A method for producing UHPC concrete using high-titanium heavy slag

Abstract

The present invention discloses a method for producing UHPC concrete using high-titanium heavy slag, belonging to the field of concrete, which comprises the following steps: preparing raw materials in the following parts by weight: 65-67 parts of cement, 13-14 parts of superfine modified silica fume, 45-46 parts of high-titanium heavy slag sand with a particle size of 10-20 mesh, 30-31 parts of high-titanium heavy slag sand with a particle size of 25-40 mesh, 31-32 parts of high-titanium heavy slag sand with a particle size of 45-80 mesh, 11-12 parts of high-titanium heavy slag sand with a particle size of 85-120 mesh, 63-65 parts of high-titanium heavy slag sand with a particle size of 125-180 mesh, 16-17 parts of high-titanium heavy slag powder with a particle size of 2000 mesh, 15-16 parts of steel fiber, and 2-4 parts of water reducing agent; stirring and mixing evenly with a water-cement ratio of 0.13-0.15 to obtain cement paste; adding water reducing agent, pouring, curing and processing, and performing quality inspection. By limiting the particle size range of the high-titanium heavy slag sand, the present invention obtains the best grading based on the theory of dense packing, enabling particles of different particle sizes to be evenly mixed and filled, and obtaining uniform and dense high-quality cement paste.

Description

Technical Field

[0001] The present invention belongs to the field of concrete and relates to a method for producing UHPC concrete using high-titanium heavy slag. Background Art

[0002] UHPC, namely ultra-high performance concrete, is a special concrete with ultra-high strength, super durability, low porosity, and strong erosion resistance. Its compressive strength can usually reach above 200 MPa, and even up to 800 MPa, far exceeding that of ordinary concrete, which makes UHPC have significant advantages under complex engineering conditions such as bearing heavy loads and large spans. In addition, UHPC has high durability and excellent performance in resisting chemical erosion, freeze-thaw, carbonation, etc., and can maintain its strength and stability for a long time in harsh environments.

[0003] The application scope of UHPC is extensive, including fields such as bridge construction, tunnel engineering, and building walls. In bridge construction, due to its high strength and high durability, UHPC is particularly suitable for the construction of large bridges, such as suspension bridges and cable-stayed bridges. In the construction field, the advantages of UHPC such as high strength, light weight, fire resistance, sound insulation, and heat insulation make it applicable in the construction of building walls.

[0004] Although UHPC (ultra-high performance concrete) has many advantages, such as high strength, high durability, and excellent construction performance, there are still the following problems in the actual production process: 1. UHPC contains a large amount of micro-powder, and the particles in various particle size ranges are stacked together, which is prone to uneven particle distribution and unstable quality; 2. UHPC contains a large amount of micro-powder, and when the water-cement ratio is reduced, the fluidity of the particles is poor, it is difficult to mix evenly, and it is prone to agglomeration. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for producing UHPC concrete using high-titanium heavy slag, which solves the problems that UHPC contains a large amount of micro-powder, is prone to uneven particle distribution and poor particle flow, ultimately resulting in uneven mixing of cement slurry and poor quality of the obtained solid concrete.

[0006] The technical solution adopted by the present invention is as follows:

[0007] A method for producing UHPC concrete using high-titanium heavy slag, comprising the following steps:

[0008] S1. Raw material preparation: Prepare the following raw materials in parts by weight: 65 - 67 parts of cement, 13 - 14 parts of superfine modified silica fume, 45 - 46 parts of 10 - 20 mesh high-titanium heavy slag sand, 30 - 31 parts of 25 - 40 mesh high-titanium heavy slag sand, 31 - 32 parts of 45 - 80 mesh high-titanium heavy slag sand, 11 - 12 parts of 85 - 120 mesh high-titanium heavy slag sand, 63 - 65 parts of 125 - 180 mesh high-titanium heavy slag sand, 16 - 17 parts of 2000 mesh high-titanium heavy slag powder, 15 - 16 parts of steel fiber, and 2 - 4 parts of water reducer;

