A kind of concrete admixture and preparation method thereof

Abstract

The invention discloses a concrete composite admixture, and belongs to the technical field of concrete construction materials. The composite admixture is prepared from the following raw materials in percentage by weight: 40% of coal ashes, 20% of tuff, 20% of slag produced by zinc smelting by pyrometallurgy, and 20% of slag produced by antimony smelting by pyrometallurgy. The preparation method comprises the following steps: (1) raw material pretreatment, namely, respectively crushing the tuff, the slag produced by pyrometallurgy zinc smelting and the slag produced by pyrometallurgy antimony smelting into coarse grains of which the particle sizes are 3cm by virtue of a fine crusher; (2) drying, namely, respectively drying the four raw materials until the moisture content is smaller than or equal to 3%; and (3) grinding, mixing the four raw materials according to the proportions, adding to a ball mill, and milling into fine grains, wherein the weight of screen residues of a square screen of which the milling fineness is 0.045mm is smaller than or equal to 15%. The composite admixture prepared by the method has the beneficial effects that the concrete activity index can be improved; concrete cracking is prevented; and the production cost is low.

Description

technical field [0001] The invention relates to the technical field of concrete construction materials, in particular to a concrete composite admixture. Background technique [0002] A large number of industrial waste slag such as fly ash, zinc ore and antimony ore, slag from pyro-zinc smelting and antimony smelting, which are wastes from thermal power plants, are piled up, causing land resources to be occupied and seriously polluting the environment. In the prior art, fly ash is used as an admixture for mortar or concrete, and fly ash is added to concrete to replace part of the cement or fine aggregate, which not only reduces the cost, but also improves the workability of the concrete mixture; Pumpability of concrete; reduce heat of hydration and thermal expansion; improve concrete impermeability; increase concrete modification. Tuff is a kind of pyroclastic rock, the composition is mainly volcanic ash, the chemical composition is mainly silicon dioxide and aluminum oxide....

AI Technical Summary

Problems solved by technology

Although zinc and antimony can be recovered from slag, the recovery cost is high, so many manufacturers do not use it, which not only causes waste of resources, but also pollutes the ecological environment

At present, concrete admixtures at home and abroad are often used only because of single use or insufficient strength and activity, or high cost, which greatly affects the use and promotion.

At present, the 7-day strength activity index of commonly used concrete admixtures only reaches 50-60%, and the 28-day strength activity index is generally lower than 70%. -20% cement usage

Moreover, adding a single admixture to concrete does not completely solve the problem of concrete cracking