关键词: 石膏基复合胶凝材料;养护方式;强度;耐水性能

Abstract: The effects of calcining temperature of raw gypsum, naphthalene-based reducer, polycarboxylate superplasticizer, curing styles on properties were studied with optimization mixing proportion of gypsum based compound cementing materials. Meanwhile,the characteristics of hydration process and mechanism of setting and hardening for the cementing materials were characterized by using scanning electron microscope and X-ray diffraction. The results show that the optimum formula proportion is 52% of flue gas desulphurization (FGD)building gypsum,25% of fly ash,20% of cement and 3% of hydrated lime,an appropriate quantity of compound exciting agent,standard at weight rate of 0. 4 water per compound cementing materials. By the way of normal atmospheric temperature of nature curing,the compressive strength of 28 d and 56 d of cementing materials are 24. 25 MPa and 26. 20 MPa,softness coefficient is 0. 816 as well. The situation of fly ash hydration of compound cementing materials is worse than the situation of fly ash hydration of normal cement based at the normal atmospheric temperature. The key question of moderate proportion of alkaline exciting agent is controlled from beginning to end. The appropriate processing parameters of steam curing for the cementing materials are 70 ℃ and 24 h,in addition,a suitable age of normal atmospheric temperature of curing is required. The rapidity of generating quantities of calcium silicate gel and ettringite (AFt)is significantly accelerated and then.

Key words: gypsum based compound cementing material;curing method;strength;water resistance property