[0009] S2. Mixing: Mix cement, superfine modified silica fume, 10 - 20 mesh high-titanium heavy slag sand, 25 - 40 mesh high-titanium heavy slag sand, 45 - 80 mesh high-titanium heavy slag sand, 85 - 120 mesh high-titanium heavy slag sand, 125 - 180 mesh high-titanium heavy slag sand, 2000 mesh high-titanium heavy slag powder, and steel fiber with water evenly. The water-cement ratio is 0.13 - 0.15 to obtain cement paste;

[0010] S3. Adding admixture: Add water reducer to the cement paste while stirring to obtain concrete;

[0011] S4. Pouring: Pour the mixed concrete into a pre-prepared mold for forming, ensure that the concrete is evenly distributed in the mold, and remove air bubbles;

[0012] S5. Curing and processing: After the concrete is poured, cure it in time, maintain a certain humidity and temperature to promote the full hydration reaction of cement;

[0013] S6. Processing: After the compressive strength of the concrete reaches 300 MPa, perform cutting and grinding to obtain UHPC concrete;

[0014] S7. Quality inspection: Conduct quality inspection on the processed UHPC concrete, including strength, compactness, and durability.

[0015] By limiting the particle size range of high-titanium heavy slag sand, based on the theory of dense packing, the optimal grading is obtained in the present invention, enabling particles of different particle sizes to be evenly mixed and filled, and obtaining a uniform and dense high-quality cement paste.

[0016] In addition, in the prior art, in order to obtain ultra-high-performance concrete, various types of slag are used as admixtures to improve the performance of concrete by utilizing the properties of different slag. Compared with the prior art, in the present invention, by optimizing the grading of slag, the types of slag used are reduced. The present invention only uses a single type of slag, high-titanium heavy slag, and the performance of the prepared concrete is superior to that of the concrete obtained by using multiple types of slag in the prior art.

[0017] In the prior art, the more types of slag incorporated, the greater the difficulty in designing the mix ratio. The main reason is that different slag admixtures have different chemical compositions and physical properties, and there may be problems with their compatibility. Too many types of slag may lead to complex chemical reactions inside the concrete, generating undesirable by-products or affecting the cement hydration process, thereby affecting the strength and durability of the concrete. In the present invention, a single type of slag can ensure the high-performance requirements of the concrete while avoiding the incompatibility of different types of slag.

[0018] The water reducer adsorbs on the surface of concrete particles, forming a stable dispersion film, effectively preventing the agglomeration and sedimentation of concrete particles, thereby improving the fluidity of the concrete. The addition of the water reducer can enhance the fluidity of the particles, making the particles evenly dispersed and obtaining a cement slurry with stable quality.

[0019] Furthermore, the water reducer comprises the following components in parts by weight: 50 - 60 parts of β-aminoketone compound, 20 - 30 parts of plant protein extract, and 2 - 3 parts of sodium bicarbonate.

[0020] The high molecular polymer is one of the main components of the existing water reducer. The water reducer of the high molecular polymer type utilizes the excellent adsorption performance of the high molecular polymer itself to adsorb on the surface of the particles to enhance the fluidity of the particles. However, due to the relatively high viscosity and slow fluidity of the high molecular polymer in the water reducer of the high molecular polymer type, the water reducer of the high molecular polymer type also has relatively high viscosity and slow fluidity. When applied to the above-mentioned cement slurry of the present invention, it is difficult for the water reducer to fill between the particle gaps in a short time and at a relatively low stirring speed. If the mixing time of the water reducer is too long, the production efficiency of the concrete will be reduced. If too high a stirring speed is given, segregation and bleeding phenomena of the cement slurry will occur.

[0021] In summary, the present invention changes the formula of the existing water reducer. The present invention uses β-aminoketone compound as the main agent, in combination with plant protein extract and sodium bicarbonate to evenly fill between the particles in a short time, and the obtained cement slurry has a uniform texture and excellent properties.

