Viscosity reduction type rock-based mineral admixture and high-strength large-flow-state concrete prepared from viscosity reduction type rock-based mineral admixture

Abstract

The invention discloses a viscosity reduction type rock-based mineral admixture which comprises the following raw materials in parts by weight: 55-70 parts of a rock component, 30-40 parts of an activation component and 2-5 parts of a modification component, wherein the rock component is particles obtained by crushing and grinding hole slag rock; the high-strength large-flow-state concrete prepared from the viscosity reduction type rock-based mineral admixture is prepared from the following raw materials in parts by weight: 380 to 450 parts of Portland cement, 48 to 144 parts of the viscosity reduction type rock-based mineral admixture, 1650 to 1950 parts of homogeneous cave slag aggregate, 1 to 10 parts of an additive and 120 to 140 parts of water. Hole residues produced in the tunnel excavation process are prepared into the homogenized viscosity-reducing rock-based mineral admixture and aggregate, the homogenized viscosity-reducing rock-based mineral admixture and aggregate are matched with other components to prepare the high-strength large-flow-state concrete, it is guaranteed that the concrete can be conveniently applied to engineering construction, the utilization rate of the tunnel hole residues reaches 100%, the green production concept is practiced, and the construction cost is reduced. The method has the advantages of environmental protection, obvious economic benefit, stable concrete quality and the like.

Description

Technical Field

[0001] The invention relates to the technical field of building materials, and in particular to a viscosity-reducing rock-based mineral admixture and high-strength, high-flow concrete prepared therefrom. Background Art

[0002] At present, tunnel slag is the main product of tunnel excavation during engineering construction. Its storage, treatment and maintenance costs are high, it occupies a large amount of land resources, and is easy to induce secondary disasters such as landslides and mudslides, posing hidden dangers to the ecological environment and people’s property safety along the project.

[0003] At the same time, traditional mineral admixtures such as fly ash and slag powder in the existing technology are necessary components to ensure the high strength and high performance of concrete. They play an important role in improving the density of concrete, reducing the temperature rise of cement hydration, controlling structural cracks and improving durability. However, the existing high-quality mineral admixture resources are becoming increasingly scarce, especially in mountainous construction projects. The inconvenient transportation has led to excessively high transportation costs for bulk materials. Therefore, the cost, construction period and quality of engineering construction face severe challenges.

[0004] In addition, high-strength concrete usually has a small water-cement ratio, a high amount and proportion of cementitious materials, resulting in high viscosity of concrete, and difficulty in construction operations such as mixing, pumping, and vibration. A large number of engineering practices have shown that the difficulty in high-strength concrete construction may lead to structural defects and threaten the quality and safety of the project. Existing patents such as "A preparation process for high-flow concrete based on recycled red brick coarse aggregate (CN202311317808.8)" use recycled red bricks as coarse aggregate to prepare high-flow concrete, and the patent "High-performance high-flow concrete and its preparation method (CN202211221452.3)" uses surface sand and stone powder filling to improve the rheological properties of concrete, but it is not certain whether the strength of the concrete in the above patents can meet the C60 strength grade. The patent "A high-flow lightweight high-strength EPS concrete and its preparation method (CN202210739247.X)" uses air entraining agent, EPS particles, and vitrified microspheres to comprehensively reduce the slurry density and improve fluidity, but its scope of application is limited to lightweight non-load-bearing structures.

[0005] At present, there is no reasonable technical solution to organically combine the high-quality utilization of tunnel slag with the preparation of high-strength, high-flowable concrete. Therefore, providing a viscosity-reducing rock-based mineral admixture and high-strength, high-flowable concrete prepared therefrom is an urgent problem to be solved by technical personnel in this field. Summary of the invention

[0006] In order to solve the above problems, the present invention proposes a viscosity-reducing rock-based mineral admixture and a high-strength and high-flowable concrete prepared therefrom.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] A viscosity-reducing rock-based mineral admixture comprises the following raw materials in parts by weight: 55-70 parts of a rock component, 30-40 parts of an activated component and 2-5 parts of a modified component;

[0009] The rock components are particles of cave slag rock that have been crushed and ground.

[0010] The present invention prepares a highly active viscosity-reducing rock-based mineral admixture by utilizing the characteristic of small internal friction of rock components prepared from cave slag rock, and forms tiny particles with a certain water film thickness on the surface in the fresh concrete slurry, which can reduce the viscosity of high-strength concrete and improve the rheological properties of high-strength concrete, thereby preparing cave slag concrete with coordinated strength grade and construction performance.

