Non-grouting dry connection type assembly type pavement base layer top surface fine leveling method

Abstract

The invention relates to the field of road construction, and discloses a non-grouting dry connection type fabricated pavement base top surface fine leveling method which comprises the following steps: S1, milling an old road; s2, a cement stabilized macadam layer is laid on the milled base layer, and the cement stabilized macadam layer is laid in two layers and compacted layer by layer; s3, a dry connection structure frame is arranged on the cement stabilized macadam layer; s4, a viscosity high-performance mortar leveling layer is laid on the dry connection structure frame; and S5, the leveling layer reaches the preset flatness through the slurry scraping and compacting technology, and wet curing is conducted after surface finishing and troweling are conducted. Compared with the prior art, the construction method has the advantages that the traditional grouting technology is not needed, rapid construction and high-precision leveling of the pavement are achieved by optimizing the material ratio and the dry connection construction method, the construction cost is reduced, later maintenance and repair are facilitated, the overall performance of the pavement is improved, and the service life of the pavement is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of road construction, in particular to a method for fine leveling the top surface of a non-grouting dry-connected assembled road base. Background Art

[0002] At present, road construction technology is constantly developing, especially prefabricated pavement construction has gradually attracted attention because it can speed up construction and improve construction quality. However, the existing pavement precision leveling methods still have many problems, which limits their application in large-scale high-grade pavement construction. Traditional pavement leveling usually relies on grouting technology. Although this method can achieve high flatness and surface quality, in large-scale construction, the fullness and density of the slurry are difficult to control, which can easily lead to uneven construction. The grouting process has a long curing time and a prolonged construction period. At the same time, it has high requirements for the preparation and construction technology of the slurry, which increases the construction cost and technical complexity.

[0003] On the other hand, although laser leveling technology can achieve high-precision leveling requirements, the equipment cost is high and has high requirements for ambient light and weather conditions. It is not suitable for use in sites that do not have an ideal construction environment. In addition, when laying the leveling layer, the limitations of material selection and construction technology also affect the quality and durability of pavement construction. Traditional cold-mix asphalt and hot-mix asphalt leveling methods also have their own limitations. Cold-mix asphalt has poor durability, and hot-mix asphalt is sensitive to construction temperature and easily affected by ambient temperature. These have brought challenges to construction management and quality control.

[0004] At the same time, in the current prefabricated pavement structure system, the connection method is mostly wet connection or adhesive connection, which can provide a certain degree of stability, but the construction steps are cumbersome, the maintenance time is long, and it is easy to have bonding failure due to material aging. Overall, the existing leveling and connection methods have obvious shortcomings in construction efficiency, cost control, quality stability and maintenance convenience. There is an urgent need for a new construction method that can solve the limitations of existing technologies and provide a more efficient and reliable road base precision leveling solution. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a method for fine leveling the top surface of a non-grouting dry-connected prefabricated pavement base layer, which solves the problems of low construction efficiency, high cost, poor quality stability and inconvenient maintenance in the existing pavement fine leveling technology, and provides an efficient, economical and stable method for fine leveling the top surface of a non-grouting dry-connected prefabricated pavement base layer.

[0006] To achieve the above purpose, the present invention is implemented by the following technical scheme: a method for fine leveling the top surface of a non-grouting dry-connected assembled pavement base layer, comprising the following steps:

[0007] S1. Milling the old roads to form the base after milling. The road milling needs to determine the milling plan based on the road condition assessment, road structure level and functional requirements. The milling plan fully considers the road disease and damage degree, as well as the structural design level and functional requirements of the overlaid road surface, including milling size, backfill plan, etc., and finally controls the base surface flatness after milling to ≤3mm;

[0008] S2, laying a 15-20 cm thick cement-stabilized gravel layer on the milled base, wherein the gravel layer is laid in two layers, and each layer is compacted separately;

[0009] S3. A dry connection structural frame is set on the cement stabilized gravel layer. The structural frame is composed of a plurality of square steel pipes, which are arranged at intervals and fixed on the anchor steel bars by welding. The cross-sectional size of the square steel pipes needs to be coordinated with the thickness of the flexible leveling transition layer structure, and the height of the anchor steel bars extending out of the ground is controlled to be below the thickness of the flexible leveling transition layer structure.

