A method for compacting the mixture around a rain grate

Abstract

This invention discloses a method for compacting asphalt mixture around a storm drain grate. The method involves spreading a pre-prepared asphalt mixture onto the base layer of the work area to form a pavement layer. The pavement layer is then divided into a core zone and a transition zone from the center of the storm drain grate opening outwards. Differential directional load compaction is applied to the core and transition zones to ensure that the mixture around the storm drain grate achieves appropriate compaction strength in different areas, avoiding localized settlement or cracking due to uneven stress. The compaction effect is evaluated by monitoring the pavement layer's condition data after the main compaction, and targeted supplementary compaction is performed based on the evaluation results to ensure the pavement layer meets the compaction standards. Finally, the pavement layer undergoes final compaction, improving the asphalt compaction quality around the storm drain grate.

Description

Technical Field

[0001] This invention relates to the field of road construction technology, and in particular to a method for compacting the mixture around a rainwater grate. Background Technology

[0002] In municipal road asphalt paving construction, the area surrounding storm drain grates becomes a weak point in the compaction process due to its unique structure. Traditionally, temporary covers are used to protect the surrounding asphalt around the storm drain grate openings. However, after construction, the asphalt around the grate becomes loose, and the mixture easily falls into the manhole. Uneven compaction leads to later settlement, creating road surface "traps." Insufficient compaction at the edges and corners allows rainwater to seep into the roadbed, weakening the road's structural stability.

[0003] Existing compaction schemes often rely on the experience of construction personnel to set parameters, but they are difficult to specifically meet the needs of large fluctuations in compaction effect and cannot solve the problem of poor asphalt compaction quality around rainwater grates. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a method for compacting the mixture around a rainwater grate.

[0005] This invention provides a method for compacting the mixture around a rainwater grate, comprising:

[0006] The work area is delineated based on the location of the rainwater grate opening, and the base layer of the work area is cleaned and dehumidified;

[0007] The pre-prepared asphalt mixture is spread on the base layer of the work area to form a road surface layer;

[0008] The pavement layer is divided into a core area and a transition area from the center of the storm drain grate outlet outwards. Differentiated directional loads are applied to the core area and the transition area respectively for initial compaction and main compaction.

[0009] Obtain the state data of the pavement layer after main compaction, and evaluate the compaction effect of the pavement layer based on the state data of the pavement layer;

[0010] Based on the evaluation results of the compaction effect of the pavement layer, the pavement layer is further compacted until the compaction effect of the pavement layer reaches the preset compaction standard;

[0011] After the compaction effect of the road surface layer reaches the preset compaction standard, the road surface layer is shaped and compacted to form a shaped road surface layer.

[0012] Preferably, the pre-prepared asphalt mixture includes a load-bearing layer mixture, a transition layer mixture, and a sealing layer mixture; the load-bearing layer mixture comprises, by weight, 5-6 parts asphalt, 4-5 parts polymer modifier, 0.4 parts high modulus agent, 1.3-1.8 parts steel fiber, 0.5-1 parts basalt fiber, 3-5 parts mineral powder, 60-65 parts basalt, 20-25 parts limestone, and 0.2-0.3 parts first additive; wherein the first additive is a mixture of antioxidant and tackifier;

[0013] The transition layer mixture comprises, by weight, 12-15 parts of polyurethane adhesive and 85-88 parts of aggregate skeleton, wherein the polyurethane adhesive comprises, by weight, 7-8 parts of polyether polyol, 5-6 parts of isocyanate, 0.1-0.2 parts of catalyst, 0.5-1 parts of toughening agent and 0.3-0.5 parts of silica filler; the aggregate skeleton comprises, by weight, 60-65 parts of graded crushed stone, 20-25 parts of stone chips, 5-8 parts of limestone mineral powder filler and 0.5-1 parts of chopped fiber;

[0014] The sealing layer mixture comprises, by weight, 6-7 parts polymer-modified asphalt, 0.3-0.5 parts high-viscosity agent, 0.05-0.1 parts fiber stabilizer, 4-6 parts limestone, 50-55 parts basalt, 30-35 parts manufactured sand, and 0.2-0.3 parts second additive; wherein the second additive is a mixture of anti-stripping agent and ultraviolet absorber.

