Iron-ore slag high-toughness high-adhesion polymerized modified cement mortar and preparation method thereof

Abstract

The invention discloses high-toughness and high-adhesion polymerized modified cement mortar with iron-ore slag and a preparation method of the high-toughness and high-adhesion polymerized modified cement mortar, and belongs to the technical field of concrete structure repair materials. High-strength, high-toughness and high-adhesion polymer modified mortar is formed, and the requirements of rapid repair engineering of a cement concrete structure for toughness and adhesion performance are met; the iron-ore slag is adopted to replace part of carborundum as the aggregate, so that the early strength of the mortar is ensured on the premise of meeting sustainable development, and the basic requirements of concrete structure repair are met; meanwhile, the fiber, the redispersible latex powder and the modified rubber powder are added, so that the toughness of the material is improved, the bonding performance is improved, and the stress coordination of the repairing material and an original concrete structure is guaranteed.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of concrete structure repair materials, and particularly relates to a high-toughness and high-bonding polymeric modified cement mortar of iron ore slag and a preparation method thereof. BACKGROUND

[0002] With the rapid advancement of infrastructure construction, the early built cement concrete structures have gradually entered the centralized maintenance stage. Influenced by multiple factors such as external load, surrounding environment and service life, these structures gradually show functional and structural damage such as cracks and other diseases. These diseases not only weaken the bearing capacity of the structure, but also accelerate the aging process of the concrete, seriously threatening the safety and service life. For the diseases of the concrete structure, the commonly used repair methods include surface sealing method, pressure grouting method and sprayed concrete, but these methods generally have problems such as long construction period, complex process or insufficient durability. In contrast, the repair mortar has become the preferred solution for concrete structure repair engineering due to its significant advantages such as efficient construction, simple process and precise repair.

[0003] According to the different compositions of materials, the repair mortar can be divided into three categories: cement-based repair mortar, modified cement-based repair mortar and epoxy repair mortar. Among them, the cement-based repair mortar has obtained extremely universal application in the repair engineering of cement concrete structures due to its significant advantages such as low cost, wide application range and convenient construction. This kind of mortar is usually made of ordinary Portland cement as cementitious material, sand as aggregate, and uniformly mixed with additives, mineral admixtures and water. However, in the process of repairing concrete structures, the cement-based repair mortar often faces problems such as insufficient early strength, poor ductility and toughness, and poor bonding performance at the new and old interface. Although there are many research results on early strength and high strength, high toughness and high bonding cement-based rapid repair mortar, the research on high-performance cement-based rapid repair mortar with early strength, high strength, high toughness, high bonding and excellent durability is still relatively scarce.

[0004] At the same time, the huge demand leads to overexploitation of non-renewable sand and stone resources, which in turn causes a series of problems such as soaring prices and resource shortage, and sand and stone resources are facing the crisis of exhaustion. Iron ore slag is rich in glass phase such as silicon dioxide, iron oxide and aluminum oxide, which are the main sources of active materials. With the continuous deepening of the research on iron ore slag, the technical path of using iron ore slag to replace traditional aggregate to prepare repair materials has gradually become a research hotspot in the field of material science.

[0005] Therefore, it is particularly important to develop an iron ore slag polymeric modified cement mortar with high toughness and high bonding performance to meet the repair requirements of concrete structures in terms of strength, toughness and bonding performance. SUMMARY

[0006] Traditional cement concrete repair mortar usually faces the problems of low early strength, poor ductile toughness and poor bonding performance at new and old interfaces; the resource of sand and stone is facing the crisis of resource exhaustion; the continuous accumulation of iron ore slag is not conducive to the construction of an eco-friendly society. In view of the current insufficient cement concrete structure repair technology and the contradiction between sustainable development of sand and stone resources and high value-added utilization of solid waste, the present application provides an iron ore slag high toughness and high bonding polymeric modified cement mortar and a preparation method thereof. The early strength and high strength characteristics of the iron ore slag high toughness and high bonding polymeric modified cement mortar can restore the use function of the repaired structure in a short time, significantly reduce the construction period, and the high toughness and high bonding performance can well adapt to the deformation of the base layer, improve the overall stability and bearing capacity of the structure, prevent the recurrence of diseases, meet the rapid repair needs of the concrete structure, thereby improving the service life and safety of the concrete structure and reducing the maintenance cost, which has important significance for promoting the development of building material science.

