Modified machine-made aggregate high-wear-resistance concrete and preparation method thereof

Abstract

The invention relates to modified machine-made aggregate high-wear-resistance concrete and a preparation method thereof. The modified machine-made aggregate high-wear-resistance concrete is prepared from the following raw materials in parts by weight: 80-120 parts of a cementing material, 320-400 parts of modified machine-made aggregate, 1-10 parts of a water reducing agent and 20-50 parts of water, wherein the modified machine-made aggregate is prepared by uniformly spraying a silane coupling agent on the surface of the machine-made aggregate. The preparation method of the modified machine-made aggregate high-wear-resistance concrete comprises the following step: uniformly mixing the cementing material, the modified machine-made aggregate, the water reducing agent and the water to obtain the high-wear-resistance concrete. The high-wear-resistance concrete is suitable for the engineering fields of roads, bridges, tunnels and the like needing high wear resistance, the preparation process is simple, the strength is high, the durability is good, the abrasion resistance is excellent, the low-price machine-made aggregate is adopted, the production cost is reduced, the problem of ecological environment damage caused by river sand exploitation is avoided, and the high-wear-resistance concrete is suitable for large-scale popularization and application. And the method has remarkable economic and environmental benefits.

Description

Technical Field

[0001] The present invention relates to the field of concrete, and particularly to a modified machine-made aggregate high-abrasion-resistant concrete and a preparation method thereof. Background Art

[0002] Concrete structures are facing more challenges in abrasive environments, such as the effects of seawater, tidal splash in coastal areas, impact of large broken ice in severe cold regions, abrasive action of sand and dust in windy and arid regions, scouring action of sediment-laden water flow in river areas, etc. The abrasion-resistant performance of concrete structures directly affects the project life and safety. Therefore, using machine-made aggregates to prepare high-abrasion-resistant concrete is the development trend of engineering construction.

[0003] Traditional abrasion-resistant concrete mostly uses materials such as silica fume and steel fibers to improve performance, but there are problems such as high manufacturing costs and high risks of shrinkage and cracking. The existing patent "A High-Strength Wear-Resistant Concrete Doped with Tailings Slag and a Preparation Method Thereof (CN202110169091.1)" uses ground tailings slag micropowder to improve the abrasion-resistant performance from the level of concrete paste. However, the aggregate volume in concrete accounts for up to 70%. Improving the abrasion-resistant performance of aggregates can improve the abrasion resistance of concrete to a greater extent. The patent "A Wear-Resistant Concrete and a Preparation Method Thereof (CN202111488828.2)" improves the abrasion resistance of concrete by incorporating iron sand, but this method changes the insulation performance of concrete and is limited in applications where insulation performance requirements exist. The patent "A High-Density Abrasion-Resistant Concrete and a Preparation Method Thereof (CN202211683754.2)" uses modified alumina ceramics as aggregates to improve the abrasion-resistant performance of concrete, but the modification process is relatively cumbersome and is not conducive to the batch production of abrasion-resistant concrete.

[0004] Currently, there is no technical solution that can effectively combine the efficient and high-quality utilization of machine-made aggregates with the preparation of high-abrasion-resistant concrete. Therefore, it is urgent to develop a high-abrasion-resistant concrete based on modified machine-made aggregates, which can optimize the surface characteristics of aggregates, improve the interfacial transition zone, and at the same time take into account high abrasion-resistant performance to solve the problem of insufficient project life of concrete in harsh abrasive environments. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a modified machine-made aggregate high-abrasion-resistant concrete and a preparation method thereof, so as to solve the problems in the prior art that traditional abrasion-resistant concrete has high manufacturing costs and high risks of shrinkage and cracking, and some existing patented technologies cannot effectively combine the efficient and high-quality utilization of machine-made aggregates with the preparation of high-abrasion-resistant concrete due to focusing on improving the abrasion-resistant performance from the level of concrete paste, changing the insulation performance of concrete, or having a cumbersome modification process, and are difficult to meet the requirements of the project life of concrete in harsh abrasive environments.

[0006] The present invention is implemented as follows. A modified mechanism aggregate high-abrasion-resistant concrete is provided, which comprises the following raw materials in parts by weight: 80 - 120 parts of cementitious materials, 320 - 400 parts of modified mechanism aggregates, 1 - 10 parts of water-reducing agent, and 20 - 50 parts of water. By modifying the high-strength but inexpensive mechanism aggregates, the present invention prepares modified mechanism aggregates, improves the interfacial bonding performance between the mechanism aggregates and the cement paste, and greatly enhances the abrasion resistance of the mechanism aggregates, thereby improving the abrasion resistance of the concrete as a whole.

