High-durability and high-impermeability mortar and preparation method thereof

Abstract

The invention relates to the field of building materials, in particular to high-durability and high-permeability-resistance mortar and a preparation method thereof.The high-durability and high-permeability-resistance mortar is prepared from, by weight, 40-60 parts of cement, 20-40 parts of quartz sand or machine-made sand, 10-20 parts of fly ash or mineral powder, 2-5 parts of polymer emulsion, 1-3 parts of an anti-permeability agent, 0.2-1 part of a water reducing agent, 0.1-0.5 part of a water-retention thickening agent and water; wherein the water cement ratio is controlled to be 0.30 to 0.35. Through collaborative optimization of multiple components, the compactness, impermeability, crack resistance and durability of the mortar are remarkably improved, the preparation process is simple and convenient, the raw materials are easy to obtain, and the mortar has excellent comprehensive performance and wide application prospects.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of building materials, and in particular to a high-durability and high-impermeability mortar and a preparation method thereof. BACKGROUND

[0002] Ordinary mortar has problems of insufficient durability and poor impermeability during long-term use. Due to poor pore structure development and uneven distribution of hydration products, connected capillary channels are easily formed during service, leading to the invasion of water and harmful ions, and further causing durability degradation phenomena such as steel corrosion and structure strength reduction.

[0003] Existing modification technologies mainly include methods such as adding admixtures, mineral admixtures, or using polymers for modification. However, single technical path often has limitations: for example, only adding mineral admixtures cannot significantly improve impermeability; and simply using polymer modification has high cost and limited long-term durability improvement.

[0004] Therefore, it is urgent to develop a new mortar system with high durability and high impermeability to meet the engineering application requirements in harsh environments. SUMMARY

[0005] The purpose of the embodiments of the present application is to provide a high-durability and high-impermeability mortar and a preparation method thereof to solve the problems raised in the background art.

[0006] To achieve the above-mentioned purpose, the embodiments of the present application provide the following technical solutions: A high-durability and high-impermeability mortar includes the following raw materials by weight: cement 40-60 parts, quartz sand or machine-made sand 20-40 parts, fly ash or mineral powder 10-20 parts, polymer emulsion 2-5 parts, impermeability agent 1-3 parts, water reducing agent 0.2-1 part, water retention thickening agent 0.1-0.5 part, and water; wherein the water-cement ratio is controlled at 0.30-0.35.

[0007] As a further scheme of the present application: includes the following raw materials by weight: cement 48 parts, quartz sand 28 parts, fly ash 12 parts, polymer emulsion 2.5 parts, impermeability agent 2 parts, water reducing agent 0.5 parts, water retention thickening agent 0.2 parts, and water; wherein the water-cement ratio is controlled at 0.33.

[0008] As a further scheme of the present application: the raw materials further include silica fume 5 parts.

[0009] As a further scheme of the present application: the impermeability agent is one of silane-based / inorganic composite type, inorganic nano-silica sol, or silane emulsion and hydrophobic agent composite type.

[0010] As a further scheme of the present application: the water reducing agent is a polycarboxylic acid type high efficiency water reducing agent.

[0011] As a further scheme of the present application: the water retaining thickening agent is a cellulose ether.

[0012] Another object of the present application is to provide a preparation method of the high durability and high impermeability mortar. (1) the cement, fly ash or mineral powder, quartz sand or machine-made sand are weighed according to the proportion; (2) the dry materials prepared in step (1) are put into a mixer, mixed uniformly and taken out; (3) the mixer is started, part of the water and the polymer emulsion are added into the mixer, and the dry materials obtained by mixing in step (2) are slowly added, and the stirring is carried out for 3-5 minutes; (4) the impermeability agent, the water reducing agent and the water retaining thickening agent are added, the remaining water is added, and the stirring is continuously carried out until the materials are uniform; (5) after the mixture is placed for 1-2 minutes, it can be used.

[0013] As a further scheme of the present application: the total amount of water used in steps (3) and (4) is controlled according to the water-cement ratio of 0.30-0.35.

[0014] As a further scheme of the present application: in step (2), the mixing time of the dry materials is 2-3 minutes; in step (4), the stirring time is 2-3 minutes.