[0022] The principle is as follows: The polar groups (such as amino groups and carbonyl groups) in the β-aminoketone compound will form a thin film on the surfaces of cement particles and slag particles, changing the interaction between the particles, thereby increasing the fluidity of the concrete; it can directly replace the role of the polymer. However, the small viscosity of the β-aminoketone compound makes its flow rate faster than that of the polymer, and it can flow rapidly and disperse evenly among the closely packed particles. In addition, the β-aminoketone compound contains amino groups and ketone groups, which have specific reaction activities. The high-titanium heavy slag sand surface contains titanium ions. As metal ions, titanium ions have the ability to form complexes with ligands. Its small ionic radius and high charge density make it easy to undergo complexation reactions with other molecules or ions. The ketone group and amino group of the β-aminoketone compound bind to the titanium ions, and this binding is achieved through the formation of coordination bonds. A coordination bond is a covalent bond formed by the lone pair electrons provided by the ligand and the empty orbitals of the central atom (here it is the titanium ion). Through this bonding, the β-aminoketone compound and the titanium ions form a stable complex. Since the β-aminoketone compound can undergo complexation reactions with the titanium ions, the β-aminoketone compound can firmly adhere to the slag surface, thereby improving the fluidity of the concrete; because the cement slurry obtained by mixing 45-46 parts of 10-20 mesh high-titanium heavy slag sand, 30-31 parts of 25-40 mesh high-titanium heavy slag sand, 31-32 parts of 45-80 mesh high-titanium heavy slag sand, 11-12 parts of 85-120 mesh high-titanium heavy slag sand, 63-65 parts of 125-180 mesh high-titanium heavy slag sand, and 16-17 parts of 2000 mesh high-titanium heavy slag powder in the present invention is very dense, the shrinkage deformation of the concrete is large. Therefore, a plant protein extract is added to the water reducing agent in the present invention. The plant protein extract will generate tiny bubbles in the cement slurry. Without affecting the performance of the concrete, on the one hand, it can reduce the shrinkage deformation, and on the other hand, it can cooperate with the β-aminoketone compound to play a blocking role between the particles. The tiny bubbles fill the gaps between the particles and can significantly block the adjacent particles, preventing particle agglomeration; Sodium bicarbonate has good compatibility with the β-aminoketone compound and the plant protein extract, and the three can form a stable mixture, and sodium bicarbonate provides an alkaline condition for the complexation of the β-aminoketone compound and the high-titanium heavy slag sand.

[0023] Further, the preparation method of the water reducing agent includes the following steps:

[0024] A. Prepare the β-aminoketone compound: Using ethanol as the organic solvent, with vanillin, methyl ethyl ketone, and ethylamine as reactants, the mass ratio of vanillin, methyl ethyl ketone, and ethylamine is 2:3:1. Under alkaline conditions, the reaction temperature is 120 °C. Dissolve vanillin, methyl ethyl ketone, and ethylamine in the organic solvent, mix evenly, and then heat to 120 °C. After reacting at a constant temperature of 120 °C for 8 hours, the β-aminoketone compound is obtained;

[0025] B. Preparation of plant protein extract: Select the required plant samples, including soybeans, mung beans, and peanuts. Grind the plant samples to obtain powder. Use physiological saline as the extract, mix the powder into the extract, and then add enzymatic hydrolysis enzyme. After continuously working overtime for 10 - 12 hours, centrifuge and filter to obtain a clear liquid containing protein, and the clear liquid containing protein is the plant protein extract;

[0026] C: Mix the β - aminoketone compound, plant protein extract, and sodium bicarbonate to obtain a water - reducing agent.

[0027] Based on the Mannich reaction, the present invention uses vanillin, methyl ethyl ketone, and ethylamine as reactants to prepare a β - aminoketone compound. The reactants have low toxicity and simple reaction conditions.