[0007] The cementitious materials are composed of Portland cement, Class F fly ash, slag powder of S95 or S105 grade, and silica fume in a mass ratio of 1:(0.22 - 0.27):(0.22 - 0.27):(0.10 - 0.15). The modified mechanism aggregates are composed of particles with a particle size of 0 - 5 mm, particles with a particle size of 5 - 10 mm, and particles with a particle size of 10 - 20 mm in a mass ratio of 1:(0.45 - 0.55):(1.10 - 1.25). The water-reducing agent is a polycarboxylate water-reducing agent with a water-reducing rate of not less than 25%.

[0008] Furthermore, the strength grade of the Portland cement is not less than 42.5.

[0009] Furthermore, the rock lithology of the modified mechanism aggregates is at least one of granite, tuff, basalt, quartzite, and gneiss.

[0010] A preparation method of a modified mechanism aggregate high-abrasion-resistant concrete After weighing the raw materials according to the parts by weight, the cementitious materials and the modified mechanism aggregates are continuously stirred at a rate of 30 r / min - 40 r / min for 25 s - 45 s, then the water-reducing agent and water are added, and stirring is continued for 2 min - 5 min to obtain the high-abrasion-resistant concrete.

[0011] Furthermore, the preparation method of the modified mechanism aggregates is as follows: The particles with a particle size of 0 - 5 mm, particles with a particle size of 5 - 10 mm, and particles with a particle size of 10 - 20 mm of the same lithology are mixed evenly in accordance with the mass ratio. During the mixing process, a spraying device is used to evenly spray the silane coupling agent on the surface of the mechanism aggregates. The mass of the silane coupling agent is 0.3% - 1.2% of the mass of the mechanism aggregates, and then it is left standing at room temperature for 24 h to obtain the modified mechanism aggregates.

[0012] Further, the silane coupling agent is at least one of amino silane, epoxy silane, vinyl silane, mercapto silane, and methacryloxy silane. The silane coupling agent can form an organic film on the surface of the manufactured aggregate, improve the interfacial bonding performance between the manufactured aggregate and the cement paste, and enhance the abrasion resistance of the concrete.

[0013] Compared with the prior art, for the modified manufactured aggregate high-abrasion-resistant concrete and its preparation method of the present invention, the production cost is low, and the project cost is significantly reduced; the comprehensive production cost of the manufactured aggregate prepared from tunnel muck, mine raw stones, etc. is significantly lower than the cost of natural river sand. At the same time, no high-price raw materials are introduced additionally during the preparation process, resulting in a significant reduction in the comprehensive cost of the prepared high-abrasion-resistant concrete, which has great advantages for alleviating the high project cost in mountainous areas; It can efficiently utilize muck and waste stones, and is friendly to the ecological environment; the sand and gravel raw materials used in the present invention are all manufactured aggregates, and natural river sand is not used as the aggregate, which is beneficial to solving the contradiction between the difficult disposal of a large amount of tunnel muck and the shortage of bulk local building materials in engineering construction, and is friendly to the ecological environment; The concrete prepared by the present invention has stable quality and good abrasion resistance; by using manufactured aggregates of the same lithology to prepare concrete, the homogeneity and quality stability of the concrete are ensured. At the same time, the modification method of the manufactured aggregate is simple and convenient, and the modified manufactured aggregate has excellent interfacial bonding performance and abrasion resistance, which greatly improves the abrasion resistance of the concrete and ensures the service life of the concrete project in an abrasive environment.

[0014] The present invention comprehensively utilizes tunnel muck, mine waste stones, etc. as manufactured aggregates, practicing the concept of green production; by unifying the lithology and material source of the manufactured aggregates, the homogeneity and uniformity of the aggregates are overall improved, reducing problems such as stress concentration and non-synergistic deformation caused by inconsistent properties of heterogeneous materials, which is beneficial to reducing the risk of concrete cracking and thus enhancing the project life. Specific Embodiments

