橡胶颗粒对砂浆流变性能影响的试验研究

EXPERIMENTAL STUDY ON EFFECTS OF RUBBER PARTICLES ON RHEOLOGICAL PROPERTIES OF MORTAR

采用BROOKFIELD R/S流变仪研究了掺橡胶颗粒砂浆浆体的流变性能,分析了在不同体积替代率的橡胶颗粒掺量下,砂浆浆体的流动度、屈服应力和塑性黏度变化情况。研究结果表明：掺橡胶颗粒砂浆浆体的流变性能符合Bingham流体模型;随着橡胶颗粒替代率的提高,砂浆浆体流动度不断降低;砂浆浆体的屈服应力和塑性黏度随着橡胶颗粒替代率的提高均增大,其中屈服应力的增大幅度明显大于塑性黏度;掺橡胶颗粒的砂浆浆体屈服应力和塑性黏度均与流动度表现出良好的线性相关性,且随着砂浆浆体流动性的增大,屈服应力和塑性黏度均降低;随着剪切速率的增大,掺橡胶颗粒砂浆浆体发生显著的剪切稀化现象,塑性黏度呈现先降低后逐步稳定的特点。

The rheological properties of rubber particles mortar pastes were determined using BROOKFIELD R/S rheometer. The fluidity,yield stress and plastic viscosity of mortar pastes at different volume substitution ratios of rubber particles content were analyzed. The results showed that the rheological properties of rubber particles mortar pastes followed the Bingham model. The fluidity of mortar pastes decreased with the increase of rubber particles substitution ratio. The yield stress and plastic viscosity of mortar pastes increased as the increase of rubber particles substitution ratio. The increased amplifications of yield stress were significant greater than that of plastic viscosity.The yield stress and plastic viscosity of rubber particles mortar pastes were found to have good linear correlation with fluidity. The rubber particles mortar pastes appeared a remarkable shear thinning behavior when the shear rate increased. The plastic viscosity decreased initially and then became stable as the shear rate increased.