[0015] As a further scheme of the present application: in step (1), the weighed raw materials further include silica fume.

[0016] Compared with the prior art, the embodiment of the present application has the following advantages: The high durability and high impermeability mortar provided by the present application significantly reduces the porosity and refines the pore structure through the synergistic optimization of the cement, the mineral admixture, the polymer emulsion, the impermeability agent, the water reducing agent and the water retaining thickening agent, effectively plugs the capillary pores, greatly improves the impermeability, and at the same time improves the mechanical properties, the volume stability and the crack resistance of the mortar, significantly reduces the dry shrinkage, and improves the freeze-thaw resistance and the chemical corrosion resistance.

[0017] The mortar preparation process is simple, the raw materials are easy to obtain, the construction performance is good, the comprehensive durability is significantly better than that of ordinary mortar, the service life of the engineering structure in a complex environment can be effectively prolonged, and the mortar has good engineering application prospect.

[0018] In summary, the present application significantly improves the compactness, the impermeability, the crack resistance and the durability of the mortar through the synergistic optimization of multiple components, the preparation process is simple, the raw materials are easy to obtain, and the mortar has excellent comprehensive performance and broad application prospect. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0020] The performance detection method of the mortar according to the present application is carried out according to the following standards: Compressive strength: determined according to GB / T 17671–1999 Cement mortar strength test method (ISO method); Permeability resistance: the maximum permeation height of the test piece is determined according to GB / T 50082–2009 Standard test methods for long-term properties and durability of normal concrete; Dry shrinkage: tested according to JC / T 603–2004 Cement mortar dry shrinkage test method. Embodiment

[0021] An embodiment of the present application provides a high-durability and high-permeability-resistant mortar, and the raw materials are taken by weight parts as follows: cement 50 parts, quartz sand 30 parts, fly ash 15 parts, polymer emulsion 3 parts, impermeable agent (silane-based / inorganic composite type) 2 parts, water reducing agent (polycarboxylic acid-based high-efficiency water reducing agent) 0.5 parts, water retention thickening agent (cellulose ether) 0.2 parts, and water; wherein the water is added according to the water-cement ratio of 0.32.

[0022] The preparation method of the high-durability and high-permeability-resistant mortar, comprising the following steps: The cement, fly ash and quartz sand are put into a mixer, dry mixed and mixed for 2 minutes to ensure uniform mixing, and then taken out; In the stirring state, part of the water and the polymer emulsion are added, and then the dry mixture is slowly added, and the stirring is continued for 3-5 minutes; The impermeable agent, water reducing agent and water retention thickening agent are added, the remaining water is added, and the stirring is continued for 2-3 minutes until the slurry is uniform and free of lumps; The mixture is placed for 1-2 minutes and then discharged for forming construction.

[0023] Performance test results: According to GB / T 17671–1999, the 28-day compressive strength is ≥48 MPa; according to GB / T 50082–2009, the maximum permeation height of the impermeability test is ≤10 mm; according to JC / T 603–2004, the dry shrinkage rate is reduced by about 20% compared with ordinary mortar; the surface of the test piece is observed, and no cracking is observed, showing excellent volume stability and durability. Embodiment

[0024] An embodiment of the present application provides a high-durability and high-anti-permeability mortar, which is prepared by using the following raw materials by weight: Cement 45 parts, quartz sand 35 parts, mineral powder 15 parts, polymer emulsion 4 parts, anti-permeability agent (inorganic nano-silica sol) 2 parts, water reducing agent (polycarboxylic acid type high-efficiency water reducing agent) 0.6 parts, water retention thickening agent (cellulose ether) 0.3 parts, and water; wherein the water is added in an amount calculated according to a water-cement ratio of 0.31.

[0025] The preparation method of the high-durability and high-anti-permeability mortar includes the following steps: The cement, the mineral powder, and the quartz sand are dry mixed for 2 minutes; Part of the water and the polymer emulsion are added, and the dry materials are added at the same time, and stirring is performed for 4 minutes; The anti-permeability agent, the water reducing agent, and the water retention thickening agent are added, and the remaining water is added, and stirring is continuously performed until uniformity is achieved; The product is used after being left to stand for 1-2 minutes.