[0015] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the following examples are used to further elaborate on the present invention in detail. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0016] A preferred embodiment of a modified machine-made aggregate high-abrasion-resistant concrete of the present invention comprises the following raw materials in parts by weight: 80 - 120 parts of a cementitious material, 320 - 400 parts of modified machine-made aggregate, 1 - 10 parts of a water reducer, and 20 - 50 parts of water; the cementitious material is composed of portland cement, Class F fly ash, slag powder of S95 or S105 grade, and silica fume in a mass ratio of 1:(0.22 - 0.27):(0.22 - 0.27):(0.10 - 0.15); the modified machine-made aggregate is composed of 0 - 5 mm size particles, 5 - 10 mm size particles, and 10 - 20 mm size particles in a mass ratio of 1:(0.45 - 0.55):(1.10 - 1.25). The reasonable combination of particles of different sizes can improve the compactness and abrasion resistance of the concrete, and the selection of specific lithology ensures the strength and abrasion resistance of the aggregate. The water reducer is a polycarboxylate water reducer with a water reduction rate of not less than 25%, which has properties such as high efficiency in water reduction and slump retention, and can effectively improve the workability of the concrete.

[0017] The strength grade of the portland cement is not less than 42.5.

[0018] The rock lithology of the modified machine-made aggregate is at least one of granite, tuff, basalt, quartzite, and gneiss. That is, the comprehensive production cost of the machine-made aggregate prepared from tunnel muck, mine raw stones, etc. is significantly lower than the cost of natural river sand. At the same time, no high-price raw materials are introduced additionally during the preparation process, resulting in a significant reduction in the comprehensive cost of the prepared high-abrasion-resistant concrete, which has great advantages for alleviating the high construction cost of mountainous projects.

[0019] For the preparation method of a modified machine-made aggregate high-abrasion-resistant concrete, after weighing the raw materials according to the parts by weight, the cementitious material and the modified machine-made aggregate are continuously stirred at a rate of 30 r / min - 40 r / min for 25 s - 45 s, then the water reducer and water are added, and stirring is continued for 2 min - 5 min to obtain the high-abrasion-resistant concrete.

[0020] The preparation method of the modified machine-made aggregate is as follows: The 0 - 5 mm size particles, 5 - 10 mm size particles, and 10 - 20 mm size particles of the same lithology are mixed evenly in accordance with the mass ratio. During the mixing process, a spraying device is used to evenly spray a silane coupling agent on the surface of the machine-made aggregate. The mass of the silane coupling agent is 0.3% - 1.2% of the mass of the machine-made aggregate, and then it is left standing at room temperature for 22 h - 28 h to obtain the modified machine-made aggregate.

[0021] The silane coupling agent is at least one of amino silane, epoxy silane, vinyl silane, mercapto silane, and methacryloxy silane. The silane coupling agent can form an organic film on the surface of the manufactured aggregate, improve the interfacial bonding performance between the manufactured aggregate and the cement paste, and enhance the abrasion resistance of the concrete.

[0022] The cementitious material is a key material that plays a cementing role in concrete and can cement aggregates such as sand and stone into a whole. Acting synergistically with the modified manufactured aggregate, it provides strength and durability to the concrete and ensures the basic mechanical properties and abrasion resistance of the concrete.

[0023] The manufactured aggregate is sand and gravel aggregate processed by mechanical crushing, screening and other processes. In the present invention, it is subjected to modification treatment. After modification, the interfacial bonding performance between the manufactured aggregate and the cement paste is improved, and the abrasion resistance of the manufactured aggregate is greatly enhanced, thereby improving the abrasion resistance of the concrete as a whole. It solves the problem of insufficient abrasion resistance of traditional concrete aggregates and extends the service life of concrete in a harsh abrasion environment.

[0024] The water reducing agent is an admixture that can reduce the water consumption, improve the strength and durability of concrete during the concrete mixing process. It reduces the water-binder ratio of the concrete, improves the compactness and abrasion resistance of the concrete, improves the workability of the concrete, and reduces the risk of shrinkage cracking. Water is a necessary medium for concrete mixing and hardening, participates in the hydration reaction of cement, and makes the concrete form a whole with strength, meeting the basic requirements of concrete mixing and hardening. The strength grade of Portland cement is not less than 42.5, which is the main component of the cementitious material and provides the basis for early strength and later strength growth. Class F I fly ash has pozzolanic activity and can react with the hydration products of cement to fill the pores of the concrete, improving the compactness and durability. S95 or S105 grade slag powder: It also has pozzolanic activity and can improve the workability and durability of the concrete. Silica fume has extremely high pozzolanic activity and microaggregate effect, and can significantly improve the strength and abrasion resistance of the concrete.

