Slag ecological type non-fine concrete and preparation method thereof

Abstract

The invention discloses slag ecological type non-fine concrete and a preparation method thereof. The slag ecological type non-fine concrete is prepared from the following raw materials in parts by weight: 1630 to 1670 parts of aggregate, 240 to 250 parts of cement, 80 to 85 parts of slag, 92 to 98 parts of water and 15 to 18 parts of reinforcing agent, and the particle size of the aggregate is 20-25 mm. The preparation method comprises the following steps: uniformly stirring and mixing the aggregate, the cement and the slag in a dry state to obtain a dry mixture; adding water and a reinforcing agent into the dry mixture, and stirring to form a total mixture; stirring the total mixture to form a uniform mixture; pouring the uniform mixture into a mold, and performing vibration exhaust to ensure compactness; and carrying out wet curing after initial setting. The coarse aggregate with the particle size of 20-25 mm is bonded with the cement paste, a porous structure is formed in the concrete, pores are large, air and moisture can be contained, and necessary conditions are provided for plant growth.

Description

Technical Field

[0001] The invention relates to concrete and a preparation method thereof, in particular to slag ecological sandless concrete and a preparation method thereof. Background Art

[0002] Concrete is a widely used building material, which is a mixture of water, sand, aggregate (such as crushed stone or gravel) and cement. After mixing, concrete will harden in a certain period of time to form a solid structure. Its advantages include high strength, good durability and the ability to adapt to various shapes and sizes. Therefore, it is widely used in construction, bridges, roads, tunnels and other projects. River slope protection is an engineering measure applied to protect river banks, rivers and their surrounding environment, prevent soil erosion, river erosion and floods from causing damage to buildings and facilities on the shore, such as concrete slope protection and vegetation slope protection made of concrete;

[0003] However, the pore structure of traditional eco-concrete is not reasonable, the pore size is uneven, and the overall porosity is low, which may limit the growth space of plant roots and make it difficult for them to fully stretch and obtain nutrients, water and air. Summary of the invention

[0004] Purpose of the invention: In order to overcome the deficiencies in the prior art, the purpose of the present invention is to provide a slag ecological sandless concrete suitable for plant growth. Another purpose of the present invention is to provide a convenient and practical method for preparing slag ecological sandless concrete.

[0005] Technical solution: The slag ecological sandless concrete described in the present invention includes the following raw materials in parts by weight: 1630-1670 parts of aggregate, 240-250 parts of cement, 80-85 parts of slag, 92-98 parts of water, and 15-18 parts of reinforcing agent; the particle size of the aggregate is 20-25 mm, and the coarse aggregate in this particle size range is bonded to the cement paste to form a porous structure in the concrete. The pores are relatively large and can accommodate air and moisture, providing necessary conditions for plant growth. After filling with soil and fertilizer, the plant roots can grow in the pores for a long time, and the overall strength of the concrete can be improved by combining with slag.

[0006] Furthermore, the fineness of the slag is S95, the particle size of the cement is 8 to 15 μm, and the particle size of the reinforcing agent is 1 to 20 μm.

[0007] Furthermore, the reinforcing agent is one or more of calcium silicate, humic acid, and spirulina. The reinforcing agent is preferably spirulina, which contains rich nutrients and can provide certain nutrients for plant growth while improving the strength of concrete.

[0008] The method for preparing a slag ecological sandless concrete according to the present invention comprises the following steps:

[0009] Step 1, 1630-1670 parts of aggregate, 240-250 parts of cement and 80-85 parts of slag are stirred and mixed evenly in a dry state to obtain a dry mixture;

[0010] Step 2, adding 92-98 parts of water and 15-18 parts of a reinforcing agent to the dry mixture and stirring to form a complete mixture;

[0011] Step 3, stirring the whole mixture to form a uniform mixture;

[0012] Step 4: pour the uniform mixture into the mold and vibrate to exhaust air to ensure density;

[0013] Step 5: After the material obtained in step 4 has initially solidified, wet curing is performed.

[0014] Furthermore, in step one, the humidity of cement and slag is within 5%. The stirring speed is 100 to 200 rpm, the stirring time is 3 to 5 minutes, and a double-paddle or three-dimensional mixing mixer is used for stirring. If the humidity of cement and slag is greater than 5%, it will cause cement and slag to agglomerate, affect the mixing uniformity, make the internal structure of the concrete uneven, and make the pore size and distribution difficult to control, thereby reducing the ability of the pores to accommodate air and moisture, which is not conducive to plant growth; at the same time, it affects the reaction of slag with alkaline substances in cement, reduces the strength of concrete, and changes the pH adjustment effect of concrete, which is not conducive to creating a microenvironment suitable for plant growth.

