CN110894153A - Waterproof mortar and preparation method thereof - Google Patents

Abstract

The invention discloses waterproof mortar and a preparation method thereof, belonging to the field of cement mortar, wherein the cement mortar comprises the following components: ordinary portland cement, emulsified asphalt powder, silica fume, carbon nanotubes, a modifier, fine aggregate, glass fiber, a water reducing agent, a defoaming agent and water; the emulsified asphalt powder is used for modifying the cement-based material, and the emulsified asphalt powder and the glass fiber act together to obtain the emulsified asphalt powder modified cement mortar with high strength, good anti-permeability and anti-cracking performance, strong waterproof performance and strong corrosion resistance.

Description

Waterproof mortar and preparation method thereof

Technical Field

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

Background

The cement-based material is a heterogeneous multi-phase porous material with hydrophilicity, and when exposed to a corrosive environment or used under severe conditions, the cement-based material can be corroded by moisture transmission and related harmful gases and ions, the volume stability of a structure is affected, the possibility of shrinkage or cracking is increased, and the material performance is deteriorated, and the structure function is failed. The water transport properties in cement-based materials significantly affect the volume stability and durability of the cement material. In recent years, researchers have employed various techniques to prevent moisture permeation and migration in cement-based materials and improve their durability, with surface treatment and internal modification being the two most commonly used methods.

The surface treatment methods of the common cement-based materials are mainly divided into three types: (a) organic surface coating treatment, which can form a continuous protective film on the surface of the cement-based material; (b) inorganic pozzolanic material treatment can reduce surface porosity and have a filling effect and (c) hydrophobic impregnation treatment can make pores in the surface structure have a certain hydrophobicity. Although these treatments exhibit good performance in some respects, certain drawbacks still remain. For example, inorganic pozzolanic materials require relatively severe curing conditions (e.g., temperature, relative humidity, and alkalinity) and relatively complex construction processes, while organic materials exhibit compatibility problems with cementitious substrates and insufficient resistance to aging, which can lead to cracking and spalling of the organic coating. The internal modification method can improve the compatibility of the modified material and the cement-based material to a certain extent, thereby improving the long-term performance of the modified material in a harsh use environment.

The polymer modified cement-based waterproof mortar is prepared by modifying a cement-based material by using a polymer modified material, and has good impermeability, fluidity and water retention rate, and can improve the toughness of the cement-based material, so the polymer modified cement-based waterproof mortar is widely applied in recent years. However, the cement-based materials modified by adding the polymer also have many problems, such as the problem of low compressive strength of the waterproof mortar is not solved, and the price and the cost of the cement mortar are greatly increased due to the high price of the polymer.

In recent years, the emulsified asphalt is widely applied to ballastless track structures of high-speed railways and plays roles in filling and damping. The emulsified asphalt powder is a redispersible powder material prepared by using emulsified asphalt as a raw material through a spray drying process, and has the advantages of convenient storage and transportation and uniform dispersion compared with the emulsified asphalt. However, the water transport behavior of emulsified asphalt powder modified materials is more complex than pure cement based materials due to the inclusion of many pores and different organic and inorganic phase materials. At present, few experimental researches on the influence of emulsified asphalt powder on the waterproofness and the durability of a cement-based material under a severe use environment at home and abroad are carried out, and the use effect of the emulsified asphalt powder is not clear.

Disclosure of Invention

The invention aims to provide waterproof mortar and a preparation method thereof, aiming at solving the problems in the prior art, the waterproof mortar modified by the emulsified asphalt powder has the characteristics of high strength, good anti-permeability and anti-cracking performance, strong waterproof performance and strong corrosion resistance, and compared with the traditional polymer cement waterproof mortar, the waterproof mortar has the advantages of simple and easily obtained raw materials, strong applicability and obvious economic advantage.

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

the invention provides waterproof mortar which comprises the following components in parts by mass:

further, the ordinary portland cement is p.o42.5.

Further, the modifier is hydroxypropyl methyl cellulose.

Further, the fine aggregate is machine-made sand and/or natural sand.

Further, the glass fiber is alkali-resistant glass fiber.

The emulsified asphalt powder and the glass fiber are used together, the degree of corrosion of the emulsified asphalt powder by the alkaline cement matrix is reduced to a certain extent, the interface between the fibers and the cement-based material is improved, and the durability is improved.

