Abstract: Based on residual slurry film thickness theory and mortar rheological threshold theory, the mortar rheological test and concrete slump flow test were used to study the correlation between the workability of medium fluidity concrete and its equivalent mortar rheological properties, so as to achieve the purpose of predicting and adjusting the workability of medium flow concrete through the rheological properties of mortar. The research result show that the volume of coarse aggregate in 1 m3 concrete decreases with the increase of mortar film thickness, and when the gradation curve, apparent density and vibration density of coarse aggregate are constant, the excess mortar film thickness and coarse aggregate volume meet the relationship of quadratic function. The mortar rheological threshold theory of self-compacting concrete has good applicability in medium fluidity concrete, and the theoretical model can be used to guide the rheological research of medium fluidity concrete. When the physical properties and dosage of coarse aggregate are determined, the workability of medium fluidity concrete and the rheological properties of its equivalent mortar have good correlation. The workability of medium fluidity concrete can be predicted or adjusted by testing the rheological properties of mortar.

Key words: highway engineering; mortar; rheological behavior; medium fluidity concrete; workability; residual slurry film thickness theory

摘要： 基于剩余浆体膜厚理论和砂浆流变阈值理论，采用砂浆流变试验和混凝土坍落扩展度试验，对中流动性混凝土工作性与其等效砂浆流变特性之间的相关性进行研究，以实现通过砂浆流变特性预测调整中流动性混凝土工作性的目的。研究结果表明：1 m3混凝土中粗骨料体积随着砂浆膜厚的增加而减小，且当粗骨料级配曲线、表观密度、振实密度一定时，剩余砂浆膜厚与粗骨料体积满足二次函数关系；自密实混凝土的砂浆流变阈值理论在中流动性混凝土中具有较好的适用性，可以运用该理论模型对中流动性混凝土流变学研究进行指导；在粗骨料物理性能和掺量确定的情况下，中流动性混凝土工作性与其等效砂浆流变特性具有很好的相关性，可以通过测试砂浆的流变性能来预测或者调整中流动性混凝土的工作性。

关键词: 道路工程；砂浆；流变特性；中流动性混凝土；工作性；剩余浆体膜厚理论