High-whiteness concrete and preparation method thereof

Abstract

The invention relates to the technical field of concrete preparation, in particular to high-whiteness concrete and a preparation method thereof, and the concrete is mainly prepared from the following raw materials in parts by weight: 15-20 parts of cement, 30-40 parts of gravel, 0.1-0.5 part of a water reducing agent, 4-9 parts of slag powder and 5-10 parts of limestone powder. According to the concrete prepared through the method, the carbon dioxide emission in the preparation process is effectively reduced, low carbon and environmental protection are achieved, in addition, the strength of the concrete is guaranteed while the slag powder and the limestone powder are doped, the finally obtained concrete is subjected to pier test pouring, bubbles are few, the appearance color is uniform, and the whiteness is white; the concrete engineering appearance quality is good.

Description

[Technical field]

[0001] The invention belongs to the technical field of concrete preparation, and particularly relates to high-whiteness concrete and a preparation method thereof. [Background technology]

[0002] Concrete is the most widely used building material in civil construction projects today. With the widespread application of concrete materials, people's requirements for concrete performance are gradually increasing. Traditional concrete refers to a general term for engineering composite materials that are formed by cementitious materials to bind aggregates into a whole. Traditional concrete basically uses cement as a cementitious material, but the cement production process will cause a large amount of carbon dioxide (CO2) emissions.

[0003] In recent years, under the implementation of the "standardization and refinement" management model for engineering construction, the use of new equipment, new processes, new materials and new technologies has become a major development direction for the standardized management of engineering construction projects.

[0004] In this context, low-carbon and environmental protection have become the inevitable direction of the development of the cement concrete industry, and the industry should actively seek sustainable development and its path. [Summary of the invention]

[0005] In view of the above, it is necessary to provide a high-whiteness concrete and a preparation method thereof. Through the method of the present invention, carbon dioxide emissions are effectively reduced during the preparation process, achieving low-carbon and environmental protection. In addition, the present invention ensures the strength of the concrete while doping slag powder and limestone powder.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A high-whiteness concrete mainly consists of the following raw materials in parts by weight: 15-20 parts of cement, 30-40 parts of sand and gravel, 0.1-0.5 parts of water reducing agent, 4-9 parts of slag powder and 5-10 parts of limestone powder.

[0008] Among them, cement used is P·O.42.5 ordinary Portland cement from China Resources Cement (Fuchuan) Co., Ltd., sand and gravel use medium sand from Hezhou Huizhong Mineral Investment Co., Ltd., slag powder is S95 mineral powder from Liuzhou Qiangshi Technology Co., Ltd., and slag powder is obtained by vertical mill ultrafine grinding after magnetic separation, limestone powder uses 400-mesh limestone powder from Guangxi Hezhou Kanglubao New Material Technology Co., Ltd., and water reducer uses polycarboxylic acid high-efficiency water reducer (slow-setting type) PCA-9 from Guangxi Subote New Material Technology Co., Ltd.

[0009] In the present invention, further, the concrete is mainly composed of the following raw materials in parts by weight: 17 parts of cement, 35 parts of sand and gravel, 0.3 parts of water reducing agent, 6 parts of slag powder and 7 parts of limestone powder.

[0010] In the present invention, further, the water reducing agent is obtained by the following method: taking a commercially available water reducing agent, and adding thereto a treating agent accounting for 15-20‰ of the water reducing agent.

[0011] In the present invention, further, the treating agent is obtained by the following method: polyorganosiloxane and soluble soybean polysaccharide are mixed, 2-3 times the amount of water of the above mixture is added thereto to dissolve, to obtain a mixed solution, the mixed solution is heated to 40-50°C, and then polyether-modified polysiloxane is added, the mixture is fully mixed, and then dried to obtain the treating agent.

[0012] In the present invention, further, the mass ratio of the polyorganosiloxane, the soluble soybean polysaccharide and the polyether-modified polysiloxane is 4-5:1:1-2.

[0013] The present invention also provides a method for preparing the above-mentioned high-whiteness concrete, the method comprising the following steps:

[0014] (1) Cement, slag powder and limestone powder are fully stirred and mixed to obtain a cementitious material;

[0015] (2) Mixing the sand and gravel with the cementitious material obtained in step (1), adding a water reducing agent and water to the obtained mixture, and stirring for 8-16 minutes to obtain the concrete.

