阅读说明：本技术 一种水泥基材料防腐剂及其使用方法 (Cement-based material preservative and use method thereof ) 是由 陈琴 秦琛 胡颖 田玉莲 周凤姣 周业琼 王林立 于 2019-11-19 设计创作，主要内容包括：本发明公开了一种水泥基材料防腐剂及其使用方法,该防腐剂包括内部防腐剂和外部防腐剂,内部防腐剂包括重量比为5-20：5-15：10-30：5-10：5-10的海泡石、硅灰石、硅藻土、蒙脱石以及煅烧层状双金属氢氧化物；外部防腐剂包括敏化剂和空穴捕获剂；使用时,按100重量份混凝胶凝材料加入5-20重量份内部防腐剂计,将水泥基材料干料和内部防腐剂加水混合均匀后筑模成型；光照、有CO<Sub>2</Sub>条件下,将成型的水泥基材料浸渍在外部防腐剂中,CO<Sub>2</Sub>与胶凝材料表面的水化产物Ca(OH)<Sub>2</Sub>矿化形成CaCO<Sub>3</Sub>,形成方解石致密防护层,从而阻止了CO<Sub>2</Sub>向材料内部的迁移。该方法制备出的水泥基材料具有快硬和早强性能,且耐Cl<Sup>-</Sup>和SO<Sub>4</Sub><Sup>2-</Sup>及碳化并存的复杂海水环境侵蚀,不易开裂,使用方便,成本低廉。(The invention discloses a cement-based material preservative and a use method thereof, wherein the preservative comprises an internal preservative and an external preservative, and the internal preservative comprises the following components in a weight ratio of (5-20): 5-15: 10-30: 5-10: 5-10 parts of sepiolite, wollastonite, diatomite, montmorillonite and calcined layered double hydroxide; the external preservative comprises a sensitizer and a hole trapping agent; when in use, the cement-based material dry material and the internal preservative are added with water and are uniformly mixed according to the weight ratio of 100 parts of the concrete cementing material to 5-20 parts of the internal preservative, and then the mixture is molded; light irradiation with CO 2 Under the condition of formingImpregnated with an external preservative, CO 2 Hydration products Ca (OH) with the surface of the cementitious Material 2 Mineralizing to form CaCO 3 Forming a dense protective layer of calcite, thereby stopping CO 2 Migration into the interior of the material. The cement-based material prepared by the method has quick hardening and early strength performances and Cl resistance ‑ And SO 4 2‑ And complex seawater environment corrosion coexisting with carbonization, difficult cracking, convenient use and low cost.)

1. A cement-based material preservative comprising an internal preservative and an external preservative, wherein the internal preservative comprises, by weight, 5-20: 5-15: 10-30: 5-10: 5-10 parts of sepiolite, wollastonite, diatomite, montmorillonite and calcined layered double hydroxide; the external preservative includes a sensitizer and a hole trap.

2. The cement-based material preservative according to claim 1, wherein: the sensitizer is one or more of rhodamine B, methylene blue and chlorophyll; the hole trapping agent is one or more of methanol, triethanolamine and lactic acid; the metal in the calcined layered double hydroxide is any two or more of magnesium, calcium, iron, zinc, magnesium and aluminum.

3. The cement-based material preservative according to claim 1, wherein: the external preservative also comprises a solvent, and the solvent, the sensitizer and the hole trapping agent form a crystal mineralized liquid.

4. The cement-based material preservative according to claim 3, wherein: the solvent is water.

5. The cement-based material preservative according to claim 3 or 4, wherein: in the crystal mineralized liquid, the sensitizerThe concentration is 1X 10^-7-5×10^-6mol/L, and the volume fraction of the hole trapping agent is 4-12%.

6. Use of a cement-based material preservative as claimed in any one of claims 1 to 5.

7. Use of the cement-based material preservative according to any of the claims 1-5, comprising the steps of: adding 5-20 parts by weight of internal preservative into the cement-based material dry material according to 100 parts by weight of the cementing material in the cement-based material, adding water, uniformly mixing, and then molding; preparing external preservative into mineralized liquid, soaking the formed cement-based material in the external preservative, and irradiating the formed cement-based material with CO₂Under the existing condition, the protective layer is soaked to the surface of the cement-based material to form a calcite compact protective layer.

8. Use according to claim 7, characterized in that: the cement-based material dry material comprises a cementing material, sand and stone in a weight ratio of 1:1.1-1.3: 2.5-2.7; the cementing material is ordinary portland cement or sulphoaluminate cement.

9. Use according to claim 7, characterized in that: the preparation method of the external preservative comprises the following steps: adding a sensitizing agent and a hole trapping agent into the solvent under the condition of keeping out of the sun, and uniformly mixing to obtain the external preservative.