[0010] S4, laying a viscosity high-performance mortar leveling layer on the dry connection structural frame;

[0011] S5. The leveling layer is made to reach a predetermined flatness through a slurry scraping and vibration compaction process, and is cured after finishing and smoothing.

[0012] Preferably, the milling step includes cleaning and repairing the surface of the base layer after milling, and the repair material is polymer mortar, which is composed of cement, fine aggregate and polymer additives. The content of the polymer additive is 5%-10% of the total weight of the polymer mortar, and the base layer after milling is subjected to high-pressure dust blowing treatment to ensure that there are no residual impurities on the surface of the base layer.

[0013] Preferably, in the cement-stabilized gravel layer, the particle size range of the gravel is 5-20 mm, the amount of cement stabilizer added is 4%-8% of the weight of cement, and the gravel is surface treated before paving the gravel layer; each layer of the cement-stabilized gravel layer is compacted layer by layer using a double-layer vibratory roller during paving.

[0014] Preferably, the square steel pipes of the dry connection structural frame are adjusted to the designed elevation position through gaskets, the gasket material is high-density polyethylene or polytetrafluoroethylene, the gasket thickness range is 3-8mm, and during the laying process of the square steel pipes, the two ends of the square steel pipes are fixed by adjustable support frames to avoid horizontal and vertical displacement during construction.

[0015] Preferably, the total length of the square steel pipes of the dry connection structural frame is 0.5-1m longer than the total length of the slab laying. Anchor points fixed to the ground are provided every 2-4m of the square steel pipes. Each anchor point is fixed with a bolt with a diameter of 10-16mm. The bolt material is galvanized steel to enhance the overall stability and anti-slip properties of the frame.

[0016] Preferably, the viscosity high-performance mortar includes, by weight percentage, 30%-35% cement, 10%-15% mineral admixture, 40%-50% fine aggregate, 1%-2% admixture, 0.2%-0.4% reinforcing fiber, 0.1%-0.2% nanomaterial, 0.5%-1.0% self-healing material additive and 10%-14% water.

[0017] Preferably, the admixtures in the viscosity high-performance mortar include, by weight percentage, 0.5%-1.0% of high-efficiency water reducing agent, 0.3%-0.7% of viscosity regulator, 0.1%-0.3% of air entraining agent and 0.1%-0.2% of waterproofing agent.

[0018] Preferably, the viscosity regulator is cellulose ether, the air entraining agent is fatty acid salt, and the waterproofing agent is silicone, and they are mixed with cement and fine aggregate in a manner of first dry mixing and then wet mixing.

[0019] Preferably, the reinforcing fiber is polypropylene fiber or basalt fiber, with a length of 6-12 mm and an amount of 0.2%-0.4%. The diameter range of the polypropylene fiber is 18-242 m, and the diameter range of the basalt fiber is 10-162 m. When mixing the fiber and other components, stir at a stirring speed of 30-60 revolutions per minute for 3-5 minutes.

[0020] Preferably, the maintenance of the leveling layer includes covering with geotextile and plastic film, and sprinkling water every 12-24 hours during the maintenance period, with each sprinkling amount of 0.3-0.6L / m 2 The maintenance environment temperature range is 10℃-30℃, and the humidity range is 50%-80%.

[0021] The present invention provides a non-grouting dry-connected assembled pavement base top surface fine leveling method. It has the following beneficial effects:

[0022] 1. The present invention adopts a construction method that combines a dry-connected structural frame with high-viscosity high-performance mortar, which avoids the long waiting time for curing in the traditional grouting process, making the construction steps simpler and more efficient. The modular installation method and dry-connection technology make the docking of the panels faster and more accurate, thereby significantly shortening the construction period and improving the progress of the overall project.

[0023] 2. The present invention reduces the reliance on high-cost adhesives and a large number of mechanical equipment during construction by adopting dry connection technology and optimized mortar formula, while simplifying the construction steps and reducing labor costs. The high-efficiency self-compacting and excellent fluidity of high-viscosity high-performance mortar further reduces material waste and rework during construction, thereby reducing overall construction costs.

