阅读说明：本技术 一种增强砂浆及其制备方法 (Reinforced mortar and preparation method thereof ) 是由 方季屏 潘微 和艺 祝正申 于 2020-07-07 设计创作，主要内容包括：本发明公开了一种增强砂浆及其制备方法,其中,该增强砂浆包括水泥砂浆、二氧化碳释放树脂球、碳酸钙粉。所述二氧化碳释放树脂球包括高吸水树脂颗粒以及吸收在所述高吸水树脂颗粒中的含二氧化碳的水溶液,所述含二氧化碳的水溶液是通过醋酸与碳酸氢盐水溶液混合反应生成。本发明通过在砂浆内部固定二氧化碳,加速碳化,从而增强砂浆力学强度,提高砂浆抗裂能力。另外,还添加碳酸钙粉,能有效地加速水泥的水化,提高砂浆强度,同时起到固定二氧化碳的效果。而且,该增强砂浆制备方法简便快捷,使用方便,可广泛在各种施工环境和加工厂加工制备和使用。(The invention discloses reinforced mortar and a preparation method thereof, wherein the reinforced mortar comprises cement mortar, carbon dioxide release resin balls and calcium carbonate powder. The carbon dioxide releasing resin ball comprises super absorbent resin particles and a carbon dioxide-containing aqueous solution absorbed in the super absorbent resin particles, wherein the carbon dioxide-containing aqueous solution is generated by mixing and reacting acetic acid and a bicarbonate aqueous solution. According to the invention, carbon dioxide is fixed in the mortar to accelerate carbonization, so that the mechanical strength of the mortar is enhanced, and the crack resistance of the mortar is improved. In addition, calcium carbonate powder is added, so that the hydration of cement can be effectively accelerated, the strength of mortar is improved, and the effect of fixing carbon dioxide is achieved. Moreover, the preparation method of the reinforced mortar is simple, convenient and quick, is convenient to use, and can be widely processed, prepared and used in various construction environments and processing plants.)

1. The reinforced mortar is characterized by comprising cement mortar, carbon dioxide release resin balls and calcium carbonate powder, wherein the carbon dioxide release resin balls and the calcium carbonate powder are respectively mixed in the cement mortar according to a preset weight ratio.

2. The mortar reinforcing method of claim 1, wherein the carbon dioxide-releasing resin balls are added in an amount of 6 to 8% by weight of the cement mortar.

3. The reinforced mortar of claim 1, wherein the carbon dioxide-releasing resin beads comprise superabsorbent resin particles and a carbon dioxide-containing aqueous solution absorbed in the superabsorbent resin particles.

4. The reinforced mortar of claim 2, wherein the expanded particle diameter of the carbon dioxide-releasing resin beads after absorption is 0.25 to 1.50mm, and the average particle diameter of the super absorbent resin particles is 200 mesh or more.

5. The reinforced mortar of claim 2, wherein the super absorbent resin particles are a cross-linked acrylic acid/sodium acrylate copolymer, and the water absorbent resin particles absorb the carbon dioxide-containing aqueous solution in an amount of 30 to 200 times their own particle weight.

6. The reinforced mortar of claim 1, wherein the calcium carbonate powder is added in an amount of 4% to 10% by weight of the cement mortar.

7. The reinforced mortar of any one of claims 1 to 6, wherein the carbon dioxide-releasing resin beads are prepared by:

uniformly mixing bicarbonate, acetic acid and water according to a preset weight ratio to form a mixed aqueous solution; and (3) putting the super absorbent resin particles into the mixed aqueous solution, stirring, soaking, and stopping soaking after the water absorbent resin particles expand to a preset particle size.

8. The reinforced mortar of claim 7, wherein the bicarbonate is calcium bicarbonate, and the weight ratio of the calcium bicarbonate to the acetic acid to the water in the mixed aqueous solution is (10-30) to 15: 50.

9. A process for the preparation of a reinforced mortar as claimed in any one of claims 1 to 8, comprising the following steps:

Preparing carbon dioxide releasing resin balls;

preparing cement mortar, mixing carbon dioxide release resin balls and calcium carbonate powder into the cement mortar, stirring, and obtaining the reinforced mortar after a preset time.

Technical Field

The invention relates to the technical field of cement, in particular to reinforced mortar and a preparation method thereof.

