【作者】 程建坤；

【导师】 潘志华；

【作者基本信息】 南京工业大学 ， 材料学， 2005， 硕士

【摘要】 本论文在无碱液态的前提下，通过试验探讨了几种无机盐单独或复合添加和聚合硫酸铝对水泥凝结性能的影响规律。根据试验结果的分析选取了无碱液态速凝剂的基础成分。在此基础上进行了无碱液态速凝剂稳定性和性能、添加速凝剂水泥硬化浆体的微观结构和速凝机理的探讨。 无机盐类速凝剂配合比探讨的分析表明，硫酸铝和硝酸铝单独或复合添加均对水泥有很好的速凝效果，但由于硫酸铝和硝酸铝溶解度的限制，配制的饱和溶液固含量低，所以满足凝结时间要求的水溶液掺量较大，故它们不适宜配制液态速凝剂。与无机盐的饱和溶液比较，聚合硫酸铝的固含量高，速凝效果更好。聚合硫酸铝制备的最佳配合比为硫酸铝：氢氧化铝胶体=1.71：1.26。 初步的试验说明聚合硫酸铝是一个极不稳定的系统。对聚合硫酸铝稳定性的研究表明，采用乳酸和三乙醇胺复合作为稳定剂，可以制得稳定时间在150天以上的聚合硫酸铝。当配合比为硫酸铝：氢氧化铝胶体=1.71：1.26、三乙醇胺和乳酸的掺量分别为3％和7％、硫酸铝浓度为27.3％、聚合温度为99℃和保温时间为30min时，制得的聚合硫酸铝外观透明，稳定时间大于150天，固含量为35.7％，密度为1.47g／ml。当聚合硫酸铝固掺量为水泥质量的2.97％时，水泥的初凝时间为3.0min，终凝时间为6.5min。将采用上述参数制得的聚合硫酸铝冠名为NSA无碱液态速凝剂，简称NSA速凝剂。 对NSA速凝剂性能的研究表明，NSA速凝剂速凝效果好，对水泥品种的适应性较好。其最大的优点是克服了碱性粉状速凝剂所导致的混凝土28天抗压强度严重损失的缺陷，不仅早期强度高，而且28天抗压强度不损失，甚至有一定的增加。当掺量为9％时，山东铝业水泥1天抗压强度比不掺时增加80％，达到10.89MPa，7天抗压强度比不掺时增加15％，28天的抗压强度比为104.2％；中国水泥厂水泥1天抗压强度比不掺时增加23％，达到14.84MPa，7天抗压强度比不掺时增加19％，28天的抗压强度比为99.8％。NSA速凝剂对水泥硬化体体积变化的影响的试验结果表明，掺NSA速凝剂后水泥砂浆和净浆均表现为收缩，收缩率随NSA速凝剂的掺量的增加而增大。 采用XRD、SEM和MIP现代分析手段对添加NSA速凝剂水泥硬化体微观更多还原

【Abstract】 The effect of some kinds of inorganic salts and polymerized aluminum sulfate on the setting behavior of ordinary Portland cement was discussed in laboratory under the prerequisite of alkali-free and liquid. The basic composition of liquid state alkali-free setting accelerator was elected according to results of the tests. The stability and property of liquid state alkali-free accelerator were investigated, along with microstructure of hardened cement pastes and setting-accelerating mechanism of liquid state alkali-free accelerator.Test results on preparation of Inorganic salts setting accelerator showed that the ordinary Portland cement was obviously accelerate either aluminum sulfate or aluminum nitrate was added into individually, or introduced simultaneously. But solubility of aluminum sulfate and aluminum nitrate is so less that their solution addition is too much meeting require of the setting property. Then they are not used as liquid state alkali-free setting accelerator. Polymerized aluminum sulfate has got better rapid setting effect than inorganic salts. Compared with inorganic salts saturated solution, solid content of polymerized aluminum is still high. The best preparation of polymerized aluminum sulfate is aluminum sulfate: aluminum hydroxide colloid =1.71: 1.26.Polymerized aluminum sulfate isn’t steady. Test results on polymerized aluminum sulfate stability proved that polymerized aluminum sulfate could be made whose stabilization time is up to over 150d when triethanolamine and lactic acid was added into simultaneously. When preparation of polymerized aluminum sulfate is aluminum sulfate : aluminum hydroxide colloid =1.71 : 1.26, addition of triethanolamine and lactic acid is 3% and 7% respectively, aluminum sulfate concentration is 27.3%, poly-reaction temperature is 99°C, and reaction holding time is 30min, resultant polymerized aluminum is transparent whose stabilization time is over 150d, and solid content of polymerized aluminum is up to over 35.7%, and density of polymerized aluminum is 1.47g/ml. When solid addition of polymerized更多还原