机制砂生态自密实混凝土的制备

Preparation of Manufactured Sand Ecological Self-compacting Concrete

传统设计法设计出的自密实混凝土集料含量偏低、胶凝材料用量较高,成本高昂,机制砂的应用增加了自密实混凝土配制难度。从集料级配优化、组成设计和流变改性着手制备一种生态机制砂自密实混凝土并研究了堆叠率、砂的体积率,胶凝材料和水粉比对Eco-SCC工作性能、物理性能的影响。研究表明:利用级配合理的机制砂,在堆叠率为0.6及砂的体积率不超过0.44的条件下能制备出性能满意的Eco-SCC;其流动性受堆叠率和砂的体积率影响显著,强度随水粉比、砂的体积率升高而降低,合理的胶凝材料的用量对SCC强度有利。

The self-compacting concrete which designed by traditional design method always contained a low level of aggregate and a high volume of cementitious materials thus high cost. The application of manufactured sand would increase the difficulty to preparation of SCC. In this paper an Eco-SCC( ecological self-compacting concrete) is prepared by aggregate gradation optimization and rheological property modification,and the influence of Packing Ratio,sand volume ratio,cementitious materials content and volume W/B ratio on the workability and physical properties of Eco-SCC is studied. Results indicated that it is possible to prepare Eco-SCC with satisfying properties with coarse aggregate packing ratio of 0.6 and sand volume ratio under 0.44.The fluidity is affected significantly by packing ratio and sand ratio,with the increasing of sand volume and volume W/B ratio,the compressive strength decreases,a reasonable cementitious materials content range of SCC benefits its strength.