A Chloride Ion Curing Agent

Abstract

The invention discloses a chloride ion immobilizing agent and an application method thereof, and belongs to the field of civil engineering materials. The chloride ion immobilizing agent is obtained by thoroughly mixing a layered double hydroxide (LDH) and a substance which can be hydrated to generate the LDH in certain parts by mass; chloride ion immobilization is realized by virtue of a chemical reaction between Ca-Al-LDH and a water reducing agent intercalation product (Ca-Al-SP-LDH) thereof, and a chlorine salt and meanwhile by use of the ion exchange characteristic of Ca-Al-Si-LDH and Mg-Al-LDH; as a result, the adverse effect of internal chloride ions on the properties of a cement-based material is reduced, the erosion action of the chloride ions to a reinforcement is relieved, and the chloride ions in the service environment are prevented from permeation and diffusion into the reinforced concrete. When the dosage of the chloride ion immobilizing agent accounts for 2%-5% of the weight parts of a cementing material, the immobilization rate of chloride ions inside the concrete is greater than 90%; internal doping or surface coating protection is capable of enabling the reinforced concrete impermeability to the chloride ions to be improved by I to II levels; the chloride ion immobilizing agent is suitable for sea sand concrete, marine concrete and mortar, magnesium oxychloride cement products, steel structures and reinforcements as well as concrete anticorrosive paints.

Description

technical field [0001] The invention specifically relates to a chloride ion curing agent, which belongs to the field of civil engineering materials. Background technique [0002] Concrete and reinforced concrete structures are widely used in civil engineering. Concrete structures combine the advantages of steel bars and concrete. They are simple in process and low in cost. They are the preferred form of civil engineering construction. The industry has taken another leap forward. However, in actual engineering construction, the problems caused by the lack of concrete durability are becoming more and more serious. The research on the durability of concrete is an important topic in the current structure research. [0003] During the service period, due to the intrusion of moisture and other corrosive media in the environment, concrete will gradually deteriorate due to physical and chemical reactions. The durability of concrete is also gradually reduced in this process, resulti...

AI Technical Summary

Problems solved by technology

First, if the aluminate phase (such as C 3 Phase A) content is too high, because the porous structure caused by the crystalline hydration product provides a channel for chloride ion erosion, this effect can even offset the advantage of its solidified chloride ion; in addition, because C 3 A High early hydration heat release, leading to internal temperature rise of concrete, which is especially unfavorable in marine structures

[0007] Patent CN200810030796.X discloses an "admixture for improving the performance of cement-based materials to solidify free chloride ions and its application method". The admixture has a good ability to solidify chloride ions. The mass ratio between nitrate, silicon aluminum oxide and nitrite is controlled at 8-9:1, and mixed with cement-based materials, it can improve the ability of the system to solidify chloride ions, but high doses of nitrite are used It is very easy to cause poisoning, cause harm to the human body, and is difficult to control, and the amount of this additive is relatively large

[0008] Patent CN200910065325.7 discloses an "auxiliary cementitious material for improving the solidification of chloride ions in concrete". The preparation method is to mix 65-98% activated coal gangue, 0-30% potentially active silicon-alumina oxide, and 2-6% activator, but the cementitious material has a great influence on the compressive strength of concrete, and Dosing too much

[0009] Patent CN200610068664.7 discloses a "chloride ion permeation resistance enhancer for harbor engineering concrete". Fine silica powder 15-20%, washed and calcined metakaolite 20-25%, high-quality fly ash 20-25%, ground blast furnace slag 20-25%, ultra-fine nanofiber 5-10%, high-efficiency water reducer 6%, slump-retaining agent 0.09%, air-entraining agent 0.09%, organic active activator 0.12% and other materials are fully mixed, but the incorporation of a large amount of ultra-fine silica fume not only increases the water demand of cement, but also silica fume resources are limited, expensive

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