Microbial capsule block for repairing water-sensitive area roadbed and application thereof

Abstract

The application discloses a microbial capsule block for repairing a water-sensitive area roadbed and application thereof, and contains the following components in mass fraction: 30-40 parts of microbial capsules, 50-60 parts of soil, and 40-45 parts of alkali-activated cementing materials; the microbial capsule has a water-soluble material as a capsule wall layer and a mixture of Bacillus pasteurii and urea as a capsule core layer; the microbial capsule is embedded in the roadbed of a water-sensitive area road section in advance, is used for preventing water damage of the roadbed when there is excessive water on the road, underground water seepage or storm weather, the microbial capsule is dissolved and activated under the soaking of water, bacteria are activated to generate carbonates, gaps are filled, the soil body is compacted, the roadbed is automatically repaired, and the effect of preventing problems from happening is achieved.

Description

Technical Field

[0001] This invention relates to the field of soil remediation technology, and in particular to a microbial capsule block for repairing roadbeds in water-sensitive areas and its application. Background Technology

[0002] Currently, in highway subgrade drainage systems, some areas experience heavy and concentrated rainfall, especially water-sensitive subgrade areas. If accumulated water (free water) is not promptly cleared, it can seep into the subgrade, causing water damage that manifests as pavement erosion, loosening, and potholes. If water damage to the asphalt pavement is not repaired in time, the seepage will further damage the subgrade. In severe cases, subgrade subsidence can lead to cracks in the pavement and base layer, allowing rainwater to seep into the base layer. Under the erosive action of rainwater, the pavement may also experience frost heave, and the service life of the subgrade will be shortened.

[0003] Currently, roadbed repair mainly employs methods such as surface repair, planing and thickening, and excavation and backfilling. These methods are only advantageous for repairing small or large areas of roadbed damage. Surface repair can only solve surface problems and has limited effectiveness for deep roadbed damage. It requires a long construction period and high costs, which can impact traffic and cause damage and pollution to the surrounding environment. Furthermore, roadbed damage can only be diagnosed and repaired after the damage has occurred and the impact can be macroscopically observed. Most roadbed repairs are only carried out when pavement damage is superficial, failing to achieve the effect of preventing problems before they occur.

[0004] Therefore, there is a need to provide a repair and prevention solution for roadbed damage caused by excessive water accumulation, in order to extend the service life of pavements in water-sensitive areas. Summary of the Invention

[0005] In view of this, this application provides a microbial capsule block for repairing roadbeds in water-sensitive areas and its application, which is used to solve the problem of how to repair and prevent roadbed damage caused by excessive water accumulation.

[0006] To achieve the above technical objectives, this application adopts the following technical solution:

[0007] In a first aspect, this application provides a microbial capsule block for repairing roadbeds in water-sensitive areas, comprising the following components in parts by weight: 30-40 parts microbial capsules, 50-60 parts soil, and 40-45 parts alkali-activated cementitious material; wherein the microbial capsules have a water-soluble material as the capsule wall layer and a mixture of Pasteurella multocida and urea as the capsule core layer.

[0008] Secondly, this application provides an auto-repair roadbed structure for water-sensitive areas containing microbial capsule blocks, which includes a block body and a grouting pavement layer covering the block body; the block body is formed by constructing and covering the roadbed surface with a plurality of microbial capsule blocks.

[0009] Preferably, an impermeable geomembrane is provided between the masonry block and the grouting pavement layer.

[0010] Preferably, the water-soluble material includes one or more of cement powder and gelatin.

[0011] Thirdly, this application provides a method for applying microbial capsule blocks for repairing roadbeds in water-sensitive areas, comprising the following steps:

[0012] S1. Mix the microbial capsules, soil, and alkali-activated cementitious material, then place them in a mold and compact them to obtain microbial capsule blocks;

[0013] S2. The microbial capsule blocks are laid and paved to cover the roadbed surface to obtain the block body;

[0014] S3. Grouting material is used to inject grout into the block body and its surroundings. After curing, an automatically repairable roadbed structure in the water-sensitive area is formed.

[0015] Preferably, between steps S2 and S3, an impermeable geomembrane is laid on the surface of the masonry block.

[0016] Preferably, the alkali-activated cementitious material includes one or more of lime powder, fly ash, and red mud.

[0017] Preferably, the grouting material includes one or more of emulsified asphalt mortar and concrete.

[0018] Preferably, in step S2, the microbial capsule blocks are constructed using an alternating method.

[0019] Preferably, the roadbed includes one or more of the following: road-bridge transition section and roadbed widening and junction section.

