高铝水泥基干混自流平砂浆流变性研究

Rheological behavior of high alumina cement-based dry-mixed self-leveling mortar

研究了高铝水泥基自流平砂浆的流变行为及流变参数与流动度间的关系。结果表明:随高铝水泥掺量的增加,自流平砂浆的剪切应力(黏度)增大,但同时会降低砂浆的流变稳定性,砂浆的触变性降低;具有一定的剪切应力的砂浆,浆体能更好的包裹于细骨料表面,将更有利于砂浆流动度的扩展及保持;当m(普硅水泥)∶m(高铝水泥)=2∶1时,砂浆的流动度经时损失最小,新拌砂浆的流动度为140 mm,扩展至130 mm所用时间最短为68 s,30 min流动度为138 mm。

This paper studies the rheological behavior of the high aluminum cement-based self-leveling mortar and the rela-tionship between rheological parameter and fluidity. The results show that the shear stress （viscosity） of self-leveling mortar in-creases,and results in the decrease of rheological stability and thixotropic properties of the mortar,with the increase of amount of admixture of high alumina cement. The mortar has a certain level of shear stress,which the slurry can better wrap around the fine aggregate surface,it will be more conducive to the expansion and maintain of the fluidity of the mortar. When the ratio of C/CA was 2：1,the fluidity loss with time was minimum. The fluidity of fresh mortar reached to 140 mm and it took a shortest time of 68 s to extend to 130 mm,after 30 min,the fluidity of mortar is 138 mm.