Anti-rust and anti-crack plastic spraying mortar and preparation method thereof

Abstract

The invention discloses anti-rust and anti-crack plastic spraying mortar and a preparation method thereof, and the components comprise the following substances in percentage by mass: 40-50% of a base material, 35-45% of aggregate, 2-3% of a composite anti-rust agent, 0.1-0.3% of anti-crack fiber, 3-5% of redispersible latex powder, 2-4% of expanded perlite powder, 0.5-1% of a polycarboxylic acid water reducer and 1-2% of nano silicon dioxide, the preparation method comprises the following steps: uniformly stirring the base material, the aggregate and the expanded perlite powder in a forced stirrer; fully dispersing the anti-crack fibers by using a vibrating screen, and adding the anti-crack fibers into a forced stirrer for three times for blending; the composite anti-rust agent has the beneficial effects that the composite anti-rust agent blocks electrochemical corrosion in a double-effect mode through passivating the metal surface and adsorbing and forming a film through the organic corrosion inhibitor, multiple corrosion factors can be more effectively resisted, embedded steel bars can be prevented from being corroded by moisture and chlorine salt, anti-crack fibers are in bridge joint with cracks, nano-silicon dioxide and base material Portland cement are hydrated to generate C-S-H gel, and the anti-crack effect is good. And the expanded perlite powder can compensate drying shrinkage and stabilize the volume, so that the anti-cracking auxiliary effect is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of mortar materials, and specifically to rust-proof and crack-resistant sprayed mortar and its preparation method. Background Technique

[0002] Sprayed mortar, also known as TCP plastic mortar and modeling mortar, is usually made by mixing cement, sand, special additives and water in a certain proportion. It can create various natural shapes such as plastic stones, wood grains, and bamboos on the construction site, meeting diverse design requirements. It is used for making rockeries, plastic stones, artificial trees, rattans, figure sculptures, etc., and is a key landscaping material for theme parks and artificial landscapes.

[0003] Traditional sprayed mortar resists cracks through ordinary aggregates and a small amount of additives, and the effect is average. It is prone to cracking under long-term outdoor environmental erosion. Moreover, ordinary sprayed mortar mostly relies on a single rust-proof component or simple physical isolation, with limited rust-proof effect and poor rust-proof performance, etc., and cannot meet the rust-proof and crack-resistant requirements of artificial landscapes. To improve the rust-proof and crack-resistant performance of sprayed mortar, this application proposes a rust-proof and crack-resistant sprayed mortar. Summary of the Invention

[0004] The purpose of the present invention is to provide a rust-proof and crack-resistant sprayed mortar and its preparation method to solve the problems raised in the above background technique.

[0005] To achieve the above purpose, the present invention provides the following technical solution for rust-proof and crack-resistant sprayed mortar. Each component includes the following substances by mass percentage: binder 40 - 50%, aggregate 35 - 45%, composite rust inhibitor 2 - 3%, anti-crack fiber 0.1 - 0.3%, redispersible latex powder 3 - 5%, expanded perlite powder 2 - 4%, polycarboxylate-based water reducer 0.5 - 1% and nano-silica 1 - 2%.

[0006] Preferably, the binder is Portland cement with a strength grade of 42.5 or 52.5.

[0007] Preferably, the aggregate is quartz sand with a particle size of 0.5 - 2 mm.

[0008] Preferably, the composite rust inhibitor is one of organic chromate, phosphate and sodium nitrite.

[0009] Preferably, the anti-crack fiber is polypropylene fiber or glass fiber with a length of 3 - 6 mm.

