Low-carbon concrete proportioning method

Abstract

The invention discloses a proportioning method of low-carbon concrete. The low-carbon concrete is prepared from the following raw materials in parts by mass: 180-220 parts of cement, 60-80 parts of kaolin powder, 60-100 parts of water granulated slag powder, 10-20 parts of a water reducing agent, 0-3 parts of a thickening agent, 350-450 parts of sand, 450-550 parts of stones and 150-250 parts of water. By re-proportioning the raw materials of the concrete, the use amount of cement is reduced, more environment-friendly kaolin powder and water granulated slag powder are used, carbon emission in the concrete production process is remarkably reduced, industrial wastes such as water granulated slag powder are used as the raw materials, cyclic utilization of resources is facilitated, and the influence on the environment is reduced; the kaolin powder and the water granulated slag powder are generally low in price and stable in supply, the production cost of the concrete can be reduced by using the materials, the kaolin powder and the water granulated slag powder can improve the strength and durability of the concrete, such as improvement of compressive strength, tensile elastic modulus and the like, the performance of the low-carbon concrete is close to that of common concrete, and the low-carbon concrete has a wide application prospect.

Description

Technical Field

[0001] The invention relates to the technical field of concrete, in particular to a low-carbon concrete proportioning method. Background Art

[0002] At present, concrete is the foundation of the construction machinery industry. All infrastructure, transportation, and infrastructure cannot be separated from the use of concrete. Under the goal of low-carbon and environmental protection advocated by the country, concrete must be more environmentally friendly and low-carbon, meeting the standard requirements for carbon emission reduction.

[0003] In related technologies, low-carbon concrete reduces the use of cement during the production process. A large amount of mineral slag, construction waste, etc. are added as aggregates in its production, which reduces the consumption of natural sand and gravel resources and indirectly reduces and reduces the emission of excessive development and excessive dust gas.

[0004] Taking C40 concrete as an example, low-carbon concrete and ordinary concrete as examples, the energy-saving effect is: one cubic meter of concrete saves 159 kg of cement and uses 132 kg of industrial waste slag. The comprehensive energy consumption of one ton of cement is reduced to 120 kg of standard coal, coal consumption is reduced by 136 kg, and electricity consumption is reduced by 92 kWh. According to China's concrete production, if 1 / 4 of the concrete adopts low-carbon concrete technology, it is estimated that 100 kg of cement can be saved per cubic meter of concrete. This alone can save 50 million tons of cement every year, which is equivalent to saving comprehensive energy consumption, coal consumption and electricity consumption, which is a considerable amount.

[0005] Recycling tailings and construction waste as aggregates in concrete can not only greatly reduce the consumption of natural resources, but also reduce the large amount of material resources consumed in processing these wastes, which is of great significance in indirectly reducing greenhouse gas emissions. Therefore, the construction waste and tailings resource recycling concrete technology should be included in the low-carbon concrete technology system.

[0006] However, after reducing the amount of cement in concrete, the mechanical properties, shrinkage properties, and freeze-thaw resistance will be weakened, resulting in the deterioration of the structural strength of the concrete building. Some buildings with higher requirements for concrete performance are difficult to use low-carbon concrete, which restricts the widespread application of low-carbon concrete. Summary of the invention

[0007] The object of the present invention is to provide a low-carbon concrete mix ratio method to solve the problems raised in the above background technology.

[0008] To achieve the above object, the present invention provides the following technical solution: a low-carbon concrete mix ratio method, comprising the following raw materials in parts by weight:

[0009] 180-220 parts of cement, 60-80 parts of kaolin powder, 60-100 parts of slag powder, 10-20 parts of water reducer, 0-3 parts of thickener, 350-450 parts of sand, 450-550 parts of gravel, and 150-250 parts of water.

[0010] Furthermore, cement, kaolin powder and slag powder are pre-mixed into a cement mixture. When mixing concrete, the pre-mixed cement mixture forms concrete faster.

[0011] Furthermore, the chloride ion content in the cement mixture is less than or equal to 0.4%, and the soluble alkali metal oxide content is less than or equal to 0.06%, which ensures that the concrete has better durability and the structure is safe and not easily damaged.