10. Use according to claim 7, characterized in that: and a polycarboxylic acid water reducing agent is also added in the cement-based material dry material mould building and forming process.

Technical Field

The invention relates to the technical field of building materials, in particular to a cement-based material preservative and a using method thereof.

Background

Ordinary cement-based materials are susceptible to Cl in seawater^-、SO₄ ^2-And H in organic soil⁺The corrosion of the cement-based materials can cause serious damage to the building structure after being in the environment for a long time, and therefore, the corrosion resistance of the cement-based materials needs to be improved. The paint for cement-base material anticorrosion includes outer protection of organic coating material, anticorrosion agent with organic matter as main component, common cement-base material admixture and organic additive compounded type anticorrosion agent, and few nano components.

However, the above materials for cement-based materials to resist corrosion have the following problems: (1) the use of a large amount of admixture can reduce the amount of alkaline substances in cement slurry and the Ca/Si ratio of C-S-H gel, and weaken the carbonization resistance of the cement slurry; (2) the nano material has high cost, large water demand per se and influences the working performance, so that the application in practical engineering is limited; (3) the organic coating is easy to age, low in acid and alkali corrosion resistance, and short in service cycle due to the problem of adhesive force between the coating and a cement-based material matrix.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a cement-based material preservative for performing double high corrosion resistance protection on a cement-based material from inside to outside.

The invention provides a cement-based material preservative, which comprises an internal preservative and an external preservative, wherein the internal preservative comprises the following components in a weight ratio of 5-20: 5-15: 10-30: 5-10: 5-10 parts of sepiolite, wollastonite, diatomite, montmorillonite and calcined layered double hydroxide; external preservatives include sensitizers and hole traps. Preferably, the sensitizer is one or more of rhodamine B, methylene blue and chlorophyll; the hole trapping agent is one or more of methanol, triethanolamine and lactic acid; the metal in the calcined layered double hydroxide is any two or more of magnesium, calcium, iron, zinc, magnesium and aluminum.

On the basis of the technical scheme, the external preservative also comprises a solvent, and the solvent, the sensitizer and the hole trapping agent form a crystal mineralized liquid. Preferably, the solvent is water.

On the basis of the technical scheme, the concentration of a sensitizer in the crystal mineralized liquid is 1 multiplied by 10^-7-5×10^-6mol/L, and the volume fraction of the hole trapping agent is 4-12%.

The invention also provides application of the cement-based material preservative.

The invention also provides a using method of the cement-based material preservative, which comprises the following steps: adding 5-20 parts by weight of internal preservative into the cement-based material dry material according to 100 parts by weight of the cementing material in the cement-based material, adding water, uniformly mixing, and then molding; preparing external preservative into mineralized liquid, soaking the formed cement-based material in the external preservative, and irradiating the formed cement-based material with CO₂Under the existing condition, the protective layer is soaked to the surface of the cement-based material to form a calcite compact protective layer.

Preferably, the cement-based material dry material comprises a cementing material, sand and stone in a weight ratio of 1:1.1-1.3: 2.5-2.7; the cementitious material is preferably ordinary portland cement or sulphoaluminate cement.

On the basis of the technical scheme, the preparation method of the crystallization mineralization liquid comprises the following steps: adding a sensitizing agent and a hole trapping agent into the solvent under the condition of keeping out of the sun, and uniformly mixing to obtain the crystallized mineralized liquid.

On the basis of the technical scheme, the polycarboxylic acid water reducing agent is also added in the cement-based material dry material mould building and forming process.

The principle of the invention is as follows:

adding sepiolite, wollastonite, diatomite, montmorillonite and calcined layered double hydroxide into a cement-based material: the water absorption characteristic of the montmorillonite is utilized to reduce the effective water-gel ratio of the marine cement-based material cementing material, accelerate the reaction and promote the setting and hardening; and a rapid mass transfer channel is provided by utilizing a porous structure rich in diatomite, and a large amount of high-activity amorphous SiO contained in diatomite is utilized₂The method has the characteristics that the method interacts with a cementing material in a cement-based material, changes the proportion of Si/Al and Ca/Si, prepares C-S-H gel with high stability and high strength, influences the formation and transformation of hydration products, reduces the porosity of a cementing system, optimizes a pore structure and promotes compactness; the micro fiber forms of sepiolite and wollastonite are mutually overlapped with cement hydration products to effectively promote compactness, improve the formation and development of microcracks and form an irregular net-shaped structure, so that the structure is more compact, the crack expansion can be effectively prevented, and the breaking strength is improved; the layered double hydroxide absorbs aggressive anions to realize corrosion prevention by utilizing the structure reconstruction and the memory effect after the calcination treatment; based on the synergistic effect, the functions of quick setting, early strength, no cracking and permeation resistance of the cement-based material are realized, and Cl is prevented^-、SO₄ ^2-、CO₃ ^2-The transmission and diffusion of the cement-based material improve the corrosion resistance of the cement-based material under the seawater service condition. The invention captures CO by catalyzing crystallization mineralization liquid by utilizing illumination outside the cement-based material₂Under the assistance of photoelectron and cavity, hydration products Ca (OH) on the surface of the material are obtained through mineralization reaction₂To fill the cracks with calcium carbonateThe gap or protective film agent can achieve surface corrosion prevention, and simultaneously improve the mechanical property, the anti-erosion capability and the self-repairing function of the cement-based material.