[0015] Preferably, the step of spreading the pre-prepared asphalt mixture on the base layer of the work area to form a road surface layer includes:

[0016] The load-bearing layer mixture, the transition layer mixture, and the sealing layer mixture are sequentially spread on the base layer of the work area, and each layer is coated with a pre-prepared interface treatment agent; wherein, the pre-prepared interface treatment agent comprises, by weight, 3-4 parts of thermoplastic elastomer, 0.5-1 parts of silane coupling agent, 1-2 parts of tackifying resin, 3-4 parts of diluent, and 0.1-0.2 parts of stabilizer.

[0017] Preferably, the step of dividing the pavement layer into a core zone and a transition zone from the center of the storm drain grate outwards, and applying differentiated directional loads to the core zone and the transition zone for initial and main compaction respectively, includes:

[0018] The road surface layer is divided into a core area and a transition area from the center of the storm drain grate outlet outwards;

[0019] Initial compaction stage: The road surface layer is statically compacted by a road roller, and then the statically compacted road surface layer is vibrated.

[0020] Main compaction stage: The core area is compacted sequentially along the radial and normal directions of the core area by a road roller in a manner with progressively increasing load. Then, the transition area is compacted sequentially along the radial and normal directions of the transition area in a manner with progressively increasing load.

[0021] Preferably, the initial load ratio between the radial and normal directions of the core area is 7:3, and the initial load ratio between the radial and normal directions of the transition area is 3:7.

[0022] Preferably, the condition data of the pavement layer includes rebound values;

[0023] The process of acquiring the state data of the pavement layer after main compaction and evaluating the compaction effect of the pavement layer based on the state data includes:

[0024] The rebound value is measured at multiple preset measurement points on the core area and the transition area using the drop hammer rebound method. The rebound values ​​at multiple preset measurement points on the core area and the transition area are obtained, and the measured rebound values ​​are averaged to obtain the average rebound value corresponding to the core area and the transition area respectively.

[0025] Based on the average rebound values ​​corresponding to the core area and the transition area respectively, determine the rebound modulus corresponding to the core area and the transition area respectively;

[0026] The resilient modulus of the pavement layer is obtained by weighting the resilient modulus corresponding to the core area and the transition area respectively; wherein the weight value of the core area is greater than the weight value of the transition area.

[0027] Based on the resilient modulus of the pavement layer, combined with the preset standard resilient modulus and the preset compaction standard, the compaction degree of the pavement layer is determined, and based on the compaction degree of the pavement layer and the preset compaction density standard, the actual compaction density of the pavement layer is determined.

[0028] The compaction effect of the pavement layer is evaluated using the actual compaction density of the pavement layer.

[0029] Preferably, the step of further compacting the pavement layer based on the evaluation results of the compaction effect of the pavement layer until the compaction effect of the pavement layer reaches a preset compaction standard includes:

[0030] Compare the actual compaction density of the pavement layer with the density difference of the preset compaction density standard. If the density difference is greater than or equal to the preset density difference threshold, then the pavement layer is compacted. In the current compaction stage, the core area is statically compacted with a load more than one times the initial load when the main pressure is applied radially, and then the transition area is statically compacted with a load more than one times the initial load when the main pressure is applied in the normal direction.

[0031] After completing the current compaction stage, the state data of the pavement layer is reacquired, and the compaction effect of the pavement layer is evaluated based on the state data. If the evaluation result still does not meet the preset compaction standard, the compaction is repeated until the preset compaction standard is met in two consecutive evaluations.

[0032] Preferably, the step of shaping and compacting the pavement layer to form a shaped pavement layer includes:

[0033] The core area is subjected to at least two rounds of vibratory compaction, the transition area is subjected to at least one round of static compaction, and the entire surface layer is subjected to kneading compaction.

[0034] Preferably, the step of acquiring the state data of the pavement layer after main compaction and evaluating the compaction effect of the pavement layer based on the state data further includes:

[0035] After the main compaction of the pavement layer is completed, the pavement layer is subjected to an appearance quality inspection. The appearance quality inspection includes at least one of the following: crack width, crack density, and joint height difference.