[0026] Performance test results: The 28-day compressive strength is greater than or equal to 50 MPa, the maximum permeation height is less than or equal to 8 mm, the dry shrinkage rate is reduced by about 25%, the strength retention rate is greater than or equal to 90% after 300 freeze-thaw cycles, and the anti-freezing performance is significantly improved. Embodiment

[0027] An embodiment of the present application provides a high-durability and high-anti-permeability mortar, which is prepared by using the following raw materials by weight: Cement 48 parts, quartz sand 28 parts, fly ash 12 parts, silica fume 5 parts, polymer emulsion 2.5 parts, anti-permeability agent (silane emulsion and hydrophobic agent composite type) 2 parts, water reducing agent (polycarboxylic acid type high-efficiency water reducing agent) 0.5 parts, water retention thickening agent (cellulose ether) 0.2 parts, and water; wherein the water is added in an amount calculated according to a water-cement ratio of 0.33.

[0028] The preparation method of the high-durability and high-anti-permeability mortar includes the following steps: The cement, the fly ash, the silica fume, and the quartz sand are dry mixed and stirred for 2-3 minutes; Part of the water and the polymer emulsion are added, and stirring is continuously performed for 4 minutes; The anti-permeability agent, the water reducing agent, and the water retention thickening agent are added, and the remaining water is added, and stirring is continuously performed for 2-3 minutes; The product is discharged and formed after being left to stand for 1-2 minutes.

[0029] Performance test results: The 28-day compressive strength is greater than or equal to 52 MPa, the permeation height is less than or equal to 6 mm, the anti-permeability performance is excellent, the dry shrinkage rate is reduced by about 30%, the sulfate corrosion resistance performance is excellent, the mass loss rate is less than or equal to 2%, and the chemical corrosion resistance performance is good.

[0030] In Examples 1-3, the polymer emulsion is not limited, and can be selected as one or more of acrylic emulsion, styrene-acrylic emulsion or styrene-butadiene emulsion as needed.

[0031] Comparative test description To verify the performance advantages of the high-durability and high-impermeability mortar of this invention, the formulations of Examples 1-3 were compared with those of ordinary cement mortar (comparative example). The comparative example mortar had the following mix proportions: 50 parts cement, 45 parts standard sand, water-cement ratio of 0.35, and no polymer emulsion, impermeable agent, or mineral admixtures were added. All performance tests were conducted according to GB / T17671–1999 "Test Method for Strength of Cement Mortar" and GB / T50082–2009 "Standard for Test Methods of Long-Term Performance and Durability of Ordinary Concrete". The test results are shown in the table below: Performance index Common mortar (comparative example) Example 1 Example 2 Example 3 28d compressive strength / MPa 36 48 50 52 Maximum penetration height / mm 18 10 8 6 Shrinkage rate (28d) / % 0.062 0.050 0.047 0.043 Strength retention rate after 300 freeze-thaw cycles / % 72 88 90 91 Mass loss rate after 90d sulfate attack / % 6.2 3.5 2.8 2.0 The performance comparison analysis is as follows: 1) Significantly improved mechanical properties: The 28-day compressive strength of the mortar of this invention is 30% to 45% higher than that of ordinary mortar, indicating that the composite modification system effectively promotes the hydration reaction and enhances the density of the matrix and the interfacial bonding strength.

[0032] 2) Significantly improved impermeability: The maximum penetration height is reduced by 40% to 65% compared to ordinary mortar, indicating that multiple mechanisms such as polymer film formation, impermeable agent crystallization and sealing, and mineral admixture micro-filling work together to significantly refine the pore structure and effectively inhibit the intrusion of water and harmful ions.

[0033] 3) Excellent volume stability: The shrinkage rate is significantly reduced, which effectively alleviates early plastic shrinkage and later drying shrinkage, significantly reduces the risk of cracking, and improves the long-term durability and integrity of the structure.

[0034] 4) Outstanding freeze resistance: After 300 freeze-thaw cycles, the strength retention rate of Examples 2 and 3 is not less than 90%, which shows excellent freeze-thaw durability and is suitable for engineering applications in cold and harsh environments.