[0011] The addition of activated components increases the active components of rock-based mineral admixtures, ensuring that high-strength concrete can still be prepared after replacing an appropriate amount of cement; the modified components further enhance the viscosity-reducing effect of rock-based mineral admixtures, improve the rheological properties of high-strength concrete, and effectively improve the construction convenience of high-strength concrete.

[0012] Preferably, the admixture has a 45 μm sieve residue of no more than 15%, an activity index of no less than 75%, and a methylene blue value of no more than 1.0 g / kg.

[0013] Preferably, the activating component includes at least one of silica fume, fly ash, slag powder, ultrafine slag powder and glass beads.

[0014] Preferably, the modified component is at least one of sodium citrate, triethanolamine, polyether monomer, polycarboxylic acid water reducer powder and air entraining agent powder.

[0015] Preferably, the cave slag rock is siliceous alumina cave slag of any one of granite, tuff and quartzite.

[0016] Preferably, the preparation method of the admixture is:

[0017] (1) weighing the raw materials according to the weight parts;

[0018] (2) The slag rock is added to a crusher and crushed into particles with a particle size of no more than 5 mm. The particles are continuously fed into a ball mill. A multi-layer screen is provided at the discharge end of the ball mill. The particles after ball milling enter a mixer under the thrust of air flow to obtain rock components. Then, an activation component and a modification component are added to the mixer, and dry mixing is performed to obtain a viscosity-reducing rock-based mineral admixture.

[0019] According to the above-mentioned application of a viscosity-reducing rock-based mineral admixture in the preparation of concrete.

[0020] A high-strength high-flow concrete comprises the following raw materials in parts by weight: 380-450 parts of silicate cement, 48-144 parts of the above-mentioned viscosity-reducing rock-based mineral admixture, 1650-1950 parts of homogeneous slag aggregate, 1-10 parts of admixture and 120-140 parts of water.

[0021] The present invention prepares the tunnel slag produced during tunnel excavation into homogeneous viscosity-reducing rock-based mineral admixtures and aggregates, and combines them with other components to make high-strength and high-flowability concrete. It also ensures that the concrete can be conveniently used in engineering construction, so that the tunnel slag utilization rate reaches 100%, implements the green production concept, and has the advantages of green environmental protection, obvious economic benefits, and stable concrete quality.

[0022] Preferably, the raw material of the homogeneous slag aggregate is the same as the slag rock of the viscosity-reducing rock-based mineral admixture, and the homogeneous slag aggregate is composed of coarse and fine aggregates of 0-5mm, 5-10mm, 10-16mm and 16-31.5mm in a weight ratio of 35-45:8-16:25-35:15-25;

[0023] The admixture is at least one of a naphthalene-based water reducer and a polycarboxylate water reducer.

[0024] The present invention adopts homogeneous and fully graded tunnel slag aggregate so that the mineral admixtures and aggregates in the concrete are from the same source, thereby ensuring good homogeneity and high stability of the concrete. At the same time, it realizes 100% full utilization of tunnel slag and practices the green production concept of taking from the tunnel and using it in the tunnel.

[0025] Preferably, the method for preparing the concrete is:

[0026] After weighing the raw materials according to the weight proportions, silicate cement, viscosity-reducing rock-based mineral admixtures, and homogeneous slag aggregate are continuously stirred at a rate of 30 r / min for 30 seconds, and then admixtures and water are added and stirred for 3 minutes to obtain high-strength and high-flow concrete.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) The technical solution of the present invention efficiently utilizes tunnel slag and is friendly to the ecological environment. The present invention processes the tunnel slag produced during the tunnel excavation process into stone, sand, and powder, and uses 100% of it as the raw material for high-strength and high-flow concrete, so that the tunnel slag is returned to the engineering construction, thereby solving the contradiction between the difficulty in disposing of huge volumes of tunnel slag in engineering construction and the shortage of bulk ground materials, and is very friendly to the ecological environment.

[0029] (2) The technical solution of the present invention has low production cost, which greatly reduces the project cost. The comprehensive production cost of rock-based mineral admixtures prepared by using tunnel slag is significantly lower than the cost of mineral admixtures such as fly ash and slag powder. The cost of sand and gravel aggregates prepared by using tunnel slag is much lower than the cost of natural river sand, which greatly reduces the comprehensive cost of the prepared high-strength and high-flow concrete, and has great advantages in alleviating the high cost of mountain projects.

