Construction method for improving carbon sequestration performance of cement concrete pavement

Abstract

The invention relates to a construction method for improving the carbon sequestration performance of a cement concrete pavement, and belongs to the technical field of road construction.IPDA is used for treating the surface of the cement concrete pavement, amino functional groups in organic amine react with carbon dioxide, and the carbon sequestration performance of the cement concrete pavement is improved; the IPDA reacts with the carbon dioxide to promote calcium carbonate generated by the concrete to form a plurality of mechanical bonds between the base materials, so that the calcium carbonate is firmly bonded with the base materials; meanwhile, pores in the cement concrete pavement can be filled with calcium carbonate to form a continuous reinforced surface in any direction, so that the compactness and the interface strength of the cement concrete pavement are improved, and an original porous system is changed into a relatively compact system. The carbon dioxide trapping and fixing capacity of the cement concrete pavement is improved, and the breaking strength, the compressive strength, the waterproof performance and the durability of the pavement after carbon fixation are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of road construction, and in particular to a construction method for improving the carbon fixation performance of cement concrete pavement Background Art

[0002] As an important basic transportation facility in roads, airport runways and other transportation places, cement concrete pavement has the advantages of high bearing capacity, strong durability and good flatness, accounting for about 7.5% of my country's highway system. With the continuous increase in the number of cars, carbon dioxide emissions from cars account for 15% of the country's total emissions, which is in conflict with the current goal of reducing carbon emissions. In addition, increased traffic volume and the greenhouse effect can also cause cracks and wear on cement concrete pavements, reducing their service life.

[0003] However, the current society is paying more and more attention to carbon emissions, especially in the field of infrastructure construction. In order to resolve this contradiction, it is very necessary to improve the carbon fixation performance of cement concrete pavements. Current methods such as adding specific materials, improving cement and concrete, and adopting carbonization maintenance technology have limitations such as high cost, unclear effect, and insufficient carbonization reaction during maintenance. Although the organic amine method is the best chemical carbon fixation method, the most mature adsorbent monoethanolamine (MEA) requires a temperature higher than 393K to effectively desorb carbon dioxide. At the same time, the existing technology is prone to cause the pH value of concrete to decrease, which has an adverse effect on the structure and performance of the material, and cannot meet the actual demand for reducing carbon emissions.

[0004] Improving the carbon sequestration performance of cement concrete pavement can not only significantly desorb carbon dioxide from automobile exhaust and air, but also improve the durability and service life of the pavement, thereby reducing maintenance costs, contributing to addressing the global greenhouse effect, and also helping to promote the application and development of green construction technology. Therefore, in order to address the limitations of existing technologies and meet environmental protection requirements, a new construction method is needed to improve the carbon sequestration performance of cement concrete pavement, thereby achieving more durable and environmentally friendly infrastructure construction. Summary of the invention

[0005] In order to achieve the above-mentioned purpose and improve the carbon fixation efficiency while ensuring the strength and durability of the cement concrete pavement, the present invention provides a construction method for improving the carbon fixation performance of the cement concrete pavement.

[0006] The present invention provides a construction method for improving the carbon sequestration performance of a cement concrete pavement, which is characterized by comprising the following steps:

[0007] S1, preparation before construction, prepare raw materials such as cement, aggregate, water, etc., conduct random inspections on all raw materials, and place the raw materials that meet the requirements in the warehouse for standby use;

[0008] S2, clean the base surface, set up formwork, spread and roll cement concrete pavement and perform maintenance, all in accordance with JTGF30-2003 specification;

[0009] S3, after the maintenance is completed, in order to ensure the subsequent coating and penetration effect of organic amines, the treated cement concrete pavement needs to be exposed to the sun for 5-7 days, which can effectively reduce the water content inside the pavement;

[0010] S4, cleaning the dried cement concrete pavement, and evenly applying an organic amine on the cleaned pavement; the organic amine is isophorone diamine (IPDA), and the organic amine is applied at room temperature (25°C) at a concentration of 1000-1400 g / m 2 The coating amount is sprayed in batches, and the next spraying is carried out after the surface is completely penetrated after each spraying;

[0011] S5, cover the coated cement concrete pavement with a vacuum film and maintain it; in order to prevent the untreated pavement from coming into contact with carbon dioxide too early and affecting the penetration effect of IPDA, it should be covered and maintained for 3-5 days.