Background

The plastering mortar is affected by physical and chemical actions in the early stage, and shrinkage deformation can occur, mainly comprising chemical shrinkage, temperature shrinkage, drying shrinkage and the like. In practice, the plastering mortar is subjected to various constraints, and thus internal tensile stress is generated when it is shrunk, and the early strength of the plastering mortar is very low, so that early cracking occurs. Therefore, in addition to adding mineral admixtures, fibers, expanding agents, shrinkage reducers and improving the mixing ratio and enhancing the maintenance in proper amount to the plastering mortar, the early strength of the plastering mortar needs to be improved to resist the tensile stress, and the current common practice is to add early strength agents, such as calcium chloride, sodium nitrite, sodium sulfate, calcium sulfate, sodium chloride, calcium nitrite, calcium formate and the like. The early strength agent can promote the hydration of cement, the early strength of the plastering mortar is improved, but harmless small holes in cement stones are increased, the pressure of capillary contraction of the early capillary of the plastering mortar is increased, the risk of early cracking of the plastering mortar is increased, the quantity of harmful large holes of more than 200nm is increased even by calcium nitrate, and after the hydration speed of the cement is accelerated for about 4 hours by calcium formate, a calcium-rich low-silicon layer coating layer is formed due to the introduction of a plurality of calcium ions, and the further hydration of the cement is hindered.

CO₂Mortar curing technology capable of effectively curing CO₂And improves the mechanical property and the durability of the mortar. CO 2₂The curing mortar is based on CO₂Mixing with cement clinker mineral tricalcium silicate (abbreviated as C3S, chemical formula of 3 CaO. SiO)₂) Dicalcium silicate (abbreviated as C2S, chemical formula 2 CaO. SiO)₂) A chemical reaction between them. The early strength development of the cement mortar can be promoted by accelerated carbonization, and the mortar curing time can be greatly shortened by accelerated carbonization, so that the cement mortar obtains good mechanical property, dimensional stability and durability. However, conventional CO₂The maintenance is a steam maintenance method, the equipment is complex and high in cost, and the maintenance can only be finished in a processing plant, so that the requirement of field construction is not met.

Disclosure of Invention

In view of the above, the reinforced mortar and the preparation method thereof are provided, wherein the reinforced mortar is convenient to maintain, simple and convenient to operate and good in reinforcing effect.

The reinforced mortar comprises cement mortar, carbon dioxide release resin balls and calcium carbonate powder, wherein the carbon dioxide release resin balls and the calcium carbonate powder are respectively mixed in the cement mortar according to a preset weight ratio.

Preferably, the adding amount of the carbon dioxide releasing resin balls is 6-8% of the weight of the cement mortar.

Preferably, the carbon dioxide-releasing resin beads include super absorbent resin particles and a carbon dioxide-containing aqueous solution absorbed in the super absorbent resin particles.

Preferably, the expanded particle diameter of the carbon dioxide releasing resin beads after absorption is 0.75 to 1.50mm, and the average particle diameter of the super absorbent resin particles is 200 meshes or more.

Preferably, the super absorbent resin particles are cross-linked acrylic acid/sodium acrylate copolymer, and the absorption capacity of the water absorbent resin particles to the carbon dioxide-containing aqueous solution is 30 times to 200 times of the weight of the self particles.

Preferably, the calcium carbonate powder is added in an amount of 4-10% by weight of the cement mortar.

Specifically, the carbon dioxide releasing resin beads are prepared by the following steps:

uniformly mixing bicarbonate, acetic acid and water according to a preset weight ratio to form a mixed aqueous solution; and (3) putting the super absorbent resin particles into the mixed aqueous solution, stirring, soaking, and stopping soaking after the water absorbent resin particles expand to a preset particle size.

Preferably, the bicarbonate is calcium bicarbonate, and the weight ratio of the calcium bicarbonate to the acetic acid to the water in the mixed aqueous solution is (10-30): 15: 50.

And, a method for preparing the reinforced mortar as described above, comprising the steps of:

preparing carbon dioxide releasing resin balls;

Preparing cement mortar, mixing carbon dioxide release resin balls and calcium carbonate powder into the cement mortar, stirring, and obtaining the reinforced mortar after a preset time.

In the reinforced mortar and the preparation method thereof, the high water absorption capacity of the carbon dioxide releasing resin balls is utilized to absorb aqueous solution which is dozens of times or even hundreds of times of the carbon dioxide releasing resin balls, so that the carbon dioxide with smaller volume is released to release high-content carbon dioxide, and carbon dioxide curing is carried out in the mortar through the carbon dioxide to reinforce the mortar, the reinforcing effect is good, and the mortar can be cured through natural drying, so that the reinforced mortar is simple and convenient to operate, convenient and quick to maintain, and can be widely applied to manufacturing various reinforced mortars and promote the construction efficiency. Furthermore, the reinforced mortar is added with calcium carbonate powder, the calcium carbonate powder has rich natural resources, wide distribution, easy acquisition and low price, when a proper amount of calcium carbonate powder is doped, the cement particles in the mortar are more sparsely and uniformly distributed, and carbon dioxide gas is easily diffused to the surfaces of the cement particles, so that the reaction between the cement and the carbon dioxide is accelerated, and the reaction degree of carbon dioxide curing is improved. In addition, the calcium carbonate powder can obviously improve the reaction degree and the early compressive strength of the carbon dioxide curing of the mortar. The calcium carbonate powder added promotes the reaction of tricalcium silicate and dicalcium silicate with carbon dioxide, and more calcium carbonate, polymerized calcium silicate or amorphous silica gel is induced to be generated, so that the mortar is more compact and has fewer pores.