[0016] In the present invention, the amount of water added in the above step (2) can be the same as that of water added in conventional concrete preparation. Those skilled in the art can perform the operation according to actual needs. For example, the amount of water added can be 3-5 times the total mass of the solid material.

[0017] The present invention has the following beneficial effects:

[0018] 1. In order to improve some of the drawbacks of concrete, the present invention proposes a high-whiteness concrete and a preparation method thereof. First, it is to solve the problem of large carbon dioxide emissions from cement concrete. General concrete uses cement as a cementitious material, which leads to a large amount of carbon dioxide emissions during the preparation of concrete, which is not conducive to low-carbon and environmental protection. This application adds slag powder and limestone powder to replace part of the cement, which can effectively reduce carbon emissions and realize comprehensive utilization of solid waste to protect the environment. In addition, it also ensures the strength of the concrete and improves the appearance quality of the concrete.

[0019] 2. During the actual test pier verification process, the present application found that after pouring concrete, appearance quality problems such as poor whiteness, many bubbles, and uneven color were prone to occur. The above problems were solved by adding a special water reducer. The water reducer of the present application, after being combined with the treatment agent, can improve the fluidity of concrete, etc. The final cast test pier has uniform color, no stratification, no bubbles, and a relatively white color, which effectively improves the appearance quality of the concrete.

Brief Description of the Drawings

[0020] Figure 1 This is a photo of the on-site concrete pouring test pier of Group A of Test 3;

[0021] Figure 2 This is a photo of the on-site concrete pouring test pier of Group B of Test 3;

[0022] Figure 3 This is a photo of the on-site concrete pouring test pier of Group C of Test 3;

[0023] Figure 4 This is a photo of the on-site concrete pouring test pier of Group D of Test 3;

[0024] Figure 5 This is a photo of the concrete pouring test pier of Group E of Test 3;

[0025] Figure 6 This is a photo of the on-site concrete pouring test pier of Group F of Test 3;

[0026] Figure 7 This is an on-site photo of the concrete pouring test pier of Group G of Test 3. [Specific implementation method]

[0027] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific implementation disclosed below.

[0028] Embodiment 1:

[0029] The present embodiment provides a high-whiteness concrete and a preparation method thereof. The concrete is mainly composed of the following raw materials in parts by weight: 15 parts of cement, 30 parts of sand and gravel, 0.1 parts of modified water reducing agent, 4 parts of slag powder and 5 parts of limestone powder.

[0030] The modified water reducer is obtained by the following method: taking a Subote water reducer, adding a treatment agent accounting for 15‰ of the water reducer. The treatment agent is obtained by the following method: mixing polyorganosiloxane and soluble soybean polysaccharide, adding 2 times the amount of water of the above mixture to dissolve, obtaining a mixed solution, heating the mixed solution to 40°C, then adding polyether-modified polysiloxane, mixing well, and then drying to obtain the treatment agent. The mass ratio of the polyorganosiloxane, soluble soybean polysaccharide, and polyether-modified polysiloxane is 4:1:1.

[0031] This embodiment also provides a method for preparing the above-mentioned high whiteness concrete, comprising the following steps:

[0032] (1) Cement, slag powder and limestone powder are fully stirred and mixed to obtain a cementitious material;

[0033] (2) Mixing the sand and gravel with the cementitious material obtained in step (1), adding a modified water-reducing agent and an appropriate amount of water to the obtained mixture, and stirring for 8 minutes to obtain the concrete.

[0034] Embodiment 2:

[0035] This embodiment provides a high-whiteness concrete and a preparation method thereof. The concrete is mainly composed of the following raw materials in parts by weight: 17 parts of cement, 35 parts of sand and gravel, 0.3 parts of water reducing agent, 6 parts of slag powder and 7 parts of limestone powder.

[0036] The modified water reducer is obtained by the following method: taking a Subote water reducer, adding a treatment agent accounting for 17‰ of the water reducer. The treatment agent is obtained by the following method: mixing polyorganosiloxane and soluble soybean polysaccharide, adding 2.5 times the amount of water of the above mixture to dissolve, obtaining a mixed solution, heating the mixed solution to 45°C, then adding polyether-modified polysiloxane, mixing well, and then drying to obtain the treatment agent. The mass ratio of the polyorganosiloxane, soluble soybean polysaccharide, and polyether-modified polysiloxane is 5:1:1.