[0030] (3) The shotcrete prepared by the present invention has stable quality and good deformation coordination. The present invention adopts the same quality of tunnel slag to prepare the same source of stone, sand and powder raw materials, so that the homogeneity and quality stability of the concrete can be well controlled. At the same time, the physical and chemical properties of the homogeneous full-graded aggregates are similar. When the high-strength and high-flow concrete structure is subjected to dynamic loads, it can play a coordinated deformation role and reduce the risk of cracking of the concrete structure. DETAILED DESCRIPTION

[0031] The following describes embodiments of the present invention, which are exemplary and intended to be used to explain the present invention, but are not to be construed as limiting the present invention.

[0032] Example 1

[0033] The present invention provides a viscosity-reducing rock-based mineral admixture, and the raw material quality ratio is as follows:

[0034] 65 parts of rock component, 32 parts of activation component and 3 parts of modification component, the activation component is a composite composed of 40 parts of silica fume, 30 parts of fly ash, 20 parts of slag powder and 10 parts of ultrafine slag powder in proportion by weight, and the modification component is a composite composed of 20 parts of sodium citrate, 35 parts of triethanolamine, 30 parts of polyether monomer and 15 parts of polycarboxylate water reducer powder in proportion by weight;

[0035] The preparation method of the rock-based mineral admixture specifically comprises the following steps:

[0036] Granite cave slag rock is added to a crusher and crushed into particles with a particle size of no more than 5 mm. The crushed particles are quantitatively input into a ball mill in a continuous feeding manner. A multi-layer screen is provided at the discharge end of the ball mill. The ball milled particles enter a mixer from a pulverizer under the thrust of airflow to form a rock component. Then, an activation component and a modification component are added to the mixer, and dry-mixed for 10 minutes to form a rock-based mineral admixture, wherein the 45 μm sieve residue of the admixture is 10%, the activity index is 81%, and the methylene blue value is 0.5 g / kg;

[0037] The prepared rock-based mineral admixture is used in the preparation of concrete

[0038] 1m 3The raw materials contained in the high-strength and high-flow concrete are as follows: 432kg of ordinary silicate cement, 96kg of rock-based mineral admixture, 1836kg of homogeneous fully-graded tunnel slag aggregate, 5.5kg of polycarboxylate water-reducing agent, 0.4kg of alkylbenzene sulfonate air-entraining agent and 130kg of water, wherein the homogeneous fully-graded tunnel slag aggregate is prepared by using tunnel slag from the same source as the rock-based mineral admixture, and the fully-graded tunnel slag aggregate is prepared by weight proportions of 40 parts of 0-5mm aggregate, 12 parts of 5-10mm aggregate, 30 parts of 10-16mm aggregate and 18 parts of 16-31.5mm aggregate;

[0039] The method for preparing concrete specifically comprises the following steps:

[0040] Ordinary Portland cement, rock-based mineral admixtures, and homogeneous fully-graded slag aggregate are added into a mixer at a rate of 30 r / min for 30 seconds, and then admixtures and water are added. After stirring for 3 minutes, high-strength and high-flowability concrete is made.

[0041] Example 2

[0042] The present invention provides a viscosity-reducing rock-based mineral admixture, and the raw material ratio is as follows:

[0043] 65 parts of rock component, 32 parts of activation component and 3 parts of modification component, the activation component is a composite composed of 50 parts of silica fume, 30 parts of glass microspheres and 20 parts of ultrafine slag powder by weight, and the modification component is a composite composed of 20 parts of sodium citrate, 35 parts of triethanolamine, 30 parts of polyether monomer and 15 parts of polycarboxylate water reducer powder by weight;

[0044] The preparation method of the rock-based mineral admixture specifically comprises the following steps:

[0045] The tuff cave slag rock is added to the crusher and crushed into particles with a particle size of no more than 5 mm. The crushed particles are quantitatively input into the ball mill in a continuous feeding manner. The discharge end of the ball mill is provided with a multi-layer screen. The particles after ball milling enter the mixer from the pulverizer under the thrust of the airflow to form a rock component. Then, the activation component and the modification component are added to the mixer, and dry-mixed for 10 minutes to form a rock-based mineral admixture, wherein the 45μm sieve residue of the admixture is 12%, the activity index is 79%, and the methylene blue value is 0.5g / kg;

[0046] The prepared rock-based mineral admixture is used in the preparation of concrete