[0028] Furthermore, the water - reducing agent comprises the following components in parts by weight: 60 parts of β - aminoketone compound, 30 parts of plant protein extract, and 3 parts of sodium bicarbonate.

[0029] Furthermore, the raw materials in step S1 comprise the following components in parts by weight: 66 parts of cement, 13.5 parts of superfine modified silica powder, 45.5 parts of 10 - 20 mesh high - titanium heavy slag sand, 30.5 parts of 25 - 40 mesh high - titanium heavy slag sand, 31.5 parts of 45 - 80 mesh high - titanium heavy slag sand, 11.5 parts of 85 - 120 mesh high - titanium heavy slag sand, 64 parts of 125 - 180 mesh high - titanium heavy slag powder, 15.5 parts of steel fiber, and 3 parts of water - reducing agent.

[0030] The present invention combines the performance of concrete and optimizes the best ratio.

[0031] Furthermore, the cement in step S1 is PO42.5 cement.

[0032] Furthermore, the superfine modified silica powder in step S1 comprises 100μm spherical silica powder modified by silane coupling agent.

[0033] Furthermore, before adding the water - reducing agent in step S3, pre - heat the cement slurry. After heating to 40°C, keep it at a constant temperature and add the water - reducing agent for stirring reaction. After reacting for 30 minutes, concrete is obtained.

[0034] When the β - aminoketone compound reacts with titanium ions in a complexation reaction, the reaction rate is the fastest at 40°C.

[0035] Furthermore, the water - cement ratio in step S2 is 0.13.

[0036] By changing the components of the water reducing agent, the lowest water-cement ratio that can be achieved while ensuring uniform mixing of the cement slurry is 0.13. The lower the water-cement ratio, the higher the strength and better the performance of the cured concrete block.

[0037] Further, the curing temperature in step S5 is 110°C, the curing humidity is 98%, and the curing time is 28 days.

[0038] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are as follows:

[0039] 1. A method for producing UHPC concrete using high-titanium heavy slag obtains the optimal gradation based on the dense packing theory by limiting the particle size range of high-titanium heavy slag sand, enabling particles of different sizes to be uniformly mixed and filled, resulting in a uniform and dense high-quality cement slurry.

[0040] 2. The present invention changes the formula of the existing water reducing agent. The present invention uses β-aminoketone compound as the main agent, combined with plant protein extract and sodium bicarbonate to be uniformly filled between particles in a short time, obtaining a cement slurry with uniform texture and excellent performance.

[0041] 3. The present invention adds plant protein extract to the water reducing agent. The plant protein extract will generate tiny bubbles in the cement slurry, which can reduce shrinkage deformation without affecting the performance of the concrete.

[0042] 4. By changing the formula of the water reducing agent, the present invention obtains a water reducing agent with good fluidity and fast flow rate. The lowest water-cement ratio that can be achieved while ensuring uniform mixing of the cement slurry is 0.13. The lower the water-cement ratio, the higher the strength and better the performance of the cured concrete block. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings, where:

[0044] Figure 1 is the electron microscopy scan of the cement slurry after adding the water reducing agent of the present invention;

[0045] Figure 2 is the electron microscopy scan of the cement slurry after adding the water reducing agent of Comparative Example 1. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0046] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. 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, that is, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Usually, the components of the embodiments of the present invention described and shown in the accompanying drawings herein can be arranged and designed in various different configurations.

[0047] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present invention.

[0048] It should be noted that relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising one..." does not exclude the presence of additional identical elements in the process, method, article or device including the said element.

[0049] The features and performance of the present invention will be further described in detail below in conjunction with the embodiments.