Further, the water reducing agent is a polycarboxylic acid water reducing agent.

Further, the defoaming agent is a silicone defoaming agent.

Further, the particle size of the emulsified asphalt powder is 10-100 μm.

The emulsified asphalt powder serving as a toughness modified material has hydrophobicity and viscoelasticity, and can be uniformly and effectively dispersed in a cement material compared with emulsified asphalt, so that the aim of combining the strength and the rigidity of the cement material is fulfilled, the performance of the cement-based material is obviously modified, and the cracking phenomenon of the cement-based material in the application process is effectively avoided.

Further, the particle size of the silica fume is 0.1-0.3 μm.

Furthermore, the diameter of the carbon nano tube is 1-5nm, and the length of the carbon nano tube is 10-100 nm.

Further, the length of the glass fiber is 20-30 mm.

Furthermore, the mesh number of the fine aggregate is 80-120 meshes.

This application comes the filling effect of full play granule through the particle diameter of injecing above-mentioned different components to form tightest pile structure, satisfy all kinds of construction requirements with the workability of guaranteeing the mixture slurry.

The application also provides a preparation method of the waterproof mortar, which comprises the following steps:

(1) sequentially adding water, a water reducing agent and the carbon nano tube into an ultrasonic dispersion instrument for dispersion for 1-2 hours, and filtering to remove impurities;

(2) adding ordinary portland cement, silica fume and fine aggregate into a ball mill, uniformly mixing, then adding emulsified asphalt powder, a modifier and glass fiber, uniformly mixing again, and placing in a container for later use;

(3) and (3) adding the components treated in the step (1) into the mixture obtained in the step (2) to be uniformly mixed, then adding a defoaming agent, and continuously stirring until the components are uniformly mixed again to obtain the waterproof mortar.

The invention discloses the following technical effects:

1. the waterproof mortar prepared by the invention fully combines the hydrophobicity and viscoelasticity of emulsified asphalt materials and the strength and rigidity of cement-based materials, achieves the effect of modifying hardness and softness, and effectively solves the problem of functional failure caused by cracking and peeling of the traditional waterproof materials. All indexes of the mortar meet the national standard JC/T984-one 2011 of polymer cement waterproof mortar with similar functions, the mortar has excellent crack resistance, impermeability, waterproofness and corrosion resistance, and is suitable for buildings, water conservancy and railway engineering with higher requirements on waterproof performance.

2. The waterproof mortar prepared by the invention fully exerts the filling effect of particles with different sizes to form the tightest stacking structure so as to ensure that the workability of the mixture slurry meets various construction requirements.

3. The emulsified asphalt powder and the glass fiber are used together, so that the degree of corrosion of the emulsified asphalt powder by the alkaline cement matrix is reduced to a certain extent, the interface of the fiber and the cement matrix is improved, and the durability is improved.

4. Based on the successful application of the emulsified asphalt material in the ballastless track of the high-speed railway, the emulsified asphalt powder with excellent hydrophobic property and strong compatibility with cement-based materials is used as a main modified material to prepare the waterproof mortar, and compared with the traditional polymer-based waterproof mortar, the waterproof mortar has stronger economic applicability.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a comparison of the water absorption rates of cement mortars of examples 1-5 and comparative example.

FIG. 2 is a comparison of water absorption amounts of cement mortars of examples 1 to 5 and comparative example.

FIG. 3 is a comparison of the penetration depth of chlorine ions in cement mortars according to examples 1 to 5 and comparative example.

FIG. 4 is a graph showing a comparison of the carbonation depths of cement mortars according to examples 1 to 5 and a comparative example.

Detailed Description

Reference will now be made in detail to various exemplary embodiments of the invention, the detailed description should not be construed as limiting the invention but as a more detailed description of certain aspects, features and embodiments of the invention.

It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Further, for numerical ranges in this disclosure, it is understood that each intervening value, between the upper and lower limit of that range, is also specifically disclosed. Every smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in a stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference herein for the purpose of disclosing and describing the methods and/or materials associated with the documents. In case of conflict with any incorporated document, the present specification will control.

