外掺材料对隧道路面用多孔水泥混凝土改性效果的研究

Research on modification effect of external addition material on porous cement concrete for tunnel pavement

文章通过测试掺加硅灰、粉煤灰、复合掺加粉煤灰硅灰的水泥净浆强度，优选外掺材料的掺加方式和用量，制作多孔水泥混凝土试件，最终确定胶结料用量。不降低水泥用量，复合掺加（10％粉煤灰＋4％硅灰）的多孔水泥混凝土强度最高，对于重载交通路段，应选择这种复合掺加方式。降低水泥用量，复合掺加（10％粉煤灰＋6％硅灰）、掺加20％粉煤灰的多孔水泥混凝土也能达到较高的强度要求，由于其水泥用量少，具有经济优势。所配制多孔水泥混凝土排水性能良好，对于重载交通路段设计空隙率为17％～18％，轻型交通路段设计空隙率为20％～21％。

The better dosage and mixing method of external materials were determined through testing the strength of a series of cement paste specimens with silica fume ,fly ash and both of them .The porous cement concrete specimens were made in order to ascertain the amount of cementing material . With the same amount of cement ,the specimen with the external addition of 10% fly ash and 4% sili-ca fume had the highest strength ,so such addition method should be used in road sections under heavy traffic .As for the specimens in which the cement dosage was reduced ,high strength also appeared in the specimens with the addition of 10% fly ash and 6% silica fume or with the addition of 20% fly ash ,so the two kinds of addition method had economic advantage because of lower dosage of cement . The porous cement concrete had fine drainage performance ,and designed void fraction was 17%-18%for the road sections under heavy traffic ,and 20%-21% for light traffic .