[0036] If the appearance quality inspection fails, the pavement layer shall be partially repaired until the appearance quality inspection passes.

[0037] Preferably, the method further includes:

[0038] The apparent damage of the shaped pavement layer is periodically inspected, and the pavement layer is locally repaired according to the apparent damage.

[0039] As can be seen from the above technical solution, the present invention lays the pre-prepared asphalt mixture on the base layer of the work area to form a pavement layer. Then, the pavement layer is divided into a core area and a transition area from the center of the storm drain grate outlet outwards. Differentiated directional load compaction is then applied to the core area and the transition area to ensure that the mixture around the storm drain grate obtains appropriate compaction strength in different areas, avoiding local settlement or cracking caused by uneven stress. By monitoring the state data of the pavement layer after the main compaction, the compaction effect of the pavement layer is evaluated, and targeted additional compaction is carried out based on the evaluation results to ensure that the compaction effect of the pavement layer meets the compaction standard. Finally, the pavement layer is shaped and compacted, which improves the asphalt compaction quality around the storm drain grate. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 A flowchart of a method for compacting the mixture around a rainwater grate;

[0042] Figure 2 A top view of the road surface layer surrounding the storm drain grate;

[0043] Figure 3 This is a front cross-sectional view of the road surface layer surrounding the storm drain grate. Detailed Implementation

[0044] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] like Figure 1 As shown in the embodiment of this application, a method for compacting the mixture around a rainwater grate is provided, including:

[0046] S100. Delineate the work area based on the location of the rainwater grate opening, and clean and dehumidify the base layer of the work area.

[0047] The work area is the area around the storm drain grate opening and extending outwards by at least 50cm. If the distance from the edge of the storm drain grate opening is used as a reference, the work area is formed by extending outwards by 70cm. It is generally a circular area. The base layer in the work area is cleaned to remove debris, dust and loose particles. Then a layer of permeable geotextile is laid, and a small road roller is used to remove moisture and compact it. After there is no water accumulation on the base layer surface, asphalt is laid and compacted to ensure that the base layer is dry and stable and to improve the adhesion performance between the subsequent asphalt layer and the base layer.

[0048] S200: The pre-prepared asphalt mixture is laid on the base layer of the work area to form the road surface layer.

[0049] The on-site temperature of the pre-prepared asphalt mixture can be controlled. For example, the on-site temperature in summer is 140-150℃ (to avoid overflow due to excessive temperature), the on-site temperature in winter is 150-160℃ (to ensure asphalt fluidity), and the on-site temperature in spring and autumn is controlled at 145-155℃ to ensure that the mixture has good workability and compaction during paving. During the paving process, an infrared thermometer is used to monitor the temperature in real time to ensure that the surface of the paved layer is uniform and free of low-temperature zones. The paving thickness is based on the design elevation plus at least 5cm for compaction.

[0050] S300: The pavement layer is divided into a core zone and a transition zone from the center of the storm drain grate outlet outwards. Differentiated directional loads are applied to the core zone and the transition zone for initial compaction and main compaction, respectively.

[0051] Among them, such as Figures 2-3 As shown, the core area is the area within 40cm of the center of the rainwater grate opening, and the transition area is the area outside the core area within the working area. By dividing the core area and the transition area, the directional load compaction process can be implemented in a targeted manner. The core area focuses on radial force to enhance structural stability and strengthen edge compaction strength, while the transition area strengthens the force in the normal direction to achieve gradual stress transfer, achieve a smooth transition, and avoid abrupt settlement.

[0052] Meanwhile, by applying differentiated directional loads to the core area and the transition area, and using different directional loads to perform initial and main compaction on the core area and the transition area respectively, the compaction path and load parameters are precisely matched.

[0053] The initial compaction stage is used to fix the shape of the asphalt and prevent spillage or displacement during subsequent compaction. The main compaction stage is the key stage to achieve the compaction target. It allocates the load ratio according to the different compaction requirements of the core area and the transition area, thereby achieving coordinated control of high density in the core area and stress relief in the transition area.

[0054] S400: Obtain the state data of the pavement layer after main compaction, and evaluate the compaction effect of the pavement layer based on the state data of the pavement layer.

