CN111533517B - Rapid repair mortar for high-speed railway concrete track slab and preparation method thereof - Google Patents

Abstract

The invention provides a quick repair mortar for a high-speed railway concrete track slab, which comprises the following raw materials in percentage by mass: 100 parts of cement, 50-250 parts of fine aggregate, 5-25 parts of mineral admixture, 0-8 parts of soluble latex powder, 0-20 parts of polymer emulsion, 0.1-1.0 part of water reducing agent, 0.2-2.0 parts of expansion component, 0.1-1.5 parts of plastic agent, 0.1-1.2 parts of early strength agent, 0.2-1.5 parts of retarding component, 0.1-0.5 part of defoaming agent and 0-30 parts of water; wherein the mass parts of the soluble latex powder and the polymer emulsion are not 0 at the same time. The invention also provides a preparation method of the rapid modification mortar and application of the rapid modification mortar in repairing non-structural damage of a ballastless high-speed railway concrete track slab. The rapid repair mortar disclosed by the invention has the characteristics of good workability, high early strength and high strength, high volume stability, good durability and the like.

Description

Rapid repair mortar for high-speed railway concrete track slab and preparation method thereof

technical field

The invention belongs to the field of concrete and railway building materials, and particularly relates to a mortar for rapid repair of concrete track slabs of high-speed railways and a preparation method thereof.

Background technique

Slab ballastless track is one of the main track structures of my country's high-speed railways, with prefabricated track slabs as the structural core. Prefabricated track slabs can be mainly divided into CRTSI type, CRTSII type and CRTSIII type. As of 2019, the total operating mileage of high-speed railways in my country has exceeded 30,000 kilometers, and the number of concrete track slabs in service on the railway lines is nearly 10 million. As the operating hours increased, the number of track slabs showing damage also increased. When the track slab has non-structural damage such as local chipping, falling blocks, and honeycomb pitting that affect operational safety and durability, it is necessary to repair the damaged part within the time period of the skylight (usually 4 hours) to stop the damage. damage, improve performance and prolong service life. Conventional cement mortar materials have shortcomings such as slow strength structure formation, poor interfacial bonding performance and volume stability, so they cannot meet the requirements of timely opening and operation of trains after repairs, and the repaired parts are damaged again within a short period of time after opening and operation.

For this reason, the mortar specially used for the rapid repair of the prefabricated track slab of the ballast track appears in the prior art. For example, the Chinese invention patent application with the publication number CN102924021A (published on February 13, 2013) discloses a composite cement-based quick-setting dry material and mortar for ballastless track maintenance and a manufacturing method thereof. The dry material is composed of 25%-45% composite cement, 7.8%-15% composite mineral admixture, 0.05%-0.1% retarder, 0.05%-0.11% defoamer, 0%-0.01% by mass. % water-retaining agent, 0.26%-1% thickener, 0.1%-0.16% water-reducing agent, 0.05%-0.1% fiber and 46%-62.5% quartz sand, the composite cement is composed of 10%-20% by mass. % Portland cement and 80%-90% sulfoaluminate cement, the composite mineral admixture is composed of 20%-60% silica fume and 40%-80% mineral powder in a mass ratio, and the retarder The agent is boric acid or tartaric acid, the defoamer is polyether modified silicon defoamer or polydimethylsiloxane, and the water retention agent is hydroxypropyl methyl cellulose ether or methyl cellulose ether. The thickening agent is redispersible latex powder, the water reducing agent is polycarboxylate superplasticizer, and the fiber is polyacrylonitrile fiber or polypropylene fiber. Although the mortar disclosed in the invention has the properties of fast setting and early strength, the mortar has high fluidity and poor plasticity, and is only suitable for filling construction in confined spaces. Moreover, the maximum compressive strength of the mortar 28d disclosed in this invention is only 45MPa (Example 2 of the specification), which does not match the strength of the track plate C60 and cannot meet the use requirements. There are also organic resin repair materials in the prior art. The cost of the material is high, the construction environment is demanding, and the process is complicated. At the same time, the resin material has poor aging resistance and durability. In addition, the sensitivity to temperature and stress-strain responsiveness of inorganic-organic materials are quite different, so it is easy to form a stress difference at the repair interface, which leads to cracks or even shedding between the repair material and the track plate substrate. It is difficult to achieve durability for maintenance. Chinese invention patent CN101560077A discloses an epoxy resin mortar composition applied to slab ballastless track. The mortar has the characteristics of heat aging resistance, chemical corrosion resistance, good elasticity and mechanical strength to cement, but the preparation process of raw materials is relatively complicated. , the stirring time is long, and it cannot well meet the requirements of rapid construction and repair of high-speed rail ballastless tracks. The epoxy resin mortar composition in this patent does not involve hourly strength, and its 28d strength is low.