[0015] Furthermore, in step 2, water is added using a metering pump, the enhancer is added using an automatic feeder, and the temperature of the entire mixture does not exceed 30° C. The stirring speed is 100 to 200 rpm, and the stirring time is 2 to 4 minutes.

[0016] Furthermore, in step three, the stirring speed is 300 to 500 rpm, the stirring time is 5 to 10 minutes, and a high-efficiency high-power mixer is used for stirring.

[0017] Furthermore, in step five, the wet curing time is 25 to 30 days, the ambient humidity is maintained between 60% and 80%, and the temperature is maintained at 20 to 25°C.

[0018] Preparation principle: Coarse aggregate is bonded with cement paste to form a porous structure, providing space for plant growth; during the solidification process, slag reacts with cement alkaline substances to generate mixed hydration products, neutralize the alkalinity, lower the pH value, and create a microenvironment suitable for plant growth; the raw materials work synergistically, and through specific stirring, mixing, curing and other process steps, slag ecological sandless concrete with good performance is prepared.

[0019] Beneficial effects: Compared with the prior art, the present invention has the following significant features:

[0020] 1. By only using coarse aggregates with a particle size range of 20 to 25 mm to bond with cement paste without fine aggregates, a porous structure with large pores can be formed in the concrete. These pores can accommodate air and moisture, providing the necessary conditions for plant growth. After filling the pores with soil and fertilizer, people can plant vegetation in the pores, and plant roots can grow in the pores for a long time. Combined with the mixed slag, the overall strength of the concrete will be improved;

[0021] 2. Slag is an alkaline material, which contains some acidic components that can react with water. During the concrete curing process, slag reacts with the alkaline substances in cement to produce different mixed hydration products, which will help neutralize the alkalinity of the cement mixture and reduce the overall pH value of the concrete, creating a microenvironment suitable for plant growth. It is very beneficial to vegetation growth and suitable for river ecological slope protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a preparation flow chart of the present invention. DETAILED DESCRIPTION

[0023] Unless otherwise specified, the materials, reagents, instruments, etc. used in the following examples can be obtained from commercial sources. Experimental methods without specific conditions in the examples are usually carried out under conventional conditions or under conditions recommended by the manufacturer.

[0024] Example 1

[0025] like Figure 1 As shown, a method for preparing slag ecological sandless concrete comprises the following steps:

[0026] S1. Weigh the required raw materials, and use a double-paddle mixer to slowly stir 1650 parts of aggregate with a particle size of 20 mm, 247.5 parts of cement and 82.5 parts of slag in a dry state. Mix them evenly at a speed of 200 rpm and a stirring time of 5 minutes. The humidity of cement and slag is within 5% to obtain a dry mixture.

[0027] S2, add 95.7 parts of water with a metering pump, add 16.5 parts of the enhancer spirulina to the dry mixture with an automatic feeder, until the enhancer is fully dispersed, and perform a second slow stirring at a stirring speed of 200 rpm for 4 minutes to obtain a complete mixture. The mixing temperature after adding water does not exceed 30 degrees Celsius.

[0028] S3. Use a high-efficiency powerful mixer to stir the whole mixture at a speed of 500 rpm for 10 minutes to form a uniform mixture.

[0029] S4. Pour the uniform mixture into the mold and vibrate to exhaust air to ensure density.

[0030] S5. After the product obtained in step S4 is initially solidified, wet curing is performed at a temperature of 25° C. and a humidity of 80% for 30 days.

[0031] The overall strength of the test sample was 25 MPa and the pH value was 7.5.

[0032] Application Example 1

[0033] The slag ecological sandless concrete obtained in this embodiment is used to maintain Bermuda grass plants, which can maintain good water permeability of 0.8 cm / s and air permeability of 15 ml / (cm2·s). Plants can better absorb necessary nutrients. At the same time, the pore structure can retain moisture and help the roots to breathe, creating a microenvironment suitable for plant growth.

[0034] Example 2

[0035] A method for preparing slag ecological sandless concrete comprises the following steps:

[0036] S1. Weigh the required raw materials, and use a three-dimensional mixing mixer to slowly stir 1630 parts of aggregate with a particle size of 25 mm, 240 parts of cement and 80 parts of slag in a dry state. Mix them evenly at a speed of 100 rpm and a stirring time of 3 minutes. The humidity of cement and slag is within 5% to obtain a dry mixture.