Detailed Description

The technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The embodiment of the invention provides reinforced mortar, which comprises cement mortar, carbon dioxide release resin balls and calcium carbonate powder, wherein the carbon dioxide release resin balls and the calcium carbonate powder are respectively mixed in the cement mortar according to a preset weight ratio. The carbon dioxide releasing resin balls can release carbon dioxide to greatly promote the maintenance of mortar, and the reaction can be continued for a long time due to the water absorbing, water retaining and releasing effects of the resin balls on the surrounding environment, so that the later strength of plastering mortar is improved. The calcium carbonate powder can interact with the carbon dioxide release resin balls to promote the formation of silica gel, accelerate the hydration of cement, improve the density of hardened cement paste, further improve the strength of mortar, and play a role in fixing carbon dioxide.

Furthermore, after the calcium carbonate powder is added, the cement particles in the mortar are more sparsely and uniformly distributed, and carbon dioxide gas is easily diffused to the surfaces of the cement particles, so that the reaction between the cement and the carbon dioxide is accelerated, and the reaction degree of carbon dioxide curing is improved. In addition, the calcium carbonate powder can obviously improve the reaction degree and the early compressive strength of the carbon dioxide curing of the mortar. The calcium carbonate powder added promotes the reaction of tricalcium silicate and dicalcium silicate with carbon dioxide, and more calcium carbonate, polymerized calcium silicate or amorphous silica gel is induced to be generated, so that the mortar is more compact and has fewer pores.

In an embodiment of the present invention, the carbon dioxide-releasing resin beads include super absorbent resin particles and a carbon dioxide-containing aqueous solution absorbed in the super absorbent resin particles, and the carbon dioxide-containing aqueous solution is formed by mixing acetic acid and a bicarbonate aqueous solution to react to generate carbonic acid dissolved in water. Preferably, the adding amount of the carbon dioxide releasing resin balls is 6-8% of the weight of the cement mortar. Preferably, the calcium carbonate powder is added in an amount of 4-10% by weight of the cement mortar.

Specifically, the super absorbent resin particles are super absorbent resin particles (SAP resin particles for short) selected from a 200-mesh or larger sieve, the super absorbent resin particles are synthetic resin type water absorbent particles, and the super absorbent resin particles include an acrylic acid grafted cellulose polymer, although in actual application, different types of super absorbent resins can be selected according to needs, and the super absorbent resin particles are not limited thereto. Preferably, the expanded particle size of the carbon dioxide releasing resin balls after absorption is 0.75-1.50 mm. Further, the super absorbent resin particles are saturated in absorbing the aqueous solution of acetic acid and calcium hydrogen carbonate, and the carbon dioxide releasing resin beads are formed by soaking the super absorbent resin particles with an excess amount of the aqueous solution of acetic acid and calcium hydrogen carbonate.

Specifically, the carbon dioxide releasing resin beads are prepared by the following steps:

uniformly mixing bicarbonate, acetic acid and water according to a preset weight ratio to form a mixed aqueous solution; and (3) putting the super absorbent resin particles into the mixed aqueous solution, stirring, soaking, and stopping soaking after the water absorbent resin particles expand to a preset particle size.

Preferably, the bicarbonate is calcium bicarbonate, and the weight ratio of the calcium bicarbonate to the acetic acid to the water in the mixed aqueous solution is (10-30): 15: 50.

The super absorbent SAP resin is a novel functional polymer material, preferably a cross-linked acrylic acid/sodium acrylate copolymer, has the water absorption function of absorbing water which is hundreds of times heavier than the self weight, and has excellent water retention performance; when the humidity of the surrounding air decreases, the SAP resin releases water to compensate for the decrease in humidity and improve its humidity distribution, resulting in a reduction in the difference in humidity in different areas. The SAP resin has a fast water absorption rate, but a very slow water release rate, which is about 4.5% to 6.4% of the water absorption rate, and absorbs water rapidly when the surrounding environment is humid; when the ambient environment is dry, the SAP resin then releases water very slowly, thereby enabling a long dry-wet cycle.