[0010] The preparation method of the rust-proof and crack-resistant sprayed mortar includes the following steps:

[0011] S1. Dry mixing and pre-dispersion: Put the binder, aggregate, and expanded perlite powder into a forced mixer and stir at 300 r / min for 2 minutes until uniform;

[0012] S2. Fiber dispersion treatment: Use a vibrating screen to fully disperse the anti-cracking fibers, and add them to a forced mixer in three portions at 30-second intervals for blending;

[0013] S3. Addition of functional additives: Add a composite rust inhibitor and nano-silica to the forced mixer in sequence, and stir for 5 minutes to form a homogeneous dry powder system;

[0014] S4. Liquid-phase modification: Take water according to the above ash content and divide it into three equal parts. Pre-dissolve the redispersible latex powder and polycarboxylate superplasticizer in one part of the water to form a modified liquid;

[0015] S5. Wet mixing: Slowly spray the modified liquid into the dry materials, supplement the remaining water in two portions, and stir until the slurry becomes a viscous paste-like mortar, and then carry out filling and sealing.

[0016] Preferably, the water intake in S4 is in a ratio of 0.22 - 0.25:1 of ash to water.

[0017] Preferably, the fluidity of the mortar after mixing in S5 is ≥180 mm.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] 1. The composite rust inhibitor passivates the metal surface, and the organic corrosion inhibitor adsorbs to form a film, which doubly blocks electrochemical corrosion, can more effectively resist various rust factors, and can protect the embedded steel bars from being corroded by moisture and chloride salts.

[0020] 2. The anti-cracking fibers bridge the cracks, nano-silica hydrates with the base material portland cement to generate C-S-H gel, reducing micro-cracks. The expanded perlite powder can compensate for drying shrinkage, stabilize the volume, and thus play an auxiliary anti-cracking effect. Specific embodiments

[0021] The present invention provides a technical solution: rust-proof and crack-resistant spray-plaster mortar, and each component includes the following substances by weight ratio: Each component includes the following substances by mass percentage: 40 - 50% of base material, 35 - 45% of aggregate, 2 - 3% of composite rust inhibitor, 0.1 - 0.3% of anti-cracking fibers, 3 - 5% of redispersible latex powder, 2 - 4% of expanded perlite powder, 0.5 - 1% of polycarboxylate superplasticizer, and 1 - 2% of nano-silica.

[0022] A preparation method of rust-proof and crack-resistant spray-plaster mortar, comprising the following steps:

[0023] S1. Dry mixing and pre-dispersion: Put the base material, aggregate, and expanded perlite powder into a forced mixer, and stir at 300 r / min for 2 minutes until uniform;

[0024] S2. Fiber dispersion treatment: Use a vibrating screen to fully disperse the anti-cracking fibers, and add them to a forced mixer in three portions at 30-second intervals for blending;

[0025] S3. Functional additive addition: Sequentially add a composite rust inhibitor and nano-silica to the forced mixer, and stir for 5 minutes to form a homogeneous dry powder system;

[0026] S4. Liquid-phase modification: Take water according to the above ash content and divide it into three equal parts. Pre-dissolve the redispersible latex powder and polycarboxylate superplasticizer with one part of the water to form a modified liquid;

[0027] S5. Wet mixing: Slowly spray the modified liquid into the dry material, supplement the remaining water in two portions, stir until the slurry becomes a viscous paste-like mortar, and then carry out filling.

[0028] Example 1:

[0029] For the anti-rust and anti-cracking spray-plaster mortar, each component is calculated by mass percentage as follows: Portland cement with a strength grade of 42.5 is 44.7%, quartz sand is 40%, sodium nitrite is 3%, polypropylene fiber is 0.3%, redispersible latex powder is 5%, expanded perlite powder is 4%, polycarboxylate superplasticizer is 1%, and nano-silica is 2%;

[0030] A preparation method for the anti-rust and anti-cracking spray-plaster mortar includes the following steps:

[0031] S1. Dry mixing and pre-dispersion: Put the Portland cement, quartz sand, and expanded perlite powder into a forced mixer, and stir at 300 r / min for 2 minutes until uniform;

[0032] S2. Fiber dispersion treatment: Use a vibrating screen to fully disperse the polypropylene fibers, and add them to a forced mixer in three portions at 30-second intervals for blending;

