偏高岭土、矿渣和赤泥对高性能混合水泥性能影响的研究

Influence of metakaolin,slag and red mud on properties of high performance blended cement

通过用硅酸盐水泥、偏高岭土等混合材、膨胀剂及减水剂等制备混合水泥的研究发现:偏高岭土和赤泥的加入使水泥的凝结时间缩短,矿渣的加入延长了水泥的凝结时间;偏高岭土和矿渣对水泥的胶砂流动性影响较小,赤泥的加入使得水泥胶砂流动性显著降低;适量偏高岭土的加入对水泥的3d和28d强度均有增强作用,适量矿渣的加入使水泥抗折强度降低,抗压强度增大;少量的赤泥对水泥强度特别是早期强度有一定的增强作用,但掺量超过20%后水泥强度迅速降低;偏高岭土对水泥微膨胀的产生有促进作用,矿渣和赤泥对水泥微膨胀有抑制作用。用80%～90%的硅酸盐水泥、10%～20%的偏高岭土以及少量的膨胀剂和减水剂能够制备出具有较优流动性、较高的强度以及微膨胀的高性能混合水泥。

During preparation of blended cement with Portland cement, metakaolin, expansive agent and superplacitizer, several conclusions were drawn as follows： the additon of metakaolin and red mud （the waste of aluminum oxide manufacture） led to the decrease of setting time of blended cement, but GGBS increased setting time of blended cement. The metakaolin and GGBS had less effect on the fluidity of bended cement mortar than the red mud did and the red mud led to the decrease of fluidity of cement mortar. The proper amount of metakaolin could increase the 3d and 28d strength of blended cement, GGBS with a content less than 20% made the flexural strength of blended cement decreased and compressive strength increased, and small amount of red mud could promote the early strength of blended cement, but when the dosage of red mud exceeded 20%, the strength would decreased. Expansion of blended cement benefited from the dosage of metakaolin and was suppressed by GGBS and red mud. High performance blended cement with good fluidity, high strength and slight expansion could be prepared with 80%-90% silicate cement, 10%-20% metakaolin and some amount expansive admixture and superplasitieier.