A retarding high-fluidity high-strength underwater concrete additive and preparation method thereof

Abstract

The invention belongs to the technical field of building materials, and particularly relates to a retarding type high-fluidity high-strength underwater concrete additive. The additive can effectively improve the strength and dispersion resistance of concrete and has the advantages of simple preparation process, low production cost and the like. The additive is characterized by comprising metakaolin and a composite modifier. The mass ratio of the metakaolin to the composite modifier is (50:1)-(15:1); the composite modifier is prepared by mixing 70-85% of polyacrylamide, 10-20% of superplasticizer and 5-15% of organic water-soluble polysaccharide substances all by mass based on a total of 100%. As an additive for underwater concrete, the additive can improve the working performance and dispersion resistance of underwater concrete and delay the setting time; and the strength at each age, particularly the early age strength of underwater concrete is remarkably improved. Meanwhile, the volume stability of underwater concrete can be effectively improved.

Description

technical field [0001] The invention belongs to the technical field of building materials, and in particular relates to a slow-setting high-fluidity high-strength underwater concrete additive and a preparation method thereof. Background technique [0002] Along with the development and progress of human society and civilization, as the land resources available for development become less and less, the tentacles of the development of human civilization will extend to the ocean, so the 21st century will be the century of ocean development. Concrete water The next construction will be more and more. The underwater concrete structure is very complex. Therefore, in addition to the strength of concrete, simple construction technology, reasonable economy, good durability and no pollution to the environment are also required. Concrete is still one of the most important and most used construction materials in underwater engineering, and the performance of underwater concrete will d...

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Problems solved by technology

[0004] However, a single concrete material system obviously cannot meet the above requirements

However, there are single-mixed cellulose and polypropylene viscosifying substances in the relevant patents to prepare underwater concrete, but the resulting concrete has low strength, and the water-to-land strength ratio is only 65%-70% (7d) and 70%-75 %(28d), and the slump loss of concrete is large, so it is not suitable for long-distance transportation and construction

Looking at the research and application results of underwater non-dispersible concrete in the past, the performance of the prepared underwater non-dispersible concrete has limitations, and the strength level of the poured underwater concrete is generally low (below C30), and the water Frost resistance of non-dispersible concrete, anti-Cl - There is also a lack of research on durability such as permeability

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