[0033] S3. Functional additive addition: Sequentially add sodium nitrite and nano-silica to the forced mixer, and stir for 5 minutes to form a homogeneous dry powder system;

[0034] S4. Liquid-phase modification: Take water according to the water-cement ratio of 0.22:1 and divide it into three equal parts. Pre-dissolve the redispersible latex powder and polycarboxylate superplasticizer with one part of the water to form a modified liquid;

[0035] S5. Wet mixing: Slowly spray the modified liquid into the dry material, supplement the remaining water in two portions, stir until the slurry becomes a viscous paste-like mortar with a fluidity ≥ 180 mm, and then carry out filling;

[0036] Pre-clean or sandblast and rust-remove the pre-spraying area, and apply epoxy primer to enhance interface bonding. Subsequently, spray the prepared anti-rust and crack-resistant sprayed plastic mortar evenly on the surface of the object to be sprayed. After initial setting, cover it with a water retention film to make the environmental humidity > 80% within 72 hours until the anti-rust and crack-resistant sprayed plastic mortar solidifies;

[0037] After testing: The corrosion resistance passes (tested by JGJ / T 192), and the 14-day tensile bond strength ≥ 1.35 Mpa.

[0038] Example 2:

[0039] The components of the anti-rust and crack-resistant sprayed plastic mortar are as follows by mass percentage: Portland cement with strength grade 52.5, 47%; quartz sand, 42%; organic chromate, 2%; glass fiber, 0.2%; redispersible latex powder, 4%; expanded perlite powder, 3%; polycarboxylate-based water reducer, 0.8%; and nano-silica, 1%;

[0040] A preparation method for anti-rust and crack-resistant sprayed plastic mortar includes the following steps:

[0041] S1. Dry mixing and pre-dispersion: Put Portland cement, quartz sand, and expanded perlite powder into a forced mixer and stir at 300 r / min for 2 minutes until uniform;

[0042] S2. Fiber dispersion treatment: Use a vibrating screen to fully disperse the glass fiber and add it to the forced mixer in three portions at 30-second intervals for blending;

[0043] S3. Addition of functional additives: Add organic chromate and nano-silica to the forced mixer in sequence and stir for 5 minutes to form a homogeneous dry powder system;

[0044] S4. Liquid phase modification: Take water according to the ratio of ash to water of 0.25:1 and divide it into three equal parts. Pre-dissolve the redispersible latex powder and polycarboxylate-based water reducer with one part of the water to form a modified liquid;

[0045] S5. Wet mixing: Slowly spray the modified liquid into the dry materials, supplement the remaining water in two portions, stir until the slurry becomes a viscous paste with a fluidity ≥ 180 mm of mortar, and then carry out filling;

[0046] Pre-clean or sandblast and rust-remove the pre-spraying area, and apply epoxy primer to enhance interface bonding. Subsequently, spray the prepared anti-rust and crack-resistant sprayed plastic mortar evenly on the surface of the object to be sprayed. After initial setting, cover it with a water retention film to make the environmental humidity > 75% within 72 hours until the anti-rust and crack-resistant sprayed plastic mortar solidifies;

[0047] After testing: The corrosion resistance passes (tested by JGJ / T 192), and the 14-day tensile bond strength ≥ 0.83 Mpa.

[0048] Example 3:

[0049] For the rust-proof and crack-resistant sprayed plastic mortar, each component includes the following substances by weight ratio: each component includes the following substances by mass percentage: Portland cement with strength grade 52.5, 50%, quartz sand, 38%, phosphate, 2.6%, polypropylene fiber with a diameter of 6mm, 0.2%, redispersible latex powder, 4%, expanded perlite powder, 3%, polycarboxylate superplasticizer, 0.8%, and nano-silica, 1.4%;

[0050] A preparation method for the rust-proof and crack-resistant sprayed plastic mortar includes the following steps:

