Anticorrosive admixture for marine concrete and marine concrete

Abstract

The present invention belongs to the technical field of building materials, and in particular discloses an anti-corrosion admixture for marine concrete, comprising, by mass percentage, 5% to 20% of an anti-seepage component, 1% to 10% of a nano-component, 0.01% to 0.05% of a defoaming component, and the remainder being water. The present invention also discloses marine concrete comprising the aforementioned anti-corrosion admixture. The anti-corrosion admixture of the present invention, on the one hand, utilizes macromolecular organic matter with a specific molecular formula, which, after being incorporated into concrete, forms a complex with metal ions generated by dissolution of cement, thereby improving the corrosion resistance of the concrete; on the other hand, the nano-component acts as a hydration nucleation agent, thereby increasing the density of the concrete matrix. Simultaneously, the defoaming component improves its construction performance and refines the internal pore structure of the concrete. The anti-corrosion admixture according to the present invention does not affect the state of fresh concrete or the strength of hardened concrete during use, has no negative impact on the shrinkage of marine concrete, and does not affect its workability. It is odorless, environmentally friendly, and convenient to construct.

Description

Technical Field

[0001] The present invention belongs to the technical field of building materials, and in particular relates to an anti-corrosion admixture for marine engineering concrete, and marine engineering concrete having the anti-corrosion admixture. Background Art

[0002] Marine concrete, also known as ocean concrete, refers to concrete designed for use in marine environments and exposed to seawater and wind. Frequent or periodic contact with seawater exposes marine concrete to the physical and chemical effects of seawater and the marine atmosphere (which contains chloride ions), significantly shortening its service life. Therefore, in addition to meeting design strength and construction requirements, marine concrete must also exhibit excellent impermeability, corrosion resistance, and resistance to steel corrosion.

[0003] The main factors affecting the durability of marine concrete are steel corrosion and sulfate attack. The primary cause of steel corrosion is chloride ions in seawater. Under wave and tidal conditions, chloride ions penetrate the concrete and reach the steel surface. Due to the dry-wet cycle, the chloride ion concentration on the steel surface increases, ultimately destroying the passive film on the steel surface, causing steel corrosion and resulting in expansion, cracking and erosion of the concrete surface.

[0004] Marine concrete is often designed with large amounts of composite, highly reactive mineral admixtures and high-performance water-reducing agents, or by increasing concrete strength, increasing the thickness of the protective layer, and applying protective coatings to enhance its durability. However, these methods fail to fundamentally inhibit the transmission of harmful media within the concrete. Therefore, considering the corrosion resistance requirements of marine concrete, the development of anti-corrosion admixtures for marine concrete is of great practical significance for improving its durability.

[0005] Corrosion media suppression materials are composite chemical building materials that, when added to concrete, can reduce its water absorption, electrical flux, and chloride ion diffusion coefficient, thereby improving its durability. These corrosion media suppression materials are generally categorized into three categories: fatty acid salts, silicones, and renewable polymer powders. Fatty acid salts are widely used, but because they effectively reduce the surface tension of liquids, they are prone to generating large amounts of bubbles during strong mechanical mixing, which can affect construction operations.

[0006] In summary, developing an anti-corrosion admixture for marine concrete that reduces bubble generation is an important direction for solving the problem of using marine concrete anti-corrosion agents. Summary of the Invention

[0007] In order to solve the problems existing in the above-mentioned prior art, the present invention provides an anti-corrosion admixture for marine engineering concrete. When applied to marine engineering concrete, the anti-corrosion admixture has the advantages of being not easy to foam and convenient to construct, and can effectively extend the service life of marine engineering concrete in harsh environments.

[0008] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0009] An anticorrosive admixture for marine concrete, comprising the following components mixed in percentage by mass:

[0010]

[0011] Among them, the anti-seepage component has a simple structural formula of R1HNOCCH2CH2COO(CHCH3CH2O) n The macromolecular organic compound CH2R2, R1 and R2 are both C5-C20 saturated alkyl groups, and the value of n is 10-50.

[0012] Furthermore, the nano-component is at least one of nano-metal oxide, nano-non-metal oxide, and nano-metal.

[0013] Furthermore, the nano-component is selected from at least one of nano-silicon dioxide, nano-titanium dioxide, nano-aluminum oxide, nano-grade nickel powder, and nano-copper oxide.

[0014] Furthermore, the defoaming component is at least one of phosphates, alcohols, amides, silicones, and polyethers.

[0015] Furthermore, the defoaming component is selected from polydimethylsiloxane, diisobutyl carbinol, polydimethylsiloxane, and carboxylic acid-N-alkylamide.

[0016] Another object of the present invention is to provide a marine concrete comprising any of the above-mentioned anti-corrosion admixtures.