[0012] The above technical solution has the following beneficial effects: 1. The present invention treats cement concrete pavement by IPDA. The amino functional group in IPDA reacts with carbon dioxide to improve the efficiency of cement concrete pavement in absorbing automobile exhaust and free carbon dioxide in the air during the use stage, thereby reducing carbon emissions over the entire life cycle of cement concrete pavement. 2. After IPDA is coated on the cement concrete pavement and carbon is fixed, the generated calcium carbonate will fill the pores inside the cement concrete pavement, forming many mechanical bonds, making the substrate more firmly bonded together; the contact cracks between the aggregate and the cement paste will form a continuous reinforcement surface in any direction, improving the density and interface strength of the cement concrete pavement, and turning the original porous system into a denser whole.

[0013] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The present invention is a flow chart of the construction method for improving the carbon fixation performance of cement concrete pavement.

[0015] Figure 2 It is a schematic diagram of a flow chart of the construction method for improving the carbon fixation performance of cement concrete pavement according to the present invention.

[0016] Figure 3 This is the microscopic morphology of ordinary cement concrete after carbon fixation.

[0017] Figure 4 This is the microscopic morphology of cement concrete coated with IPDA after carbon fixation. Specific implementation methods

[0018] The aforementioned and other technical contents, features and effects of the present invention will be clearly presented in the following detailed description of the embodiments with reference to the drawings of the present application. The structural contents mentioned in the following embodiments are all based on the drawings of the specification as reference.

[0019] 1. Specific implementation steps

[0020] like Figure 1 As shown, the present invention discloses a construction method for improving the carbon sequestration performance of cement concrete pavement, and the embodiment includes the following steps:

[0021] S1, preparation before construction, prepare raw materials such as cement, aggregate, water, etc., conduct random inspections on all raw materials, and place the raw materials that meet the requirements in the warehouse for standby use;

[0022] S2, clean the surface of the base, set up the formwork according to the specifications, spread and roll the cement concrete pavement and perform maintenance;

[0023] S3, after the maintenance is completed, the treated cement concrete pavement is exposed to the sun;

[0024] S4, cleaning the dried cement concrete pavement and evenly applying the organic amine on the cleaned pavement;

[0025] S5, covering the coated cement concrete pavement with a vacuum film and maintaining it.

[0026] The construction of the cement concrete pavement to be coated is carried out in accordance with the JTG F30-2003 specification. After the construction is completed, the treated cement concrete pavement needs to be exposed to the sun for 5-7 days. The organic amine is isophorone diamine (IPDA), and the coating amount of the organic amine is 1000-1400g / m 2 The coating temperature is 25°C, and the coating method is to use a sprayer or spray gun for spraying. The coating can be divided into multiple passes for spraying, and the next process is required to be carried out after the previous pass is fully penetrated to ensure the penetration effect of the organic amine; after the spraying is completed, the coated cement concrete pavement needs to be covered with a vacuum film for 3-5 days.

[0027] By adopting the above technical solution, selecting standard road construction raw materials and carrying out construction in accordance with specifications, the quality of the road surface is guaranteed; the road surface is first exposed to the sun and dried and cleaned before coating the road surface, which can effectively reduce the influence of moisture inside the road surface on the penetration of organic amines, and reduce the influence of debris on the road surface on the coating of organic amines, thereby improving the coverage area and penetration effect of organic amines; the organic amine is selected from IPDA, which has excellent absorption efficiency and good durability under low carbon dioxide concentration; after IPDA coating, the amino functional group of the organic amine reacts with carbon dioxide to generate IPDACOO - , in high humidity environment, IPDACOO - A portion reacts with IPDA to generate IPDA + COO - (H + ), and the other part will be hydrolyzed to generate At the same time, carbon dioxide will also react with water to produce Eventually converted into a large amount of calcium carbonate.

[0028] like Figure 2 As shown, by adopting the above technical solution, the calcium carbonate generated by IPDA coating and carbon fixation treatment will fill the pores inside the cement concrete, fill the contact cracks between the aggregate and the cement paste, form a continuous reinforcement surface in any direction, and improve the density and interface strength of the cement concrete. This makes the originally porous system more compact, which helps to improve the overall performance and durability of the cement concrete. At the same time, IPDA itself has good wettability and can be fully diffused into the cement concrete, so that more IPDA reacts with carbon dioxide to generate calcium carbonate. These generated calcium carbonates, together with the calcium carbonate generated by the carbonation of calcium hydroxide in the cement, are in closer contact with the substrate, forming many mechanical bonds, thereby firmly bonding with the substrate. These processes help to improve the overall performance of cement concrete, enhance its durability and mechanical strength, and are also conducive to reducing carbon emissions and achieving environmental protection goals.

