矿物掺合料对硫铝酸盐水泥-普通硅酸盐水泥复合体系性能的影响

研究了矿粉、硅灰和粉煤灰3种矿物掺合料对硫铝酸盐水泥-普通硅酸盐水泥复合体系的标准稠度用水量、凝结时间、水化放热、胶砂抗折及抗压强度、砂浆干缩率、抗硫酸盐侵蚀性能和水化产物的影响。结果表明:随矿物掺合料掺量的增加,复合体系的标准稠度用水量增大,凝结时间延长;掺加矿物掺合料后水化放热峰出现时间延后,总水化放热量减少,其中掺加矿粉和硅灰的试件初期水化速率减慢程度较掺加粉煤灰试件更明显;3种矿物掺合料对复合体系强度的影响差别较大,掺加3%硅灰的试件3 d抗压强度增长较快;硅灰的掺加会使砂浆干缩率增大,矿粉、粉煤灰的掺加可以减小砂浆试件的干缩;矿物掺合料的掺加会提高胶砂试件抗硫酸盐侵蚀性能,掺粉煤灰的试件抗硫酸盐侵蚀性能最好。

Effect of admixtures on properties of sulphoaluminate cement-common Portland cement composite system

The influence of mineral powder,silica fume and fly ash on the standard water consumption and setting time,hydration heat release,flexural strength and compressive strength,shrinkage,ability of sulfate resistance and hydration products of sulphoaluminate cement-Portland cement composite system were studied in this paper.The results indicated:with the increase of admixtures content,the standard water consumption of the composite system was increased and the setting time was prolonged;after the addition of the admixtures,the hydration heat peak was delayed,and the total hydration heat was reduced.The initial hydration rate of cement system with slag and silica fume is slower than that with fly ash;the compressive strength,especially early strength of cement was effected by admixtures and the compressive strength(3 days)has a relatively faster increase when the silica fume content is 3%;the addition of silica fume increases the dry shrinkage rate of the mortar,and the addition of slag and fly ash can weaken the shrinkage of cement mortar;the addition of admixtures improved the sulfate resistance of the cement mortar and the cement mortar with fly ash show best sulfate resistance property.