[0024] 3. The high-viscosity high-performance mortar used in the present invention has high strength, high adhesion and high crack resistance, can quickly reach the design strength after construction is completed, and maintain good flatness and structural integrity during long-term use. The use of nanomaterials and self-repairing additives in the mortar further enhances the wear resistance and anti-aging ability of the road surface, allowing it to maintain high stability under repeated loads and severe weather conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a cross-sectional view after construction of the present invention;

[0026] Figure 2 It is a schematic diagram of the method flow of the present invention. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the specification 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.

[0028] Please see attached Figure 1 -Attached Figure 2 The present invention provides a non-grouting dry-connected assembled pavement base top surface fine leveling method, which can significantly improve the flatness and durability of the pavement base, while shortening the construction period and reducing construction and maintenance costs. The following is a detailed description of the method.

[0029] S1. Milling of old roads

[0030] First, the old road to be treated is milled to form a flat and stable base. The milling depth is controlled at 5-10cm to ensure that the surface wear and damage layer is removed to expose a relatively complete lower structure, while repairing cracks or uneven areas formed due to long-term use. The flatness of the milling needs to be controlled at ≤3mm to ensure the quality of the subsequent structural layer.

[0031] In this embodiment, milling the old road specifically includes:

[0032] 1. Use precision-controlled milling machines for construction to achieve precise depth control and flatness requirements.

[0033] 2. Clean the milled surface to remove all debris, oil and other impurities to ensure a good bond between the underlying layer and the newly laid layer.

[0034] 3. For cracks and sunken areas exposed after milling, polymer mortar is used for repair. The polymer mortar is composed of cement, fine aggregate and polymer additives (such as acrylic ester materials), and the content of the polymer additives is 5%-10% of the total weight of the polymer mortar.

[0035] S2. Laying cement stabilized gravel layer

[0036] A 15-20cm thick cement stabilized gravel layer is laid on the treated milled base, laid and compacted in two layers. The purpose of the cement stabilized gravel layer is to provide a solid and stable foundation to carry the load of the upper structure layer and evenly distribute the load.

[0037] In this embodiment, laying the cement-stabilized gravel layer specifically includes:

[0038] 1. Material preparation: The particle size of the crushed stone ranges from 5-20mm. It is mixed with a certain proportion of cement according to the design requirements. The amount of cement added is controlled at 4%-8% of the weight of the crushed stone. Before paving, the crushed stone is surface treated (such as moistening with water) to improve the adhesion of the cement slurry.

[0039] 2. Layer laying and compaction:

[0040] The first step is to lay the first layer of gravel and compact it using a vibrating roller, ensuring that each layer is compacted no less than 6 times.

[0041] The second step is to lay the second layer of gravel, also using a vibrating roller to compact it layer by layer to ensure the density and uniformity of the gravel layer.

[0042] 3. After each layer is compacted, the flatness should be tested to ensure that it meets the design requirements and provides a good foundation for the next construction.

[0043] S3. Set up the dry connection structure frame

[0044] A dry connection structural frame is set on the compacted cement stabilized gravel layer. The dry connection structural frame consists of multiple square steel pipes, which are arranged parallel to the road surface direction, placed at intervals of 3m, and fixed to the steel bars by spot welding. The cross-sectional size of the square steel pipes needs to be coordinated with the thickness of the flexible leveling transition layer structure, and the height of the anchor steel bars extending out of the ground should be controlled to be below the thickness of the flexible leveling transition layer structure. The dry connection technology does not rely on the traditional grouting bonding method, but achieves rapid plate installation and high-precision leveling through mechanical fixing and adjustment.

[0045] In this embodiment, setting the dry connection structure framework specifically includes:

[0046] 1. Arrangement of square steel pipes: In this embodiment, the thickness of the flexible leveling transition layer structure is 2.5 mm, and the cross-sectional size of the square steel pipe is designed to be 2.5 cm×2.5 cm. It is made of high-strength steel to ensure its compression and shear resistance during the construction process.

[0047] 2. Height adjustment: The square steel pipe is adjusted to the designed elevation position through high-density polyethylene (HDPE) or polytetrafluoroethylene (PTFE) gaskets with a gasket thickness range of 3-8mm to accurately control the height.

[0048] 3. Fixing method: Both ends of the square steel pipe are fixed with adjustable support frames and fixed to the base steel bars by spot welding. An anchor point fixed to the ground is set every 2-4m, and the anchor point is fixed with galvanized steel bolts with a diameter of 10-16mm to enhance the stability and anti-slip performance of the frame.