SUMMARY OF THE INVENTION

The main purpose of the present invention is to provide a quick repair mortar for high-speed railway concrete track slab and a preparation method thereof. The quick repair mortar has the advantages of simple construction, good interfacial adhesion and matching, high volume stability, excellent impermeability and durability.

In order to realize the above-mentioned technical effect, the present invention adopts the following technical scheme:

A kind of quick repair mortar for high-speed railway concrete track slab, raw materials by mass fraction include: cement 100 parts, fine aggregates 50-250 parts, mineral admixtures 5-25 parts, soluble latex powder 0-8 parts parts, polymer emulsion 0-20 parts, water reducing agent 0.1-1.0 parts, swelling component 0.2-2.0 parts, plasticizer 0.1-1.5 parts, early strength agent 0.1-1.2 parts, retarding component 0.2 to 1.5 parts, 0.1 to 0.5 parts of defoamer, and 0 to 30 parts of water; wherein the parts by mass of the soluble latex powder and the polymer emulsion are not 0 at the same time.

Preferably, for the rapid repair mortar for high-speed railway concrete track slab, the raw materials, in terms of mass fraction, include: 100 parts of cement, 100 to 180 parts of fine aggregate, 10 to 25 parts of mineral admixture, and 0 parts of soluble latex powder. parts to 5 parts, 0 parts to 15 parts of polymer emulsion, 0.1 part to 0.6 part of water reducing agent, 0.2 part to 1.5 part of swelling component, 0.1 part to 1.0 part of plasticizer, 0.1 part to 1.0 part of early strength agent, 0.2 to 1.0 parts of coagulation component, 0.1 to 0.3 parts of defoamer, and 3 to 25 parts of water; wherein the parts by mass of the soluble latex powder and the polymer emulsion are not 0 at the same time.

Preferably, the cement is selected from one or any ratio of sulfoaluminate cement, Portland cement or ultrafine cement.

Preferably, the Portland cement is selected from one or a plurality of any proportions of Portland cement of grade 52.5 and Portland cement of grade 62.5.

Preferably, the sulfoaluminate cement is one or more than one of grade 42.5 sulfoaluminate cement and grade 52.5 sulfoaluminate cement.

Preferably, the specific surface area of the ultrafine cement is not less than 500 m ² /kg.

Preferably, the fine aggregate is selected from one or more of quartz sand, river sand and mountain sand with a continuous particle gradation of 40 mesh to 120 mesh and a moisture content of not more than 0.5% (w/w). kind.

Preferably, the mineral admixture is selected from one or more than one selected from the group consisting of silica fume, ground slag powder, Class I fly ash and Class II fly ash.

The silica fume is any one or more kinds of silica fume that meet the requirements of the standard GB/T27690 "Silica Fume for Mortar and Concrete", including ordinary silica fume and/or modified silica fume.

Preferably, the soluble latex powder is selected from one or any ratio of vinyl acetate-ethylene copolymer rubber powder, styrene-butadiene copolymer rubber powder, and acrylate-styrene copolymer rubber powder.

Preferably, the polymer emulsion is selected from modified acrylic emulsion, styrene-butadiene emulsion, styrene-acrylic emulsion, carboxylated styrene-butadiene emulsion and vinyl acetate latex, or a plurality of them in any proportion.

Also preferably, the solid content of the polymer emulsion is 30% to 50% (w/w).

Preferably, the water-reducing agent is selected from one or a plurality of arbitrary proportions of aminocarboxylic acid water-reducing agent, polycarboxylic acid water-reducing agent and naphthalene-based water-reducing agent.

Preferably, the expansion component is selected from one or a plurality of any ratios of aluminum powder, plastic expansion agent, UEA expansion component, CSA expansion component, calcium oxide expansion component and magnesium oxide expansion component.

Also preferably, the aluminum powder is scaly aluminum powder or granular aluminum powder with a fineness greater than 200 meshes.

