Cement-based abrasion-resistant material as well as preparation method and application thereof

Abstract

The invention discloses a cement-based abrasion-resistant material and a preparation method and application thereof.The preparation method comprises the steps that composite aggregate and low-heat Portland cement are mixed according to a preset proportion and placed in a microwave field to be subjected to microwave pretreatment, then stirring is conducted, and a first mixture is obtained; applying an axial magnetic field to steel fibers, and stirring with the first mixture to obtain a second mixture; mixing polypropylene fibers and a silane coupling agent solution, spraying the mixture on the second mixture, and stirring to obtain a third mixture; and injecting a compound superplasticizer, water, an air entraining agent and an admixture into the third mixture in stages, and stirring to obtain the cement-based abrasion-resistant material. The anti-abrasion performance of the cement-based anti-abrasion material can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of material preparation, and in particular to a cement-based anti-wear material, a preparation method and an application thereof. Background Art

[0002] In many water conservancy and hydropower projects, port terminals, mine chutes and other facilities, cement-based anti-abrasion material structures are subjected to harsh working conditions such as high-speed water flow, sand-containing water flow, and ore particle impact for a long time, and are prone to abrasion loss problems.

[0003] Although traditional ordinary Portland cement-based anti-abrasion materials are widely used in the engineering field, their high hydration heat characteristics will cause the temperature gradient inside the cement-based anti-abrasion materials to increase, thereby forming cracks, providing channels for the invasion of abrasive media, and accelerating the destruction process of the material. At the same time, the mechanical properties and toughness of this type of cement-based anti-abrasion materials are difficult to meet the requirements of high-intensity abrasion environments. The accumulation of hydration heat not only affects the durability of the cement-based anti-abrasion material structure, but also reduces its anti-abrasion performance, leading to premature failure of the structure. In addition, ordinary cement-based anti-abrasion materials have obvious deficiencies in anti-abrasion performance and cannot effectively resist the continuous impact of high-speed water flow and solid particles. These problems seriously restrict the service life and safety of cement-based anti-abrasion materials under harsh working conditions. Summary of the Invention

[0004] In order to overcome the deficiencies of the prior art, the present application provides a cement-based anti-impact and wear material, a preparation method and an application thereof, aiming to improve the anti-impact and wear performance of the cement-based anti-impact and wear material.

[0005] A cement-based anti-impact and wear material, the components of the anti-impact and wear material and the proportions of each component include: low-heat Portland cement: 20 to 40 parts; composite fiber material: 3 to 5 parts; admixture: 5 to 10 parts; composite aggregate: 60 to 100 parts; water: 7 to 18 parts; compound high-efficiency water reducing agent: 1 to 2 parts; and air entraining agent: 1 to 2 parts.

[0006] Optionally, the mass ratio of the water to the low-heat Portland cement is 0.35 to 0.45:1.

[0007] Optionally, the composite fiber material includes steel fibers and polypropylene fibers.

[0008] Optionally, the compound high-efficiency water reducer includes a polycarboxylic acid high-performance water reducer and a naphthalene-based water reducer.

[0009] Optionally, the admixture includes any one of silica fume and mineral powder.

[0010] Optionally, the composite aggregate includes coarse aggregate and fine aggregate, and the mass ratio of the coarse aggregate to the fine aggregate is 0.5 to 2:1.

[0011] The present application also provides a method for preparing a cement-based anti-impact and wear material, which includes: mixing composite aggregate and low-heat silicate cement in a preset proportion, placing the mixture in a microwave field for microwave pretreatment, and stirring to obtain a first mixture; applying an axial magnetic field to steel fibers, and stirring the mixture with the first mixture to obtain a second mixture; mixing polypropylene fibers with a silane coupling agent solution and spraying the mixture on the second mixture, and stirring to obtain a third mixture; injecting a compounded high-efficiency water reducer, water, an air entraining agent, and an admixture into the third mixture in stages, and stirring to obtain a cement-based anti-impact and wear material.

[0012] Optionally, the mixing of composite aggregate and low-heat Portland cement and placing them in a microwave field for microwave pretreatment includes: forming a precoating layer on the surface of the composite aggregate; mixing the composite aggregate with the precoating layer and the low-heat Portland cement in stages; heating the mixed composite aggregate and cement with microwaves; and spraying a coolant on the surface of the heated mixture of composite aggregate and cement for cooling.

[0013] Optionally, the preparation method further comprises: injecting the compounded high-efficiency water reducer, water, air entraining agent, and admixture into the third mixture in stages during stirring, and adding paraffin wax and silica core-shell phase change microspheres.

[0014] The present application also provides an application of a cement-based anti-impact and wear material, wherein the anti-impact and wear material is prepared based on any of the above methods, and the anti-impact and wear material is applied to mines and industrial chute systems.

[0015] The beneficial effects of the present application are as follows: the present application significantly reduces the hydration heat of cement-based anti-impact and wear materials while ensuring the mechanical properties of cement-based anti-impact and wear materials through the synergistic effect of specific raw material ratios and composite fiber materials, effectively inhibits the formation of temperature cracks in cement-based anti-impact and wear materials, and improves the anti-impact and wear durability of cement-based anti-impact and wear materials by optimizing aggregate grading and fiber reinforcement mechanism. It has the outstanding advantages of reducing the temperature gradient inside the structure and extending the service life under harsh working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a flow chart of a method for preparing a cement-based anti-wear material provided in one embodiment of the present application;

[0017] Figure 2 It is a microscopic diagram of traditional ordinary Portland cement-based anti-wear material;

[0018] Figure 3 This is a microscopic schematic diagram of a cement-based anti-wear material provided in another embodiment of the present application. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0020] A cement-based anti-wear material provided in an embodiment of the present application is made of the following raw materials in parts by weight: 20 to 40 parts of low-heat Portland cement, 3 to 5 parts of composite fiber material, 5 to 10 parts of admixture, 60 to 100 parts of composite aggregate, 7 to 18 parts of water, 1 to 2 parts of compound high-efficiency water reducer and 1 to 2 parts of air entraining agent.