In the reinforced mortar, acetic acid is an organic monoacetic acid and is the main component of vinegar, 1 acetic acid molecule reacts with 1 calcium bicarbonate molecule to generate 2 water molecules and 2 carbon dioxide molecules, and the formula is as follows:

Ca(HCO₃)₂+2CH₃COOH＝Ca(CH₃COO)₂+2H₂O+2CO₂↑

wherein, the carbon dioxide has higher density than air, can be dissolved in water and reacts with the water to generate carbonic acid. Carbon dioxide is soluble in water (ratio of 1: 1) at ambient temperature and pressure to form carbonic acid, which is shown in the following formula:

CO₂+H₂O＝H₂CO₃

according to the principle, acetic acid and calcium bicarbonate are mixed, proper water is added, and the mixture is uniformly stirred to form aqueous solution; putting into super absorbent resin particles for soaking to form carbon dioxide release resin balls, and the main principle is as follows:

(1)CO₂dissolving in water to form carbonic acid;

(2) the carbonic acid ionizes hydrogen ions, bicarbonate ions and carbonate ions;

(3) the carbonate ion reacts with calcium ion in the pore solution and dicalcium silicate and tricalcium silicate to generate CaCO which is difficult to dissolve in water₃And calcium silicate hydrate gel nuclei. The solid phase is gradually separated out, covers unhydrated cement particles and fills concrete pores;

(4) the calcium silicate hydrate gel further reacts with carbonate radical to be finally converted into silicon gel and CaCO₃。

Thus, by this high water absorbability, the pre-formed aqueous carbon dioxide solution is absorbed into the particles, i.e., the mixed aqueous solution of acetic acid and calcium hydrogen carbonate is impregnated into the high water absorbent resin particles. In the mixed solution, the acetic acid reacts with the calcium bicarbonate to generate CO ₂，CO₂Dissolving in water to form carbonic acid, ionizing hydrogen ion, bicarbonate radical and carbonate radical ion, allowing the carbonate radical ion to penetrate through the resin ball, reacting with calcium ion, dicalcium silicate and tricalcium silicate in the pore solution of plastering mortar to generate CaCO insoluble in water₃And calcium silicate hydrate gel nuclei. The solid phase is gradually separated out, the unhydrated cement particles are covered, and the inner pores of the plastering mortar are filled; the calcium silicate hydrate gel further reacts with carbonate radical to be finally converted into silicon gel and CaCO₃. The calcium carbonate powder further promotes the reaction of tricalcium silicate and dicalcium silicate with carbon dioxide, and more calcium carbonate, polymerized calcium silicate or amorphous silica gel is induced to be generated, so that the mortar is more compact and has fewer pores. Thereby improving the early strength of the plastering mortar and having the crack resistance. As the resin balls have the functions of absorbing, retaining and releasing water for the surrounding environment, the reaction can be continued for a long time, and the later strength of the plastering mortar is also improved.

The embodiment of the invention also provides a preparation method of the reinforced mortar, which comprises the following steps:

preparing carbon dioxide releasing resin balls;

preparing cement mortar, mixing carbon dioxide release resin balls and calcium carbonate powder into the cement mortar, stirring, and obtaining the reinforced mortar after a preset time.

When mixing, the addition amount of the carbon dioxide releasing resin balls and the calcium carbonate powder is according to the weight ratio. More preferably, the optimal adding amount of the carbon dioxide releasing resin ball is 7% of the weight of cement mortar, the optimal adding amount of calcium carbonate powder is 6-10% of the weight of cement mortar, and more preferably, the optimal adding amount of calcium carbonate powder is 10% of the weight of cement mortar. The predetermined time is preferably 24 hours or more.

When the reinforced mortar is used, the following construction steps are adopted:

1. cleaning base (before coating mortar)

The dust, oil stain, floating pulp, sundries and the like on the surface of the base layer are cleaned and moistened by sprinkling water, and the water is not accumulated until the ground shows a watermark. If the local unevenness is generated, the convex part should be chiseled and the concave part should be filled with M20 cement mortar.

2. Maintenance (after coating mortar)

And (5) after the mortar is leveled and compacted for 24 hours, watering and curing, wherein the curing period is 7 days. When the maintenance is on time, people can not step on the shoes, and sanding is prevented. The sand used is not too fine, the graded medium sand is adopted, the laying thickness of each layer of mortar is uniform and in place, so that the waterproof layer is prevented from hollowing and cracking, the cement is stable, and the plastering degree is proper.

The following examples illustrate the reinforced mortar with different addition amounts, the preparation method thereof, the performance of the reinforced mortar, and the like, and the parts are all parts by weight.