[0037] This embodiment also provides a method for preparing the above-mentioned high whiteness concrete, comprising the following steps:

[0038] (1) Cement, slag powder and limestone powder are fully stirred and mixed to obtain a cementitious material;

[0039] (2) Mixing the sand and gravel with the cementitious material obtained in step (1), adding a modified water-reducing agent and an appropriate amount of water to the obtained mixture, and stirring for 12 minutes to obtain the concrete.

[0040] Embodiment 3:

[0041] The present embodiment provides a high-whiteness concrete and a preparation method thereof. The concrete is mainly composed of the following raw materials in parts by weight: 20 parts of cement, 40 parts of sand and gravel, 0.5 parts of modified water reducing agent, 9 parts of slag powder and 10 parts of limestone powder.

[0042] The modified water reducer is obtained by the following method: taking a Subote water reducer, adding a treatment agent accounting for 20‰ of the water reducer. The treatment agent is obtained by the following method: mixing polyorganosiloxane and soluble soybean polysaccharide, adding 3 times the amount of water of the above mixture to dissolve, obtaining a mixed solution, heating the mixed solution to 50°C, then adding polyether-modified polysiloxane, mixing well, and then drying to obtain the treatment agent. The mass ratio of the polyorganosiloxane, soluble soybean polysaccharide, and polyether-modified polysiloxane is 5:1:2.

[0043] This embodiment also provides a method for preparing the above-mentioned high whiteness concrete, comprising the following steps:

[0044] (1) Cement, slag powder and limestone powder are fully stirred and mixed to obtain a cementitious material;

[0045] (2) Mixing the sand and gravel with the cementitious material obtained in step (1), adding a modified water-reducing agent and an appropriate amount of water to the obtained mixture, and stirring for 16 minutes to obtain the concrete.

[0046] Test example:

[0047] In order to illustrate the effect of this application, the applicant conducted the following experiments:

[0048] Experiment 1: Testing the carbon dioxide emissions under different preparation methods

[0049] The groups are as follows:

[0050] Test group: concrete was prepared in the manner of Example 2 of the present application;

[0051] Control group: cement was used as the cementitious material, limestone powder and slag powder were removed, and other methods were the same as the first group.

[0052] Comparing the carbon dioxide emissions of the two groups during the concrete preparation process, the experimental group used 254 kg of cement in one square of concrete and produced 218.4 kg of CO2, while the control group used 390 kg of cement in one square of concrete and produced 335.4 kg of CO2. The above comparison shows that the preparation of concrete using the method of this application can reduce carbon emissions and is beneficial to environmental protection. Experiment 2: Testing the strength of concrete obtained by different preparation methods

[0053] The groups are as follows:

[0054] The first group: concrete obtained by the preparation method of Example 2 of the present application;

[0055] Group 2: slag powder is replaced by fly ash, and other methods are the same as those of Group 1;

[0056] The third group: concrete raw material composition: 15 parts of cement, 30 parts of sand and gravel, 0.1 parts of modified water reducing agent, 12 parts of slag powder and 7 parts of limestone powder, the other methods are the same as the first group;

[0057] Group 4: Concrete raw material composition: 15 parts of cement, 30 parts of sand and gravel, 0.1 parts of modified water reducing agent, 9 parts of slag powder and 10 parts of limestone powder, other methods are the same as those of Group 1;

[0058] Group 5: Concrete raw material composition: 15 parts of cement, 30 parts of sand and gravel, 0.1 parts of modified water reducing agent, 6 parts of slag powder and 12 parts of limestone powder, other methods are the same as the first group;

[0059] Group 6: Remove slag powder and limestone powder, and other methods are the same as the first group.

[0060] Comparing the strength of the concrete obtained in the above manner, the results are shown in Table 1:

[0061] Table 1 Comparison of strength of each group of concrete

[0062] 7d strength (MPa) 28d strength (MPa) Group 1 43.0 55.8 Group 2 39.0 51.8 Group 3 39.1 52.1 Group 4 40.2 52.9 Group 5 38.4 50.1 Group 6 45.2 57.8

[0063] According to the results in Table 2, the concrete finally obtained by using the raw material combination of the present application has a relatively high strength, which is not much different from that of the sixth group using pure cement as the cementitious material, indicating that the method of the present application for preparing concrete can ensure the reduction of carbon emissions while also ensuring the strength of the concrete.

