阅读说明：本技术 一种混凝土钢筋阻锈剂及其制备方法和使用方法 (Concrete reinforcement corrosion inhibitor and preparation method and use method thereof ) 是由 余林文 蒋金钰 毕仁可 余杨 陈梦竹 吴芳 唐静 于 2020-05-13 设计创作，主要内容包括：本发明涉及一种混凝土钢筋阻锈剂及其制备方法和使用方法,属于建筑材料技术领域。该混凝土钢筋阻锈剂为经木质素磺酸钠表面改性后的层状双金属氢氧化物,层状双金属氢氧化物经木质素磺酸钠表面改性后,其比表面积得到了大幅增加,从而增加了其表面吸附能力及层间阴离子交换能力,进而提高了对氯离子的固结能力。该阻锈剂为内掺型阻锈剂,能有效改善混凝土的孔结构,从而延缓外界腐蚀性介质进入混凝土内部的速率。该阻锈剂原料简单易得,成本低廉,制备过程简单无毒,为环境友好型阻锈剂,可直接将其加入混凝土中使用,克服了传统阻锈剂的不足,并具有阻锈效果优、环保、高效等优点,可广泛应用于钢筋混凝土工程,具有广阔的应用前景。(The invention relates to a concrete reinforcement corrosion inhibitor, a preparation method and a use method thereof, and belongs to the technical field of building materials. The concrete reinforcement rust inhibitor is a layered double hydroxide subjected to surface modification by sodium lignosulfonate, and the specific surface area of the layered double hydroxide is greatly increased after the surface modification by the sodium lignosulfonate, so that the surface adsorption capacity and the interlayer anion exchange capacity of the layered double hydroxide are increased, and the consolidation capacity to chloride ions is further improved. The rust inhibitor is an internal-doped rust inhibitor, and can effectively improve the pore structure of concrete, thereby delaying the rate of external corrosive media entering the interior of the concrete. The rust inhibitor has the advantages of simple and easily obtained raw materials, low cost, simple and nontoxic preparation process, is an environment-friendly rust inhibitor, can be directly added into concrete for use, overcomes the defects of the traditional rust inhibitor, has the advantages of excellent rust inhibition effect, environmental protection, high efficiency and the like, can be widely applied to reinforced concrete engineering, and has wide application prospect.)

1. The concrete reinforcement corrosion inhibitor is characterized by being a layered double hydroxide subjected to surface modification by sodium lignosulfonate.

2. The concrete bar rust inhibitor of claim 1, wherein the layered double hydroxide is one of calcium aluminum nitrate type hydrotalcite or magnesium aluminum nitrate type hydrotalcite.

3. The method for preparing the concrete reinforcing steel bar rust inhibitor as claimed in claim 2, which is characterized by comprising the following steps:

(1) weighing sodium lignosulfonate, sodium nitrate, sodium hydroxide, calcium nitrate tetrahydrate or magnesium nitrate hexahydrate and aluminum nitrate nonahydrate;

(2) dissolving calcium nitrate tetrahydrate or magnesium nitrate hexahydrate and aluminum nitrate nonahydrate in boiling water to obtain a solution I; dissolving sodium lignosulfonate, sodium nitrate and sodium hydroxide in boiling water together to obtain a solution II; uniformly mixing the solution I and the solution II to obtain a reaction solution;

(3) and (3) moving the reaction liquid to a reaction kettle, carrying out hydrothermal reaction at the temperature of 120-180 ℃ for 24-48h, carrying out suction filtration and washing to obtain a filter cake, carrying out vacuum drying on the filter cake at the temperature of 40-60 ℃, and then grinding.

4. The method of claim 3, wherein in step (1), the mass ratio of the sodium lignosulfonate, the sodium nitrate, the sodium hydroxide, the calcium nitrate tetrahydrate and the aluminum nitrate nonahydrate is 0.5-1.5:16-18:10-21:22.5-25: 8.5-20.

5. The method of claim 3, wherein in step (1), the mass ratio of the sodium lignosulfonate, the sodium nitrate, the sodium hydroxide, the magnesium nitrate hexahydrate and the aluminum nitrate nonahydrate is 0.5-1.5:16-18:10-21:24.5-27: 8.5-20.

6. The method of claim 3, wherein in the step (2), calcium nitrate tetrahydrate or magnesium nitrate hexahydrate is dissolved in boiling water together with aluminum nitrate nonahydrate and then subjected to ultrasonic treatment to obtain a solution I; dissolving sodium lignosulfonate, sodium nitrate and sodium hydroxide in boiling water, and performing ultrasonic treatment to obtain a solution II.