[0021] In the technical solution provided in this application, the hydration heat of low-heat silicate cement is lower than that of ordinary silicate cement, which can delay the hydration reaction process of the cement-based anti-impact material system, thereby reducing the temperature rise; the composite fiber material can improve the toughness of the cement-based anti-impact material while improving its tensile strength; the admixture can improve the microstructure of the cement-based anti-impact material and reduce the porosity of the cement-based anti-impact material; the composite aggregate can reduce the amount of cement by dense stacking; the compound high-efficiency water-reducing agent has the dual functions of water reduction and slump prevention; the air-entraining agent can introduce tiny enclosed air The invention discloses a novel air entraining agent for cement-based anti-abrasion materials, which can improve the freeze-thaw resistance and impermeability of cement-based anti-abrasion materials, and realizes the reinforcing effect of both rigidity and flexibility through the composite fiber system. In this embodiment, sodium dodecylbenzene sulfonate is selected as the air entraining agent; low-heat silicate cement and admixtures synergistically reduce the temperature rise, and composite aggregates further reduce the amount of cementitious materials. The synergistic effect of multiple components enables the cement-based anti-abrasion materials to maintain strength while significantly improving the crack resistance and durability. The temperature gradient inside the matrix of the cement-based anti-abrasion materials is significantly reduced, thereby improving the ability of the cement-based anti-abrasion materials to resist water flow abrasion and particle impact.

[0022] Optionally, the mass ratio of water to low-heat Portland cement ranges from 0.35 to 0.45:1.

[0023] By controlling the water content per unit of cement, the hydration reaction rate is controlled while ensuring the fluidity of the cement-based anti-abrasion material, thereby suppressing the concentrated release of hydration heat. Excessive water content can lead to the formation of localized high-temperature zones during the exothermic hydration phase, exacerbating temperature gradients and potentially causing internal hydration heat accumulation within the cement-based anti-abrasion material. Excessive water content can lead to uneven dispersion of low-heat Portland cement particles, preventing them from fully hydrating. By controlling the mass ratio of water to low-heat Portland cement within the range of 0.35 to 0.45:1, the hydration reaction rate of the low-heat Portland cement is optimized, balancing the hydration reaction progress with the heat release rate, resulting in a more uniform temperature distribution within the cement-based anti-abrasion material. This reduces the risk of microcracks caused by thermal stress, improves the overall structural density of the cement-based anti-abrasion material, reduces the possibility of abrasive media intrusion along cracks, and enhances the material's durability in high-velocity water flow environments.

[0024] Optionally, the composite fiber material is a mixture of steel fiber and polypropylene fiber; the mass ratio of the steel fiber to the polypropylene fiber ranges from 1:1 to 3.

[0025] Steel fiber is a metal fiber material with high tensile strength. It forms a three-dimensional mesh support structure inside the cement-based anti-impact and wear material to resist the stress concentration caused by external impact loads, and can improve the impact resistance of the cement-based anti-impact and wear material; polypropylene fiber absorbs crack propagation energy through interfacial bonding, and its high elastic modulus can inhibit the expansion of microcracks inside the cement-based anti-impact and wear material. The mass ratio of steel fiber to polypropylene fiber is controlled in the range of 1:1 to 3, which can ensure the stability of the cement-based anti-impact and wear material, and enable the cement-based anti-impact and wear material to disperse the stress field when it is impacted, thereby improving the anti-impact and wear performance.

[0026] Optionally, the length of the steel fiber ranges from 6 to 12 mm, the diameter of the steel fiber ranges from 0.05 to 0.8 mm, and the tensile strength of the steel fiber is greater than or equal to 2000 MPa.

[0027] The length of steel fiber in the range of 6 to 12 mm can improve its spatial distribution span in the cement-based anti-impact and wear material matrix, balance the dispersion of steel fiber in the cement-based anti-impact and wear material matrix and the contact area with the cement-based anti-impact and wear material matrix. Too short steel fiber will lead to insufficient fiber reinforcement effect, and too long steel fiber length will easily agglomerate. The diameter of steel fiber in the range of 0.05 to 0.8 mm ensures the stiffness of the steel fiber itself, while avoiding the decrease in the interfacial bonding force of the cement-based anti-impact and wear material matrix due to excessive diameter; the tensile strength of steel fiber is greater than or equal to 2000 MPa, which improves the ability of cement-based anti-impact and wear material to bear external loads and delays the expansion of cracks in cement-based anti-impact and wear material. When cement-based anti-impact and wear material is subjected to high-speed water flow or particle impact, steel fiber can effectively absorb impact energy and inhibit crack expansion. At the same time, by optimizing the matching relationship between fiber size and strength, performance degradation caused by premature fiber breakage or uneven dispersion is avoided, thereby improving the service life of the structure in a long-term impact and wear environment.

[0028] Optionally, the length of the polypropylene fibers ranges from 6 to 12 mm, and the diameter of the polypropylene fibers ranges from 0.05 to 0.5 mm.