[0064] Test 3: Testing the appearance of each group of concrete

[0065] The groups are as follows:

[0066] Group A: the concrete described in Example 2 of the present application;

[0067] Group B: The water reducer is Luzhi water reducer, and other methods are the same as Group A;

[0068] Group C: The water reducing agent is not modified, and the other methods are the same as those of Group A;

[0069] Group D: The preparation method of the modified water reducing agent is as follows: 2.5 times the amount of water is added to the polyorganosiloxane, heated to 45°C, and then polyether-modified polysiloxane is added, mixed thoroughly, and then dried to obtain the treatment agent. The mass ratio of the polyorganosiloxane to the polyether-modified polysiloxane is 5:1, and the other methods are the same as those of Group A;

[0070] Group E: The preparation method of the modified water reducing agent is: mix polyorganosiloxane and soluble soybean polysaccharide, add 2.5 times the amount of water of the above mixture to dissolve, obtain a mixed solution, and dry it to obtain the treatment agent. The mass ratio of the polyorganosiloxane to the soluble soybean polysaccharide is 5:1, and the other methods are the same as those of Group A;

[0071] Group F: In the preparation of modified water reducing agent, the treatment agent is SXP-101-2 defoamer purchased from China Resources Chemical Co., Ltd., and the other methods are the same as those of Group A;

[0072] Group G: The treatment agent is SXP-101-2 defoamer purchased from China Resources Chemical Co., Ltd., and other methods are the same as those of Group B.

[0073] The appearance quality of the concrete prepared by the above grouping method was tested, and the various indicators are shown in Table 3:

[0074] Table 2 Comparison of appearance quality of concrete in each group

[0075] 3 days whiteness 7 days whiteness Appearance Group A 42 45 Uniform color, basically no bubbles, whiter Group B 34 36 Uneven color, a few small bubbles, insufficient whiteness Group C 32 34 Uneven color, obvious stratification, many small bubbles, insufficient whiteness Group D 38 41 Uniform color, more bubbles overall, whiter Group E 37 40 Uniform color, more bubbles, whiter Group F 34 35 Uneven color, almost no bubbles, insufficient whiteness Group G 39 42 Uniform color, many bubbles of different sizes, relatively white

[0076] In addition, the applicant also collected the renderings of the concrete pouring test piers of Groups A to G. Figure 1-7 The concrete pouring test pier effect diagrams of Group A to Group G are shown in Table 2 and Figure 1-7 The results show that the concrete prepared by the method of the present application also has the characteristics of good appearance quality.

[0077] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high whiteness concrete, characterized in that: The concrete is mainly composed of the following raw materials in parts by weight: 15-20 parts of cement, 30-40 parts of sand and gravel, 0.1-0.5 parts of modified water reducing agent, 4-9 parts of slag powder and 5-10 parts of limestone powder.

2. The high whiteness concrete according to claim 1, characterized in that: The concrete is mainly composed of the following raw materials in parts by weight: 17 parts of cement, 35 parts of sand and gravel, 0.3 parts of water reducing agent, 6 parts of slag powder and 7 parts of limestone powder.

3. The high whiteness concrete according to claim 1, characterized in that: The modified water reducing agent is obtained by the following method: taking a water reducing agent, and adding a treating agent accounting for 15-20‰ of the water reducing agent thereto.

4. The high whiteness concrete according to claim 3, characterized in that: The treating agent is obtained by the following method: polyorganosiloxane and soluble soybean polysaccharide are mixed, 2-3 times the amount of water as the above mixture is added thereto for dissolution to obtain a mixed solution, the mixed solution is heated to 40-50°C, and then polyether-modified polysiloxane is added, the mixture is fully mixed, and then dried to obtain the treating agent.

5. The high whiteness concrete according to claim 4, characterized in that: The mass ratio of the polyorganosiloxane, the soluble soybean polysaccharide and the polyether-modified polysiloxane is 4-5:1:1-2.

6. The method for preparing high whiteness concrete according to claims 1-5, characterized in that: The method comprises the following steps: (1) Cement, slag powder and limestone powder are fully stirred and mixed to obtain a cementitious material; (2) Mixing the sand and gravel with the cementitious material obtained in step (1), adding a modified water reducing agent and water to the obtained mixture, and stirring for 8-16 minutes to obtain the concrete.

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