[0049] S4. Laying high-performance mortar screed layer with high viscosity

[0050] A high-performance mortar screed is laid on the dry-jointed structural frame. This high-performance mortar is composed of a variety of materials and has the characteristics of self-compacting, non-segregation, high filling, high adhesion and high crack resistance, and can achieve precise leveling.

[0051] In this embodiment, laying the viscosity high-performance mortar leveling layer specifically includes:

[0052] Recipe composition:

[0053] Cement: 30%-35%

[0054] Mineral admixtures (such as fly ash, silica fume): 10%-15%

[0055] Fine aggregate (medium sand): 40%-50%

[0056] Admixtures (high-efficiency water reducing agent, viscosity regulator, air entraining agent, waterproofing agent): 1%-2%

[0057] Reinforcement fiber (polypropylene fiber or basalt fiber, length 6-12mm, diameter 18-24 2m): 0.2%-0.4%

[0058] Nanomaterials (nano silicon dioxide or nano aluminum oxide, particle size 20-50nm): 0.1%-0.2%

[0059] Self-repairing material additive (microencapsulated calcium carbonate precipitation inducer): 0.5%-1.0%

[0060] Water: 10%-14%

[0061] 2. Mixing process:

[0062] First, mix the dry materials (such as cement, mineral admixtures, fine aggregates) evenly, then add admixtures and reinforcing fibers, and then add a predetermined proportion of water and stir for 5-8 minutes to ensure uniformity and viscosity requirements.

[0063] Finally, add the nanomaterial and self-healing material additives and continue stirring for 3-5 minutes to ensure that these additives are evenly distributed.

[0064] 3.Mortar laying and leveling:

[0065] Spread the mixed mortar evenly in the dry joint structure frame and use a hand-held flat plate compactor for preliminary compaction.

[0066] Use a gravity scraper to scrape the mortar along the direction of the square steel pipe to ensure the uniform flatness and thickness of the mortar layer. If insufficient mortar is found, it is necessary to add mortar in time and re-scrape to ensure overall flatness.

[0067] S5. Compacting, finishing and curing of the levelling layer

[0068] After the leveling layer is laid, the leveling layer is made to reach the predetermined flatness through scraping and compaction processes, and then maintained after the surface is smoothed.

[0069] In this embodiment, the compaction, finishing and maintenance of the leveling layer specifically include:

[0070] 1. Compaction process: Use hand-held plate compactor and gravity scraper for vibration and slurry scraping to ensure that the leveling layer material tightly fills all gaps in the frame to achieve the designed density and flatness.

[0071] 2. Surface finishing and smoothing: After compaction, use a special smoothing machine to smooth the surface to further improve the surface smoothness and uniformity, and reduce shrinkage cracks and local uneven areas.

[0072] 3. Maintenance measures: Wet maintenance is carried out by covering with geotextile and plastic film. The maintenance time is 7-14 days. Water is sprinkled every 12-24 hours during the maintenance period. The amount of water sprinkled each time is 0.3-0.6L / m 2 The maintenance environment temperature is controlled at 10℃-30℃, and the humidity range is 50%-80%.

[0073] The non-grouting dry-connected assembled pavement base top surface fine leveling method of the present invention adopts dry connection technology and modular installation mode, avoiding the long curing process required by the traditional grouting leveling method, and can significantly shorten the construction period. The high-performance mortar with high viscosity used has high strength and high crack resistance, can maintain flatness and structural integrity during long-term use, and effectively resist the influence of pavement load and environmental changes. In addition, the dry-connected structural framework and modular design allow damaged pavement panels to be quickly replaced and repaired, greatly simplifying the later maintenance work.

[0074] 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 method for fine leveling the top surface of a non-grouting dry-connected assembled pavement base, characterized in that: The following steps are involved: S1. Mill the old roads to form the base after milling. The road milling needs to determine the milling plan according to the road condition assessment, road structure level and functional requirements, including milling size and backfill plan, and finally control the flatness of the base surface after milling to ≤3mm; S2, laying a 15-20 cm thick cement-stabilized gravel layer on the milled base, wherein the gravel layer is laid in two layers, and each layer is compacted separately; S3, setting a dry connection structural frame on the cement stabilized gravel layer, wherein the structural frame is composed of a plurality of square steel pipes, which are arranged at intervals and fixed to the anchor steel bars by welding; S4, laying a viscosity high-performance mortar leveling layer on the dry connection structural frame; S5. The leveling layer is made to reach a predetermined flatness through a slurry scraping and vibration compaction process, and is cured after finishing and smoothing.

