矿质混合料堆积与混凝土致密正填配合比设计

The packing of mineral admixture and concrete's dense positive-fill mix proportion design

本文首次提出混凝土"致密正填配合比设计法":先按照固态材料粒度由粗到细的顺序进行逐次填加,寻求矿质混合料体系的正填致密堆积,即粗细集料、矿物掺合料(本文中采用碎石、中砂和粉煤灰)组成的固态颗粒混合物的最大单位重与"最佳填塞率"的关系;再选取合适的水胶比和水泥浆富裕系数进一步进行经济合理的混凝土致密正填配合比设计。在相同的水胶比0 36和减水剂用量SP=1 0%的情况下,致密正填配合比设计法由于矿质混合料的致密堆积,掺入大量(与水泥质量比为77 13%)具有一定细度和活性的粉煤灰,与传统的超量取代法相比,不但在节约水泥30%的情况下强度稳步增长,还将混凝土的抗渗性能提高了20%,对于进一步改善混凝土的耐久性十分有益。

This paper first proposes'Concrete's Dense Positive-fill Mix Proportion Design'.The way at first seeks the positive-fill dense packing of mineral admixture from big to small according to the maximum diameter of solid state raw materials,i.e.the maximum unit weight and best filling ratio of coarse aggregate(crushed stone)and fine aggregate(medium sand)as well as fly ash.This paper chooses the same W/B=0.36 and the volume of superplasticizer SP=1.0% further carries out the economical and reasonable Dense Positive-fill Mix Proportion Design.The concrete made in this way because of dense packing of mineral admixture and large volume fly ash (the mass ratio to cement is 77.13%)with certain fineness and activation,compared with traditional over-quantity-replace way,only possesses relative high strength,but also improves the impermeability 20%,which does much good for concrete to resist the environmental corrosions and attain fine durability.