针对采用轻骨料与普通骨料制备的新拌混合骨料混凝土因骨料密度差异易出现分层匀质性变差的问题,基于流体力学原理建立了新拌混合骨料混凝土的骨料粒子运动方程,在此基础上研究了骨料粒径、矿物掺和料与纤维对新拌混合骨料混凝土匀质性的影响规律。研究结果表明:新拌混合骨料混凝土的匀质性与骨料粒径、水泥浆体黏度及其密度差相关;降低骨料粒径、引入粉煤灰和硅灰、掺加纤维均可提高混合骨料混凝土的匀质性。
The homogeneity of fresh concrete prepared with combined aggregates is poor because of the density difference between the two kinds of aggregates. According to this, the coarse aggregate particles kinematic equation was established based on the fluid mechanics principles, and the influences of particle diameter, mineral admixtures and fiber on the homogeneity of fresh concrete were studied in this paper. The results showed that the homogeneity of fresh concrete related to aggregate diameter, cement paste viscosity and the density difference between aggregates and cement paste; the homogeneity of fresh concrete could be meliorated by reducing the diameter of aggregates, adding proper dose of mineral admixtures or polypropylene fibers.