7. The method of claim 3, wherein in step (2), the solution I and the solution II are mixed uniformly as follows: mixing the solution I and the solution II at 60-70 ℃, and stirring for 30-45 min.

8. The method according to claim 3, wherein in the step (3), the suction filtration washing is specifically: firstly, filtering and washing with water for 3-5 times, and then filtering and washing with absolute ethyl alcohol for 3-5 times.

9. The method according to claim 3, wherein in the step (3), the grinding is carried out by: grinding until the powder is sieved by a 200-mesh sieve.

10. The use method of the concrete reinforcement rust inhibitor, which is described in claim 1 or 2, is characterized in that the method comprises the following steps: the concrete reinforcement rust inhibitor is mixed into the reinforced concrete according to 2-4% of the weight of the cementing material in the concrete.

Technical Field

The invention belongs to the technical field of building materials, and particularly relates to a concrete reinforcement corrosion inhibitor, and a preparation method and a use method thereof

Background

As an economical and practical building material, the reinforced concrete is widely applied to facilities such as bridges, wharfs and the like. With the improvement of the requirement on the use performance of the reinforced concrete, the durability problem of the reinforced concrete in a complex environment is more prominent. Chloride corrosion is currently recognized as one of the major causes of failure in reinforced concrete structures, being the most hazardous exposed environment that reinforced concrete may encounter during its useful life. The corrosion of the steel bars can reduce the service life of the reinforced concrete, seriously affect the service performance and the durability of the building and cause huge economic loss. Therefore, the research on the rust-resisting measures of the reinforced concrete has important significance for prolonging the service life of the concrete and reducing the maintenance cost.

Layered double hydroxide (L DH) [ M ]²⁺ _1-xM³⁺ _x(OH)₂]Aⁿ _-x/n·yH₂O) two-dimensional laminate with nanometer magnitude is longitudinally and orderly arranged to form a three-dimensional crystal structure, the skeleton of the laminate is provided with positive charges, anions exist among layers, the laminate is connected with a main body laminate through weak chemical bonds (hydrogen bonds, ionic bonds and the like) and balanced with the main body laminate, and the whole laminate is electrically neutralInorganic intercalation material with Cl < - >. However, the above materials still have problems such as poor dispersibility in cement base materials, and the corrosion resistance of concrete reinforcements is limited, and further improvement is still needed.

The addition of the rust inhibitor is one of measures for improving the durability of reinforced concrete, and the rust inhibitor can effectively delay the corrosion of chloride ions to reinforcing steel bars. However, the traditional rust inhibitor has the defects of high price, poor rust inhibition effect, toxicity, harm, environmental friendliness and the like, so that the research on the reinforcing steel bar rust inhibitor which is low in price, good in rust inhibition effect, non-toxic, harmless, environment-friendly and beneficial to popularization is still the development direction of the current rust inhibitor.

Disclosure of Invention

In view of the above, an object of the present invention is to provide a concrete reinforcement corrosion inhibitor; the second purpose is to provide a preparation method of the concrete reinforcement rust inhibitor; the third purpose is to provide a use method of the concrete reinforcement rust inhibitor.

In order to achieve the purpose, the invention provides the following technical scheme:

1. the concrete reinforcement corrosion inhibitor is a layered double hydroxide which is subjected to surface modification by sodium lignosulfonate.

Preferably, the layered double hydroxide is one of calcium aluminum nitrate type hydrotalcite or magnesium aluminum nitrate type hydrotalcite.

2. The preparation method of the concrete reinforcement rust inhibitor comprises the following steps:

(1) weighing sodium lignosulfonate, sodium nitrate, sodium hydroxide, calcium nitrate tetrahydrate or magnesium nitrate hexahydrate and aluminum nitrate nonahydrate;

(2) dissolving calcium nitrate tetrahydrate or magnesium nitrate hexahydrate and aluminum nitrate nonahydrate in boiling water to obtain a solution I; dissolving sodium lignosulfonate, sodium nitrate and sodium hydroxide in boiling water together to obtain a solution II; uniformly mixing the solution I and the solution II to obtain a reaction solution;

(3) and (3) moving the reaction liquid to a reaction kettle, carrying out hydrothermal reaction at the temperature of 120-180 ℃ for 24-48h, carrying out suction filtration and washing to obtain a filter cake, carrying out vacuum drying on the filter cake at the temperature of 40-60 ℃, and then grinding.