[0050] Embodiment 1

[0051] A method for producing UHPC concrete using high-titanium heavy slag provided by a preferred embodiment of the present invention includes the following steps:

[0052] S1. Raw material preparation: Prepare the following raw materials in parts by weight: 66 parts of cement, 13.5 parts of ultrafine modified silica powder, 45.5 parts of 10-20 mesh high-titanium heavy slag sand, 30.5 parts of 25-40 mesh high-titanium heavy slag sand, 31.5 parts of 45-80 mesh high-titanium heavy slag sand, 11.5 parts of 85-120 mesh high-titanium heavy slag sand, 64 parts of 125-180 mesh high-titanium heavy slag sand, 16.5 parts of 2000 mesh high-titanium heavy slag powder, 15.5 parts of steel fiber, and 3 parts of water reducing agent;

[0053] S2. Stirring: Mix cement, superfine modified silica powder, 10-20 mesh high-titanium heavy slag sand, 25-40 mesh high-titanium heavy slag sand, 45-80 mesh high-titanium heavy slag sand, 85-120 mesh high-titanium heavy slag sand, 125-180 mesh high-titanium heavy slag sand, 2000 mesh high-titanium heavy slag powder, and steel fiber with water evenly. The water-cement ratio is 0.13 to obtain cement slurry.

[0054] S3. Adding admixture: Heat the cement slurry in advance before adding the water reducer. After heating to 40 °C, keep it at a constant temperature and add the water reducer for stirring reaction. After reacting for 30 minutes, concrete is obtained.

[0055] S4. Pouring: Pour the stirred concrete into a pre-prepared mold for shaping, ensuring that the concrete is evenly distributed in the mold and removing air bubbles.

[0056] S5. Curing and processing: After the concrete is poured, cure it in time, maintaining a certain humidity and temperature to promote the full hydration reaction of cement. The curing temperature is 110 °C, the curing humidity is 98%, and the curing time is 28 days.

[0057] S6. Processing: After the compressive strength of the concrete reaches 300 MPa, cut and grind it to obtain UHPC concrete.

[0058] S7. Quality inspection: Conduct quality inspection on the processed UHPC concrete, including strength, compactness, and durability.

[0059] The cement is PO42.5 cement.

[0060] The superfine modified silica powder in step S1 is 100 μm spherical silica powder modified by silane coupling agent.

[0061] The water reducer includes the following components in parts by weight: 60 parts of β-aminoketone compound, 30 parts of plant protein extract, and 3 parts of sodium bicarbonate.

[0062] The preparation method of the water reducer includes the following steps:

[0063] A. Preparing β-aminoketone compound: Using ethanol as an organic solvent, with vanillin, methyl ethyl ketone, and ethylamine as reactants, the mass ratio of vanillin, methyl ethyl ketone, and ethylamine is 2:3:1. Under alkaline conditions, the reaction temperature is 120 °C. Dissolve vanillin, methyl ethyl ketone, and ethylamine in the organic solvent and mix evenly, then heat to 120 °C and keep it at a constant temperature for reaction for 8 hours to obtain β-aminoketone compound.

[0064] B. Preparation of plant protein extract: Select the required plant samples, including soybeans, mung beans, and peanuts. Grind the plant samples to obtain powder. Use physiological saline as the extract, mix the powder into the extract, and then add enzymatic hydrolysis enzyme. After continuously working overtime for 10 - 12 hours, centrifuge and filter to obtain a clear liquid containing protein, and the clear liquid containing protein is the plant protein extract;

[0065] C: Mix the β - aminoketone compound, plant protein extract, and sodium bicarbonate to obtain a water - reducing agent.

[0066] Figure 1 This is the electron micrograph of the cement paste after adding the water - reducing agent in the present invention. As shown in the figure, the cement paste particles are closely packed and evenly distributed.

[0067] Example 2

[0068] On the basis of Example 1, the difference in this example is that in S1, it includes the following components in parts by weight: 65 parts of cement, 13 parts of ultrafine modified silica powder, 45 parts of 10 - 20 mesh high - titanium heavy slag sand, 30 parts of 25 - 40 mesh high - titanium heavy slag sand, 31 parts of 45 - 80 mesh high - titanium heavy slag sand, 11 parts of 85 - 120 mesh high - titanium heavy slag sand, 63 parts of 125 - 180 mesh high - titanium heavy slag sand, 16 parts of 2000 - mesh high - titanium heavy slag powder, 15 parts of steel fiber, and 2 parts of water - reducing agent.