[0047] 1m 3The raw materials contained in the high-strength and high-flow concrete are as follows: 384kg of ordinary silicate cement, 96kg of rock-based mineral admixture, 1836kg of homogeneous fully-graded tunnel slag aggregate, 5.5kg of polycarboxylate water-reducing agent, 0.4kg of alkylbenzene sulfonate air-entraining agent and 130kg of water, wherein the homogeneous fully-graded tunnel slag aggregate is prepared by using tunnel slag from the same source as the rock-based mineral admixture, and the fully-graded tunnel slag aggregate is prepared by weight proportions of 40 parts of 0-5mm aggregate, 12 parts of 5-10mm aggregate, 30 parts of 10-16mm aggregate and 18 parts of 16-31.5mm aggregate;

[0048] The method for preparing concrete specifically comprises the following steps:

[0049] Ordinary Portland cement, rock-based mineral admixtures, and homogeneous fully-graded slag aggregate are added into a mixer at a rate of 30 r / min for 30 seconds, and then admixtures and water are added. After stirring for 3 minutes, high-strength and high-flowability concrete is made.

[0050] Example 3

[0051] The present invention provides a viscosity-reducing rock-based mineral admixture, and the raw material ratio is as follows:

[0052] 65 parts of rock component, 32 parts of activation component and 3 parts of modification component, the activation component is a composite composed of 40 parts of silica fume, 20 parts of fly ash, 20 parts of slag powder and 20 parts of ultrafine slag powder by weight, and the modification component is a composite composed of 20 parts of sodium citrate, 35 parts of triethanolamine, 30 parts of polyether monomer and 15 parts of polycarboxylate water reducer powder by weight;

[0053] The preparation method of the rock-based mineral admixture specifically comprises the following steps:

[0054] The quartzite cave slag rock is added to the crusher and crushed into particles with a particle size of no more than 5 mm. The crushed particles are quantitatively input into the ball mill in a continuous feeding manner. The discharge end of the ball mill is provided with a multi-layer screen. The particles after ball milling enter the mixer from the pulverizer under the thrust of the airflow to form a rock component. Then, the activation component and the modification component are added to the mixer, and dry-mixed for 10 minutes to form a rock-based mineral admixture, wherein the 45μm sieve residue of the admixture is 9%, the activity index is 80%, and the methylene blue value is 0.5g / kg;

[0055] The prepared rock-based mineral admixture is used in the preparation of concrete

[0056] 1m 3The raw materials contained in the high-strength and high-flow concrete are as follows: 384kg of ordinary silicate cement, 96kg of rock-based mineral admixture, 1836kg of homogeneous fully-graded tunnel slag aggregate, 5.5kg of polycarboxylate water-reducing agent, 0.4kg of alkylbenzene sulfonate air-entraining agent and 130kg of water, wherein the homogeneous fully-graded tunnel slag aggregate is prepared by using tunnel slag from the same source as the rock-based mineral admixture, and the fully-graded tunnel slag aggregate is prepared by weight proportions of 40 parts of 0-5mm aggregate, 12 parts of 5-10mm aggregate, 30 parts of 10-16mm aggregate and 18 parts of 16-31.5mm aggregate;

[0057] The method for preparing concrete specifically comprises the following steps:

[0058] Ordinary Portland cement, rock-based mineral admixtures, and homogeneous fully-graded slag aggregate are added into a mixer at a rate of 30 r / min for 30 seconds, and then admixtures and water are added. After stirring for 3 minutes, high-strength and high-flowability concrete is made.

[0059] Comparative Example 1

[0060] 1m 3 The raw materials contained in the high concrete are as follows: 384 kg of ordinary Portland cement, 96 kg of limestone powder, 1836 kg of granite aggregate the same as in Example 1, 5.5 kg of polycarboxylate water reducer, 0.4 kg of alkylbenzene sulfonate air entraining agent and 130 kg of water. The preparation method is the same as in Example 1.

[0061] Comparative Example 2

[0062] 1m 3 The raw materials contained in the concrete are as follows: 384 kg of ordinary Portland cement, 96 kg of limestone powder, 1836 kg of tuff aggregate, 5.5 kg of polycarboxylate water reducer, 0.4 kg of alkylbenzene sulfonate air entraining agent and 130 kg of water. The preparation method is the same as that of Example 1.

[0063] Comparative Example 3

[0064] 1m 3 The raw materials contained in the concrete are as follows: 384 kg of ordinary Portland cement, 96 kg of limestone powder, 1836 kg of quartzite aggregate, 5.5 kg of polycarboxylate water reducer, 0.4 kg of alkylbenzene sulfonate air entraining agent and 130 kg of water. The preparation method is the same as that of Example 1.