[0017] The anticorrosive admixture of the present invention, one of which utilizes an organic macromolecule with a hydrophobic structure as a whole, that is, the end groups at both ends are lipophilic macromolecular saturated alkyl groups, wherein the ester bond is hydrolyzed under the alkaline conditions of the concrete, and the carboxylic acid structure with a macromolecular alkyl group and the amino structure generated by hydrolysis and the metal ions (such as calcium ions, etc.) generated by cement dissolution form new hydrophobic complexes under the action of charge, which are distributed in the pores of the concrete, to play a role in suppressing water transmission and improve the corrosion resistance of the concrete; the second one utilizes nano components to promote hydration nucleation and improve the concrete matrix density; the third one wherein the defoaming component improves the construction performance of this anticorrosive admixture, while refining the internal pore structure of the concrete, and promoting uniform pore distribution. The anticorrosive admixture provided by the present invention does not affect the state of fresh concrete and the strength of hardened concrete during use, that is, the marine concrete with the anticorrosive admixture does not have a negative impact in terms of shrinkage, is odorless, environmentally friendly, and is easy to construct. The workability of the marine concrete with the aforementioned anticorrosive admixture does not have a negative impact or even has an improvement effect, and corrosion resistance and durability are also improved. DETAILED DESCRIPTION

[0018] Hereinafter, embodiments of the present invention will be described in detail. However, the present invention may be implemented in many different forms, and the present invention should not be construed as being limited to the specific embodiments set forth herein. Instead, these embodiments are provided to explain the principles of the present invention and its practical application, thereby enabling other persons skilled in the art to understand the various embodiments of the present invention and various modifications suitable for specific intended applications.

[0019] In response to the problems of foaming and construction difficulties with existing marine concrete preservatives, the present invention has developed a new marine concrete preservative admixture. The preservative admixture includes the components shown in Table 1 below.

[0020] Table 1 Components of anticorrosive admixtures

[0021] Unit: wt%

[0022]

[0023] In Table 1, the anti-seepage component has a simple molecular formula of R1HNOCCH2CH2COO(CHCH3CH2O) n The macromolecular organic compound CH2R2, R1 and R2 are both C5-C20 saturated alkyl groups, which can be straight-chain alkyl groups or branched alkyl groups, and the value of n is 10-50.

[0024] The above-mentioned macromolecular organic matter is obtained by separating the components R1NH2, HOOCCH2CH2COOH, HO(CHCH3CH2O) nCH2R2 is placed in a reaction kettle in proportion, heated to 110℃~150℃, reacted for 4h~8h, and then cooled.

[0025] The nano component is selected from at least one of nano metal oxides, nano non-metal oxides, and nano metals, specifically at least one of nano silicon dioxide, nano titanium dioxide, nano aluminum oxide, nano nickel powder, and nano copper oxide.

[0026] Furthermore, the defoaming component is selected from at least one of phosphates, alcohols, amides, silicones, and polyethers, such as at least one of polydimethylsiloxane, diisobutyl carbinol, polydimethylsiloxane, and carboxylic acid-N-alkylamide.

[0027] The anti-corrosion admixture of the present invention, on the one hand, utilizes a molecular formula that is a hydrophobic structure as a whole, that is, the end groups at both ends are lipophilic macromolecular saturated alkyl groups, wherein the ester bond is hydrolyzed under the alkaline conditions of the concrete, and the carboxylic acid structure and amino structure with macromolecular alkyl generated by hydrolysis and the metal ions (such as calcium ions, etc.) generated by cement dissolution form new hydrophobic complexes under the action of charge, which are distributed in the pores of the concrete to inhibit the transmission of moisture and improve the corrosion resistance of the concrete; on the other hand, the nano-components are used to play the role of hydration nucleation to improve the density of the concrete matrix. At the same time, the defoaming component therein improves the construction performance of this anti-corrosion admixture, and at the same time, it can refine the internal pore structure of the concrete when applied, and promote the uniform distribution of pores. The anti-corrosion admixture does not affect the state of the fresh concrete and the strength of the hardened concrete during use, so that the marine concrete to which it is applied does not have a negative impact on shrinkage, has no odor, is environmentally friendly, and is easy to construct.

[0028] In addition to the aforementioned performance advantages, this antiseptic admixture also features a simple preparation method. The corresponding anti-seepage component, nano-component, and defoaming component need only be dissolved in water according to the corresponding ratios. Generally speaking, the nano-component can be prepared by first preparing an aqueous dispersion of the nano-component, and then dissolving the aqueous dispersion, the anti-seepage component, and the defoaming component in water. Preferably, a nano-component / aqueous dispersion with a concentration of 5% to 30% (wt%) can be prepared first.

[0029] The marine concrete containing the aforementioned anti-corrosion admixture of the present invention has excellent anti-corrosion effect, and its erosion resistance and durability are improved. Its workability is not negatively affected and is even improved to a certain extent. Moreover, the amount of foaming during the application process is controllable, which is beneficial to construction.