Preferably, the plasticizer is selected from one or more of bentonite, hydroxypropyl methyl cellulose ether, carbomer resin and modified starch in any proportion.

Preferably, the early strength agent is selected from calcium formate, triethanolamine, lithium carbonate and lithium hydroxide, or a plurality of them in any proportion.

Preferably, the setting retarding component is selected from one or a plurality of any ratios of sodium gluconate, borax, sodium citrate, boric acid and tartaric acid.

Preferably, the defoamer is a silicone defoamer.

Preferably, the quick repair mortar for high-speed railway concrete track slabs of the present invention may further include a toner.

Preferably, the mass part of the toner is not more than 0.5 part.

Preferably, the toner is selected from one or more of ink, graphite and carbon black in any proportion.

Among the above-mentioned raw materials, cement, fine aggregate, mineral admixture, soluble latex powder, water reducing agent, swelling component, plasticizer, early strength agent, retarding component and toner are solid raw materials; polymer emulsion , defoamer and water are non-solid raw materials.

Another object of the present invention is to provide the above-mentioned preparation method for the rapid repair mortar for high-speed railway concrete track slab, comprising the following operations:

1. Prepare each raw material according to the proportion;

II. The solid raw materials (cement, fine aggregate, mineral admixture, soluble latex powder, water reducing agent, swelling component, plasticizer, early strength agent, retarding component and toner (if any), etc. )well mixed;

III. Add non-solid raw materials (defoamer, polymer emulsion (if any) and water), stir and mix evenly.

Preferably, the steps II and III are carried out in equipment with stirring means.

Further preferably, in the equipment with a stirring device, the stirring speed of the step II is not less than 60r/min, the stirring time is not less than 30s, the stirring speed of the step III is not less than 120r/min, and the stirring time is not less than 60s.

The third object of the present invention is to provide the above quick repair mortar and the application of the quick repair mortar prepared by the above method in non-structural damage repair of ballastless high-speed railway concrete track slabs.

The high-speed railway ballastless track concrete track slab includes CTRSI type, CTRSII type and CTRIIII type.

Specifically, the non-structural damage repair of the ballastless high-speed railway concrete track slab includes the following steps:

Step 1: Clean the parts to be repaired, and remove the weak structure and dust and other debris on the surface of the parts to be repaired;

Step 2: Pre-treat the parts to be repaired, paint the interface agent, and plant reinforcement if necessary to enhance the bonding performance and durability of the repair mortar and the concrete matrix;

The third step: pouring the quick repair mortar;

Step 4: Carry out the follow-up treatment of the repaired parts according to the actual situation, such as painting protective paint, etc.

In this specification, unless otherwise specified, technical terms have their usual meanings. For example, "workability" refers to a comprehensive technical index of fresh mortar (or concrete), usually including performance indicators such as fluidity, water retention, bleeding, and cohesion.

In this specification, the mass fraction of each component refers to the relative dosage ratio relationship of each component, rather than the specific mass of each component. 1 mass part can be 500g, 1kg, 10kg, or any mass according to specific circumstances.

The purpose of the present invention is to provide a quick and easy solution for non-structural damages such as honeycomb pitted surface, local fragmentation or falling blocks, damage to the bearing platform, damage to the prestressed anchor hole sealing mortar of the high-speed railway slab-type ballastless track concrete track slab, etc. Repair mortar. The quick repair mortar is based on the characteristics of short maintenance period (usually 4 hours) and construction requirements of high-speed railway skylights, by optimizing the gradation of fine aggregates, and by expanding components, water reducing agents, soluble rubber powder, polymer emulsion The compound technology of components such as early strength agent and retarder component makes the mortar have the characteristics of good workability, early strength and high strength, high volume stability and good durability. In addition, the quick repair mortar provided by the present invention has good interfacial cohesion and matching, and has good consistency with the base of the concrete track slab.