[0029] Polypropylene fibers can effectively inhibit crack expansion. Fibers with a diameter of 0.05 to 0.5 mm absorb energy through interfacial bonding with the cement-based anti-impact and wear material matrix. Their flexible properties can delay the expansion of the crack tip. When the diameter of the polypropylene fiber is too large, the stiffness decreases and it is difficult to resist external stress impacts. By limiting the range of length and diameter, the uniformity of the dispersion of polypropylene fibers in the cement-based anti-impact and wear material is guaranteed, and by optimizing the mechanical response characteristics of a single polypropylene fiber, the energy dissipation mechanism of the cement-based anti-impact and wear material under dynamic load is significantly improved, thereby extending the service life of the cement-based anti-impact and wear material.

[0030] Optionally, the admixture is one of silica fume and mineral powder; and the mass ratio of the admixture to the composite fiber material ranges from 0.1 to 0.3:1.

[0031] Silica fume or mineral powder can fill the pores between low-heat silicate cement particles in cement-based anti-abrasion materials, reduce porosity and optimize the structure of the interface transition zone; the silica fume has a silica content greater than 95%, a particle size range of 0.6 to 1 μm, has high volcanic ash activity, and can promote the secondary hydration reaction of the cement-based anti-abrasion material matrix; mineral powder is a powdered material processed from blast furnace slag powder, and its chemical composition is mainly calcium oxide, silicon dioxide and aluminum oxide. It has water hardness and can continuously improve the cement-based anti-abrasion material in the later stage. Strength; The mass ratio of admixture to composite fiber material is 0.1 to 0.3:1, which ensures the ability of admixture to improve the matrix density of cement-based anti-impact and wear material, and avoids the phenomenon of decreased fiber dispersion caused by excessive addition of admixture, and effectively solves the dual problems of temperature cracks caused by high hydration heat and insufficient anti-impact and wear performance; The reasonable selection of admixture reduces the amount of cement and optimizes the hydration reaction process, and at the same time forms a complementary reinforcement effect with the composite fiber material, which significantly improves the service life of cement-based anti-impact and wear material under harsh working conditions such as sand-containing water flow impact.

[0032] Optionally, the compound high-efficiency water reducer is a combination of a polycarboxylic acid high-performance water reducer and a naphthalene-based water reducer;

[0033] The mass ratio of the composite fiber material to the compounded high-efficiency water reducer ranges from 0.5 to 4:1.

[0034] The combination of polycarboxylic acid-based water-reducing agent and naphthalene-based water-reducing agent reduces the water-cement ratio of the cement-based anti-abrasion material system and reduces the generation of hydration heat. The composite fiber material is evenly dispersed with the assistance of the composite high-efficiency water-reducing agent, avoiding excessive use of the composite high-efficiency water-reducing agent to cause the viscosity of the cement-based anti-abrasion material to be too low.

[0035] In the present application, the mass ratio of polycarboxylic acid high-performance water-reducing agent to naphthalene-based water-reducing agent is 1 to 4:1. During the mixing process of cement-based anti-impact and wear-resistant materials, the composite fiber material and the compounded high-efficiency water-reducing agent are used in a ratio of 0.5 to 4:1. When the ratio is lower than 0.5, an excessive amount of compounded high-efficiency water-reducing agent will lead to a decrease in the interfacial bonding force between the composite fiber material and the cement matrix; when the ratio is higher than 4, insufficient water-reducing agent will make it impossible to fully disperse the composite fiber material; by maintaining this ratio range, it is possible to ensure that the water-reducing agent fully exerts its dispersing effect and ensure the spatial distribution state of the composite fiber material in the cement-based anti-impact and wear-resistant material, thereby synergistically improving the anti-impact and wear resistance and durability of the cement-based anti-impact and wear-resistant material.

[0036] Compared with the prior art, the use amount and ratio of the fiber material and the water reducing agent in the conventional cement-based anti-abrasion material formula lack scientific basis, and the phenomena of uneven dispersion of the fiber or excessive use of the water reducing agent often occur. The scheme establishes a synergistic mechanism of fiber reinforcement and water reducing agent dispersion by limiting a specific mass ratio, solves the technical contradiction of fiber aggregation and water reducing agent failure, realizes uniform distribution of the fiber reinforced phase in the cement-based anti-abrasion material matrix, effectively blocks the crack propagation path, and reduces the hydration heat peak value through precise regulation and control of the compounded high-efficiency water reducing agent. The synergistic effect makes the surface abrasion rate of the cement-based anti-abrasion material significantly reduced when the cement-based anti-abrasion material bears the high-speed water flow impact, and the internal structure integrity is effectively maintained.

[0037] Optionally, the composite aggregate includes coarse aggregate and fine aggregate; and the mass ratio of the coarse aggregate to the fine aggregate ranges from 0.5 to 2:1.

[0038] In the embodiment, the coarse aggregate is basalt crushed stone, which is used to construct the internal skeleton structure of the cement-based anti-abrasion material and bear mechanical load; the fine aggregate is natural river sand, which is used to fill the gaps between the coarse aggregates and improve the compactness of the cement-based anti-abrasion material; and the mass ratio of the coarse aggregate to the fine aggregate ranges from 0.5 to 2:1, which can balance the ratio of the internal skeleton structure to the filling structure of the cement-based anti-abrasion material and reduce the problem of increased porosity caused by unreasonable grading of the coarse aggregate and the fine aggregate.

