基于分散模型的混凝土流动机理研究

Flow Mechanism of Concrete Based on Dispersion Model

摘要:

基于粗骨料分散于砂浆中的混凝土结构模型，研究了砂浆流变性及用量对混凝土流动性的影响规律.结果表明：基于砂浆流变的粗骨料润滑作用和依赖于砂浆用量的粗骨料空间分离作用是造成混凝土体系失稳进而流动的主要因素，这两个因素相互影响，当一个因素超过临界值时，另一因素的作用效果被削弱；利用分散模型研究混凝土流动性，能够充分体现混凝土组成、结构与性能的关联作用，通过深入解析两个因素的作用规律，将现有混凝土调控参数分解、转化成砂浆流变和用量2个参数，可为混凝土性能预测及调控提供新思路.

Abstract:

Concrete can be divided into two components:mortar and coarse aggregate. The influence of both rheology and amount of mortar on concrete flowability was studied. The results show that the lubrication among coarse aggregate is determined by the rheology of mortar, and spatial separation of coarse aggregate is determined by the amount of mortar. Both factors decrease the stability of concrete system, and thus promote to flow. The factors are influenced each other, that is to say, when one factor exceeds a critical value, the effect of the other will be weakened. The dispersion model can fully explain the correlation of composition, structure and performance. The change of concrete proportions can transform into change of the two factors, that is a new way to predict and control the concrete performance.