Preferably, in the step (1), the mass ratio of the sodium lignosulfonate, the sodium nitrate, the sodium hydroxide, the calcium nitrate tetrahydrate and the aluminum nitrate nonahydrate is 0.5-1.5:16-18:10-21:22.5-25: 8.5-20.

Preferably, in the step (1), the mass ratio of the sodium lignosulfonate, the sodium nitrate, the sodium hydroxide, the magnesium nitrate hexahydrate and the aluminum nitrate nonahydrate is 0.5-1.5:16-18:10-21:24.5-27: 8.5-20.

Preferably, in the step (2), calcium nitrate tetrahydrate or magnesium nitrate hexahydrate and aluminum nitrate nonahydrate are dissolved in boiling water together and then are subjected to ultrasonic treatment to obtain a solution I; dissolving sodium lignosulfonate, sodium nitrate and sodium hydroxide in boiling water, and performing ultrasonic treatment to obtain a solution II.

Preferably, in the step (2), the solution I and the solution II are mixed uniformly as follows: mixing the solution I and the solution II at 60-70 ℃, and stirring for 30-45 min.

Preferably, in the step (3), the suction filtration and washing specifically comprises: firstly, filtering and washing with water for 3-5 times, and then filtering and washing with absolute ethyl alcohol for 3-5 times.

Preferably, in the step (3), the grinding is specifically: grinding until the powder is sieved by a 200-mesh sieve.

3. The use method of the concrete reinforcement corrosion inhibitor comprises the following steps: the concrete reinforcement rust inhibitor is mixed into the reinforced concrete according to 2-4% of the weight of the cementing material in the concrete.

The invention has the beneficial effects that: the invention provides a concrete reinforcement rust inhibitor and a preparation method and a use method thereof. The corrosion inhibitor is a doped corrosion inhibitor, and can effectively improve the pore structure of concrete, thereby delaying the rate of external corrosive media entering the interior of the concrete. The rust inhibitor has the advantages of simple and easily-obtained raw materials, low cost, simple and nontoxic preparation process, is an environment-friendly green concrete reinforcement rust inhibitor, can be directly added into concrete for use, overcomes the defects of the traditional rust inhibitor, has the advantages of excellent rust inhibiting effect, environmental protection, high efficiency and the like, can be widely applied to reinforced concrete engineering, and has wide application prospect.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the means of the instrumentalities and combinations particularly pointed out hereinafter.

Drawings

For the purposes of promoting a better understanding of the objects, aspects and advantages of the invention, reference will now be made to the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is an SEM photograph of Ca-S L S-L DH prepared in example 1 and Ca-L DH prepared in comparative example (in FIG. 1, a is an SEM photograph of Ca-S L S-L DH prepared in example 1, and b is an SEM photograph of Ca-L DH prepared in comparative example in FIG. 1);

FIG. 2 is XRD patterns of Ca-S L S-L DH prepared in example 1 and Ca-L DH prepared in comparative example;

FIG. 3 is a FT-IR chart of Ca-S L S-L DH prepared in example 1 and Ca-L DH prepared in comparative example;

FIG. 4 is a graph showing isothermal equilibrium adsorption of chloride ions of Ca-S L S-L DH prepared in example 1 and Ca-L DH prepared in comparative example (a in FIG. 4 is a graph showing isothermal equilibrium adsorption of chloride ions of Ca-S L S-L DH prepared in example 1, and b in FIG. 4 is a graph showing isothermal equilibrium adsorption of chloride ions of Ca-L DH prepared in comparative example);

FIG. 5 shows the self-etching potentials with Cl for each set of examples 4^-Graphs showing the trend of the addition concentration (in FIG. 5, a is Ca-L DH (2%), Ca-L DH (4%), Ca-L DH (6%) and the self-etching potential of the control group with Cl^-The trend graph of the added concentration is shown in b in FIG. 5 as Ca-S L S-L DH (2%), Ca-S L S-L DH (4%), Ca-S L S-L DH (6%)And control group self-corrosion potential with Cl^-Add concentration trend graph);

FIG. 6 shows the immersion period of 18 days (C) for each set of the steel bars in example 4_Cl0.18 mol/L) (a 1 in fig. 6 is the Nyquist diagram of the electrochemical impedance spectrum, and a2 in fig. 6 is the Bode diagram of the electrochemical impedance spectrum);

FIG. 7 is a graph showing the test results of the effect of different amounts of Ca-S L S-L DH and Ca-L DH on the compressive strength of mortar in example 5.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.