[0020] The beneficial effects of this application are as follows: The automatic repair roadbed structure in water-sensitive areas of this application pre-buries microbial capsules in the roadbed of water-sensitive sections to prevent water damage to the roadbed that may be caused by excessive water accumulation, groundwater seepage, or heavy rain. The microbial capsules dissolve and activate bacteria under water immersion, generating carbonates that fill the gaps, making the soil dense and automatically repairing the roadbed, thus playing a preventive role. Attached Figure Description

[0021] Figure 1A schematic diagram of the roadbed structure for automatic repair in water-sensitive areas; in the diagram: 1. Microbial capsule block; 2. Grouting pavement layer; 3. Impermeable geomembrane.

[0022] Figure 2 This is a plan view of the masonry block structure;

[0023] Figure 3 A process flow diagram for automatically repairing roadbed structures in water-sensitive areas was prepared. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0025] This application provides a microbial capsule block for repairing roadbeds in water-sensitive areas, comprising the following components in parts by weight: 30-40 parts microbial capsules, 50-60 parts soil, and 40-45 parts alkali-activated cementitious material; wherein the microbial capsules have a water-soluble material as the capsule wall layer and a mixture of Pasteurella multocida and urea as the capsule core layer.

[0026] This application provides an automatic repair roadbed structure for water-sensitive areas, which includes a block body and a grouting pavement layer covering the block body; the block body is formed by constructing and covering the roadbed surface with a number of microbial capsule blocks.

[0027] Repairing water seepage in water-sensitive areas (such as road-bridge transition sections and widening junctions of expanded roadbeds) cannot be done immediately, and there are no comprehensive protective measures to prevent water damage in advance. Most methods involve either installing drainage systems to remove accumulated water or, for soils with excessive moisture content, loosening and drying or uniformly mixing in lime powder to reduce moisture content, followed by re-compaction once the optimal moisture content is reached. Currently, once water seepage occurs in the roadbed, a certain curing time is required after road construction repairs, consuming significant manpower and resources; maintaining the drainage system is also a considerable expense. This application's self-repairing roadbed structure for water-sensitive areas embeds microbial capsules in the roadbed of water-sensitive sections in advance. This is to prevent water damage to the roadbed that may occur when there is excessive water accumulation, groundwater seepage, or heavy rain. The microbial capsules dissolve and activate bacteria when soaked in water, reacting to generate carbonates that fill the voids, making the soil denser and automatically repairing the roadbed, thus playing a preventative role.

[0028] In some embodiments, an impermeable geomembrane is also provided between the masonry blocks and the grouting pavement layer. The good air permeability and water permeability of the geotextile allow water to flow through, thereby effectively intercepting the loss of sand and soil and preventing the masonry blocks or roadbed from collapsing.

[0029] In this application, the microbial capsule block comprises microbial capsules, soil, and alkali-activated cementitious material. The microbial capsules use a water-soluble material as the capsule wall layer and a mixture of *Pasteurella spp.* (purchased from the China European Microbial Culture Collection Center) and urea as the capsule core layer. The microbial capsules contain microbial powder, namely *Pasteurella spp.* and urea nutrient powder. *Pasteurella spp.* produces a large amount of urease during its metabolism. Due to the special structure of the urease-producing bacterial cell wall, the bacterial surface is usually negatively charged and continuously adsorbs metal ions from the surrounding environment. Simultaneously, the urease produced by the bacteria during metabolism decomposes urea into NH3 and CO2. After the gas dissolves in water, it combines with the metal ions on the bacterial surface to form carbonates. As the precipitation increases, it gradually completely encapsulates the soil particles. Most of the carbonates act as bridges connecting the particles, cementing the soil particles together to achieve reinforcement and water-blocking effects. This not only prevents roadbed damage caused by excessive water accumulation but also allows for repair when the roadbed is already damaged.

[0030] The microcapsules of this application have a particle size between 20-30 nm, which does not affect the soil structure; they are small particles that adhere to the soil. The preparation method of the microbial capsules in this application is a common method used by those skilled in the art, and the preparation method is as follows: S1: Select a water-soluble material as the capsule wall layer; taking gelatin as an example, soak the gelatin in warm water, and after it softens, inject it into the capsule mold to form it. After a certain period of time, the capsule wall layer can be removed. S2: Prepare the mixture of microbial powder and urea into powder form according to the requirements (the mass ratio of Pasteurella multocida to urea is 1:10), and screen it to remove impurities. Then, place it in a container, and use a pin to press the microbial powder and urea into the capsule cavity. S3: Seal the capsule. There are usually two methods: wet sealing and dry sealing. In this example, wet sealing is used. Coat both ends of the capsule with a gelatin solution, and let the gelatin solidify to form a sealed state.