[0012] Furthermore, the kaolin powder is processed by a calcination process.

[0013] A low-carbon concrete mix ratio method comprises the following mixing steps:

[0014] Step 1, weigh cement, kaolin powder, slag powder, water reducing agent, thickener, sand, gravel, and water according to weight parts;

[0015] Step 2: Detect the moisture content of cement, kaolin powder, slag powder and sand, and adjust the amount of water according to the moisture content results;

[0016] Step 3: Add a small amount of water to the mixer, add gravel and mix, then add cement, kaolin powder, slag powder, sand and water to mix into concrete slurry;

[0017] Step 4: Add water reducer and thickener based on the viscosity of the concrete slurry to adjust the fluidity of the concrete slurry.

[0018] Further, concrete slurry is cast into concrete blocks, and the concrete blocks are cured within 12 hours after casting. Spraying, watering or covering with wet cloth is used to keep the concrete surface moist. The curing time is 7-14 days, and the performance of the concrete blocks is tested.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] (1) By re-proportioning the raw materials of concrete, the amount of cement used is reduced, and more environmentally friendly kaolin powder and slag powder are used, which significantly reduces carbon emissions during the concrete production process.

[0021] (2) Using industrial waste such as slag powder as raw materials helps to achieve resource recycling and reduce the impact on the environment. Kaolin powder and slag powder are usually low in price and have a stable supply. Using these materials can reduce the production cost of concrete.

[0022] (3) Kaolin powder and slag powder can improve the strength and durability of concrete, such as improving compressive strength and tensile elastic modulus. The performance of low-carbon concrete is close to that of ordinary concrete and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Example:

[0026] See also Figure 1 , the present invention provides a technical solution: a low-carbon concrete proportioning method;

[0027] The invention is composed of the following raw materials in parts by weight: 180-220 parts of cement, 60-80 parts of kaolin powder, 60-100 parts of slag powder, 10-20 parts of water reducing agent, 0-3 parts of thickener, 350-450 parts of sand, 450-550 parts of gravel, and 150-250 parts of water;

[0028] The particle sizes of the three materials, cement, kaolin powder and slag powder, are 600-1200 meshes, the chloride ion content in the cement mixture is less than or equal to 0.4%, the soluble alkali metal oxide content is less than or equal to 0.06%, and the kaolin powder is processed by a calcination process;

[0029] Three portions of concrete raw materials are prepared, and the number of portions of the three portions of concrete raw materials is shown in Table 1;

[0030] Table 1, Proportion of three low-carbon concrete raw materials

[0031]

[0032] Based on the proportions of mix one, mix two, and mix three, cement, kaolin powder, and slag powder are premixed into a cement mixture. Evenly mixing the cement, kaolin powder, and slag powder in advance can shorten the mixing time and speed up the production of concrete during subsequent mixing of the concrete.

[0033] Concrete mix proportioning includes the following mixing steps:

[0034] Step 1, taking the corresponding number of raw materials according to the number of proportions 1, 2 and 3;

[0035] Step 2: Detect the moisture content of cement, kaolin powder, slag powder and sand, and adjust the amount of water according to the moisture content results to avoid the concrete slurry being too fluid or too weak, so as to facilitate the pouring of the concrete slurry;

[0036] Step 3: Add a small amount of water to the mixer and then add gravel to mix, wet the gravel, then add cement, kaolin powder, slag powder, sand, and water to mix into concrete slurry. This order of addition can reduce the amount of dust, improve the working environment, and help improve the environmental protection and efficiency of the concrete production process;

[0037] Step 4: Add water reducer and thickener based on the viscosity of the concrete slurry. The water reducer can effectively reduce the amount of water in the concrete while maintaining or improving the fluidity of the concrete. The thickener increases the viscosity of the concrete slurry and improves the stability and water retention of the concrete.

[0038] Take concrete slurry and cast it into concrete blocks. Start curing within 12 hours after the concrete blocks are cast. Use spraying, watering or covering with wet cloth to keep the concrete surface moist. The curing time is 7-14 days, and the performance of the concrete blocks is tested.