It will be apparent to those skilled in the art that various modifications and variations can be made in the specific embodiments of the present disclosure without departing from the scope or spirit of the disclosure. Other embodiments will be apparent to those skilled in the art from consideration of the specification. The specification and examples are exemplary only.

As used herein, the terms "comprising," "including," "having," "containing," and the like are open-ended terms that mean including, but not limited to.

The "parts" in the present invention are all parts by mass unless otherwise specified.

The waterproof mortar comprises the following components in parts by mass:

the ordinary portland cement is P.O42.5;

the modifier is hydroxypropyl methyl cellulose;

the fine aggregate is machine-made sand and/or natural sand, and the mesh number is 80-120 meshes;

the glass fiber is alkali-resistant glass fiber, and the length of the glass fiber is 20-30 mm;

the water reducing agent is polycarboxylic acid, such as LJ-JSS;

the defoaming agent is a silicone defoaming agent, such as AT-470;

the particle size of the emulsified asphalt powder is 10-100 mu m;

the particle size of the silica fume is 0.1-0.3 mu m;

the diameter of the carbon nano tube is 1-5nm, and the length of the carbon nano tube is 10-100 nm.

Examples 1 to 5

The formula is as follows: as shown in table 1.

The preparation method comprises the following steps:

(1) sequentially adding water, a water reducing agent and the carbon nano tube into an ultrasonic dispersion instrument for dispersion for 1-2 hours, and filtering to remove impurities;

(2) adding ordinary portland cement, silica fume and fine aggregate into a ball mill, uniformly mixing, then adding emulsified asphalt powder, a modifier and glass fiber, uniformly mixing again, and placing in a container for later use;

(3) and (3) adding the components treated in the step (1) into the mixture obtained in the step (2) to be uniformly mixed, then adding a defoaming agent, and continuously stirring until the components are uniformly mixed again to obtain the waterproof mortar.

Comparative example

The emulsified asphalt powder in example 1 was replaced with styrene-acrylic emulsion, and the other components and preparation method were the same as in example 1, and the formulation is shown in table 1.

TABLE 1

The examples 1-5 and the comparative example were subjected to performance tests according to national standard JC/T984-2011 of polymer cement waterproof mortar, national standard DL/T5126-2001 of polymer modified cement mortar and a common test method in the industry, and the test results are shown in Table 2.

TABLE 2

The above-described embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solutions of the present invention can be made by those skilled in the art without departing from the spirit of the present invention, and the technical solutions of the present invention are within the scope of the present invention defined by the claims.

Claims (10)

1. The waterproof mortar is characterized by comprising the following components in parts by mass:

2. the waterproof mortar of claim 1, wherein the Portland cement is P.O42.5.

3. The waterproof mortar of claim 1, wherein the modifier is hydroxypropyl methylcellulose.

4. The waterproof mortar of claim 1, wherein the fine aggregate is machine-made sand and/or natural sand; the mesh number of the fine aggregate is 80-120 meshes.

5. The waterproof mortar of claim 1, wherein the glass fiber is alkali-resistant glass fiber; the length of the glass fiber is 20-30 mm.

6. The waterproof mortar of claim 1, wherein the water reducing agent is a polycarboxylic acid water reducing agent.

7. The waterproof mortar of claim 1, wherein the defoaming agent is a silicone defoaming agent.

8. The waterproof mortar of claim 1, wherein the particle size of the emulsified asphalt powder is 10-100 μm; the particle size of the silica fume is 0.1-0.3 μm.

9. The waterproof mortar of claim 1, wherein the carbon nanotubes have a diameter of 1-5nm and a length of 10-100 nm.

10. A process for the preparation of a waterproofing mortar according to any of claims 1 to 9, characterized in that it comprises the following steps:

(1) sequentially adding water, a water reducing agent and the carbon nano tube into an ultrasonic dispersion instrument for dispersion for 1-2 hours, and filtering to remove impurities;

(2) adding ordinary portland cement, silica fume and fine aggregate into a ball mill, uniformly mixing, then adding emulsified asphalt powder, a modifier and glass fiber, uniformly mixing again, and placing in a container for later use;

(3) and (3) adding the components treated in the step (1) into the mixture obtained in the step (2) to be uniformly mixed, then adding a defoaming agent, and continuously stirring until the components are uniformly mixed again to obtain the waterproof mortar.

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