早期水化产物生成数量多，但对水泥水化产物类型没有影响，硅酸盐硫铝酸盐复合水泥体系8、12、16 h的抗压强度显著提高。

关键词：硅酸盐水泥;硫铝酸盐水泥;水化硅酸钙凝胶;凝结硬化;水化反应

中图分类号：TU528.04   文献标志码：A   文章编号：2096-6717（2021）02-0138-10

Abstract： The effects of nano-C—S—H/PCE on the setting time， early hydration and compressive strength of Portland-Sulphoaluminate composite cement were studied. XRD， TG， pH meter and SEM were used to characterize the early hydration products and liquid alkalinity. The enhancement mechanism of nano-C—S—H/PCE on Portland-Sulphoaluminate composite cement was studied. The results showed that the addition of nano-C—S—H/PCE could effectively shorten both the initial setting time and final setting time of fresh composite cement paste. When the C—S—H content was more than 1.0%， the initial time difference of the composite cement was obviously shortened. The nano-C—S—H/PCE accelerated the hydration heat releasing rate of the composite cement， and increased the total hydration heat. The early-age hydration products were increased obviously， however， it had no effect on the type of cement hydration products. The compressive strength of the composite cement mortars at 8 h， 12 h and 16 h were significantly increased.

Keywords： portland cement; sulphoaluminate cement; calcium silicate hydrated gel; setting and hardening; hydration reaction

随着纳米技术的飞速发展，纳米材料因其颗粒尺寸细小，比表面积巨大等特点，已经在电子、陶瓷、涂料、催化和医药等领域有着广泛的应用[1-5]。基于此，越来越多的研究者开展关于纳米材料对硅酸盐水泥水化性能影响的研究[6-10]。研究表明，在硅酸盐水泥中掺加纳米材料能够显著加速水泥水化，提高硬化水泥浆体的强度，尤其是对早期强度提升效果明显。Liu等[6]研究了纳米SiO2在大掺量粉煤灰蒸养混凝土中抗压强度的发展规律，发现掺加4%的纳米SiO2混凝土9 h抗压强度提高了206%。Meng等[8]开展了纳米CaCO3在水泥稳定土中的研究，发现掺加3%的纳米CaCO3后30 d强度提高了14.2%。……