[0051] S1. Dry mixing and pre-dispersion: Put the Portland cement, quartz sand, and expanded perlite powder into a forced mixer and stir at 300 r / min for 2 minutes until uniform;

[0052] S2. Fiber dispersion treatment: Use a vibrating screen to fully disperse the polypropylene fiber and add it to the forced mixer in three portions at 30-second intervals for blending;

[0053] S3. Addition of functional additives: Add phosphate and nano-silica to the forced mixer in sequence and stir for 5 minutes to form a homogeneous dry powder system;

[0054] S4. Liquid-phase modification: Take water according to the ratio of ash to water of 0.25:1 and divide it into three equal parts. Pre-dissolve the redispersible latex powder and polycarboxylate superplasticizer with one part of the water to form a modified liquid;

[0055] S5. Wet mixing: Slowly spray the modified liquid into the dry materials, supplement the remaining water in two portions, stir until the mortar becomes a viscous paste with a fluidity ≥ 180 mm, and then carry out filling;

[0056] Pre-clean or sandblast and rust-remove the pre-spraying part in advance, and apply epoxy primer to enhance the interfacial bonding. Then, evenly spray the prepared rust-proof and crack-resistant sprayed plastic mortar on the surface of the object to be sprayed. Cover with a water retention film after initial setting to make the environmental humidity > 78% within 72 hours until the rust-proof and crack-resistant sprayed plastic mortar solidifies;

[0057] After testing: The corrosion resistance passes the test of (JGJ / T 192), and the tensile bond strength at 14 d ≥ 1.15 Mpa.

[0058] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. Anti-rust and anti-cracking spray mortar, characterized in that: The components include the following substances by mass percentage: 40-50% base material, 35-45% aggregate, 2-3% composite rust inhibitor, 0.1-0.3% anti-cracking fiber, 3-5% redispersible latex powder, 2-4% expanded perlite powder, 0.5-1% polycarboxylic acid water reducer and 1-2% nano silicon dioxide.

2. The rust-proof and crack-resistant sprayed mortar according to claim 1, characterized in that: The base material is silicate cement with strength grade 42.5 or 52.

5.

3. The anti-rust and anti-cracking sprayed mortar according to claim 1 is characterized in that: The aggregate is quartz sand with a particle size of 0.5-2 mm.

4. The anti-rust and anti-cracking sprayed mortar according to claim 1 is characterized in that: The composite rust inhibitor is one of organic chromate, phosphate and sodium nitrite.

5. The anti-rust and anti-cracking sprayed mortar according to claim 1 is characterized in that: The anti-cracking fiber is 3-6 mm polypropylene fiber or glass fiber.

6. A method for preparing rust-proof and crack-resistant sprayed mortar, characterized in that: The following steps are involved: S1. Dry mixing pre-dispersion: put the base material, aggregate and expanded perlite powder into a forced mixer and stir at 300r / min for 2 minutes until uniform; S2. Fiber dispersion treatment: Use a vibrating screen to fully disperse the anti-cracking fiber, and add it into a forced mixer for blending three times at 30-second intervals; S3, adding functional additives: adding composite rust inhibitor and nano silicon dioxide to the forced mixer in sequence, and stirring for 5 minutes to form a homogeneous dry powder system; S4, liquid phase modification: take water according to the above ash amount and divide it into three equal parts, pre-dissolve the redispersible latex powder and polycarboxylic acid series water reducer with one part of the water to form a modified liquid; S5. Wet mixing: slowly spray the modified liquid into the dry material, add the remaining water in two times, stir until the slurry becomes a viscous paste-like mortar, and then fill and seal.

7. The method for preparing the rust-proof and crack-resistant sprayed mortar according to claim 6, characterized in that: The water intake in S4 is a gray-water ratio of 0.22-0.25:

1.

8. The method for preparing the rust-proof and crack-resistant sprayed mortar according to claim 6, characterized in that: The fluidity of the mortar after proportioning in S5 is ≥180mm.