Nano modified composite powder for ocean-engineering concrete structure

Abstract

The invention relates to the technical fields of ocean-engineering materials and engineering, and aims at providing nano modified composite powder for an ocean-engineering concrete structure. The composite powder is formed by mixing the following raw material components in parts by weight: 20 to 30 parts of pulverized fuel ash, 25 to 40 parts of blast-furnace slag powder, 10 to 20 parts of silica fume, 5 to 10 parts of nano CaCO3 and 0.8 to 1 part of nano dispersant. By using the nano modified composite powder, the limitation that a single mineral component influences concrete performance is effectively removed; a compound multifunctional component can be used for effectively optimizing the grain composition of the concrete structure; the purpose of greatly improving the durability of the concrete structure is achieved. According to the nano modified composite powder, the high activity and the microcrystal nucleus effect of nano grains are sufficiently exerted; the effects of improving the impermeability and the durability of the ocean-engineering concrete structure are far superior to those of an ordinary mineral admixture. By using the nano modified composite powder, the reasonable composition and the uniform mixing of the high-activity grains are promoted; the optimization of formula design is achieved; a product has the properties of excellent corrosion resistance, shrinkage reduction, low hydration heat, shrinkage compensation and the like.

Description

technical field [0001] The invention relates to the field of marine engineering materials and engineering technology, in particular to a nano-modified composite ultrafine powder specially used for marine concrete structures and a preparation method thereof. Background technique [0002] With the rapid development of my country's marine economy, many large-scale marine projects such as harbor terminals, sea-crossing bridges, and submarine tunnels have begun to be built in large quantities. play a vital role. However, due to the particularity of the marine environment, it will cause serious erosion and damage to the concrete structure: on the one hand, due to the large amount of Cl in seawater - , SO 4 2- , Mg 2+ Such corrosive ions and microorganisms require concrete to have excellent corrosion resistance; on the other hand, the impact, wear, fatigue and cavitation of waves will cause a certain degree of damage to the concrete structure. Therefore, concrete in the marine ...

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Problems solved by technology

[0003] The use of mineral admixtures to prepare high-performance concrete is an important measure to improve the corrosion resistance of marine concrete. However, after adding traditional mineral admixtures, although it can also improve the compactness of the concrete structure, it may also lead to The alkalinity of reinforced concrete decreases, causing the stability of the passivation film on the surface of concrete reinforcement to decrease. When chloride ions penetrate into the surface of concrete reinforcement from the outside, it will cause corrosion of reinforcement faster, and it is difficult to meet the current design requirements of 100 years.

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