[0065] The concrete prepared in Examples 1-3 and Comparative Examples 1-3 was tested, wherein the expansion and air content were tested in accordance with GB / T50080-2016 "Standard for Test Methods for Performance of Ordinary Concrete Mixtures", and the compressive strength was tested in accordance with GB / T 50081-2019 "Standard for Test Methods for Physical and Mechanical Properties of Concrete". The comprehensive cost was calculated according to the average price of raw materials on the market. The relevant results are shown in Table 1;

[0066] Table 1 Concrete test results

[0067] Expansion / mm Gas content / % 28d compressive strength / MPa <![CDATA[Total cost / yuan × m -3 > Example 1 580 4.8 81.8 433 Example 2 570 4.3 81.2 435 Example 3 580 4.5 80.3 428 Comparative Example 1 560 4.2 76.1 446 Comparative Example 2 560 4.3 74.3 446 Comparative Example 3 550 4.2 76.4 446

[0068] It can be seen from the table that when the rock-based mineral admixture in Examples 1-3 is 20%, a high-flow concrete with an expansion ≥570 mm is prepared, and the 28d compressive strength of the concrete is greater than or equal to 80 MPa, and the performance is significantly better than that of Comparative Examples 1-3 prepared with 20% limestone powder, and the comprehensive cost of Examples 1-3 is lower than that of Comparative Examples 1-3.

[0069] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A viscosity-reducing rock-based mineral admixture, characterized in that: The raw materials include the following parts by weight: 55-70 parts of rock component, 30-40 parts of activation component and 2-5 parts of modification component; The rock components are particles of cave slag rock that have been crushed and ground.

2. A viscosity-reducing rock-based mineral admixture according to claim 1, characterized in that: The admixture has a 45 μm sieve residue of no more than 15%, an activity index of no less than 75%, and a methylene blue value of no more than 1.0 g / kg.

3. The viscosity-reducing rock-based mineral admixture according to claim 1, characterized in that: The activation component includes at least one of silica fume, fly ash, slag powder, ultrafine slag powder and glass microspheres.

4. The viscosity-reducing rock-based mineral admixture according to claim 1, characterized in that: The modified component is at least one of sodium citrate, triethanolamine, polyether monomer, polycarboxylic acid water reducer powder and air entraining agent powder.

5. The viscosity-reducing rock-based mineral admixture according to claim 1, characterized in that: The cave slag rock is any one of siliceous and aluminous cave slag of granite, tuff and quartzite.

6. The viscosity-reducing rock-based mineral admixture according to claim 1, characterized in that: The preparation method of the admixture is: (1) weighing the raw materials according to the weight parts; (2) The slag rock is added to a crusher and crushed into particles with a particle size of no more than 5 mm. The particles are continuously fed into a ball mill. A multi-layer screen is provided at the discharge end of the ball mill. The particles after ball milling enter a mixer under the thrust of air flow to obtain rock components. Then, an activation component and a modification component are added to the mixer, and dry mixing is performed to obtain a viscosity-reducing rock-based mineral admixture.

7. Use of a viscosity-reducing rock-based mineral admixture according to any one of claims 1 to 6 in preparing concrete.

8. A high-strength, high-flow concrete, characterized in that: The invention comprises the following raw materials in parts by weight: 380-450 parts of silicate cement, 48-144 parts of the viscosity-reducing rock-based mineral admixture described in any one of claims 1-6, 1650-1950 parts of homogeneous slag aggregate, 1-10 parts of an admixture and 120-140 parts of water.

9. The high-strength, high-flow concrete according to claim 8, characterized in that: The raw material of the homogeneous slag aggregate is the same as the slag rock of the viscosity-reducing rock-based mineral admixture, and the homogeneous slag aggregate is a mixture of coarse and fine aggregates of 0-5mm, 5-10mm, 10-16mm and 16-31.5mm in a weight ratio of 35-45:8-16:25-35:15-25; The admixture is at least one of a naphthalene-based water reducer and a polycarboxylate water reducer.

10. The high-strength, high-flow concrete according to claim 8, characterized in that: The preparation method of the concrete is: After weighing the raw materials according to the weight proportions, silicate cement, viscosity-reducing rock-based mineral admixtures, and homogeneous slag aggregates are stirred and mixed, and then admixtures and water are added and stirred to obtain high-strength and high-flow concrete.