[0007] One of the technical solutions provided by the present application is:

[0008] An iron ore slag high toughness and high bonding polymeric modified cement mortar comprises the following components: composite cementitious material, aggregate and admixture; the composite cementitious material comprises sulphoaluminate cement, ordinary Portland cement and high-strength gypsum; the aggregate comprises carborundum, iron ore slag, quartz sand medium sand and quartz sand coarse sand; the admixture comprises water reducing agent, defoaming agent, micro-expanding agent, nano-silicon dioxide, early strength agent, retarder, accelerator, fiber, redispersible latex powder and modified latex powder; the mass of water added is 25-75% of the sum of the mass of the sulphoaluminate cement and the mass of the ordinary Portland cement.

[0009] Further, the iron ore slag high toughness and high bonding polymeric modified cement mortar comprises the following components according to mass parts: sulphoaluminate cement 42-4300 parts, ordinary Portland cement 710-920 parts, high-strength gypsum 350-700 parts, carborundum 930-1130 parts, iron ore slag 370-490 parts, quartz sand medium sand 1290-1600 parts, quartz sand coarse sand 1300-1600 parts, water reducing agent 18-25 parts, defoaming agent 8-14 parts, micro-expanding agent 37-49 parts, nano-silicon dioxide 37-51 parts, early strength agent 64-76 parts, retarder 11-20 parts, accelerator 3-5 parts, redispersible latex powder 75-125 parts, modified latex powder 45-55 parts, and the water-cement ratio is the standard consistency water requirement, and the fiber addition amount is 0.1v / v% of the iron ore slag high toughness and high bonding polymeric modified cement mortar.

[0010] Compared with other similar materials, the present application provides a common silicon-sulfoaluminate-gypsum ternary composite cementitious material system, wherein the sulfoaluminate cement makes up for the insufficient early strength of ordinary portland cement, consumes the hydration product Ca(OH)2 thereof, and improves the stability in an alkaline environment; the high-strength gypsum acts as a "two-way regulator" to delay the rapid hydration of the sulfoaluminate cement and generate high-strength AFt together with the two; the aggregate of the present application includes carborundum, quartz sand and iron ore slag, wherein the carborundum and the quartz sand form a multi-stage wear-resistant framework to resist impact and wear; the iron ore slag fills the pores after hydration, enhances the bonding of the aggregate cementitious interface, and improves the overall strength; the iron ore slag reacts to generate C-S-H gel, reduces shrinkage, and together with the rigid aggregate, inhibits cracks and optimizes the volume stability; by reasonably matching the common silicon-sulfoaluminate-gypsum ternary composite cementitious material system and the above-mentioned aggregate with an admixture, a high-toughness high-bonding modified mortar is formed to meet the requirements of the rapid repair project of cement concrete structures for toughness, bonding and durability; the iron ore slag is used to replace part of the carborundum as the aggregate to ensure the early strength of the mortar and meet the basic requirements of concrete structure repair under the premise of sustainable development; the addition of fibers, redispersible latex powder and modified glue powder improves the toughness, bonding and durability of the material, and is conducive to ensuring the coordination of the stress of the repaired material and the original concrete structure.

[0011] Further, the water reducing agent is selected from at least one or more of a lignin-based water reducing agent, a naphthalene-based water reducing agent, an aliphatic water reducing agent, an ultra-early strength polycarboxylic acid water reducing agent, a terminal silane modified polycarboxylic acid water reducing agent, and an AD43GX type water reducing agent.

[0012] Further, the defoaming agent includes at least one or more of a dimethyl silicone oil defoaming agent, a polyether defoaming agent, an alcohol defoaming agent, a fatty acid defoaming agent, and an AD42A type defoaming agent.

[0013] Further, the early strength agent includes at least one or more of calcium nitrate, lithium carbonate, calcium chloride, and triethanolamine ester.

[0014] Further, the accelerating agent includes at least one or more of lithium carbonate, aluminum sulfate, aluminum nitrate, and water glass.

[0015] Further, the retarding agent includes at least one or more of citric acid, glucose, and tartaric acid.