[0031] In some embodiments, the water-soluble material includes one or more of cement powder and gelatin, which can be dissolved in water. The purpose is to allow the microcapsules to dissolve in time when groundwater seeps in or comes into contact with water, thereby achieving the effect of repairing the roadbed.

[0032] A method for applying microbial capsule blocks for repairing roadbeds in water-sensitive areas includes the following steps:

[0033] S1. Mix the microbial capsules, soil, and alkali-activated cementitious material, then place them in a mold and compact them to obtain microbial capsule blocks;

[0034] S2. Construct and pave the microbial capsule blocks to cover the roadbed surface to obtain the block body;

[0035] S3. Grouting material is used to inject grout into the block and its surroundings. After curing, an automatically repairable subgrade structure in the water-sensitive area is formed.

[0036] This invention employs biochemical technology to address water damage issues in water-sensitive road sections. Upon activation, *Pasteurella spp.* induces carbonate precipitation, which consumes water in the soil, reducing the roadbed's moisture content. Simultaneously, the generated carbonate precipitates fill voids, compacting the soil and significantly reducing water damage to the foundation. The construction cycle is short, achieving an environmentally friendly roadbed improvement, treatment, and pretreatment technology that is green and pollution-free, meeting the requirements of environmental protection and ecological maintenance.

[0037] In some embodiments, between steps S2 and S3, an impermeable geomembrane is laid on the surface of the masonry block.

[0038] In some embodiments, the alkali-activated cementitious material includes one or more of lime powder and fly ash; the purpose is to provide sufficient calcium ions to form a better framework when microorganisms induce carbonate cementitious materials, and to provide an alkaline environment to improve the efficiency of microbial induction.

[0039] In some embodiments, the grouting material includes one or more of emulsified asphalt mortar and concrete; the grouting pavement layer formed by the grouting material plays a role in waterproofing, leveling, shock absorption, and buffering.

[0040] In some embodiments, in step S2, the microbial capsule blocks are laid in an alternating manner. The purpose of this alternating placement is to allow more microbial capsule blocks to be quickly activated when water seepage occurs.

[0041] This application provides an application of an automatically repairable subgrade structure in water-sensitive areas for subgrade repair. The subgrade objects to which this application is made include, but are not limited to, bridge-road transition sections, joints, and subgrades in water-sensitive areas containing groundwater. When damaged by water, the microbial capsules in the automatically repairable subgrade structure dissolve under water immersion, activating bacteria to produce carbonates. The calcium carbonate generated during this process seals the interconnected pores, achieving both reinforcement and water-blocking effects. This reduces the water content in the subgrade while automatically repairing soil cracks, thereby reducing pavement maintenance costs and extending the service life of water-sensitive road sections.

[0042] The following specific embodiments further illustrate this solution.

[0043] Example 1

[0044] like Figure 1 As shown, an automatic repair roadbed structure for water-sensitive areas includes a block body and a grouting pavement layer covering the block body. An impermeable geomembrane is also provided between the block body and the grouting pavement layer. The block body is formed by interlacing several microbial capsule blocks and covering the entire roadbed surface. Figure 2 As shown, the planar dimensions of the microbial capsule block are 24cm*12cm, the thickness is 10cm, the thickness of the grouting pavement layer is 2cm, and the thickness of the impermeable geomembrane is 0.2cm.

[0045] The microbial capsule building block contains the following components by mass fraction: 30 parts microbial capsules, 50 parts soil, and 40 parts coal ash; the microbial capsules have gelatin as the capsule wall layer and a mixture of Pasteurella multocida and urea as the capsule core layer, with a mass ratio of Pasteurella multocida to urea of ​​1:10.

[0046] Example 2

[0047] like Figure 3 As shown, a method for applying microbial capsule blocks for repairing roadbeds in water-sensitive areas includes the following steps:

[0048] S1. Mix 20 parts of microbial capsules, 60 parts of soil, and 50 parts of lime powder, then place the mixture in a mold and compact it to prefabricate microbial capsule blocks. The planar dimensions of the microbial capsule blocks are 24cm*12cm and the thickness is 10cm.

[0049] S2. The microbial capsule blocks are laid in an alternating pattern and spread across the roadbed surface. The microbial capsules are then stacked in an alternating pattern to obtain the block body. An impermeable geomembrane is then laid on the surface of the block body.