Specifically, the soluble rubber powder and/or polymer emulsion can make the mortar paste have high bonding performance, which helps to improve the adhesion between the repair mortar and the interface, and the mortar curing and polymer film formation are carried out simultaneously, which significantly The compactness of the repair mortar is improved, and the impermeability and frost resistance of the mortar are further improved. The compounding of different expansion components significantly improves the volume stability of the repair mortar at various stages during the hardening process. Subsequent examples show that the compressive strength of the quick repair mortar provided by the present invention reaches over 21 MPa in 2 hours, over 42 MPa in 1 d, and up to 70 MPa in 28 days. The flexural strength of mortar can reach above 4.3MPa, above 6.3MPa and above 11.7MPa at 2h, 1d and 28d, respectively. In addition, the examples also show that the mortar shrinkage rate of 28d is less than 0.01%, and the interface stress between the repair mortar and the track plate substrate is reduced, thereby ensuring the durability of the repair effect. The plasticizer effectively improves the workability of the mortar and at the same time enhances the plasticity retention of the repair mortar, thus reducing the difficulty of construction and improving the work efficiency.

Detailed ways

The present invention will be described below with reference to specific examples. Those skilled in the art can understand that these examples are only for illustrating the present invention, and they do not limit the scope of the present invention in any way.

The experimental methods in the following examples are conventional methods unless otherwise specified. The raw materials, reagent materials, etc. used in the following examples are all commercially available products unless otherwise specified.

Embodiment 1 A kind of quick repair mortar for high-speed railway concrete track slab

The rapid repair mortar raw materials and their mass fractions in this embodiment are shown in Table 1; wherein,

The cement is grade 52.5 fast-hardening sulfoaluminate cement; the mineral admixture is grade I fly ash; the fine aggregate is machine-made sand with continuous particle gradation of 40 mesh to 120 mesh; the swelling component is a mass ratio of 1:10 Plastic expansion agent and UEA expansion agent; plastic agent is hydroxypropyl methyl cellulose ether; water reducing agent is polycarboxylate water reducing agent; early strength agent is lithium carbonate; retarding component is tartaric acid with a mass ratio of 1:1 and boric acid; the soluble rubber powder is acrylate and styrene copolymer rubber powder (mass ratio 1:1); the defoamer is a silicone defoamer; the toner is carbon black; the polymer emulsion is modified with a solid content of 48%. acrylic emulsion.

The quick repair mortar is prepared by the following method:

After all solid raw materials (cement, fine aggregate, mineral admixture, soluble latex powder, water reducer, swelling component, plasticizer, early strength agent, retarder component and toner) are measured in proportion After adding it into the mixer, stir at a speed of 60r/min for 45s, and mix it evenly; then add defoamer, polymer emulsion and water in proportion, and stir at 150r/min for 90s, that is, it is obtained.

Embodiment 2 A kind of quick repair mortar for high-speed railway concrete track slab

The rapid repair mortar raw materials and their mass fractions in the present embodiment are shown in Table 1, wherein:

The cement is grade 52.5 fast-hardening sulfoaluminate cement and ultrafine Portland cement with a mass ratio of 4:1; the mineral admixtures are silica fume and grade I fly ash with a mass ratio of 2:3; the fine aggregate is water-containing 40 mesh to 120 mesh river sand with a ratio of 0.1%; the expansion component is 200 mesh scaly aluminum powder with a mass ratio of 1:2:12, plastic expansion agent and UEA expansion component; the plasticizer is hydroxypropyl methyl fiber Plain ether; water reducing agent is polycarboxylate water reducing agent; early strength agent is lithium carbonate and calcium formate with mass ratio of 1:10; retarding component is tartaric acid and citric acid with mass ratio of 1:1; soluble rubber powder is Acrylate and styrene copolymerized rubber powder (mass ratio is 1:2); the defoamer is a silicone defoamer; the toner is carbon black; the polymer emulsion is a modified acrylic emulsion with a solid content of 48%.

The quick repair mortar is prepared by the following method:

After the solid raw materials (cement, fine aggregate, mineral admixture, soluble latex powder, water reducer, swelling component, plasticizer, early strength agent, retarder component and toner) are measured in proportion, etc. Add it to the mixer, stir at a speed of 60r/min for 45s, and mix it evenly; then add defoamer, polymer emulsion and water according to the proportion, and stir at 150r/min for 90s, that is, it is obtained.