[0016] Further, the micro-expanding agent includes at least one or more of calcium oxide, magnesium oxide, and calcium sulfoaluminate.

[0017] Further, the fiber includes at least one or more of basalt fiber, carbon fiber, steel fiber, and glass fiber.

[0018] By adding fibers, redispersible latex powder and modified latex powder to the mortar, the toughness of the material can be improved, and the bonding performance can be improved.

[0019] The modified latex powder in the application is a white powder, which is prepared by introducing a silane coupling agent for surface grafting modification based on VAE type redispersible latex powder, so that the toughness and adhesion of the modified latex powder are obviously improved.

[0020] Further, the fineness of the nanosilica is 15-20 nm; the fineness of the corundum is 20-40 mesh; the fineness of the iron ore slag is 20-40 mesh; the fineness of the medium quartz sand is 40-70 mesh; the fineness of the coarse quartz sand is 70-140 mesh; and the iron ore slag can reduce maintenance cost and meet sustainable development.

[0021] The technical solution two provided by the application is as follows:

[0022] A preparation method of the high-toughness and high-bonding polymer modified cement mortar of the iron ore slag, comprising the following steps:

[0023] The raw materials are weighed according to the mass fraction, the sulphate aluminate cement, the ordinary portland cement, the high-strength gypsum and water are uniformly stirred and mixed, and then cured to obtain the composite cementitious material; the composite cementitious material, the aggregate and the additive are uniformly stirred and mixed, and then cured to prepare the high-toughness and high-bonding polymer modified cement mortar of the iron ore slag.

[0024] The application has the following beneficial effects:

[0025] The application forms a high-strength, high-toughness and high-bonding polymer modified mortar by reasonably matching the aggregate composed of corundum, quartz sand and iron ore slag with the ternary composite cementitious material system of common silicon-sulphate-aluminate-gypsum and the additive, meets the demand of the rapid repair project of the cement concrete structure for toughness and bonding performance, uses the iron ore slag to replace part of the corundum as the aggregate, meets the premise of sustainable development, ensures the early strength of the mortar and meets the basic requirement of the repair of the concrete structure, and the addition of fibers, redispersible latex powder and modified latex powder improves the toughness of the material and the bonding performance, which is beneficial to ensuring the coordination of the stress of the repair material and the original concrete structure. DETAILED DESCRIPTION

[0026] The detailed description of the various exemplary embodiments of the application should not be considered as limiting the application, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the application.

[0027] 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 present application. Additionally, for a range of values of, for example, the upper limit and lower limit of a range of values are included in the range. Each intermediate value of the range, as well as every sub-range between any two intermediate values of the range, is also included in the present application. The upper and lower limits of these smaller ranges can independently be included or excluded in the range.

[0028] Unless otherwise defined, 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 application belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present application, the preferred methods and materials are described. All documents mentioned herein are incorporated by reference to disclose and describe the methods and / or materials in connection with which the documents are cited. In case of conflict, the present specification will control.

[0029] Various modifications and changes can be made to the specific embodiments of the present application described herein without departing from the scope or spirit of the application. Other embodiments of the application will be apparent to those of ordinary skill in the art from the description and examples presented herein. The specification and examples given herein are exemplary and should not be used to limit the present application, unless otherwise specifically stated herein.

[0030] As used herein, the terms "comprises", "comprising", "includes", "including", "has", "having" or variants thereof are open-ended, and specifically do not exclude additional, unrecited elements or method steps.

[0031] The present application forms a high-toughness and high-bonding modified mortar by reasonably matching the aggregate composed of common silicon-sulfur aluminum-gypsum ternary composite cementitious material system, carborundum, quartz sand and iron ore slag, and an additive, especially modified latex powder, to meet the demand of the rapid repair project of cement concrete structure for toughness and bonding performance. Compared with other similar materials, the present application uses iron ore slag to replace part of carborundum as the aggregate to ensure the early strength of the mortar under the premise of sustainable development, to meet the basic requirements of concrete structure repair; at the same time, the addition of fiber, redispersible latex powder and modified latex powder improves the toughness and bonding performance of the material, generates C-S-H gel, inhibits microcracks, improves structural tightness and enhances bonding performance, improves the chloride ion penetration resistance of the mortar and thus improves the durability of the repair material, thereby facilitating the coordination of the repair material and the stress of the original concrete structure.

