Pulpy metakaolin-base concrete admixture, and preparation method and application of admixture

Abstract

The invention provides a pulpy metakaolin-base concrete admixture and a preparation method of the admixture. The admixture comprises a dry base, a composite dispersant and water, wherein the dry base consists of 30-90% by mass percentage of metakaolin and 10-70% by mass percentage of fly ash sinking beads; a mass ratio of the water to the dry base is (30-180):100; the composite dispersant consists of hydroxyethyl cellulose and a naphthalene water reducing agent; the hydroxyethyl cellulose accounts for 0.005-2.0% of the mass of the dry base; the naphthalene water reducing agent accounts for 0.001-1.0% of the mass of the dry base. The admixture reduces an adverse effect of the metakaolin on the working performance of concrete by utilizing combined action of the metakaolin, the fly ash sinking beads and the dispersant, and significantly improves the strength uniformity, the dispersity and the stability of a test block.

Description

technical field [0001] The invention belongs to the technical field of building materials, and in particular relates to a slurry-like metakaolin-based concrete admixture and a preparation method and application thereof. Background technique [0002] With the development and progress of human society and civilization, improving the mechanical properties and durability of concrete is an important topic that material scientists from all over the world are constantly researching and exploring. Active admixtures such as ash are an effective way to prepare high-performance concrete, and the addition of silica fume is the best. However, as a by-product of refining silicon-ferrosilicon alloy and metal silicon, silica fume has less sources and is expensive. To implement the national economic sustainable development strategy and environmental protection requirements, it is particularly important to seek an active mineral admixture that can be industrially produced. [0003] Metakaoli...

AI Technical Summary

Problems solved by technology

However, due to the small particle size of metakaolin (mainly distributed between 1 and 10 μm), high surface energy, and a layer-like shape, metakaolin particles are prone to agglomeration

Used as an admixture in cement and concrete, when the agglomerated metakaolin powder is mixed, it is easy to absorb a large amount of water to form a flocculation structure, and the water for lubrication is seriously insufficient, resulting in a significant decrease in fluidity and slump, resulting in Metakaolin cannot be uniformly dispersed in concrete

The use of metakaolin and fly ash sinking beads in concrete can improve the fluidity of concrete to a certain extent, but it still cannot meet the conventional technical requirements

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