Embodiment 3 A kind of quick repair mortar for high-speed railway concrete track slab

The rapid repair mortar raw materials and their mass fractions in the present embodiment are shown in Table 1, wherein:

The cement is grade 42.5 fast-hardening sulfoaluminate cement; the mineral admixture is silica fume; the fine aggregate is 40-120 mesh river sand with a moisture content of 0.1%; the expansion component is a plastic expansion agent with a mass ratio of 1:12 and UEA swelling component; plasticizer is modified starch and hydroxypropyl methylcellulose ether in mass ratio of 1:1; water reducing agent is polycarboxylate water reducing agent; early strength agent is lithium hydroxide; retarder group It is divided into 2:1 borax and citric acid; the defoamer is a silicone defoamer; the toner is carbon black; the polymer emulsion is a modified acrylic emulsion with a solid content of 48%.

The quick repair mortar is prepared by the following method:

Add the solid raw materials (cement, fine aggregate, mineral admixture, water reducing agent, swelling component, plasticizer, early strength agent, retarder component and toner) in proportion to the mixer, etc. Stir at a speed of 60r/min for 45s, and mix it evenly; then add defoamer, polymer emulsion and water in proportion, and stir at 150r/min for 90s, that is, it is obtained.

Embodiment 4 A kind of quick repair mortar for high-speed railway concrete track slab

The rapid repair mortar raw materials and their mass fractions in the present embodiment are shown in Table 1, wherein:

The cement is grade 52.5 fast-hardening sulfoaluminate cement and ultrafine Portland cement with a mass ratio of 1:1; the mineral admixtures are I-grade fly ash and silica fume with a mass ratio of 2:1; the fine aggregate is water-containing Machine-made silica sand and dried river sand with a mass ratio of 1:1 and a mass ratio of not more than 0.1%; the expansion components are 200 mesh granular aluminum powder with a mass ratio of 1:1:10, plastic expansion agent and UEA expansion component; plasticizer It is bentonite and hydroxypropyl methyl cellulose ether with a mass ratio of 3:1; the water reducing agent is a high-performance polycarboxylate superplasticizer; the early strength agent is calcium formate and lithium hydroxide with a mass ratio of 5:1; retarder The components are sodium gluconate and tartaric acid in a mass ratio of 4:1; the defoamer is a silicone defoamer; the toner is carbon black; the polymer emulsion is a modified acrylic acid with a solid content of 48% in a mass ratio of 1:1 Emulsion and 50% solids styrene-acrylic emulsion.

The quick repair mortar is prepared by the following method:

Add the solid raw materials (cement, fine aggregate, mineral admixture, water reducing agent, swelling component, plasticizer, early strength agent, retarder component and toner) in proportion to the mixer, etc. Stir at a speed of 60r/min for 45s, and mix it evenly; then add defoamer, polymer emulsion and water in proportion, and stir at 150r/min for 90s, that is, it is obtained.

Embodiment 5 A kind of quick repair mortar for high-speed railway concrete track slab

The rapid repair mortar raw materials and their mass fractions in the present embodiment are shown in Table 1, wherein:

The cement is grade 52.5 fast-hardening sulfoaluminate cement; the mineral admixtures are grade I fly ash and silica fume with a mass ratio of 1:1; Silica sand and dried river sand; the swelling component is the plastic expansion agent and the CSA expansion component with a mass ratio of 1:10; the plasticizer is bentonite and hydroxypropyl methyl cellulose ether with a mass ratio of 10:1; the water reducing agent is Polycarboxylate high-performance water reducing agent; early strength agent is lithium carbonate; retarding component is sodium gluconate and boric acid with a mass ratio of 3:1; defoamer is silicone defoamer; toner is carbon black; The polymer emulsion is a styrene-butadiene emulsion with a solid content of 50%.

The quick repair mortar is prepared by the following method:

Add the solid raw materials (cement, fine aggregate, mineral admixture, water reducing agent, swelling component, plasticizer, early strength agent, retarder component and toner) in proportion to the mixer, etc. Stir at a speed of 60r/min for 45s, and mix it evenly; then add defoamer, polymer emulsion and water in proportion, and stir at 150r/min for 90s, that is, it is obtained.

Embodiment 6 A kind of quick repair mortar for high-speed railway concrete track slab

The composition of the quick repair mortar of this embodiment is exactly the same as that of embodiment 5, and is prepared by the following method:

The solid raw materials (cement, fine aggregate, mineral admixture, water reducing agent, swelling component, plasticizer, early strength agent, retarder component and toner) are measured in proportion and put into high-speed mixing In the machine, high-speed mixing and stirring for 12 minutes to obtain dry powder, package, and standby; at the emergency repair construction site, add the dry powder, defoamer, polymer emulsion and water according to the mixing ratio into the mixer, and stir at 150r/min for 120s, That's it.

