Sulphate-attack-resistant concrete admixture and preparation method thereof

Abstract

The invention provides a sulphate-attack-resistant concrete admixture and a preparation method thereof. The concrete admixture is prepared from, by mass, 100 parts of asphalt, 5-8 parts of a macromolecule emulsifier, 0-1 part of a stabilizer, 0-1 part of a protective adhesive, 5-10 parts of an excipient, 5-10 parts of a modifier, and 100-120 parts of water, wherein the macromolecule emulsifier refers to sodium polycarboxylate salt containing a polyoxyethylene ether lateral group, and the molecular weight range is from 10000 to 22000. The macromolecule emulsifier, the modifier, the excipient and other reagents are adopted, emulsified asphalt is prepared and modified, through the modification effect of all the components, emulsified asphalt has a good sulphate-attack-resistant effect when used in a cement system, the original mechanical properties of concrete are maintained, and modified sulphate-attack-resistant emulsified asphalt which has good corrosion resistance and is easy to apply and high in performance-price ratio is prepared.

Description

technical field [0001] The invention belongs to the technical field of concrete admixtures, in particular to a sulfate-resistant concrete admixture and a preparation method thereof. Background technique [0002] Concrete is one of the most widely used and used building materials in the world today. It plays roles and functions that cannot be replaced by other materials, and its durability research has attracted widespread attention. Among them, the erosion damage caused by sulfate is one of the important factors affecting the durability of concrete. In recent years, the sulfate corrosion of concrete has become more frequent and more serious in various places. The sulfate corrosion of concrete has reduced the functionality and safety of concrete components and brought serious losses to the national economy. The treatment methods that have been used for many years The old method of concrete sulfate attack and old materials can no longer fully meet the current needs of corrosi...

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Problems solved by technology

[0003] Currently commercially available concrete sulfate corrosion admixtures mainly include two types: one is to add fly ash, mineral powder, silica fume and other admixtures, such as patent CN 101913841A, CN 101475334 A, etc., but this type of admixture requires a large The effect of sulfate corrosion resistance can only be achieved by using a large amount of admixtures. The use of a large amount of admixtures will reduce the mechanical properties and anti-carbonation performance due to the reduction in the amount of cement. In addition, the use of admixtures alone does not fundamentally prevent external sulfates from attacking. The erosion of concrete can only delay the formation of expansion corrosion products to a certain extent, and there is still a risk of performance degradation of concrete under long-term corrosion

The second category is chemical reagent synthesis admixtures, such as publication number CN 103641355 A, publication number CN 105601162 A, publication number CN 106082774 A and other patents. The concentration of sulfate ions, preventing the entry of erosion solution, and hindering the crystallization process can fundamentally reduce the risk of concrete erosion. However, the synthesis conditions of this type of admixture are relatively strict, the preparation process is complicated, the engineering operation is inconvenient, and the cost is high. The use of this type of admixture increases the cost of concrete by more than 30%, and there is a huge gap between the selling price and the price accepted by the buyer, which seriously affects the application market and user needs of the product. The actual engineering application of this type of modifier is seldom

[0004] Emulsified asphalt itself is a kind of organic gelling material with waterproof, moisture-proof and anti-corrosion effects, and it is cheap and cost-effective. However, literature records and test data show that it has a certain air-entraining effect when it is added to the cement system alone, causing cement slurry The compactness decreases, and after dehydration and solidification, it deposits between the cement particles to prevent the expansion and fusion of the cement hydration gel, resulting in a decrease in the compressive strength of the cement paste, so it is not suitable to be used alone as a concrete anti-corrosion admixture

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