[0039] Specifically, when the content of the coarse aggregate is too low, the skeleton support in the cement-based anti-abrasion material matrix is insufficient, and when the content of the coarse aggregate is too high, the fine aggregate cannot fully fill the gaps between the coarse aggregates; and when the content of the fine aggregate is too high, the friction between the aggregates decreases. The application limits the ratio range of the coarse aggregate to the fine aggregate, so that the aggregates of different particle sizes form a multi-level embedded structure, the impact load can be dispersed and transmitted along the skeleton network, the local damage propagation is reduced, the compressive strength of the cement-based anti-abrasion material is ensured, the energy absorption capacity of the cement-based anti-abrasion material against impact is improved, and the damage to the cement-based anti-abrasion material caused by high-speed water flow or particle impact is reduced.

[0040] Optionally, the coarse aggregate includes 20wt% to 30wt% coarse aggregate with a particle size of 5mm to 10mm, 30wt% to 60wt% coarse aggregate with a particle size of 10mm to 15mm, and 20wt% to 30wt% coarse aggregate with a particle size of 15mm to 20mm; and the fineness modulus of the fine aggregate ranges from 2.6 to 3.0, and the clay content of the fine aggregate is less than 2%.

[0041] The graded proportioning of coarse aggregates achieves close stacking of coarse aggregates by combining coarse aggregates in different particle size ranges. By adopting coarse aggregates in three particle size ranges of 5mm to 10mm, 10mm to 15mm and 15mm to 20mm and mixing them in specific proportions, a multi-level skeleton structure can be formed inside the matrix of the cement-based anti-impact material, thereby enhancing the mechanical bite effect between the coarse aggregates and reducing the problem of excessive porosity of the cement-based anti-impact material due to a single particle size. The fineness modulus of the fine aggregate is adjusted by mixing the particle size of river sand. A too low fineness modulus affects the workability of the cement-based anti-impact material, balances the fluidity and water retention of the cement-based anti-impact material, and avoids segregation caused by too coarse or too fine sand particles. The mud content of the fine aggregate is below 2%, which can effectively reduce the interference of impurities on the hydration reaction of low-heat silicate cement and improve the uniformity of the internal structure of the cement-based anti-impact material. This scheme significantly improves the density, uniformity and impact load resistance of the aggregate system through continuous grading optimization of three-level particle size coarse aggregates.

[0042] Figure 1 This is a flow chart of a method for preparing a cement-based anti-wear material provided in an embodiment of the present application. Figure 1 As shown, the method includes the following steps:

[0043] S100: mixing composite aggregate and low-heat Portland cement and placing them in a microwave field for microwave pretreatment, followed by stirring to obtain a first mixture;

[0044] S200: applying an axial magnetic field to the steel fiber and stirring the steel fiber with the first mixture to obtain a second mixture;

[0045] In this step, applying an axial magnetic field during the steel fiber addition process can align the steel fibers in a specific direction within the cement-based anti-wear material matrix through magnetic orientation, reducing random entanglement and agglomeration. This magnetic field-guided orientation distribution significantly improves the spatial uniformity and effective working length of the steel fibers within the cement-based anti-wear material, allowing them to more fully exert their reinforcing effects of bridging cracks and dispersing stress. This not only improves the tensile strength and impact toughness of the anti-wear material, but also optimizes the interfacial bonding between the steel fibers and the cement paste, thereby enhancing the reliability and durability of the anti-wear material under stress or abrasion conditions.

[0046] S300: mixing the polypropylene fiber and the silane coupling agent solution and spraying the mixture onto the second mixture, and stirring to obtain a third mixture;

[0047] In this step, polypropylene fibers are mixed with a silane coupling agent solution. The purpose is to form an active functional layer on the surface of the polypropylene fibers through the coupling agent, thereby enhancing the interfacial bonding between the fibers and the cement matrix. Since polypropylene fibers themselves have a smooth surface and low polarity, they are prone to problems such as interfacial debonding and unstable reinforcement effects in cement-based anti-abrasion materials. Silane coupling agents can establish a "chemical bridge" between organic fibers and inorganic cementitious materials, enhancing interfacial bonding strength and promoting synergistic stress transfer, thereby effectively inhibiting crack propagation, improving anti-abrasion performance and the overall toughness of the material. Therefore, this treatment method can ensure that the polypropylene fibers are not only physically evenly distributed in the cement, but also have a strong mechanical connection, exerting a better reinforcement effect.

[0048] S400: Inject the compounded high-efficiency water-reducing agent, water, air-entraining agent and admixtures into the third mixture in stages, and obtain the cement-based anti-wear material after stirring.

[0049] The above preparation method can achieve multi-scale and multi-mechanism coordinated optimization by successively introducing technical means such as microwave pretreatment, magnetic field orientation, chemical modification and staged stirring. Among them, microwave pretreatment can enhance the interfacial activity of aggregate and cement particles and control the release of hydration heat; the magnetic field effect can improve the orientation distribution of steel fibers and enhance impact resistance; coupling agent-modified polypropylene fibers can improve their adhesion in the cement matrix and inhibit the expansion of microcracks; by introducing water reducers, air entraining agents and admixtures in stages, the water-cement ratio and pore structure can be effectively regulated, and the density, freeze-thaw resistance and impact resistance of cement-based anti-wear materials can be improved, which is beneficial to enhance the durability and mechanical properties of cement-based anti-wear materials under harsh working conditions.