Comparative Example 1 A mortar

The mortar raw materials and their mass fractions in this comparative example are shown in Table 1, wherein:

The cement is grade 52.5 fast-hardening sulfoaluminate cement and ultrafine Portland cement with a mass ratio of 1:1; the mineral admixtures are I-grade fly ash and silica fume with a mass ratio of 2:1; the fine aggregate is water-containing Machine-made silica sand and dried river sand with a mass ratio of 1:1 and a mass ratio of not more than 0.1%; the expansion components are 200 mesh granular aluminum powder with a mass ratio of 1:1:10, plastic expansion agent and UEA expansion component; plasticizer It is bentonite and hydroxypropyl methyl cellulose ether with a mass ratio of 3:1; the water reducing agent is a high-performance polycarboxylate superplasticizer; the early strength agent is calcium formate and lithium hydroxide with a mass ratio of 5:1; retarder The components are sodium gluconate and tartaric acid in a mass ratio of 4:1; the defoaming agent is an organosilicon defoaming agent; and the toner is carbon black.

The quick repair mortar is prepared by the following method:

After all the raw materials are measured in proportion, add them to the mixer, stir at a speed of 60r/min for 45s, and mix them evenly; then add water according to the proportion, and stir at 150r/min for 90s.

Comparative Example 2 A mortar

The mortar raw materials and their mass fractions in this comparative example are shown in Table 1, wherein:

The cement is grade 42.5 fast-hardening sulfoaluminate cement; the mineral admixture is silica fume; the fine aggregate is 8-40 mesh river sand with a moisture content of 0.1%; the expansion component is a plastic expansion agent with a mass ratio of 1:12 and UEA swelling component; plasticizer is modified starch and hydroxypropyl methylcellulose ether in mass ratio of 1:1; water reducing agent is polycarboxylate water reducing agent; early strength agent is lithium hydroxide; retarder group It is divided into 2:1 borax and citric acid; the defoamer is a silicone defoamer; the toner is carbon black; the polymer emulsion is a modified acrylic emulsion with a solid content of 48%.

The quick repair mortar is prepared by the following method:

Add the solid raw materials (cement, fine aggregate, mineral admixture, water reducing agent, swelling component, plasticizer, early strength agent, retarder component and toner) in proportion to the mixer, etc. Stir at a speed of 60r/min for 45s, and mix it evenly; then add defoamer, polymer emulsion and water in proportion, and stir at 150r/min for 90s, that is, it is obtained.

Test Example 1 Performance determination of the quick repair mortar for high-speed railway concrete track slab prepared in Examples 1-6 and the mortar prepared in Comparative Examples 1-2

In accordance with "Test Method for Strength of Cement Mortar" GB/T 17671-1999, "Test Procedure for Polymer Modified Cement Mortar" DL/T5126-2001, "Standard for Long-term Performance and Durability Test of Ordinary Concrete" GB/T50082-2009, etc. The standard stipulates that the quick repair mortars prepared in the above examples 1-6 and the mortars prepared in the comparative examples 1-2 are respectively tested for performance. The test results are shown in Table 2.

The test results in Table 2 show that the 2h compressive strength of the rapid repair mortar of the present invention is greater than 21MPa, and the 2h flexural strength is greater than or equal to 4.3MPa, indicating that the rapid repair mortar has early strength and early hardness, and can meet the requirements of a short maintenance window for high-speed railways. The compressive strength of the quick repair mortar 28d of the present invention is greater than 67MPa, and the flexural strength of the 28d is greater than or equal to 11.7MPa, which is matched with the strength of the track plate. In addition, the impermeability of the quick repair mortar is greater than P20, the 28d shrinkage rate is not higher than 0.008%, and the frost resistance grade reaches P300. These data all show that the rapid repair mortar of the present invention has high volume stability, impermeability and Features of excellent durability.

Compared with Example 4, in Comparative Example 1, except for omitting the polymer emulsion and increasing the amount of water, other raw materials and their mass fractions are the same as those in Example 4. In Comparative Example 1, due to the lack of polymer emulsion, the mixing of mortar and the addition of water increased. Although the compressive strength of the prepared mortar was slightly increased, the flexural strength of the mortar was slightly reduced, and the 28d shrinkage rate was >0.01%. This shows that the lack of polymer emulsion makes the elasticity and toughness of the mortar deteriorate, which in turn leads to the deterioration of the anti-shearing, anti-deformation and other fatigue resistance properties of the mortar. In addition, the resistance to chloride ion penetration of mortar also decreased slightly. All of the above have an adverse effect on the durability of the mortar.