[0039] The conventional concrete blocks for comparative testing were added, and the parts of the raw materials of the conventional concrete were shown in Table 2;

[0040] Table 2, the proportion of conventional concrete raw materials

[0041]

[0042] Based on the number of raw materials in mix ratio 4, concrete blocks are manufactured (the size of the concrete blocks obtained from mix ratios 1, 2, and 3 is the same).

[0043] The compressive strength test was carried out on the concrete blocks of mixes 1 to 4. The concrete blocks of mixes 1 to 4 were cured for 7 days, 14 days and 28 days. The test results are shown in Table 3.

[0044] Table 3, test results of compressive strength of concrete blocks

[0045]

[0046] It can be seen from Table 3 that the compressive strength of low carbon concrete is similar to that of conventional concrete.

[0047] The shrinkage performance test was carried out on the concrete blocks of mix ratios 1 to 4. The concrete blocks of mix ratios 1 to 4 were cured for 28 days. The test results are shown in Table 4.

[0048] Table 4, test results of concrete block shrinkage performance

[0049]

[0050] It can be seen from Table 4 that the shrinkage performance of low carbon concrete is similar to that of conventional concrete.

[0051] The freeze-thaw resistance test was carried out on the concrete blocks of mixes 1 to 4. The concrete blocks of mixes 1 to 4 were cured for 28 days. After 200 freeze-thaw cycles, the test results are shown in Table 5. The mass loss rate = (mass loss / mass before freeze-thaw) × 100%, and the strength loss rate = (strength loss / strength before freeze-thaw) × 100%;

[0052] Table 5. Test results of freeze-thaw resistance of concrete blocks

[0053]

[0054] After the freeze-thaw test, after adding kaolin powder and slag powder to concrete, kaolin can also accelerate the strength of concrete. As a mineral admixture in concrete, slag powder has micro-aggregate effect and volcanic ash effect, which can improve the density and strength of concrete. In addition, the addition of slag powder can also reduce the hydration heat of concrete and reduce the occurrence of cracks, thereby further improving the density of concrete and improving the freeze-thaw resistance of low-carbon concrete.

[0055] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A low-carbon concrete mix method, characterized in that: It is composed of the following raw materials by weight: 180-220 parts of cement, 60-80 parts of kaolin powder, 60-100 parts of slag powder, 10-20 parts of water reducer, 0-3 parts of thickener, 350-450 parts of sand, 450-550 parts of gravel, and 150-250 parts of water.

2. A low-carbon concrete mix method according to claim 1, characterized in that: Cement, kaolin powder and slag powder are premixed into a cement mixture.

3. A low-carbon concrete mix method according to claim 1, characterized in that: The particle sizes of cement, kaolin powder and slag powder are 600-1200 meshes.

4. A low-carbon concrete mix method according to claim 2, characterized in that: The chloride ion content in the cement mixture is less than or equal to 0.4%, and the soluble alkali metal oxide content is less than or equal to 0.06%.

5. A low-carbon concrete mix method according to claim 1, characterized in that: The kaolin powder is processed by a calcination process.

6. A low-carbon concrete mix method according to any one of claims 1 to 5, characterized in that: The mixing steps include: Step 1, weigh cement, kaolin powder, slag powder, water reducing agent, thickener, sand, gravel and water according to weight parts; Step 2: Detect the moisture content of cement, kaolin powder, slag powder and sand, and adjust the amount of water according to the moisture content results; Step 3: Add a small amount of water to the mixer, add gravel and stir, then add cement, kaolin powder, slag powder, sand and water to stir into concrete slurry; Step 4: Add water reducer and thickener based on the viscosity of the concrete slurry to adjust the fluidity of the concrete slurry.

7. A low-carbon concrete mix method according to claim 6, characterized in that: The concrete slurry is cast into concrete blocks, and the performance of the concrete blocks is tested.

8. A low-carbon concrete mix method according to claim 7, characterized in that: The concrete blocks are cured within 12 hours after being poured, and the concrete surface is kept moist by spraying, watering or covering with a wet cloth. The curing time is 7-14 days.

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