2. A method for fine leveling the top surface of a non-grouting dry-connected assembled pavement base according to claim 1, characterized in that: The milling step includes cleaning and repairing the surface of the base layer after milling. The repair material is polymer mortar, which is composed of cement, fine aggregate and polymer additives. The content of the polymer additive is 5%-10% of the total weight of the polymer mortar. The base layer after milling is subjected to high-pressure dust blowing treatment to ensure that there are no residual impurities on the surface of the base layer.

3. A method for fine leveling the top surface of a non-grouting dry-connected assembled pavement base according to claim 1, characterized in that: In the cement stabilized gravel layer, the particle size of the gravel is in the range of 5-20 mm, the amount of cement stabilizer added is 4%-8% of the weight of cement, and the gravel is surface treated before paving the gravel layer; each layer of the cement stabilized gravel layer is compacted layer by layer using a double-layer vibratory roller during paving.

4. A method for fine leveling the top surface of a non-grouting dry-connected assembled pavement base according to claim 1, characterized in that: The square steel pipes of the dry connection structural frame are adjusted to the designed elevation position through gaskets. The gasket material is high-density polyethylene or polytetrafluoroethylene, and the gasket thickness ranges from 3 to 8 mm. During the laying process of the square steel pipes, both ends of the square steel pipes are fixed by adjustable support frames to avoid horizontal and vertical displacement during construction.

5. A method for fine leveling the top surface of a non-grouting dry-connected assembled pavement base according to claim 1, characterized in that: The total length of the square steel pipes of the dry connection structural frame is 0.5-1m longer than the total length of the slab laying. Anchor points fixed to the ground are provided every 2-4m of the square steel pipes. Each anchor point is fixed with bolts with a diameter of 10-16mm. The bolts are made of galvanized steel to enhance the overall stability and anti-slip properties of the frame.

6. A method for fine leveling the top surface of a non-grouting dry-connected assembled pavement base according to claim 1, characterized in that: The viscosity high-performance mortar comprises, by weight percentage, 30%-35% of cement, 10%-15% of mineral admixture, 40%-50% of fine aggregate, 1%-2% of admixture, 0.2%-0.4% of reinforcing fiber, 0.1%-0.2% of nano material, 0.5%-1.0% of self-healing material additive and 10%-14% of water.

7. A method for fine leveling the top surface of a non-grouting dry-connected assembled pavement base according to claim 6, characterized in that: The admixtures in the viscosity high-performance mortar include, by weight percentage, 0.5%-1.0% of a high-efficiency water reducing agent, 0.3%-0.7% of a viscosity regulator, 0.1%-0.3% of an air entraining agent and 0.1%-0.2% of a waterproofing agent.

8. A method for fine leveling the top surface of a non-grouting dry-connected assembled pavement base according to claim 7, characterized in that: The viscosity regulator is cellulose ether, the air entraining agent is fatty acid salt, and the waterproofing agent is silicone, and they are mixed with cement and fine aggregate in a manner of first dry mixing and then wet mixing.

9. A method for fine leveling the top surface of a non-grouting dry-connected assembled pavement base according to claim 6, characterized in that: The reinforcing fiber is polypropylene fiber or basalt fiber, with a length of 6-12 mm and a dosage of 0.2%-0.4%. The diameter of the polypropylene fiber is in the range of 18-242 m, and the diameter of the basalt fiber is in the range of 10-162 m. When mixing the fiber with other components, stir at a stirring speed of 30-60 revolutions per minute for 3-5 minutes.

10. A method for fine leveling the top surface of a non-grouting dry-connected assembled pavement base according to claim 1, characterized in that: The maintenance of the leveling layer includes covering with geotextile and plastic film, and sprinkling water every 12-24 hours during the maintenance period, with each sprinkling amount of 0.3-0.6L / m 2 The maintenance environment temperature range is 10℃-30℃, and the humidity range is 50%-80%.

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