[0069] Example 3

[0070] On the basis of Example 1, the difference in this example is that in S1, it includes the following components in parts by weight: 67 parts of cement, 14 parts of ultrafine modified silica powder, 46 parts of 10 - 20 mesh high - titanium heavy slag sand, 31 parts of 25 - 40 mesh high - titanium heavy slag sand, 32 parts of 45 - 80 mesh high - titanium heavy slag sand, 12 parts of 85 - 120 mesh high - titanium heavy slag sand, 65 parts of 125 - 180 mesh high - titanium heavy slag sand, 17 parts of 2000 - mesh high - titanium heavy slag powder, 16 parts of steel fiber, and 2 - 4 parts of water - reducing agent.

[0071] Example 4

[0072] On the basis of Example 1, the difference in this example is that the water - reducing agent includes the following components in parts by weight: 50 parts of β - aminoketone compound, 20 parts of plant protein extract, and 2 parts of sodium bicarbonate.

[0073] Example 5

[0074] On the basis of Example 1, the difference in this example is that the water - reducing agent includes the following components in parts by weight: 55 parts of β - aminoketone compound, 25 parts of plant protein extract, and 2.5 parts of sodium bicarbonate.

[0075] Example 6

[0076] Based on Example 1, the difference in this example from Example 1 is that the water-cement ratio is 0.14.

[0077] Example 7

[0078] Based on Example 1, the difference in this example from Example 1 is that the water-cement ratio is 0.15.

[0079] Comparative Example 1

[0080] The difference between this comparative example and Example 1 is that the water-reducing agent in this comparative example is the DH-4005 type polycarboxylate-based high-performance water-reducing agent.

[0081] Figure 2 This is the SEM image of the cement paste after adding the water-reducing agent in this comparative example. Comparing Figure 1 with Figure 2 it can be seen that in Example 1 of the present invention, particles at all levels are evenly filled and evenly mixed to obtain a uniformly mixed cement paste; in Comparative Example 1, the cement paste shows agglomeration and other situations, indicating that the existing polycarboxylate-based high-performance water-reducing agent is not suitable for the formula of the present invention. Figure 2 The edges of the particles of the cement paste shown do not have clear boundaries, and the edges of the cement paste are blurred due to the agglomeration of multiple particles.

[0082] Comparative Example 2

[0083] The difference between this comparative example and Example 1 is that the β-aminoketone compound is not used in the water-reducing agent of this comparative example.

[0084] Comparative Example 3

[0085] The difference between this comparative example and Example 1 is that the plant protein extract is not used in the water-reducing agent of this comparative example.

[0086] Comparative Example 4

[0087] The difference between this comparative example and Example 1 is that sodium bicarbonate is not used in the water-reducing agent of this comparative example.

[0088] Comparative Example 5

[0089] The difference between this comparative example and Example 1 is that the water-reducing agent includes the following components in parts by weight: 65 parts of β-aminoketone compound, 35 parts of plant protein extract, and 4 parts of sodium bicarbonate.

[0090] If the content of each component in the water-reducing agent is too high, the content of the tiny bubbles generated will be too much, which will instead affect the compressive strength of the concrete block.

[0091] Comparative Example 6

[0092] The difference between this comparative example and Example 1 is that the water-cement ratio is 0.12.

[0093] It cannot be processed and the mixing is uneven, resulting in non-uniform cement slurry.

[0094] Comparative Example 7

[0095] The difference between this comparative example and Example 1 is that the water-cement ratio is 0.16.

[0096] Test Example

[0097] The compressive strength, permeability, and durability of the UHPC concrete prepared in Examples 1-7 and Comparative Examples 1-7 were detected, and the test results are shown in Table 1.