[0050] S3. Use emulsified asphalt mortar to grout the surface and surrounding area of ​​the impermeable geomembrane, and solidify it to form a grouting pavement layer with a thickness of 2cm.

[0051] The microbial capsule building block contains the following components by mass fraction: 30 parts microbial capsules, 50 parts soil, and 40 parts coal ash; the microbial capsules have gelatin as the capsule wall layer and a mixture of Pasteurella multocida and urea as the capsule core layer, with a mass ratio of Pasteurella multocida to urea of ​​1:10.

[0052] Example 3

[0053] A method for applying microbial capsule blocks for repairing roadbeds in water-sensitive areas is the same as in Example 2, except that it does not include laying an impermeable geomembrane on the surface of the block.

[0054] Example 4

[0055] A microbial capsule building block comprises the following components by mass fraction: 30 parts microbial capsules, 50 parts soil, and 40 parts coal ash; the microbial capsules have gelatin as the capsule wall layer and a mixture of Pasteurella multocida and urea as the capsule core layer, with a mass ratio of Pasteurella multocida to urea of ​​1:10.

[0056] Comparative Example 1

[0057] A method for applying microbial capsule blocks for repairing roadbeds in water-sensitive areas is the same as in Example 2, except that it does not include the addition of microbial capsules.

[0058] Testing and Evaluation

[0059] The self-healing water-sensitive area subgrade structures obtained in Example 2 and Comparative Example 1 were laid on the simulated pavement transition section, with a spacing of 20cm. 3 Spray water with pH 6 at a rate of / h, stop spraying after 10 days, and observe the condition of the simulated road transition section.

[0060] The results showed that after water spraying, the simulated road surface transition section in Example 2 was smooth, while cracks appeared in the simulated road surface transition section in Comparative Example 1.

[0061] This invention proposes a microbial capsule block for repairing roadbeds in water-sensitive areas and its application, enabling timely self-repair of water-sensitive roadbeds after water damage from water accumulation, floods, or heavy rain. The design involves prefabricating microbial microcapsule blocks and embedding them in water-sensitive roadbeds prone to water damage, employing a prefabricated building concept. Furthermore, the blocks can autonomously repair themselves upon contact with water, preventing water damage in its early stages and continuously retaining Pasteurella multocida in the soil to improve the roadbed and enhance sustainable development. This approach prevents water damage to roadbeds in water-sensitive areas, preventing further expansion and aggravation of water damage.

[0062] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A microbial capsule block for repairing roadbeds in water-sensitive areas, characterized in that, It comprises the following components in parts by weight: 30-40 parts microbial capsules, 50-60 parts soil, and 40-45 parts alkali-activated gelling material; the microbial capsules have a water-soluble material as the capsule wall layer and a mixture of Pasteurella multocida and urea as the capsule core layer; the water-soluble material includes one or more of cement powder and gelatin.

2. A self-repairing roadbed structure for water-sensitive areas comprising microbial capsule blocks as described in claim 1, characterized in that, It includes a block body and a grouting pavement layer covering the block body; the block body is formed by building a number of microbial capsule blocks and covering the roadbed surface.

3. The automatically repairable roadbed structure in water-sensitive areas according to claim 2, characterized in that, An impermeable geomembrane is also provided between the masonry block and the grouting pavement layer.

4. A method for applying microbial capsule blocks for repairing roadbeds in water-sensitive areas as described in claim 1, characterized in that, Includes the following steps: S1. After mixing the microbial capsules, soil, and alkali-activated cementitious material, place them in a mold and compact them to obtain microbial capsule blocks; S2. The microbial capsule blocks are laid and paved to cover the roadbed surface to obtain the block body; S3. Grouting material is used to inject grout into the block body and its surroundings. After curing, an automatically repairable roadbed structure in the water-sensitive area is formed.

5. The application method according to claim 4, characterized in that, Between steps S2 and S3, an impermeable geomembrane is laid on the surface of the masonry block.

6. The application method according to claim 4, characterized in that, The alkali-activated cementitious material includes one or more of lime powder, fly ash, and red mud.

7. The application method according to claim 4, characterized in that, The grouting material includes one or more of emulsified asphalt mortar and concrete.

8. The application method according to claim 4, characterized in that, In step S2, the microbial capsule blocks are constructed using an alternating method.

9. The application method according to claim 4, characterized in that, The roadbed includes one or more of the following: road-bridge transition section and roadbed widening and junction section.

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