[0029] 2. Comparative Examples

[0030] Considering that the carbon dioxide content in automobile exhaust is high when the road is open to traffic, this embodiment selects carbon fixation at a carbon dioxide concentration of 20%. After carbon fixation at a temperature of 25°C for 3 days, the carbon fixation performance and road performance of cement concrete pavements with different IPDA coating amounts are compared, as shown in Table 1:

[0031] Table 1 Performance data of IPDA coating at different coating amounts

[0032] As can be seen from Table 1 above, the construction method provided by the present invention can effectively improve the carbon fixation efficiency of cement concrete pavement, and the compressive strength, flexural strength, water resistance and resistance to chloride ion erosion after carbon fixation are significantly improved. Comparing test examples 1 to 4, it can be found that as the amount of IPDA coating gradually increases, the calcium carbonate content after 3 days of carbon fixation also increases, which means that the carbon fixation efficiency of cement concrete pavement is also greatly increased; and the compressive strength and flexural strength of the pavement after 3 days of carbon fixation increase with the increase of IPDA coating; water absorption, mass loss after 80 freeze-thaw cycles and chloride ion migration coefficient D RCM As the coating amount of IPDA increases, it decreases. When the coating amount increases from 0 to 1000g / m 2 In the process, the carbon fixation efficiency, mechanical properties and durability of cement concrete pavement are significantly improved; when the coating amount is increased from 1000g / m 2 Increased to 1400g / m 2 In the process of carbon fixation efficiency, mechanical properties and durability of cement concrete pavement, the improvement tends to be flat. Therefore, considering the cost performance and penetration effect, the preferred IPDA coating amount of the present invention is 1000g / m 2 .

[0033] Through specific effect inspection, it is found that the construction method for improving the carbon fixation performance of cement concrete pavement provided by the present invention can form a cement concrete pavement with good carbon fixation performance, and after carbon fixation, the base material in the pavement is tighter, the mechanical strength is higher, and the waterproofness and durability are better.

[0034] The above description is only for illustrating the present invention. It should be understood that the present invention is not limited to the above embodiments, and various variations that conform to the concept of the present invention are within the protection scope of the present invention.

Claims

1. A construction method for improving the carbon sequestration performance of cement concrete pavement, characterized in that: The construction method comprises the following steps: S1, preparation before construction, prepare raw materials such as cement, aggregate, water, etc., conduct random inspections on all raw materials, and place the raw materials that meet the requirements in the warehouse for standby use; S2, clean the surface of the base, set up the formwork according to the specifications, spread and roll the cement concrete pavement and perform maintenance; S3, after the maintenance is completed, the treated road surface is exposed to the sun; S4, cleaning the dried cement concrete pavement, and evenly applying the organic amine on the cleaned pavement; S5, covering the coated road surface with a vacuum film and maintaining it.

2. The construction method for improving the carbon sequestration performance of cement concrete pavement according to claim 1, characterized in that: The construction and maintenance methods of the cement concrete pavement to be treated are carried out in accordance with the JTG F30-2003 specification.

3. The construction method for improving the carbon sequestration performance of cement concrete pavement according to claim 1 or 2, characterized in that: The exposure time is 5-7 days.

4. The construction method for improving the carbon sequestration performance of cement concrete pavement according to claims 1-3, characterized in that: The organic amine is isophoronediamine (IPDA).

5. The construction method for improving the carbon sequestration performance of cement concrete pavement according to claims 1-4, characterized in that: The coating amount of the organic amine is 1000-1400g / m 2 .

6. The construction method for improving the carbon sequestration performance of cement concrete pavement according to claims 1-5, characterized in that: The temperature during coating of the organic amine is 25°C.

7. The construction method for improving the carbon sequestration performance of cement concrete pavement according to claims 1-6, characterized in that: The coating method is to use a sprayer or a spray gun to spray in batches, and after each spraying, the surface is completely penetrated before the next spraying.

8. The construction method for improving the carbon sequestration performance of cement concrete pavement according to claims 1-7, characterized in that: The vacuum film covering treatment time is 3-5 days to prevent the untreated cement concrete pavement from coming into contact with carbon dioxide too early.

Images