骨料对自密实混凝土性能的影响

研究了粗骨料最大粒径、粗骨料级配、砂率等因素对掺不同矿物掺合料,如粉煤灰、矿渣粉或硅灰的自密实混凝土的工作性与强度性能的影响。试验结果表明,粗骨料最大粒径越小,自密实混凝土的流动性越大、粘聚性越好。随着粉煤灰、矿渣粉的掺量增大,自密实混凝土的流动性明显增大,粘聚性显著下降。复合掺入合适比例的矿物掺合料,可有效改善自密实混凝土工作性与强度。粗骨料级配是影响自密实混凝土性能的重要因素之一。随着砂率增大,自密实混凝土拌合物的流动性增大,粘聚性减小,流动性损失减小,早期和后期抗压强度也随之下降。

INFLUENCE OF AGGREGATES ON PERFORMANCE OF SELF-DENSE CONCRETE

In this paper,effects of maximum particle diameter,gradation of coarse aggregate,sand ratio on workability and strength properties of self-compacting concrete(SCC) incorporated with mineral admixtures such as fly ash,ground blast-furnace slag powder or silica fume etc.were studied.The results indicate that,with decrease of maximum particle diameter of coarse aggregate,the fluidity and cohesion of SCC increase.With the addition content of fly ash or ground blast-furnace slag increases,the fluidity of SCC increases greatly and its cohesion reduce significantly.The composite addition of mineral admixtures with appropriate proportion improves workability and strength of SCC.The gradation of coarse aggregate is one of most important factors affecting properties of SCC.With the sand ratio of SCC increases,fluidity of SCC increases,and its cohesion,fluidity loss and compressive strength at early ages or later ages reduce.