[0025] Example 1: The present invention provides a modified manufactured aggregate high-abrasion-resistant concrete, and the raw material mix ratio is as follows: 100 parts of cementitious material, 387.5 parts of modified manufactured aggregate, 1.3 parts of water reducing agent, and 28.1 parts of water. The cementitious material is composed of P·Ⅰ 42.5 Portland cement, Class F I fly ash, S95 grade slag powder, and silica fume according to a mass ratio of 1:0.23:0.23:0.12. The water reducing agent is a polycarboxylate water reducing agent with a water reducing rate of 28%.

[0026] Preparation Example 1: The preparation method of the modified aggregate described in Example 1 is as follows: Select the mechanism aggregate with basalt lithology. The particles with a particle size of 0 - 5 mm, 5 - 10 mm, and 10 - 20 mm are composed according to a mass ratio of 1:0.5:1.2. Add all the particles to the mixing device. During the mixing process, use a spraying device to evenly spray vinyl silane on the surface of the mechanism aggregate. The mass of vinyl silane is 0.5% of the mass of the mechanism aggregate. Then, let it stand for 24 h at room temperature to obtain the modified mechanism aggregate.

[0027] The preparation method of the high abrasion-resistant concrete with the modified mechanism aggregate described in Example 1 is as follows: After weighing the raw materials by weight, continuously stir the cementitious material and the modified mechanism aggregate at a rate of 30 r / min for 30 s, then add the water reducer and water, and continue stirring for 3 min to obtain the high abrasion-resistant concrete.

[0028] Example 2: The present invention provides a high abrasion-resistant concrete with a modified mechanism aggregate, and the raw material mix ratio is as follows: 100 parts of cementitious material, 375 parts of modified mechanism aggregate, 1.5 parts of water reducer, and 29.5 parts of water. The cementitious material is composed of P·Ⅰ42.5 Portland cement, Class F Ⅰ fly ash, S105 slag powder, and silica fume according to a mass ratio of 1:0.23:0.23:0.12. The water reducer is a polycarboxylate water reducer with a water reduction rate of 25%.

[0029] Preparation Example 2: The preparation method of the modified aggregate described in Example 2 is as follows: Select the mechanism aggregate with gneiss lithology. The particles with a particle size of 0 - 5 mm, 5 - 10 mm, and 10 - 20 mm are composed according to a mass ratio of 1:0.5:1.2. Add all the particles to the mixing device. During the mixing process, use a spraying device to evenly spray epoxy silane on the surface of the mechanism aggregate. The mass of vinyl silane is 0.7% of the mass of the mechanism aggregate. Then, let it stand for 24 h at room temperature to obtain the modified mechanism aggregate.

[0030] The preparation method of the high abrasion-resistant concrete with the modified mechanism aggregate described in Example 2 is as follows: After weighing the raw materials by weight, continuously stir the cementitious material and the modified mechanism aggregate at a rate of 30 r / min for 30 s, then add the water reducer and water, and continue stirring for 3 min to obtain the high abrasion-resistant concrete.

[0031] Example 3 The present invention provides a high abrasion-resistant concrete with a modified mechanism aggregate, and the raw material mix ratio is as follows: 100 parts of gelling material, 375 parts of modified manufactured aggregate, 1.3 parts of water reducer, and 28.1 parts of water. The gelling material is composed of P·Ⅰ 42.5 portland cement, Class F Ⅰ fly ash, S105 slag powder, and silica fume in a mass ratio of 1:0.23:0.23:0.12. The water reducer is a polycarboxylate water reducer with a water reduction rate of 28%.

[0032] Preparation Example 3: The preparation method of the modified aggregate described in Example 3 is as follows: Select manufactured aggregate with quartzite lithology. The particles with a particle size of 0 - 5 mm, 5 - 10 mm, and 10 - 20 mm are composed in a mass ratio of 1:0.5:1.2. Add all the particles into the stirring device. During the mixing and stirring process, use the spraying device to evenly spray methacryloxy silane on the surface of the manufactured aggregate. The mass of vinyl silane is 0.8% of the mass of the manufactured aggregate. Then, let it stand for 24 h at room temperature to obtain the modified manufactured aggregate.

[0033] The preparation method of the high abrasion-resistant concrete with the modified manufactured aggregate described in Example 3 is as follows: After weighing the raw materials by weight, continuously stir the gelling material and the modified manufactured aggregate at a rate of 30 r / min for 30 s, then add the water reducer and water, and continue to stir for 3 min to obtain the high abrasion-resistant concrete.