[0050] In another exemplary embodiment, in step S100, the mixing of composite aggregate and low-heat Portland cement and placing them in a microwave field for microwave pretreatment comprises the following steps:

[0051] S101: forming a pre-coating layer on the surface of the composite aggregate;

[0052] In this step, before the composite aggregate and cement are mixed, a layer of a diluent containing a silane coupling agent and a surfactant (at a concentration of 0.5% to 1%) is sprayed onto the surface of the composite aggregate to form a pre-coating layer on the surface of the composite aggregate. This coating helps to enhance the microwave absorption capacity and promote the interfacial adsorption activation of cement particles.

[0053] S102: mixing composite aggregate for forming a pre-coating layer on the surface and low-heat Portland cement in stages;

[0054] In this step, cement and fine aggregate are first mixed, followed by the addition of coarse aggregate and stirring to create a uniform particle size distribution gradient. Specifically, the fine aggregate and cement easily and evenly absorb energy in the microwave field, forming a continuous "absorbing layer" that improves the uniformity of thermal energy distribution. The subsequent introduction of coarse aggregate acts as a "spacer support framework" to prevent localized overheating or agglomeration. This approach not only enhances the penetration depth and uniform excitation of microwave energy throughout the mixture, but also reduces energy reflection and hotspot accumulation, effectively improving the overall activation efficiency and uniformity of material pretreatment.

[0055] S103: placing the mixed composite aggregate and cement in a microwave treatment device (for example, microwave power is set to 2.45HGz, power is set to 1200W, and time is set to 3 minutes) for microwave heating;

[0056] S104: After the heating is completed, a coolant (pure water or water mixed with 0.1% nano-SiO2 sol) is sprayed on the surface of the mixture of composite aggregate and cement for cooling;

[0057] In this step, by spraying coolant, micro cracks caused by thermal expansion and contraction can be induced, the surface coating of the aggregate can be broken, more active sites can be formed, and premature hydration of the cement can be avoided at the same time.

[0058] S105: stirring the cooled mixture of composite aggregate and cement again to obtain a first mixture.

[0059] In this step, stirring again helps to break up the micro-agglomerated particles and improve the overall uniformity, thereby forming a first mixture in an activated state.

[0060] In another exemplary embodiment, in step S400, injecting the compounded high-efficiency water reducer, water, air entraining agent, and admixture into the third mixture in stages includes the following steps:

[0061] S401: injecting the compound high-efficiency water reducer and 50% of the total water into the third mixture and stirring to obtain a fourth mixture;

[0062] S402: mixing an air entraining agent and nano-SiO2 sol, injecting the mixture into the fourth mixture, and stirring to obtain a fifth mixture;

[0063] S403: Add the admixture and the remaining water to the fifth mixture, and stir to obtain a cement-based anti-wear material.

[0064] In this embodiment, the compounded high-efficiency water-reducing agent and part of the water are first injected, which helps to establish a good dispersion environment in advance, so that the composite fibers and the gelling system are quickly wetted and the initial agglomeration is avoided; then the mixed liquid of the air-entraining agent and the nano-SiO2 sol is introduced, which can effectively utilize the low-viscosity system established in the early stage, which is conducive to the formation of uniform and stable distribution of bubbles. At the same time, nano-SiO2 can be preferentially adsorbed and participate in the interfacial reaction at this stage, thereby improving the density of the matrix; finally, the addition of the admixture and the remaining water can ensure its full hydration reaction and cooperate with the previous reaction, thereby avoiding poor dispersion due to the high viscosity of the early reaction environment.

[0065] On the contrary, if all components are mixed at once instead of being injected in stages, it is easy to cause fiber flocculation, air entraining agent failure (foam rupture), admixture wrapping cement particles to form a "wrapping effect" or incomplete reaction, which will eventually lead to problems such as decreased fluidity, uneven structure, insufficient strength and deterioration of impact and wear resistance of cement-based impact and wear resistant materials, thereby seriously affecting the working performance and durability of the impact and wear resistant materials.

[0066] In another exemplary embodiment, the preparation method further comprises: adding paraffin wax and silica core-shell phase change microspheres during the process of adding the admixture and the remaining water to the fifth mixture and stirring.

[0067] In this embodiment, during the process of adding the admixture and the remaining water to the fifth mixture and stirring, the present application can construct a microscopic temperature control system with active temperature regulation capability by introducing paraffin wax and silica core-shell phase change microspheres, wherein paraffin wax, as a phase change material, can absorb a large amount of latent heat during the hydration exothermic process of the cement-based anti-wear material, thereby effectively reducing the peak temperature and delaying the temperature rise rate, thereby suppressing the risk of thermal cracks caused by the temperature gradient; silica can provide good chemical stability and interface affinity, allowing the microspheres to be evenly distributed in the cement-based anti-wear material without being destroyed, maintaining the long-term reversibility of the phase change performance. In addition, the silica shell can also participate in the secondary hydration reaction, filling the capillary pores and improving the density of the matrix.

[0068] Below, the present application specifically describes the cement-based anti-wear material and its preparation method involved in the present application by combining specific examples and comparative examples:

[0069] Example 1

[0070] 80 parts of composite aggregate and 35 parts of low-heat Portland cement are mixed and placed in a microwave field for microwave pretreatment, followed by stirring to obtain a first mixture;

[0071] applying an axial magnetic field to 2.67 parts of the steel fiber and stirring the steel fiber with the first mixture to obtain a second mixture;

[0072] Mixing 1.33 parts of polypropylene fiber with the silane coupling agent solution and spraying the mixture onto the second mixture, followed by stirring to obtain a third mixture;

[0073] 1.5 parts of compound high-efficiency water reducing agent, 12 parts of water, 1 part of air entraining agent and 6 parts of admixture (mineral powder) were injected into the third mixture in stages, and the cement-based anti-wear material was obtained after stirring.