[0055] Among them, by monitoring the state data of the pavement layer after main compaction, it is determined whether the compaction density of the pavement layer meets the design requirements.

[0056] S500. Based on the evaluation results of the compaction effect of the pavement layer, the pavement layer is further compacted until the compaction effect of the pavement layer reaches the preset compaction standard.

[0057] If the assessment results show that the compaction density of a local area of ​​the pavement layer is insufficient, the pavement layer will be compacted. During the compaction, the corresponding load direction will be selected according to the area attributes until the compaction effect of the pavement layer reaches the preset compaction standard.

[0058] S600 After the compaction effect of the pavement layer reaches the preset compaction standard, the pavement layer is shaped and compacted to form the shaped pavement layer.

[0059] Among these steps, shaping and compaction are used to prevent later settlement and protect the compaction results. During shaping and compaction, a flexible edge ring is generally added to the compaction head to avoid damage to the asphalt surface.

[0060] It should be noted that this application involves spreading pre-prepared asphalt mixture on the base layer of the work area to form a pavement layer. The pavement layer is then divided into a core zone and a transition zone from the center of the storm drain grate outlet outwards. Differential directional load compaction is then applied to the core zone and the transition zone to ensure that the mixture around the storm drain grate obtains appropriate compaction strength in different areas, avoiding local settlement or cracking caused by uneven stress. The compaction effect of the pavement layer is evaluated by monitoring the state data of the pavement layer after the main compaction. Based on the evaluation results, targeted additional compaction is carried out to ensure that the compaction effect of the pavement layer meets the compaction standard. Finally, the pavement layer is shaped and compacted, which improves the asphalt compaction quality around the storm drain grate.

[0061] The pre-prepared asphalt mixture includes a load-bearing layer mixture, a transition layer mixture, and a sealing layer mixture. The load-bearing layer mixture, expressed in parts by weight, includes: 5-6 parts asphalt, 4-5 parts polymer modifier, 0.4 parts high modulus agent, 1.3-1.8 parts steel fiber, 0.5-1 parts basalt fiber, 3-5 parts mineral powder, 60-65 parts basalt, 20-25 parts limestone, and 0.2-0.3 parts first additive. The first additive is a mixture of antioxidant and tackifier.

[0062] The total proportion (by weight) of the load-bearing layer mixture is 100 parts. The polymer modifier is a composite modifier of SBS and epoxy resin, which improves the compatibility between the light and heavy components of asphalt. The high modulus agent is a composite material of polyester fiber and organosiloxane, whose synergistic effect can significantly improve the high temperature stability and fatigue resistance of asphalt mastic and effectively inhibit aggregate slippage during compaction. The first additive is a 1:1 mixture of antioxidant and tackifier, which delays asphalt aging and enhances aggregate adhesion, thereby improving durability and interfacial bonding during compaction.

[0063] The process of preparing the load-bearing layer mixture is as follows: Pretreatment: Basalt, limestone, and mineral powder (finely ground limestone) are dried, basalt is preheated to 180~190℃, limestone and mineral powder are preheated to 170~180℃; steel fibers and basalt fibers are broken up and clumped.

[0064] Preparation of modified asphalt: Heat the asphalt to 150~160℃, add polymer modifier and high modulus agent, stir and shear for 40~60min (4000r / min), then add the first additive and stir at low speed for 20min to make modified asphalt masterbatch (temperature maintained at 160~170℃).

[0065] Feeding and mixing: First, put limestone and mineral powder into the mixing pot and dry mix for 30 seconds; then add modified asphalt and wet mix for 60 seconds; finally, add steel fiber and basalt fiber in batches and wet mix at high speed for 90~120 seconds to ensure that the fibers are fully dispersed and without clumping.

[0066] Discharge control: The discharge temperature of the mixture is 170~180℃. Check the uniformity of mixing. If there is no white material or fiber clumping, it can be used. Keep it warm and prevent cooling throughout the process.

[0067] The components of the transition layer mixture, expressed in parts by weight, include: 12-15 parts of polyurethane adhesive and 85-88 parts of aggregate skeleton. The components of the polyurethane adhesive, expressed in parts by weight, include: 7-8 parts of polyether polyol, 5-6 parts of isocyanate, 0.1-0.2 parts of catalyst, 0.5-1 parts of toughening agent, and 0.3-0.5 parts of silica filler. The components of the aggregate skeleton, expressed in parts by weight, include: 60-65 parts of graded crushed stone, 20-25 parts of stone chips, 5-8 parts of limestone mineral powder filler, and 0.5-1 parts of chopped fiber.