[0034] Comparative Example 1: The raw materials contained in 1 m³ of concrete are as follows: 298 kg of P·Ⅰ 42.5 portland cement, 72 kg of Class F Ⅰ fly ash, 72 kg of S95 slag powder, 38 kg of silica fume, 1860 kg of basalt manufactured aggregate, 6.5 kg of polycarboxylate water reducer, and 135 kg of water. The preparation method is the same as that of Preparation Example 1.

[0035] Comparative Example 2: The raw materials contained in 1 m³ of concrete are as follows: 298 kg of P·Ⅰ 42.5 portland cement, 72 kg of Class F Ⅰ fly ash, 72 kg of S105 slag powder, 38 kg of silica fume, 1800 kg of gneiss manufactured aggregate, 7.2 kg of polycarboxylate water reducer, and 142 kg of water. The preparation method is the same as that of Preparation Example 2.

[0036] Comparative Example 3: The raw materials contained in 1 m³ of concrete are as follows: 298 kg of P·Ⅰ 42.5 portland cement, 72 kg of Class F Ⅰ fly ash, 72 kg of S105 slag powder, 38 kg of silica fume, 1860 kg of gneiss manufactured aggregate, 6.5 kg of polycarboxylate water reducer, and 135 kg of water. The preparation method is the same as that of Preparation Example 3.

[0037] The concretes prepared in Examples 1 - 3 and Comparative Examples 1 - 3 were tested. Among them, the 28-day compressive strength was carried out in accordance with GB / T50081 - 2019 "Standard for Test Methods of Physical and Mechanical Properties of Concrete", and the abrasion resistance of cement concrete was carried out in accordance with JTG 3420 - 2020 "Test Regulations for Cement and Cement Concrete in Highway Engineering". The relevant results are shown in Table 1; Table 1 Concrete test results As can be seen from the table, the compressive strength and abrasion resistance of the concretes in Examples 1 - 3 are significantly higher than those in Comparative Examples 1 - 3.

[0038] The above examples are only used to illustrate the technical solutions of the present invention, rather than limiting it; although the present invention has been described in detail with reference to the foregoing examples, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing examples, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A modified mechanism aggregate high abrasion-resistant concrete, characterized in that, It includes the following raw materials in parts by weight: 80 - 120 parts of cementitious material, 320 - 400 parts of modified manufactured aggregate, 1 - 10 parts of water reducing agent, and 20 - 50 parts of water; the cementitious material is composed of portland cement, Class F fly ash, blast furnace slag powder of S95 or S105 grade, and silica fume in a mass ratio of 1:(0.22 - 0.27):(0.22 - 0.27):(0.10 - 0.15); the modified manufactured aggregate is composed of 0 - 5 mm size particles, 5 - 10 mm size particles, and 10 - 20 mm size particles in a mass ratio of 1:(0.45 - 0.55):(1.10 - 1.25); the water reducing agent is a polycarboxylate water reducing agent with a water reducing rate of not less than 25%.

2. The modified mechanism aggregate high abrasion resistant concrete according to claim 1, characterized in that The strength grade of the portland cement is not less than 42.

5.

3. A modified mechanism aggregate high abrasion resistant concrete according to claim 1, characterized in that, The rock lithology of the modified manufactured aggregate is at least one of granite, tuff, basalt, quartzite, and gneiss.

4. A modified mechanism aggregate high abrasion resistant concrete and its preparation method according to any one of claims 1-3, characterized in that, After weighing the raw materials according to the above parts by weight, continuously stir the cementitious material and the modified manufactured aggregate at a rate of 30 r / min - 40 r / min for 25 s - 45 s, then add the water reducing agent and water, and continue to stir for 2 min - 5 min to obtain high abrasion resistant concrete.

5. The modified mechanism aggregate high-abrasion-resistant concrete and its preparation method according to claim 4, characterized in that, The preparation method of the modified manufactured aggregate is as follows: Mix the 0 - 5 mm size particles, 5 - 10 mm size particles, and 10 - 20 mm size particles of the same lithology evenly according to the mass ratio. During the mixing process, use a spraying device to evenly spray the silane coupling agent on the surface of the manufactured aggregate. The mass of the silane coupling agent is 0.3% - 1.2% of the mass of the manufactured aggregate, and then let it stand at room temperature for 24 h to obtain the modified manufactured aggregate.

6. The modified mechanism aggregate high abrasion resistant concrete and its preparation method according to claim 5, characterized in that The silane coupling agent is at least one of amino silane, epoxy silane, vinyl silane, mercapto silane, and methacryloxy silane.

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