[0074] Example 2

[0075] 82 parts of composite aggregate and 33 parts of low-heat Portland cement are mixed and placed in a microwave field for microwave pretreatment, followed by stirring to obtain a first mixture;

[0076] applying an axial magnetic field to 2.1 parts of the steel fiber and stirring the steel fiber with the first mixture to obtain a second mixture;

[0077] Mixing 1.4 parts of polypropylene fiber with the silane coupling agent solution and spraying the mixture onto the second mixture, followed by stirring to obtain a third mixture;

[0078] 1.5 parts of compound high-efficiency water reducing agent, 13 parts of water, 1 part of air entraining agent and 8 parts of admixture (silica fume) were injected into the third mixture in stages, and the cement-based anti-wear material was obtained after stirring.

[0079] Example 3

[0080] 85 parts of composite aggregate and 32 parts of low-heat Portland cement are mixed and placed in a microwave field for microwave pretreatment and cooled, and then stirred to obtain a first mixture;

[0081] applying an axial magnetic field to 2.67 parts of the steel fiber and stirring the steel fiber with the first mixture to obtain a second mixture;

[0082] Mixing 1.33 parts of polypropylene fiber with the silane coupling agent solution and spraying the mixture onto the second mixture, followed by stirring to obtain a third mixture;

[0083] 1.5 parts of compound high-efficiency water reducer, 14 parts of water, 1 part of mixture of air entraining agent and nano-SiO2 sol, and 9 parts of admixture (mineral powder) were injected into the third mixture in stages, and after stirring, 0.5 parts of paraffin wax and silica core-shell microspheres were added to finally obtain a cement-based anti-wear material.

[0084] Example 4

[0085] 90 parts of composite aggregate and 30 parts of low-heat Portland cement are mixed and placed in a microwave field for microwave pretreatment and cooled, and then stirred to obtain a first mixture;

[0086] applying an axial magnetic field to 3.375 parts of the steel fiber and stirring the steel fiber with the first mixture to obtain a second mixture;

[0087] Mixing 1.125 parts of polypropylene fiber with the silane coupling agent solution and spraying the mixture onto the second mixture, followed by stirring to obtain a third mixture;

[0088] 2 parts of compound high-efficiency water reducer, 13 parts of water, 1.2 parts of mixture of air entraining agent and nano-SiO2 sol, and 10 parts of admixture (silica fume) are injected into the third mixture in stages, and after stirring, 1 part of paraffin wax and silica core-shell microspheres are added to finally obtain a cement-based anti-wear material.

[0089] Comparative Example 1

[0090] 80 parts of composite aggregate and 35 parts of ordinary Portland cement are directly mixed and then stirred to obtain a first mixture;

[0091] 2.5 parts of steel fibers were directly added to the first mixture without applying a magnetic field, and stirred to obtain a second mixture;

[0092] 1.5 parts of polypropylene fiber (not treated with a silane coupling agent) was directly added to the second mixture and stirred to obtain a third mixture;

[0093] 1 part of the compound high-efficiency water reducing agent, 13 parts of water, 0.8 parts of the air entraining agent and 6 parts of the admixture are injected into the third mixture at one time, and the cement-based anti-impact and wear material is obtained after stirring.

[0094] Comparative Example 2

[0095] 82 parts of composite aggregate and 34 parts of low-heat Portland cement were directly mixed (without microwave treatment), and then stirred to obtain a first mixture;

[0096] 1.0 part of steel fiber (without magnetic field treatment) was directly added to the first mixture, and mixed to form a second mixture;

[0097] 0.8 parts of polypropylene fiber was directly added to the second mixture (not modified with a coupling agent) and stirred to obtain a third mixture;

[0098] 13 parts of water, 1 part of air entraining agent and 6 parts of admixture are added into the third mixture at one time and stirred to form a cement-based anti-abrasion material.

[0099] Comparative Example 3

[0100] 80 parts of composite aggregate and 32 parts of low-heat Portland cement are directly mixed (without microwave pretreatment), and stirred to obtain a first mixture;

[0101] Adding 4.5 parts of steel fiber (without magnetic field treatment) to the first mixture, and mixing to form a second mixture;

[0102] 3.5 parts of polypropylene fiber (not treated with a silane coupling agent) was directly added to the second mixture and mixed to form a third mixture;

[0103] Water 14 parts, admixture (silica ash) 6 parts, air entraining agent 1.1 parts were added at one time into the third mixture and stirred, and no water reducing agent was used.

[0104] Performance test

[0105] The performance test was carried out on the impact-resistant materials provided by Examples 1 to 4 and Comparative Examples 1 to 3 of the present application. Table 1 is the performance test results.

[0106] Compressive strength test: the impact-resistant materials prepared in Examples 1 to 4 and Comparative Examples 1 to 7 were respectively taken, and the impact-resistant materials were made into cubic standard specimens with a specification of 100mm*100mm*100mm. The compressive strength of the impact-resistant materials prepared in each example and comparative example was detected after 28d and 90d of curing according to DL / T 5150 2017 "Test code for hydraulic cement-based impact-resistant materials". The compressive strength calculation formula is as follows:

[0107]

[0108] In the formula:

[0109] f is the compressive strength (MPa);

[0110] P is the failure load (N);

[0111] A is the cross-sectional area of the compression surface of the specimen (mm 2 ).

