【24h】

PARAMETERS DETERMINING THE FLOW OF CONCRETE MATRIX

机译:确定混凝土基体流动的参数

获取原文
获取原文并翻译 | 示例

摘要

The rheology of concrete is often approached by using a particle-matrix model, which roughly can be described as coarser aggregate dispersed in a suspension of fines less than 125μm. Parameters determining the flow resistance (taken as the area under the shear stress versus shear rate curve) of concrete matrix have been discussed. The following parameters are treated in some detail; water-to-cement ratio (w/c), cement type (including mineralogy and fineness), silica fume dosage and plasticizers (type, dosage and time of addition).It is shown, for instance, that the w/c for a cement fit very well to the so called Krieger-Dougherty equation for suspensions where the apparent viscosity is dominated by the volume fraction of solids.Another finding is a linear correlation between the flow resistance of cement pastes and the specific surface of the cements multiplied with a weighed sum of cubic C3A and C3S, or in other words the surface fraction of the most hydraulic active minerals in the fresh state.Cements ground from the same clinker show an exponential relation between fineness and flow resistance of pastes.Flow resistance of pastes decreases with increasing volume replacement of silica fume until 9 vol% and increases again thereafter.Polyether grafted polyacrylates (PA) are better plasticizers than naphthalene sulphonate-formaldehyde condensate (SNF) and sodium lignosulphonate (LS). Unlike for SNF and LS, paste show no improved rheology by delayed addition of PA.
机译:通常使用颗粒矩阵模型来研究混凝土的流变性,该模型可以大致描述为分散在小于125μm的细小悬浮液中的粗骨料。讨论了确定混凝土基体流动阻力的参数(取为剪切应力与剪切速率曲线下的面积)。以下参数已得到详细处理;水灰比(w / c),水泥类型(包括矿物学和细度),硅粉用量和增塑剂(类型,用量和添加时间)例如,表明水泥非常适合悬浮液的所谓Krieger-Dougherty方程,其中表观粘度由固体的体积分数决定,另一个发现是水泥浆的流动阻力与水泥比表面之间的线性关系乘以a。立方C3A和C3S的总和,或者换句话说是新鲜状态下水硬性最高的矿物的表面分数。从同一熟料中研磨出的水泥显示出浆料的细度与流动阻力之间的指数关系,随着流动性的降低,浆料的流动阻力降低硅粉的体积替代量增加到9%(体积),此后又增加。聚醚接枝聚丙烯酸酯(PA)比萘磺酸盐,甲醛缩合物(SNF)和锂钠更好。 gnosulphonate(LS)。与SNF和LS不同,糊剂通过延迟添加PA不会显示出改善的流变性。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号