[0032] As a typical but non-limiting example, the water reducing agent in the embodiment of the present application is.D43GX water reducing agent; the defoaming agent is AD42A defoaming agent; the micro-expanding agent is calcium oxide; the early strength agent is calcium nitrate; the retarder is citric acid; the quick-setting agent is lithium carbonate; and the fiber is basalt fiber.

[0033] The raw materials required in the embodiments of the present application are all commercially available, wherein the modified latex powder is a commercially available modified GP-70 glue powder.

[0034] The sulphoaluminate cement used in the embodiments of the present application is R.SAC42.5, and the ordinary portland cement is P.O42.5.

[0035] In the embodiments of the present application, the water-cement ratio corresponds to the water quantity for standard consistency, that is, the mass of water added is 25-75% of the sum of the mass of the sulphoaluminate cement and the mass of the ordinary portland cement, and in the following embodiments, the mass of water added is 45% of the sum of the mass of the sulphoaluminate cement and the mass of the ordinary portland cement.

[0036] In the embodiments of the present application, “parts” are “mass parts” unless otherwise specified.

[0037] Embodiment 1: Preparation method of a high-toughness and high-bonding polymer-modified cement mortar of iron ore slag

[0038] The following raw materials are weighed according to mass parts: sulphoaluminate cement 4057 parts, ordinary portland cement 811 parts, diamond sand 20-40 mesh 1033 parts, iron ore slag 20-40 mesh 443 parts, quartz sand 40-70 mesh 1476 parts, quartz sand 70-140 mesh 1475 parts, water reducing agent 21 parts, defoaming agent 11 parts, calcium oxide 42 parts, nano silicon dioxide 42 parts, early strength agent 69 parts, retarder 16 parts, accelerator 4 parts, high-strength gypsum 500 parts, redispersible latex powder 100 parts, modified latex powder 50 parts, and the water-cement ratio corresponds to the water quantity for standard consistency; in addition, basalt fiber is added in a volume fraction of 0.1% (that is, the volume of the basalt fiber is 0.1% of the total volume of the other raw materials excluding water and basalt fiber).

[0039] The preparation method is as follows:

[0040] (1) Preparation of the composite cementitious material: water, sulphoaluminate cement, ordinary portland cement and high-strength gypsum are placed in a stirrer, which is rotated at a low speed (62±5 rmp) for 120 s, and the cementitious material adhered to the blades and inner wall is scraped clean and into the pot, and the stirrer is turned off after stirring for 120 s, and the mixture is poured into a mold, vibrated, and then placed in a standard curing box for curing;

[0041] (2) Preparation of the high-toughness and high-bonding polymer-modified cement mortar of iron ore slag: the composite cementitious material, aggregate and admixture prepared in step (1) are added to the stirrer, which is rotated at a low speed for 30 s, stopped for 15 s, and the slurry on the inner wall and blades is scraped to the middle, and then stirred at a low speed for 30 s, poured into a mold, vibrated, and then placed in a standard curing box for curing.

[0042] The curing condition in the embodiment of the present application is: the curing temperature is 20±2℃, the relative humidity is above 90%, the test piece is placed on a shelf in a standard curing room, and the distance between the test pieces is 10-20mm, so that the test piece is cured in a uniform temperature and humidity environment, and the normal coagulation and hardening of the test piece is ensured, and the stable growth of the strength is ensured.

[0043] A preparation method of a high-toughness and high-bonding polymeric modified cement mortar of iron ore slag

[0044] The following raw materials are weighed according to mass parts: sulphoaluminate cement 4057 parts, ordinary portland cement 811 parts, corundum sand 20-40 mesh 1476 parts, quartz sand 40-70 mesh 1476 parts, quartz sand 70-140 mesh 1475 parts, water reducing agent 21 parts, defoaming agent 11 parts, calcium oxide 42 parts, nano silicon dioxide 42 parts, early strength agent 69 parts, retarder 16 parts, accelerator 4 parts and high-strength gypsum 500 parts.

[0045] The preparation method is the same as that in Example 1.