Compared with the prior art, the invention has the following advantages and beneficial effects:

1. the method adopts the method of coupling photosynthesis and biomineralization, does not need to adopt special means for maintenance, has the characteristics of high efficiency, simplified maintenance conditions, simple preparation process, no pollution and the like, and the formed mineral has stable property and strong durability, and carbon dioxide generated in the process can be effectively captured and utilized to slow down the greenhouse effect.

2. After the surface of the cement-based material is subjected to surface anticorrosion treatment, the material is fast to harden and good in early strength performance, the chloride ion electric flux test result of the material is less than 200C, the strength loss of the sample after 28 times of sulfate dry-wet circulation is less than 1%, the bending strength and the compressive strength of the sample in 1 day age are respectively improved by 1MPa-3MPa and 5MPa-20MPa, and the cement-based material is free of shrinkage and cracking.

Drawings

FIG. 1 is a schematic diagram of the preparation process and mechanism of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be further described below. The cement used in the following examples was PO42.5 cement, the sand had an average particle size of 1-1.4mm and the stone had an average particle size of 2.36-4.75 mm.

Comparative example 1

Preparing raw materials according to the mixing ratio of the conventional cement-based material C30 (cementing material: sand: stone: water: 1:1.18:2.63: 0.41); stirring the prepared sand and stone in a concrete mixer for 2min to obtain aggregate; then adding the prepared cementing material into a concrete mixer, and mixing and stirring for 3min to obtain a concrete dry mixed material; stirring the concrete dry mixed material, adding three-quarters of the prepared water within 30s, and continuing stirring for 2 min; blending the polycarboxylate superplasticizer into the remaining one fourth of the mixed water, adding the mixture within 10s, and finally stirring for 2min to obtain a concrete wet material; pouring the concrete wet material into a mould, and then placing the mould on a vibration table to vibrate for 10 s; placing the vibrated concrete wet material in a cement-based material standard box, maintaining for 24 hours, and demolding; and (3) submerging the demolded cement-based material in water, and standing for 24 hours at room temperature under natural illumination to obtain the cement-based material.

Comparative example 2

Preparing raw materials according to the mixing ratio of the conventional cement-based material C40 (cementing material: sand: stone: water: 1:1.08:2.41: 0.40); stirring the prepared sand and stone in a concrete mixer for 2min to obtain aggregate; then adding the prepared cementing material into a concrete mixer, and mixing and stirring for 3min to obtain a concrete dry mixed material; stirring the concrete dry mixed material, adding three-quarters of the prepared water within 30s, and continuing stirring for 2 min; blending the polycarboxylate superplasticizer into the remaining one fourth of the mixed water, adding the mixture within 10s, and finally stirring for 2min to obtain a concrete wet material; pouring the concrete wet material into a mould, and then placing the mould on a vibration table to vibrate for 10 s; placing the vibrated concrete wet material in a cement-based material standard box, maintaining for 24 hours, and demolding; and (3) submerging the demolded cement-based material in water, and standing for 24 hours at room temperature under natural illumination to obtain the cement-based material.

Comparative example 3

Preparing raw materials according to the mixing ratio of the conventional cement-based material C35 (cementing material: sand: stone: water: 1:1.37:2.78: 0.46); stirring the prepared sand and stone in a concrete mixer for 2min to obtain aggregate; then adding the prepared cementing material into a concrete mixer, and mixing and stirring for 3min to obtain a concrete dry mixed material; stirring the concrete dry mixed material, adding three-quarters of the prepared water within 30s, and continuing stirring for 2 min; blending the polycarboxylate superplasticizer into the remaining one fourth of the mixed water, adding the mixture within 10s, and finally stirring for 2min to obtain a concrete wet material; pouring the concrete wet material into a mould, and then placing the mould on a vibration table to vibrate for 10 s; placing the vibrated concrete wet material in a cement-based material standard box, maintaining for 24 hours, and demolding; and (3) submerging the demolded cement-based material in water, and standing for 24 hours at room temperature under natural illumination to obtain the cement-based material.