[0030] The beneficial effects of the aforementioned anti-corrosion admixture of the present invention will be demonstrated below through specific examples. To this end, various compositions of the anti-corrosion admixture are provided and applied to marine concrete.

[0031] Table 1 shows the specific components of the antiseptic admixtures in different proportions in Examples 1-11.

[0032] Table 1 Components of the anticorrosive admixtures in Examples 1-11

[0033] Unit: wt%

[0034]

[0035]

[0036] Table 2 shows the composition of marine concrete containing the anti-corrosion admixtures listed in Table 1. The basic components are not specifically limited here, and those skilled in the art will refer to existing technologies. The marine concrete shown in Table 2 is marine concrete containing the anti-corrosion admixtures listed in Table 1. The basic components of the marine concrete in each example are the same, differing only in the specific components of the anti-corrosion admixtures. Table 2 does not list each of the 11 examples one by one.

[0037] Table 2 Composition of marine concrete

[0038] Unit: kg / m 3

[0039]

[0040] In order to demonstrate the effect of the anticorrosive admixture in the present invention, concrete without anticorrosive admixture was used as a control test. The difference between the ordinary concrete and the marine concrete in the above embodiment is that the ordinary concrete does not contain anticorrosive admixture, and the corresponding amount is added to the water amount; that is, the water amount in the ordinary concrete is 154 kg / m 3 .

[0041] At the same time, in order to reflect the effects of each component in the aforementioned anti-corrosion admixture of the present invention, an anti-corrosion agent obtained without one of the components was used as a control test, as shown in Table 3; and comparative marine concrete was obtained according to the components of the marine concrete shown in Table 2 above.

[0042] Table 3 Components of comparative preservatives in Comparative Examples 1-3

[0043] Unit: wt%

[0044]

[0045] The air content, water absorption rate and 28d compressive strength of each marine concrete and ordinary concrete obtained in Examples 1-11 and each comparative marine concrete obtained in Comparative Examples 1-3 were tested, as shown in Table 4.

[0046] Table 4 Performance test of marine concrete, ordinary concrete and comparative marine concrete

[0047]

[0048] The workability of marine concrete is characterized by the slump of concrete. The larger the slump is within the appropriate range, the better the workability. The anti-corrosion performance is mainly characterized by the water absorption rate of the hardened concrete. The higher the water absorption rate, the worse the anti-corrosion performance. The air content indicates the degree of blistering during the application process. The greater the air content, the more blistering there is, which is less conducive to construction operations.

[0049] By comparing the data of ordinary concrete in Table 4 with the marine concrete in Examples 1-11, it can be seen that, firstly, the slump of the marine concrete in the above 11 examples is improved compared with that of ordinary concrete, indicating that the aforementioned anti-corrosion admixture of the present invention has no negative effect on the workability of the marine concrete to which it is applied, and may even improve the workability; secondly, the aforementioned anti-corrosion admixture of the present invention can improve the air content of concrete and have good corrosion resistance and mechanical properties. By comparing the data of the comparative marine concrete in Comparative Examples 1-3 with the marine concrete in Examples 1-11, it can be seen that each component of the aforementioned anti-corrosion admixture is indispensable, otherwise it will lead to adverse consequences such as decreased anti-corrosion performance, easy blistering during use, or decreased compressive strength. It can be seen that the three components of the anti-corrosion admixture work together in the marine concrete to improve the corrosion resistance and workability of the marine concrete.

[0050] While the invention has been shown and described with reference to particular embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the claims and their equivalents.

Claims

1. An anticorrosive admixture for marine concrete, characterized in that: It is composed of the following components mixed in percentage by mass: Among them, the anti-seepage component has a simple structural formula of R1HNOCCH2CH2COO(CHCH3CH2O) n The macromolecular organic compound of CH2R2, R1 and R2 are both C5-C20 saturated alkyl groups, and the value of n is 10-50; The anti-seepage component is prepared by mixing components R1NH2, HOOCCH2CH2COOH, HO(CHCH3CH2O) n CH2R2 is added to a reaction kettle in proportion, heated to 110℃~150℃, and reacted for 4h~8h to prepare the product; The nano-component is selected from at least one of nano-metal oxides, nano-silicon dioxide, and nano-grade nickel powder.

2. The antiseptic admixture according to claim 1, characterized in that The nano metal oxide is selected from at least one of nano titanium dioxide, nano aluminum oxide, and nano copper oxide.

3. The antiseptic admixture according to claim 2, characterized in that The defoaming component is at least one of phosphates, alcohols, amides, silicones and polyethers.

4. The antiseptic admixture according to claim 3, characterized in that The defoaming component is selected from polydimethylsiloxane, diisobutyl carbinol, polydimethylsiloxane, and carboxylic acid-N-alkylamide.

5. A marine concrete, characterized in that: The invention comprises the antiseptic admixture as described in any one of claims 1 to 4.

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