石粉含量和含泥量对砂浆流变性能的影响

Influence of Stone Powder Content and Mud Content on Rheological Properties of Mortar

基于目前机制砂大量用于混凝土砂浆拌制的现状,对机制砂中石粉含量和MB值对砂浆流变性能的影响程度进行试验,结果表明:在低水胶比条件下,一定含量的石粉有利于降低砂浆的粘度,石粉含量在3%和6%时,砂浆流动效果较明显;剪切速率小于30 rpm,含泥量高的砂浆触变环大,剪切速率大于30 rpm时,含泥量低的砂浆触变环大,表现出明显的触变性;机制砂中含泥量较小时,不会明显降低减水剂作用,砂浆浆体的屈服应力和塑性黏度随着含泥量增加而增大。

Based on the current situation that mechanical sand is widely used in mixing concrete mortar, the influence degree of stone powder content and MB value on the rheological property of mortar is tested. Under the condition of low water-binder ratio, a certain content of stone powder is beneficial to reduce the viscosity of mortar. When the content of stone powder is 3% and 6%, the flow effect of mortar is more obvious. When the shear rate is less than 30 rpm, the mortar with high mud content has a large thixotropic ring and when the shear rate is greater than 30 rpm, the mortar with low mud content has a large thixotropic ring, showing obvious thixotropy. When the mud content in machine-made sand is small, the effect of water reducing agent will not be decreased obviously, and the yield stress and plastic viscosity of mortar slurry increase with the increase of mud content.