[0068] The total proportion (parts by weight) of the transition layer mixture is 100 parts. The catalyst used is an organotin catalyst, such as dibutyltin dilaurate, to accelerate curing. The toughening agent is carboxyl-terminated liquid nitrile rubber, which improves the elongation at break and low-temperature toughness of the adhesive. The silica filler is surface-silanized to enhance interfacial adhesion and toughness.

[0069] The preparation process of the transition layer mixture includes: aggregate pretreatment: graded crushed stone, stone chips, and limestone mineral powder are dried, cooled to room temperature of 20~30℃, and chopped polyester fibers are added and dry-mixed for 20s to form an aggregate skeleton.

[0070] Preparation of polyurethane adhesive: Mix polyether polyol (component A), toughening agent and silica filler in parts by weight for 30 minutes until uniform, then add isocyanate (component B) and catalyst, and stir at low speed for 15-20 seconds to prepare polyurethane adhesive (prepare immediately and use before initial setting).

[0071] Composite mixing: Spray polyurethane adhesive evenly into the aggregate skeleton and mix at low speed for 40~60s to ensure that the surface of the aggregate skeleton is covered with a 1~2mm thick adhesive film, without clumping or exudation, forming an elastic mixture in which the adhesive film covers the aggregate and the fibers connect the skeleton.

[0072] Discharge and set aside: The temperature of the mixed material after mixing should be controlled at 25~35℃, and the paving and compaction should be completed within 30 minutes to avoid premature curing and loss of elasticity of polyurethane.

[0073] The components of the sealing layer mixture, expressed in parts by weight, include: 6-7 parts polymer-modified asphalt, 0.3-0.5 parts high-viscosity agent, 0.05-0.1 parts fiber stabilizer, 4-6 parts limestone, 50-55 parts basalt, 30-35 parts manufactured sand, and 0.2-0.3 parts second additive; wherein the second additive is a mixture of anti-stripping agent and ultraviolet absorber.

[0074] The total proportion (by weight) of the sealing layer mixture is 100 parts. The polymer-modified asphalt is a composite modified asphalt of SBS and rubber powder, with SBS content of 4-6% and rubber powder content of 8-12%, which is subjected to high-speed shearing for 90 minutes to form a stable phase. The high-tack agent is ethylene-acrylic acid copolymer, which improves the adhesion between asphalt and aggregate. The fiber stabilizer is polyacrylonitrile fiber, which effectively inhibits the segregation of the mixture during construction. The anti-stripping agent is a silane coupling agent, which enhances the interfacial adhesion between asphalt and aggregate. The ultraviolet absorber is hydroxybenzophenone, which effectively delays asphalt aging.

[0075] The preparation process of the sealing layer mixture includes: pretreatment: the manufactured sand and mineral powder are dried and preheated to 160~170℃; the ultraviolet absorber and anti-stripping agent are dissolved in the modified asphalt masterbatch in advance.

[0076] Preparation of composite modified asphalt: The base asphalt is heated to 145~155℃, SBS modifier and rubber powder are added and sheared for 50min, then high viscosity agent and fiber stabilizer are added, and the mixture is stirred at low speed for 30min to make high elastic modified asphalt.

[0077] Feeding and mixing: Preheat fine aggregate and mineral powder into the pot and dry mix for 20 seconds, add high-elasticity modified asphalt and wet mix for 50 seconds, then mix at low speed for 40 seconds to ensure that the fine aggregate is fully coated and there is no white residue.

[0078] Discharge control: Discharge temperature 60~170℃ (slightly lower than the load-bearing layer to avoid high temperature damage to the grate metal parts), the mixture is of uniform coarseness and no fiber clumping, meeting the requirements for thin-layer paving and compaction.

