垃圾焚烧飞灰早期胶凝活性激发研究

Study on Activating the Early Cementitious Activity of MSWI Fly Ash

从城市生活垃圾焚烧飞灰在水泥混凝土材料领域中的资源化利用角度出发,采用比强度分析方法试验研究了飞灰的胶凝活性,探讨了化学激发剂对飞灰-水泥复合胶凝体系早期强度的活性激发以及相关的机理。结果表明:飞灰早期胶凝活性较低,尤其当掺量高于20%后,表现十分明显。分别掺入1%～3%的CaSO4,KAl(SO4)2,Al2(SO4)3和Na2SiO3的化学激发剂后,浆体的早期抗压强度明显提高,激发效果显著,但随龄期的延长,激发效果减弱。

In the light of utilizing MSWI fly ash in cement-based materials, cementitious activity by means of specific compressive strength, the effect of chemical activators on cementitious activity of cement paste containing MSWI fly ash in the hydration of early ages and their effective mechanism of action were investigated and analyzed. Results show that MSWI fly ash has a low cementitious activity at early hydration, especially when the replacement was more than 20%. Therefore, in order to make sure pastes with MSWI fly ash have enough early strength, chemical activators CaSO4, KAl（SO4）2, Al2（SO4）3 and Na2SiO3 with a dosage ranging from 1% to 3% were used to activate the early cementitious activity of fly ash - cement paste, respectively. And, it shows that they all can significantly improve compressive strength of cement pastes containing MSWI fly ash, activating the early cementitious activity of the system inside. However, this effect decreased as the curing time prolonged.