[0037] S2. Add 92 parts of water with a metering pump and 15 parts of the enhancer humic acid with an automatic feeder to the dry mixture until the enhancer is fully dispersed, and perform a second slow stirring at a stirring speed of 100 rpm for 2 minutes to obtain a complete mixture. The mixing temperature after adding water does not exceed 30 degrees Celsius.

[0038] S3. Use a high-efficiency powerful mixer to stir the whole mixture at a speed of 300 rpm for 5 minutes to form a uniform mixture.

[0039] S4. Pour the uniform mixture into the mold and vibrate to exhaust air to ensure density.

[0040] S5. After the product obtained in step S4 is initially solidified, wet curing is performed at a temperature of 20° C. and a humidity of 60% for 25 days.

[0041] The overall strength of the test sample was 23 MPa and the pH value was 7.2.

[0042] Example 3

[0043] A method for preparing slag ecological sandless concrete comprises the following steps:

[0044] S1. Weigh the required raw materials, and use a three-dimensional mixer to slowly stir 1670 parts of aggregate with a particle size of 23 mm, 250 parts of cement and 85 parts of slag in a dry state. Mix them evenly at a speed of 10050 rpm and a stirring time of 4 minutes. The humidity of cement and slag is within 5% to obtain a dry mixture.

[0045] S2. Add 98 parts of water with a metering pump and 18 parts of calcium silicate, a reinforcing agent, to the dry mixture with an automatic feeder until the reinforcing agent is fully dispersed, and perform a second slow stirring at a stirring speed of 150 rpm for 3 minutes to obtain a complete mixture. The mixing temperature after adding water does not exceed 30 degrees Celsius.

[0046] S3. Use a high-efficiency powerful mixer to stir the whole mixture at a speed of 400 rpm for 5 to 10 minutes to form a uniform mixture.

[0047] S4. Pour the uniform mixture into the mold and vibrate to exhaust air to ensure density.

[0048] S5. After the product obtained in step S4 is initially solidified, wet curing is performed at a temperature of 20-25° C. and a humidity of 60-80% for 25-30 days.

[0049] The overall strength of the test sample was 26MPa and the pH value was 7.6.

[0050] Example 4

[0051] A method for preparing slag ecological sandless concrete comprises the following steps:

[0052] S1. Weigh the required raw materials, and use a double-paddle mixer to slowly stir 1640 parts of aggregate with a particle size of 20 mm, 245 parts of cement and 81 parts of slag in a dry state. Mix them evenly at a speed of 100 rpm and a stirring time of 3 minutes. The humidity of cement and slag is within 5% to obtain a dry mixture.

[0053] S2. Add 95 parts of water with a metering pump and 17 parts of the enhancer humic acid with an automatic feeder to the dry mixture until the enhancer is fully dispersed, and perform a second slow stirring at a stirring speed of 100 rpm for 4 minutes to obtain a complete mixture. The mixing temperature after adding water does not exceed 30 degrees Celsius.

[0054] S3. Use a high-efficiency powerful mixer to stir the whole mixture at a speed of 300 rpm for 10 minutes to form a uniform mixture.

[0055] S4. Pour the uniform mixture into the mold and vibrate to exhaust air to ensure density.

[0056] S5. After the product obtained in step S4 is initially solidified, wet curing is performed at a temperature of 20° C. and a humidity of 60% for 30 days.

[0057] The overall strength of the test sample was 24 MPa and the pH value was 7.3.

[0058] Example 5

[0059] A method for preparing slag ecological sandless concrete comprises the following steps:

[0060] S1. Weigh the required raw materials, and use a three-dimensional mixing mixer to slowly stir 1660 parts of aggregate with a particle size of 25 mm, 243 parts of cement and 84 parts of slag in a dry state. Mix them evenly at a speed of 200 rpm and a stirring time of 3 minutes. The humidity of cement and slag is within 5% to obtain a dry mixture.

[0061] S2. Add 97 parts of water with a metering pump and 16 parts of calcium silicate, a reinforcing agent, to the dry mixture with an automatic feeder until the reinforcing agent is fully dispersed, and perform a second slow stirring at a stirring speed of 200 rpm for 2 minutes to obtain a complete mixture. The mixing temperature after adding water does not exceed 30 degrees Celsius.

[0062] S3. Use a high-efficiency powerful mixer to stir the entire mixture at a speed of 500 rpm for 5 minutes to form a uniform mixture.

[0063] S4. Pour the uniform mixture into the mold and vibrate to exhaust air to ensure density.

[0064] S5. After the product obtained in step S4 is initially solidified, wet curing is performed at a temperature of 25° C. and a humidity of 80% for 25 days.

[0065] The overall strength of the test sample was 25.5MPa and the pH value was 7.4.