[0079] In some embodiments, the pre-prepared asphalt mixture is laid on the base layer of the work area to form a pavement layer, including: laying the load-bearing layer mixture, the transition layer mixture, and the sealing layer mixture sequentially on the base layer of the work area, and coating each layer with a pre-prepared interface treatment agent; wherein the pre-prepared interface treatment agent comprises, by weight, 3-4 parts of thermoplastic elastomer, 0.5-1 parts of silane coupling agent, 1-2 parts of tackifying resin, 3-4 parts of diluent, and 0.1-0.2 parts of stabilizer.

[0080] During the paving process, the load-bearing layer mixture, transition layer mixture, and sealing layer mixture are laid sequentially from bottom to top, and the thickness of each layer is generally ordered from largest to smallest as load-bearing layer mixture, transition layer mixture, and sealing layer mixture.

[0081] To ensure good adhesion between layers, the corresponding interface treatment agent should be sprayed evenly before each layer is laid to ensure that the coating is continuous and without omissions; the paving temperature should be controlled as follows: 150-160℃ for the load-bearing layer, 155-165℃ for the transition layer, and 140-150℃ for the sealing layer.

[0082] The total proportion (by weight) of the interface treatment agent is 10 parts. In the interface treatment agent, the thermoplastic elastomer is an SBS+SEBS composite to improve the interface toughness and shear resistance; the silane coupling agent enhances the chemical bonding between inorganic aggregates and organic asphalt; the tackifying resin is C5 petroleum resin to improve the initial tack; the diluent is 120# solvent oil to adjust the construction viscosity; and the stabilizer is a compound of antioxidant 1010 and ultraviolet absorber UV-326 to prevent performance degradation during storage.

[0083] The preparation process of the interface treatment agent includes:

[0084] Melting of base material: Heat the thermoplastic elastomer to 120~130℃ to melt it, add the tackifying resin and stir for 40 minutes until the resin is completely dissolved to form the bonding base material.

[0085] Treatment agent feeding: Add silane coupling agent and catalyst to the binder base material, stir at high speed for 20 minutes, and use the coupling agent to form "chemical bridges" to enhance the adhesion to the aggregate / grate metal surface. Then add aromatic oil diluent, stir at low speed for 30 minutes, and adjust the viscosity to 1500~2000 mPa·s to ensure no particles and no stratification, thus obtaining the interface treatment agent. The prepared interface treatment agent should be kept at 80~90℃, sealed and stored. Stir evenly before use, and it can be directly sprayed / brushed. It forms a film quickly at room temperature to form a bonding transition layer.

[0086] In some embodiments, the pavement layer is divided into a core area and a transition area from the center of the storm drain grate outwards, and differential directional loads are applied to the core area and the transition area for initial compaction and main compaction, respectively. This includes: dividing the pavement layer into a core area and a transition area from the center of the storm drain grate outwards; initial compaction stage: static compaction of the pavement layer by a road roller, followed by vibratory compaction of the statically compacted pavement layer; main compaction stage: compacting the core area sequentially along the radial and normal directions of the core area with an increasing load gradient by a road roller, and then compacting the transition area sequentially along the radial and normal directions of the transition area with an increasing load gradient.

[0087] In the initial compaction stage, the pavement layer is statically compacted once with a road roller at a speed controlled at 2.0 km / h to ensure a smooth surface free of wheel tracks. This is followed by a vibratory compaction pass at a frequency of 30 Hz with moderate excitation force to prevent the mixture from shifting. Both static and vibratory compaction follow the principle of "edges first, then center; lower areas first, then higher areas," with a minimum overlap width of 20 cm for uniform compaction. Immediately after initial compaction, the temperature is checked; the core area should be no lower than 135℃ and the transition zone no lower than 140℃ before proceeding to the main compaction stage.

[0088] During the main compaction stage, directional compaction is adopted. The core area is compacted radially (from the center to the edge) to ensure the compaction degree of the core area. Then, reinforcement compaction is carried out along the normal direction (perpendicular to the pavement layer) to enhance the shear resistance. In addition, the core area is rolled in a manner with progressively increasing load. The first pass applies 70% of the reference load, the second pass increases to 90%, and the final pass reaches more than 100% to ensure uniform compaction and no damage to the surrounding structure. The transition zone is first compacted radially twice, and then reinforced with three passes along the normal direction. The load is progressively increased in a gradient of 80%→90%→100% to enhance the connection with the surrounding pavement.