[0098] The test method for compressive strength is as follows: After curing for 28 days, a concrete test block is pressurized using a compression testing machine until the test block fails, and the maximum pressure strength at the time of failure is recorded, with the unit of MPa.

[0099] The test method for permeability is as follows: According to the ASTM C1202 standard for the electrical flux test of concrete resistance to chloride ion penetration, the electrical flux of the UHPC concrete resistance to chloride ion penetration cured for 7 days is measured, with the unit of Coulomb, expressed as C.

[0100] Durability: The concrete sample is placed in an environment with alternating temperatures between -18°C and 23°C for multiple cycles to evaluate the freeze-thaw resistance of the concrete. The standard ASTM C666 / C666M-15 "Standard Test Method: Determining the Freeze-Thaw Resistance of Concrete Materials" can be used to determine the freeze-thaw resistance of UHPC. In the Chinese concrete code, the frost resistance grade is determined by the maximum number of cycles when, for a standard concrete specimen at 28 days of age in a water-saturated state, after repeated freeze-thaw cycle tests, the strength loss does not exceed 25% and the weight loss does not exceed 5% simultaneously.

[0101] Table 1 Performance Detection of UHPC Concrete

[0102]

[0103]

[0104] Combined with the data in Table 1, it can be seen that the lowest water-cement ratio of the present invention can only reach 0.13. After it is lower than 0.13, it cannot be processed at all. When the water-cement ratio is greater than 0.16, the compressive strength of the obtained UHPC concrete cannot reach 150 MPa. The fact that the compressive strength of the UHPC concrete is lower than 150 MPa indicates that the compressive performance of the UHPC concrete is poor, which is basically equivalent to the compressive strength that can be achieved by the prior art. Therefore, the present invention uses 150 MPa as the lowest standard for measuring the compressive performance of UHPC concrete, and the highest compressive strength of the UHPC concrete of the present invention can reach 300 Mpa.

[0105] After repeated freeze-thaw cycle tests, the more the maximum number of cycles when the strength loss does not exceed 25% and the weight loss does not exceed 5% are simultaneously satisfied, the higher the frost resistance grade of the UHPC concrete and the better the frost resistance grade performance. The number of cycles of the present invention is greater than 1000, and it has good frost resistance performance;

[0106] The lower the electric flux of the UHPC concrete cured for 7 days for chloride ion permeability, the stronger the chloride ion permeability. By comparing Examples 1-7 with Comparative Examples 1-7, it can be seen that the chloride ion penetration amount of the present invention is basically negligible, indicating that the UHPC concrete of the present invention has strong chloride ion permeability.

[0107] In summary, combining the data in Table 1, it can be seen that Example 1 of the present invention is the best ratio.

[0108] The above are only the preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, and improvements made by those skilled in the art within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for producing UHPC concrete using high-titanium heavy slag, characterized in that: It includes the following steps: S1. Raw material preparation: Prepare the following raw materials in parts by weight: 65 - 67 parts of cement, 13 - 14 parts of ultrafine modified silica fume, 45 - 46 parts of 10 - 20 mesh high - titanium heavy slag sand, 30 - 31 parts of 25 - 40 mesh high - titanium heavy slag sand, 31 - 32 parts of 45 - 80 mesh high - titanium heavy slag sand, 11 - 12 parts of 85 - 120 mesh high - titanium heavy slag sand, 63 - 65 parts of 125 - 180 mesh high - titanium heavy slag sand, 16 - 17 parts of 2000 - mesh high - titanium heavy slag powder, 15 - 16 parts of steel fiber, 2 - 4 parts of water - reducing agent; S2. Mixing: Mix cement, ultrafine modified silica fume, 10 - 20 mesh high - titanium heavy slag sand, 25 - 40 mesh high - titanium heavy slag sand, 45 - 80 mesh high - titanium heavy slag sand, 85 - 120 mesh high - titanium heavy slag sand, 125 - 180 mesh high - titanium heavy slag sand, 2000 - mesh high - titanium heavy slag powder, and steel fiber with water evenly. The water - cement ratio is 0.13 - 0.15 to obtain cement paste; S3. Adding admixture: Add water - reducing agent to the cement paste while stirring to obtain concrete; S4. Pouring: Pour the mixed concrete into a pre - prepared mold for shaping, ensuring that the concrete is evenly distributed in the mold and removing air bubbles; S5. Curing and processing: After the concrete is poured, cure it in time, maintaining a certain humidity and temperature to promote the full hydration reaction of cement; S6. Processing: After the compressive strength of the concrete reaches 300 MPa, perform cutting and grinding to obtain UHPC concrete; S7. Quality inspection: Conduct quality inspection on the processed UHPC concrete, including strength, density, and durability; The water - reducing agent includes the following components in parts by weight: 50 - 60 parts of β - aminoketone compound, 20 - 30 parts of plant protein extract, 2 - 3 parts of sodium bicarbonate; The ultrafine modified silica fume in step S1 is 100μm spherical silica fume modified by silane coupling agent.