Compared with Example 3, in Comparative Example 2, the composition of raw materials and their mass fractions are the same as those in Example 3, except that the fine aggregates are 8-40 mesh sand. Through the comparison of the results, it can be seen that the change of the fine aggregate gradation leads to a decrease in the compressive/flexural strength of the prepared mortar, and the resistance to chloride ion penetration and the shrinkage rate of the mortar become worse. Inventing a specific ratio for the preparation of mortar will make the mortar performance worse.

Claims (10)

1. A rapid repair mortar for high-speed railway concrete track slabs, in terms of mass fraction, the composition of raw materials is: 100 parts of cement, 100 to 180 parts of fine aggregates, 10 to 25 parts of mineral admixtures, and soluble latex 0 to 5 parts of powder, 0 to 15 parts of polymer emulsion, 0.1 to 0.6 parts of water reducing agent, 0.2 to 1.5 parts of swelling components, 0.1 to 1.0 parts of plasticizer, 0.1 to 1.0 parts of early strength agent , 0.2 to 1.0 parts of retarding components, 0.1 to 0.3 parts of defoamer, and 3 to 25 parts of water; wherein the mass fractions of the soluble latex powder and the polymer emulsion are not 0 at the same time; The fine aggregate is selected from quartz sand or river sand with a continuous particle gradation of 40 mesh to 120 mesh and a moisture content of not more than 0.5% (w/w); The mineral admixture is selected from one or both of silica fume and Class I fly ash; The soluble latex powder is acrylate and styrene copolymerized rubber powder; The polymer emulsion is selected from one or more of modified acrylic emulsion, styrene-butadiene emulsion and styrene-acrylic emulsion with a solid content of 30% to 50% by mass percentage; The water reducing agent is a polycarboxylate water reducing agent; The expansion component is selected from one or more of aluminum powder, plastic expansion agent, UEA expansion component and CSA expansion component; The plasticizer is selected from one or more of bentonite, hydroxypropyl methylcellulose ether and modified starch; Described early strength agent is selected from one or more in lithium carbonate, calcium formate and lithium hydroxide; The retarding component is selected from one or more of sodium gluconate, borax, sodium citrate, boric acid and tartaric acid; The defoamer is a silicone defoamer. 2. quick repair mortar according to claim 1, is characterized in that, described cement is selected from one or a plurality of arbitrary proportions in sulfoaluminate cement, Portland cement or ultrafine cement; The Portland cement is selected from one or any proportion of Portland cement of grade 52.5 and Portland cement of grade 62.5; Described sulfoaluminate cement is one or a variety of arbitrary proportions in 42.5-grade sulfoaluminate cement and 52.5-grade sulfoaluminate cement; The specific surface area of the ultrafine cement is not less than 500m ² /kg. 3 . The quick repair mortar according to claim 1 , wherein the aluminum powder is scaly aluminum powder or granular aluminum powder with a fineness greater than 200 meshes. 4 . 4. The quick repair mortar according to any one of claims 1 to 3, characterized in that, the quick repair mortar may further comprise a toner. 5. The quick repair mortar according to claim 4, characterized in that, the mass part of the toner is not more than 0.5 part. 6 . The quick repair mortar according to claim 4 , wherein the toner is selected from one or more of ink, graphite and carbon black in any proportion. 7 . 7 . The quick repair mortar according to claim 5 , wherein the toner is selected from one or more of ink, graphite and carbon black in any proportion. 8 . 8. the preparation method of the quick repair mortar described in any one of claim 1 to 7, comprises the following operations: I. Prepare each raw material according to the proportion; II. Mix the solid raw materials evenly; III. Add non-solid raw materials, stir and mix evenly. 9. The preparation method according to claim 8, wherein the step II and the step III are carried out in a device with a stirring device. 10. preparation method according to claim 9 is characterized in that, in the equipment with stirring device, described step II stirring speed is not less than 60r/min, and stirring time is not less than 30s, and described step III stirring speed is not less than 30s. Less than 120r/min, stirring time not less than 60s.