[0046] A preparation method of a high-toughness and high-bonding polymeric modified cement mortar of iron ore slag

[0047] The following raw materials are weighed according to mass parts: sulphoaluminate cement 4057 parts, ordinary portland cement 811 parts, corundum sand 20-40 mesh 1033 parts, iron ore slag 20-40 mesh 443 parts, quartz sand 40-70 mesh 1476 parts, quartz sand 70-140 mesh 1475 parts, water reducing agent 21 parts, defoaming agent 11 parts, calcium oxide 42 parts, nano silicon dioxide 42 parts, early strength agent 69 parts, retarder 16 parts, accelerator 4 parts and high-strength gypsum 500 parts.

[0048] The preparation method is the same as that in Example 1.

[0049] A preparation method of a high-toughness and high-bonding polymeric modified cement mortar of iron ore slag

[0050] The following raw materials are weighed according to mass parts: sulphoaluminate cement 4057 parts, ordinary portland cement 811 parts, corundum sand 20-40 mesh 1033 parts, iron ore slag 20-40 mesh 443 parts, quartz sand 40-70 mesh 1476 parts, quartz sand 70-140 mesh 1475 parts, water reducing agent 21 parts, defoaming agent 11 parts, calcium oxide 42 parts, nano silicon dioxide 42 parts, early strength agent 69 parts, retarder 16 parts, accelerator 4 parts, high-strength gypsum 500 parts and basalt fiber volume fraction 0.1%.

[0051] The preparation method is the same as that in Example 1.

[0052] A preparation method of a high-toughness and high-bonding polymeric modified cement mortar of iron ore slag

[0053] The following raw materials are weighed according to mass parts: sulphoaluminate cement 4057 parts, ordinary portland cement 811 parts, carborundum 20-40 mesh 1033 parts, iron ore slag 20-40 mesh 443 parts, quartz sand 40-70 mesh 1476 parts, quartz sand 70-140 mesh 1475 parts, water reducing agent 21 parts, defoaming agent 11 parts, calcium oxide 42 parts, nano silicon dioxide 42 parts, early strength agent 69 parts, retarder 16 parts, accelerator 4 parts, high-strength gypsum 500 parts, basalt fiber volume fraction 0.1%, and redispersible latex powder 100 parts.

[0054] The preparation method is the same as that in Example 1.

[0055] Performance test test one

[0056] The modified cement mortar prepared in Example 1 and Comparative Examples 1-4 is placed in a mold and cured under natural conditions for 4h, 1d, 7d and 28d, and the performance is detected; the bonding strength of the modified cement mortar prepared in Example 1 and Comparative Examples is determined at 14d, and the flexibility of the modified cement mortar prepared in Example 1 and Comparative Examples 1-4 is tested after curing for 28d; wherein the compressive and flexural strengths are determined according to the relevant requirements of the “Hydraulic Concrete Test Regulations” (DL / T 5150), the flexibility and bonding strength are determined according to the relevant requirements of the “Hydraulic Concrete Test Regulations” (DL / T 5150), and the determination results are shown in Table 1.

[0057] Table 1

[0058]

[0059]

[0060] As can be seen from Table 1, the compressive strength of the iron ore slag high-toughness high-bonding polymer modified cement mortar prepared in Example 1 is 25.61 MPa at 4h, and the compressive strength is 59.85 MPa at 28d, which is much higher than the basic requirement of concrete structure rapid repair (the minimum compressive strength required for structure concrete repair by Michigan Department of Transportation (MDOT) is 13.2 MPa within 4h and 31.0 MPa within 28d).

[0061] In the compressive strength test, compared with Comparative Example 1, the compressive strength of Comparative Example 2 is improved by 32.3% at 4h, 7.6% at 1d, 13.5% at 7d, and 22.4% at 28d, which shows that the additional iron ore slag in Comparative Example 2 significantly improves the early strength and the compressive strength after standard molding at 4h and 28d.