2. The method for producing UHPC concrete using high-titanium heavy slag according to claim 1, wherein: The preparation method of the water - reducing agent includes the following steps: A. Preparation of β - aminoketone compound: Using ethanol as an organic solvent, with vanillin, methyl ethyl ketone, and ethylamine as reactants, the mass ratio of vanillin, methyl ethyl ketone, and ethylamine is 2:3:

1. Under alkaline conditions, the reaction temperature is 120°C. Dissolve vanillin, methyl ethyl ketone, and ethylamine in the organic solvent and mix evenly, then heat to 120°C and react at 120°C for 8 hours to obtain β - aminoketone compound; B. Preparation of plant protein extract: Select the required plant samples, including soybeans, mung beans, and peanuts. Grind the plant samples into powder, use physiological saline as the extract, mix the powder into the extract, and then add enzymatic hydrolysis enzyme. After continuously working overtime for 10 - 12 hours, centrifuge and filter to obtain a protein - containing clear liquid, and the protein - containing clear liquid is the plant protein extract; C: Mix the β - aminoketone compound, plant protein extract, and sodium bicarbonate to obtain the water - reducing agent.

3. A method for producing UHPC concrete using high-titanium heavy slag according to claim 1, characterized in that: The water - reducing agent includes the following components in parts by weight: 60 parts of β - aminoketone compound, 30 parts of plant protein extract, 3 parts of sodium bicarbonate.

4. A method for producing UHPC concrete using high-titanium heavy slag according to claim 3, characterized in that: The raw materials in the step S1 include the following parts by weight: 66 parts of cement, 13.5 parts of superfine modified silica powder, 45.5 parts of 10-20 mesh high-titanium heavy slag sand, 30.5 parts of 25-40 mesh high-titanium heavy slag sand, 31.5 parts of 45-80 mesh high-titanium heavy slag sand, 11.5 parts of 85-120 mesh high-titanium heavy slag sand, 64 parts of 125-180 mesh high-titanium heavy slag sand, 16.5 parts of 2000 mesh high-titanium heavy slag powder, 15.5 parts of steel fiber, and 3 parts of water reducing agent.

5. A method for producing UHPC concrete using high-titanium heavy slag according to claim 3, characterized in that: The cement in the step S1 is PO42.5 cement.

6. A method for producing UHPC concrete using high-titanium heavy slag according to claim 1, characterized in that: In the step S3, the cement slurry is preheated before adding the water reducing agent, heated to 40 °C, and then the water reducing agent is added at a constant temperature for stirring reaction. After reacting for 30 minutes, concrete is obtained.

7. A method for producing UHPC concrete using high-titanium heavy slag according to claim 4, characterized in that: The water-cement ratio in the step S2 is 0.

13.

8. A method for producing UHPC concrete using high-titanium heavy slag according to claim 4, characterized in that: The curing temperature in the step S5 is 110 °C, the curing humidity is 98%, and the curing time is 28 days.

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