【摘要】 通过对水泥胶砂试件限制膨胀率的测试，研究两种废渣在复掺不同石膏种类、不同复掺比下，水泥胶砂试件膨胀率的变化规律，同步研究锂渣-粉煤灰-磷石膏做膨胀剂的最佳配比，采用SEM分析其在水泥水化浆体中的微观形貌。结果表明：锂渣复掺石膏后能显著改善水泥胶凝体系的膨胀效果，而粉煤灰复掺石膏时，改善作用较小。其中复掺的石膏种类决定了体系收缩膨胀的整体趋势，而两者复掺比决定了膨胀率和收缩率的峰值大小。锂渣复掺无水石膏时膨胀效果优于复掺磷石膏、半水石膏。掺无水石膏时，各龄期膨胀率随复掺比的增大而减小。掺磷石膏时，一定龄期的膨胀率随复掺比的增大而增大。而粉煤灰复掺石膏，仅在复掺无水石膏且复掺比大于1时，各龄期膨胀才有明显提高。利用锂渣、粉煤灰和磷石膏复掺配置混凝土膨胀剂具有研究价值。最优配置方案为：锂渣30份，粉煤灰50份，磷石膏20份。该膨胀剂以磷石膏、锂渣中的SO₃提供硫酸根离子，锂渣、粉煤灰提供铝相，以钙矾石为膨胀源，前7 d膨胀速率快，膨胀能高，21 d收缩变小且趋于稳定。更多还原

【Abstract】 By testing the limiting expansion rate of cementitious sand specimens, we study the change rule of expansion rate of cementitious sand specimens under different gypsum types and different compounding ratios of two kinds of waste slag compounding. And study the optimal ratio of lithium slag-fly ash-phosphogypsum as expansion material, and use SEM to analyze its microscopic morphology in the cement hydration slurry. The results show that: Lithium slag mixed with gypsum can significantly improve the expansion effect of cement cementing system, while fly ash mixed with gypsum, the improvement effect is smaller. The type of gypsum doped determines the overall trend of system contraction and expansion, while the ratio of the two dopes determines the peak size of expansion and contraction. When lithium slag is compositely added with anhydrite, the expansion effect is superior to that achieved by composite addition with phosphogypsum or bassanite. When anhydrite gypsum is doped, the expansion rate at each age decreases with the increase of compounding ratio. When mixed with phosphogypsum, the expansion rate at a certain age increases with the increase of compounding ratio. The fly ash mixed with gypsum, only when mixed with anhydrite gypsum and the mixing ratio is greater than 1, the expansion at all ages is significantly improved. The use of lithium slag, fly ash and phosphogypsum compound mixing configuration of concrete expansion agent has research value. Configuration program: 30 parts of lithium slag, 50 parts of fly ash, 20 parts of phosphogypsum. The expansion agent to phosphogypsum, lithium slag in the SO₃ to provide sulfate ions, lithium slag, fly ash to provide aluminum phase, calcium alumina as the source of expansion, the first 7 d expansion rate is fast, the expansion energy is high, the 21 d contraction is getting smaller and reached stability.更多还原