二水石膏和普通水泥复掺对铝酸盐水泥基砂浆性能的影响

Influence of Compound Admixture of Dihydrate Gypsum and Ordinary Cement on Properties of Aluminum Cementitious Mortar

以铝酸盐水泥为主要胶凝材料,复掺二水石膏(11%、13%、15%、17%)和普通水泥(2%、4%、6%、8%),制备出铝酸盐水泥基砂浆。通过测试宏观抗压强度,同时采用物相分析(XRD)和微观结构(SEM)两种表征手段,探究了二水石膏和普通水泥复掺对铝酸盐水泥基砂浆性能的影响。研究结果表明:改性铝酸盐水泥基砂浆试件抗压强度随着养护龄期的增长而逐渐增加,且二水石膏掺量在11%~13%,普通水泥掺量在2%~4%时,铝酸盐水泥基砂浆力学性能较好;各铝酸盐水泥基砂浆28d龄期试件内部主要含有AFt和铝胶,AFt、CAH_(10)及C_3AH_6等水化产物相互交叉、搭接,铝胶和C-S-H凝胶将各水化产物胶结在一起,且各水化产物数量的分布差异,造成其力学性能差异。

Aluminum cementitious mortars were prepared using aluminum cement and combined admixture of dihydrate gypsum （11%、13% 、15% 、17%） and ordinary cement （2% 、4% 、6% 、8%）. The influence of combined admixture of dihydrate gypsum and ordinary cement on performance of aluminum cementitious mortar were studied by testing compressive strength, using phase analysis （XRD） and microstructure （SEM） as characterization means. The results show that the compressive strength of the modified aluminum eementitious mortars gradually increase with the increase of curing age, and when the amount of dihydrate gypsum is 11%-13% and the amount of ordinary cement is 2%～4%, the meehanieal properties of aluminum cementitious mortars are better. The aluminum cementitious mortar specimens of 28d age contain AFt and Al（OH）3. AI （OH）3, C-S-H gel and hydration products, such as AF, CAH10 and C3AH6, will be cemented together. The difference of the distribution of hydration products results in the difference of mechanical properties.