[0062] In the material flexural performance, toughness is the ability of material to resist damage and absorb energy when subjected to bending load, the material with good toughness can withstand larger deformation without brittle fracture when subjected to breakage. The flexural compressive ratio of modified cement mortar 1d prepared in example 1 is increased by 0.99% compared with comparative example 1, and the flexural compressive ratio of 7d is increased by 3.3% compared with comparative example 1. At the same time, the shear strength and splitting tensile strength of example 1 at 14d are 2.69MPa and 2.14MPa respectively, which are increased by 9.8% and 8.6% respectively compared with comparative example 4. This shows that the material not only has a certain strength to withstand external force, but also can consume energy through its own deformation during the process of force, thereby showing good flexural performance.

[0063] In the flexibility test, the toughness of comparative example 3 is increased by 36.5% compared with comparative example 2, the toughness of comparative example 4 is increased by 17.0% compared with comparative example 3, and the toughness of example 1 is increased by 21.2% compared with comparative example 4, so the bending deformation ability is improved. This effect of improving both strength and flexibility overcomes the shortcomings of traditional repair materials, that is, the decrease of flexibility when the strength is improved, or the lack of strength when the flexibility is good, which provides more options for the selection of repair materials.

[0064] Performance test two

[0065] The anti-chloride ion permeability experiment of the modified cement mortar prepared by example 1 and comparative examples 1-4 is carried out by electric flux tester on the test piece after 28d curing, and the electric flux is measured as shown in table 2.

[0066] Table 2

[0067] Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Example 1 Electric Flux (C) 556.52 492.81 365.42 307.93 190.16 Resistance Rating Q-Ⅳ Q-Ⅴ Q-Ⅴ Q-Ⅴ Q-Ⅴ

[0068] The electric flux of example 1 is 190.16C, the anti-permeability grade is Q-Ⅴ grade, which meets the requirements of C50 and above concrete in the specification, can effectively prevent the erosion of chemical substances such as chloride ion and sulfate, improve the durability, and prolong the service life of the structure.

[0069] The electric flux of different formula mortar is ranked as: comparative example 1> comparative example 2> comparative example 3> comparative example 4. In the anti-chloride ion permeability test, the electric flux refers to the amount of electric charge passing through the mortar test piece in a certain time, the larger the electric flux, the more chloride ions pass through the mortar test piece in the same time, which means that the anti-permeability of the mortar test piece is worse, that is, the anti-chloride ion permeability of different mortar formulas is ranked from large to small as: comparative example 4> comparative example 3> comparative example 2> comparative example 1.

[0070] The slag in Comparative Example 2-4 and Example 1 is active by itself, and when the slag replaces part of the sand, the slag can react with the calcium hydroxide in the mortar to form C-S-H gel, thereby improving the compactness of the mortar, and the slag has a physical adsorption effect on chloride ions, so that the chloride ion penetration resistance of the mortar is improved after the slag replaces part of the sand.

[0071] The basalt fibers in the mortar test pieces of Comparative Example 3, Comparative Example 4 and Example 1 can inhibit the initiation and propagation of microcracks, making the mortar structure more compact, thereby reducing the chloride ion penetration channel and reducing the electric flux to improve the impermeability of the mortar.

[0072] The redispersible latex powder in Comparative Example 4 and Example 1 can significantly improve the toughness and adhesion of the mortar, making the internal structure of the mortar more compact and effectively hindering the penetration of chloride ions, thereby improving the chloride ion penetration resistance of the mortar.

[0073] The modified latex powder in Example 1 further improves the adhesion of the mortar, making the internal structure of the mortar more compact and having a stronger blocking effect on chloride ions, so that the chloride ion penetration resistance of Example 1 is the best, and the impermeability grade is Grade V, which meets the requirements of the specification for concrete above C50. Mortar with low electric flux usually has higher compactness and stronger freeze-thaw resistance, and can effectively prevent the erosion of chemicals such as chloride ions and sulfates, thereby improving the durability and prolonging the service life of the structure.

[0074] The present application forms a high-toughness high-stickiness modified mortar by reasonably matching the aggregate composed of silica-aluminum-sulfur-gypsum ternary composite cementitious material system, corundum, quartz sand and iron slag, and an admixture, to meet the demand for toughness and adhesion of cement concrete structure rapid repair engineering; iron slag is used to replace part of the corundum as aggregate to meet the premise of sustainable development and ensure the early strength of the mortar, to meet the basic requirements of concrete structure repair; fibers, redispersible latex powder and modified latex powder are added to improve the toughness of the material and improve the adhesion, which is beneficial to ensure the stress compatibility of the repair material and the original concrete structure.