[0112] Shrinkage test: the impact-resistant materials prepared in Examples 1 to 4 and Comparative Examples 1 to 7 were respectively taken, and the impact-resistant materials were made into cubic standard specimens with a specification of 100mm*100mm*100mm. Three specimens were taken as one group, and the metal measuring head was firmly embedded. After the specimen was formed, it was sent into a standard curing room for curing, and the mold was removed after 48h, and then the standard curing was continued. The specimen was taken out from the standard curing room one by one at the age of 3d from the time when the cement-based impact-resistant material was added with water, and should be immediately moved into a constant temperature and humidity room to measure the reference length one by one. The dry shrinkage age of the specimen was calculated after the reference length was measured, and the length of the specimen at the age of 28d and 90d was measured. The method and direction of length measurement should be the same as those when the reference length was measured. To prevent the measuring head from rusting, a thin layer of butter can be applied to the end of the measuring head after each length measurement, and the next time the length is measured, it should be carefully cleaned. The shrinkage calculation formula is as follows:

[0113]

[0114] In the formula:

[0115] ε t is the dry shrinkage (wet expansion) rate (%) at the age of t days;

[0116] Lt is the length of the specimen at the age of t days (mm);

[0117] L0 is the reference length of time (mm);

[0118] △ is the length of the metal probe (mm).

[0119] Strength loss rate after dry-wet cycle test: The impact-resistant materials prepared in Examples 1 to 4 and Comparative Examples 1 to 7 were respectively prepared into standard cubic specimens with a specification of 100 mm * 100 mm * 100 mm. The strength loss rate of the impact-resistant materials prepared in each Example and Comparative Example in a dry-wet alternating environment was measured according to GB / T 50082-2009 "Standard for Test Methods for Long-term Performance and Durability of Ordinary Cement-based Impact-resistant Materials". The strength loss rate after dry-wet cycle is calculated as follows:

[0120]

[0121] Where:

[0122] S 300 is the strength loss rate after 300 dry-wet cycles (%);

[0123] f 300 is the compressive strength after 300 dry-wet cycles (MPa);

[0124] f t The compressive strength (MPa) of the test pieces tested simultaneously under the same standard curing environment without drying and wetting cycles;

[0125] Abrasion resistance test: The abrasion resistant materials prepared in Examples 1 to 4 and Comparative Examples 1 to 7 were respectively taken and tested using a centrifugal cement-based abrasion resistant material abrasion resistance tester. With the rotation axis of the rectangular tube as the center, 9 concentric rings (central angle 40°) with an inner diameter of 420 mm and an outer diameter of Ф660 mm x 150 mm formed a closed specimen ring. According to DL / T5150 to 2017 "Test Procedure for Hydraulic Cement-Based Abrasion Resistant Materials", the abrasion resistance of the abrasion resistant materials prepared in each embodiment and comparative example after curing for 28 days and 90 days was tested. The abrasion resistance calculation formula is as follows:

[0126]

[0127] Where:

[0128] f a Abrasion resistance of 10 to 6 h / (kg / m 2 );

[0129] n is the number of rectangular tube outlets;

[0130] b is the horizontal width of the rectangular pipe outlet (mm);

[0131] T is the cumulative grinding time (h);

[0132] A is the impact area of ​​the specimen (m 2 );

[0133] l is half the length of the rectangular tube (mm);

[0134] Δm is the mass lost by the specimen after the T time impact (kg).

[0135] Three samples were taken for each example and comparative example, and the test results were averaged. The specific test results are shown in Table 1.

[0136] Table 1

[0137]

[0138]

[0139] As can be seen from Table 1, the present application selects composite aggregates to form a dense skeleton structure through particle size optimization when preparing cement-based anti-impact materials. Low-heat silicate cement and admixtures work together to form a low-porosity matrix. Composite fiber materials form a three-dimensional network in the matrix, effectively preventing crack expansion. The compound high-efficiency water reducer reduces the water-cement ratio while ensuring fluidity, and the tiny bubbles introduced by the air entraining agent relieve internal stress concentration; traditional solutions mostly use single fiber reinforcement or ordinary cement matrix, and only use steel fiber reinforcement, resulting in insufficient toughness and limited hydration heat control effect. However, this solution achieves a reinforcing effect of both rigidity and flexibility through a composite fiber system. Low-heat silicate cement and admixtures work together to reduce temperature rise, and the composite aggregate grading design further reduces the amount of admixtures used. This multi-component synergistic effect enables cement-based anti-impact materials to significantly improve crack resistance and durability while maintaining strength.

[0140] Furthermore, according to Table 1, in Example 1, the 90-day compressive strength reached 95.6 MPa, the highest among all groups, showing excellent bearing capacity; at the same time, the shrinkage rates at 28 days and 90 days were 0.02% and 0.03%, respectively, which were much lower than those of other examples and comparative examples, indicating that its volume stability was the best and crack generation could be effectively suppressed; the strength loss rate after 300 dry-wet cycles was only 0.5%, indicating its excellent long-term durability; in addition, its 90-day impact and abrasion resistance was as high as 3078×10 -6 h / (kg / m 2 ), the highest among all samples, showing strong resistance to water flow and particle erosion. In summary, Example 1 achieves the best performance in terms of strength, stability, durability and anti-abrasion performance, and can be regarded as the optimal example.