[0035] 5) Strong resistance to chemical corrosion: Example 3 shows excellent corrosion resistance in sulfate environment, with a mass loss rate of ≤2% after 90 days of immersion, which is far superior to ordinary mortar and is suitable for corrosive environments such as industrial buildings and underground structures.

[0036] Conclusion: The mortar of this invention is significantly superior to ordinary mortar in key performance indicators such as compressive strength, impermeability, crack resistance, frost resistance and chemical erosion resistance, and its overall durability is greatly improved. It can effectively extend the service life of engineering structures and has good application value.

[0037] The above embodiments of the present invention provide a high-durability, high-impermeability mortar and its preparation method. Through a reasonable combination of raw materials and an additive system, the mortar structure is made denser, significantly improving its impermeability and service life. The main advantages are as follows: 1) The porosity is significantly reduced, the capillaries are effectively blocked, and the impermeability is improved by more than 30%; 2) Introducing polymer emulsions improves mortar toughness and reduces the risk of cracking; 3) Composite admixtures (fly ash / mineral powder / silica fume) optimize the structure of hydration products and enhance long-term durability; 4) The process is simple, the raw materials are readily available, and it is suitable for industrial production.

[0038] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these should also be considered within the scope of protection of the present invention. These will not affect the effectiveness of the implementation of the present invention or the practicality of the patent.

Claims

1. A high-durability, high-impermeability mortar, characterized in that, Includes the following raw materials by weight: The ingredients are: 40–60 parts cement, 20–40 parts quartz sand or manufactured sand, 10–20 parts fly ash or mineral powder, 2–5 parts polymer emulsion, 1–3 parts anti-permeability agent, 0.2–1 part water-reducing agent, 0.1–0.5 parts water-retaining thickener, and water; wherein the water-cement ratio is controlled at 0.30–0.

35.

2. The high-durability and high-impermeability mortar according to claim 1, characterized in that, Includes the following raw materials by weight: The ingredients are 48 parts cement, 28 parts quartz sand, 12 parts fly ash, 2.5 parts polymer emulsion, 2 parts anti-permeability agent, 0.5 parts water-reducing agent, 0.2 parts water-retaining and thickening agent, and water; wherein the water-cement ratio is controlled at 0.

33.

3. The high-durability and high-impermeability mortar according to claim 2, characterized in that, The raw materials also include 5 parts silica fume.

4. The high-durability, high-impermeability mortar according to any one of claims 1-3, characterized in that, The antipermeability agent is one of the following: silane / inorganic composite, inorganic nano silica sol, or a composite of silane emulsion and hydrophobic agent.

5. The high-durability, high-impermeability mortar according to claim 4, characterized in that, The water-reducing agent is a polycarboxylate-based high-efficiency water-reducing agent.

6. The high-durability and high-impermeability mortar according to claim 5, characterized in that, The water-retaining and thickening agent is a cellulose ether.

7. A method for preparing high-durability, high-impermeability mortar as described in any one of claims 1-6, characterized in that, Includes the following steps: (1) Weigh out cement, fly ash or mineral powder, quartz sand or manufactured sand according to the proportion; (2) Put the dry material obtained in step (1) into a mixer, mix it evenly and take it out; (3) Start the mixer, add some water and polymer emulsion to the mixer, and slowly add the dry material obtained in step (2) at the same time, and stir for 3–5 minutes; (4) Add anti-permeability agent, water-reducing agent and water-retaining thickener, add the remaining water, and continue stirring until the material is uniform; (5) After the mixture has stood for 1–2 minutes, it is ready to use.

8. The method for preparing high-durability and high-impermeability mortar according to claim 7, characterized in that, The total amount of water used in steps (3) and (4) is controlled at a water-cement ratio of 0.30–0.

35.

9. The method for preparing high-durability and high-impermeability mortar according to claim 8, characterized in that, In step (2), the mixing time for the dry materials is 2–3 minutes; In step (4), continue stirring for 2–3 minutes.

10. The method for preparing high-durability and high-impermeability mortar according to claim 9, characterized in that, In step (1), the raw materials weighed also include silica fume.