[0066] Comparative Example 1

[0067] This comparative example is the same as Example 1 in steps, except that in step S1, the particle size of the aggregate is replaced with 15 mm. It is found that the concrete strength is reduced to 18 MPa and the pH value is changed to 7.8. As the aggregate particle size becomes smaller, the pore structure becomes denser, the porosity decreases, and the storage space for air and water is reduced, which affects the respiration of plant roots and water absorption, and is not conducive to plant growth. At the same time, the bonding area between the smaller particle size aggregate and the cement paste is relatively small, resulting in a decrease in the overall strength of the concrete.

[0068] Comparative Example 2

[0069] This comparative example is the same as Example 1 in steps, except that in step S1, the particle size of the aggregate is replaced with 30 mm. The results show that the strength of the concrete is greatly reduced to 15 MPa, and the pH value is 8.0. The pores formed by the aggregate with a particle size of 30 mm are too large, and the density of the concrete is seriously insufficient. It is easy to crack and damage when under pressure, resulting in a significant decrease in strength. In addition, the excessively large pores make the water permeability too large, and it is difficult for water to be effectively retained in the pores. It is difficult for plant roots to continuously obtain water, which affects plant growth.

[0070] Comparative Example 3

[0071] This comparative example is the same as Example 1 in steps, except that in step S1, the reinforcing agent Spirulina is replaced by a common inorganic reinforcing agent. The results show that the concrete strength is reduced to 20 MPa and the pH value is 7.7. Common inorganic reinforcing agents can only play a certain physical reinforcing role, and cannot provide rich nutrients for plant growth like Spirulina, resulting in slow plant growth and poor root development. At the same time, the optimization of the internal pore structure of concrete and the alkalinity regulation effect are not as good as Spirulina, which is not conducive to the growth of plant roots in the pores and the absorption of nutrients.

[0072] Table 1 Test data of concrete obtained from Examples 1 to 5 and Comparative Examples 1 to 3

[0073]

[0074] From Table 1, the best embodiment is Embodiment 1.

Claims

1. A slag ecological sandless concrete, characterized in that: The invention comprises the following raw materials in parts by weight: 1630-1670 parts of aggregate, 240-250 parts of cement, 80-85 parts of slag, 92-98 parts of water and 15-18 parts of reinforcing agent; the particle size of the aggregate is 20-25 mm.

2. The slag ecological sandless concrete according to claim 1, characterized in that: The fineness of the slag is S95, the particle size of the cement is 8-15 μm, and the particle size of the reinforcing agent is 1-20 μm.

3. The slag ecological sandless concrete according to claim 1, characterized in that: The enhancer is one or more of calcium silicate, humic acid and spirulina.

4. A method for preparing slag ecological sandless concrete, characterized in that: The following steps are involved: Step 1, 1630-1670 parts of aggregate, 240-250 parts of cement and 80-85 parts of slag are stirred and mixed evenly in a dry state to obtain a dry mixture; Step 2, adding 92-98 parts of water and 15-18 parts of a reinforcing agent to the dry mixture, stirring to form a complete mixture; Step 3, stirring the whole mixture to form a uniform mixture; Step 4: pour the uniform mixture into the mold and vibrate to exhaust air to ensure density; Step 5: After the material obtained in step 4 has initially solidified, wet curing is performed.

5. The method for preparing a slag ecological sandless concrete according to claim 4, characterized in that: In the step 1, the moisture content of cement and slag is within 5%.

6. The method for preparing a slag ecological sandless concrete according to claim 4, characterized in that: In the step 1, the stirring speed is 100 to 200 rpm, the stirring time is 3 to 5 minutes, and a double-blade or three-dimensional mixing mixer is used for stirring.

7. The method for preparing a slag ecological sandless concrete according to claim 4, characterized in that: In the step 2, water is added using a metering pump, and the enhancer is added using an automatic feeder, and the temperature of the entire mixture does not exceed 30°C.

8. The method for preparing slag ecological sandless concrete according to claim 4, characterized in that: In the step 2, the stirring speed is 100 to 200 rpm, and the stirring time is 2 to 4 minutes.

9. The method for preparing a slag ecological sandless concrete according to claim 4, characterized in that: In the step 3, the stirring speed is 300 to 500 rpm, the stirring time is 5 to 10 minutes, and a high-efficiency high-power mixer is used for stirring.

10. The method for preparing slag ecological sandless concrete according to claim 4, characterized in that: In the step 5, the wet curing time is 25 to 30 days, the ambient humidity is maintained between 60% and 80%, and the temperature is maintained at 20 to 25°C.

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