[0075] The above-described examples are only preferred modes of the present application and do not limit the scope of the present application, and various modifications and improvements to the technical solutions of the present application made by those skilled in the art without departing from the design spirit of the present application shall fall within the protection scope determined by the claims of the present application.

Claims

1. An iron slag high-toughness and high-bonding polymer-modified cement mortar, characterized in that: The raw materials include composite cementitious materials, aggregates and admixtures; the composite cementitious materials include sulphoaluminate cement, ordinary Portland cement and high-strength gypsum; the aggregates include corundum, iron ore slag, medium quartz sand and coarse quartz sand; the admixtures include water reducers, defoamers, micro-expansion agents, nano-silica, early strength agents, retarders, quick-setting agents, fibers, redispersible latex powder and modified latex powder; the mass of added water is 25-75% of the sum of the mass of the sulphoaluminate cement and ordinary Portland cement.

2. The iron slag high-toughness and high-bonding polymer-modified cement mortar according to claim 1, characterized in that: Calculated by weight, the invention comprises the following components: 3800-4300 parts of sulphoaluminate cement, 710-920 parts of ordinary Portland cement, 350-700 parts of high-strength gypsum, 930-1130 parts of corundum, 370-490 parts of iron slag, 1290-1600 parts of medium quartz sand, 1300-1600 parts of coarse quartz sand, 18-25 parts of water reducer, 8-14 parts of defoamer, 37-49 parts of micro-expansion agent, 37-51 parts of nano-silica, 64-76 parts of early strength agent, 11-20 parts of retarder, 3-5 parts of accelerator, 75-125 parts of redispersible latex powder and 45-55 parts of modified latex powder. The corresponding water-cement ratio is the water consumption for standard consistency. The amount of fiber added is 0.1 v / v% of the iron slag high-toughness and high-bonding polymer modified cement mortar.

3. The iron slag high-toughness and high-bonding polymer-modified cement mortar according to claim 2, characterized in that: The water reducer is selected from at least one or more of lignin-based water reducers, naphthalene-based water reducers, aliphatic water reducers, super-early-strength polycarboxylate water reducers, and terminal silane-modified polycarboxylate water reducers.

4. The iron slag high-toughness and high-bonding polymer-modified cement mortar according to claim 2, characterized in that: The defoaming agent includes at least one or more of dimethyl silicone defoaming agent, polyether defoaming agent, alcohol defoaming agent and fatty acid defoaming agent.

5. The iron slag high-toughness and high-bonding polymer-modified cement mortar according to claim 2, characterized in that: The early strength agent includes at least one or more of calcium nitrate, lithium carbonate, calcium chloride and triethanolamine ester.

6. The iron slag high-toughness and high-bonding polymer-modified cement mortar according to claim 2, characterized in that: The quick-setting agent includes at least one or more of lithium carbonate, aluminum sulfate, aluminum nitrate and water glass.

7. The iron slag high-toughness and high-bonding polymer-modified cement mortar according to claim 2, characterized in that: The retarder includes at least one or more of citric acid, glucose, and tartaric acid.

8. The iron slag high-toughness and high-bonding polymer-modified cement mortar according to claim 2, characterized in that: The micro-expanding agent includes at least one or more of calcium oxide, magnesium oxide and calcium sulfoaluminate.

9. The iron slag high-toughness and high-bonding polymer-modified cement mortar according to claim 2, characterized in that: The fineness of the nano-silicon dioxide is 15nm-20nm; the fineness of the corundum is 20-40 mesh; the fineness of the iron slag is 20-40 mesh; the fineness of the medium quartz sand is 40-70 mesh; and the fineness of the coarse quartz sand is 70-140 mesh.

10. A method for preparing the high-toughness and high-bonding polymer-modified cement mortar made from iron slag according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: weighing raw materials according to parts by mass, uniformly mixing the sulphoaluminate cement, ordinary Portland cement, high-strength gypsum and water, and curing to obtain the composite cementitious material; and uniformly mixing the composite cementitious material, aggregate and admixture, and curing to prepare the iron slag high-toughness and high-bonding polymer-modified cement mortar.

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