“635”水利枢纽导流洞硅粉混凝土研究和应用

根据"635"水利枢纽导流泄洪洞底板混凝土设计使用要求,进行了室内混凝土配合比性能试验研究,结果表明,掺有HLC Ⅲ硅粉剂的混凝土与不掺外加剂的混凝土相比,其28d抗压强度提高了87 1%,抗折强度提高了10 6%,抗冲磨强度提高了97 5%,同时用丙乳砂浆处理新老混凝土结合面能起到提高黏结性的作用.根据现场情况经配合比调整试验优选出宜于施工的硅粉混凝土配合比.在硅粉混凝土浇筑过程中,由于采取了合理的搅拌、运输、基面处理等措施,使得在高温、高蒸发环境下浇筑的硅粉混凝土质量得到了保证.

Study on silica fume concrete and its application to construction of diversion tunnel in "635" hydro-power project

Mix proportion design and laboratory performance tests of the silica fume concrete were carried out according to the requirement of concrete design for base plate of the diversion tunnel for "635" hydro-power project. The result showed that the compressive strength, flexural strength, and resistance to abrasion and cavitation of the concrete mixed with HLC-III silica fume admixture at 28 days increased by 871%, 106% and 975%, respectively as compared with those of the normal concrete, and that the bond property was improved by treatment of the interface of fresh and original concrete with polyacrylic emulsion cement mortar. Meanwhile, the optimal silica fume-concrete mix proportion suitable for the construction was determined based on field tests. Owing to the adoption of such measures as mixing, transportation, and foundation surface treatment, the quality of silica fume concrete was guaranteed under high temperature and evaporation.