[0141] Figure 2 It is a microscopic diagram of traditional ordinary Portland cement-based anti-wear material; Figure 3 This is a microscopic diagram of a cement-based anti-wear material provided by another embodiment of the present application. Figure 2 As shown in the figure, the microstructure of traditional cement-based anti-wear materials is mainly composed of large coarse aggregates filled in a relatively uniform cement paste. The number of CSH gel and ettringite crystals is small and sparsely distributed. The porosity in the matrix is ​​strong, and the overall structure shows low density and lacks fiber reinforcement. This structure is prone to temperature gradient cracks and gradually deteriorates under erosion conditions. Figure 3 The microstructure of the cement-based anti-abrasion material prepared by the method described in this application is more compact, with a more reasonable distribution of coarse and fine aggregate sizes, dense filling, and fine aggregates evenly wrapped to form a nested skeleton. A large number of evenly distributed CSH clusters and slender ettringite crystals appear in the matrix, further indicating that its hydration products are richer. In addition, Figure 3 The presence of reinforcing fibers can be seen in the material, indicating that the material system has introduced steel fibers and polypropylene fibers into the design to form a three-dimensional support network, which greatly improves its toughness and crack control ability. Figure 3 The cement-based anti-impact and wear materials represented are superior to traditional materials in porosity, interfacial bonding, fiber reinforcement and hydration reaction activity, reflecting the significant advantages of this application in the coordinated optimization of impact and wear resistance, durability and microstructure.

[0142] In another exemplary embodiment, the present application also provides an application of a cement-based anti-wear material, wherein the anti-wear material is prepared based on any of the aforementioned embodiments, and the anti-wear material is applied to mines and industrial chute systems.

[0143] In this embodiment, structures such as mine ore transmission chutes, pre-crushing material conveying troughs, and ore dressing plant slurry diversion troughs are subjected to continuous erosion and wear of coarse-grained ore and high-sand content slurry all year round, as well as fatigue degradation caused by periodic dry-wet alternation. Conventional cement-based anti-wear materials are prone to failure problems such as peeling, cracking, and severe wear. When the anti-wear material prepared based on this application is applied to mine and industrial chute systems, it can effectively resist the impact and wear of ore particles, high-sand content slurry and other media during high-speed flow by virtue of its excellent anti-wear performance, high strength and low shrinkage characteristics, and significantly delay the surface erosion and wear process of the structure; at the same time, the composite fiber reinforcement system improves the toughness and crack resistance of the material, inhibits the expansion of microcracks, and avoids early failure of the material; the design of low hydration heat and high density also improves its long-term durability in dry-wet alternation and corrosive environments, thereby significantly extending the service life of the chute system and reducing maintenance frequency and operating costs.

[0144] Finally, it should be noted that the above description is merely an optional example of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art may still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A cement-based anti-wear material, characterized in that: The components of the anti-wear material and the number of components include: Low-heat Portland cement: 20 to 40 parts; Composite fiber material: 3 to 5 parts; Admixture: 5 to 10 parts; Composite aggregate: 60 to 100 parts; Water: 7 to 18 parts; Compound high-efficiency water reducer: 1 to 2 parts; Air entraining agent: 1 to 2 parts.

2. The wear-resistant material according to claim 1, characterized in that: The mass ratio of the water to the low-heat Portland cement is 0.35 to 0.45:

1.

3. The wear-resistant material according to claim 1, characterized in that: The composite fiber material comprises steel fibers and polypropylene fibers.

4. The wear-resistant material according to claim 1, characterized in that: The compound high-efficiency water reducer comprises a polycarboxylic acid high-performance water reducer and a naphthalene-based water reducer.

5. The wear-resistant material according to claim 1, characterized in that: The admixture includes any one of silica fume and mineral powder.

6. The wear-resistant material according to claim 1, characterized in that: The composite aggregate includes coarse aggregate and fine aggregate, and the mass ratio of the coarse aggregate to the fine aggregate is 0.5 to 2:

1.

7. A method for preparing a cement-based anti-wear material, characterized in that: The method comprises: Mixing composite aggregate and low-heat Portland cement in a preset ratio, placing the mixture in a microwave field for microwave pretreatment, and stirring to obtain a first mixture; applying an axial magnetic field to the steel fiber and stirring the steel fiber with the first mixture to obtain a second mixture; mixing polypropylene fiber and silane coupling agent solution and spraying the mixture onto the second mixture, and stirring to obtain a third mixture; The compounded high-efficiency water-reducing agent, water, air-entraining agent and admixture are injected into the third mixture in stages, and the cement-based anti-impact and wear material is obtained after stirring.

8. The preparation method according to claim 7, characterized in that The mixing of composite aggregate and low-heat Portland cement and placing them in a microwave field for microwave pretreatment comprises: forming a pre-coat layer on the surface of the composite aggregate; mixing composite aggregate and low-heat Portland cement for forming a pre-coating layer on the surface in stages; heating the mixed composite aggregate and cement with microwaves; The surface of the heated mixture of composite aggregate and cement is cooled by spraying coolant.

9. The preparation method according to claim 7, characterized in that The preparation method further comprises: The compounded high-efficiency water-reducing agent, water, air-entraining agent and admixture are injected into the third mixture in stages and stirred, and paraffin wax and silicon dioxide core-shell phase change microspheres are added.

10. An application of a cement-based anti-wear material, characterized in that: The anti-impact and wear material is prepared based on the method according to any one of claims 7 to 9, and the anti-impact and wear material is used in mines and industrial chute systems.

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