[0089] Meanwhile, in order to flexibly control the load, the initial load ratio in the radial and normal directions of the core area is 7:3, and the initial load ratio in the radial and normal directions of the transition area is 3:7.

[0090] For example, the initial radial load of the core area is 1.54 MPa, and the initial normal load is 0.66 MPa; the initial radial load of the transition area is 0.54 MPa, and the initial normal load is 1.26 MPa. By setting the load ratio, precise reinforcement of weak areas around the well can be achieved, while ensuring overall compaction uniformity.

[0091] In some embodiments, the pavement layer state data includes rebound values. In this case, the state data of the pavement layer after main compaction is obtained, and the compaction effect of the pavement layer is evaluated based on the pavement layer state data, including: measuring rebound values ​​at multiple preset measurement points in the core area and transition area using the drop hammer rebound method to obtain the rebound values ​​at multiple preset measurement points in the core area and transition area, and averaging the measured rebound values ​​to obtain the average rebound values ​​corresponding to the core area and transition area respectively; determining the rebound modulus corresponding to the core area and transition area respectively based on the average rebound values ​​corresponding to the core area and transition area respectively; performing weighted processing on the rebound modulus corresponding to the core area and transition area respectively to obtain the rebound modulus of the pavement layer; wherein the weight value of the core area is greater than the weight value of the transition area; determining the compaction degree of the pavement layer based on the rebound modulus of the pavement layer, combined with a preset standard rebound modulus and a preset compaction degree standard, and determining the actual compaction density of the pavement layer based on the compaction degree of the pavement layer and a preset compaction density standard; and evaluating the compaction effect of the pavement layer using the actual compaction density of the pavement layer.

[0092] Among them, the drop hammer rebound method uses a 2kg standard drop hammer to fall freely from a height of 50cm, records the rebound height after impacting the road surface, and calculates the average rebound value corresponding to the core area and the transition area by setting up 5 measuring points in the core area and 3 measuring points in the transition area.

[0093] The specific value of the rebound modulus is determined based on the corresponding fitting relationship between the rebound value and the elastic modulus. The calculation formula is: E=a 2 R+bR+c, where E is the elastic modulus, R is the rebound value, and a, b, and c are calibration coefficients (calibrated in the laboratory to be 0.15, 3.2, and 8.5, respectively).

[0094] The resilient modulus of the pavement layer is obtained by weighting the resilient moduli corresponding to the core area and the transition area, respectively. The core area has a weight of 0.7, and the transition area has a weight of 0.3. The weight of the core area is greater than that of the transition area, thus highlighting the dominant role of the core area in the overall structural stability. Finally, the weighted resilient modulus of the pavement layer is combined with a preset compaction standard, and an environmental modulus correction coefficient is introduced to obtain the compaction degree of the pavement layer:

[0095]

[0096] In the formula, K represents the compaction degree of the pavement layer. This is the weighted resilient modulus of the pavement layer. The preset standard resilience modulus (e.g., 1200MPa) is used, and k is the environmental temperature and humidity correction coefficient. Generally, k is 1.04 in winter, 0.95 in summer, and 1.00 in spring and autumn. The preset compaction standard (value is 98%).

[0097] Then, by combining the calculated compaction degree of the pavement layer with the preset compaction density standard, the actual compaction density of the pavement layer is determined as follows:

[0098]

[0099] In the formula, This represents the actual compaction density of the pavement layer. The preset compaction density standard (i.e., the standard density of asphalt mixture) is determined through indoor Marshall tests to obtain the maximum theoretical density or measured bulk density, such as a value of 2.3-2.4 g / cm³. 3 ).

[0100] In some embodiments, the pavement layer is further compacted based on the evaluation results of its compaction effect until the compaction effect reaches a preset compaction standard. This includes: comparing the actual compaction density of the pavement layer with the density difference of a preset compaction density standard; if the density difference is greater than or equal to a preset density difference threshold, the pavement layer is further compacted; in the current compaction stage, a roller applies static compaction to the core area with a load greater than one times the initial load when applying main pressure radially, and then applies static compaction to the transition area with a load greater than one times the initial load when applying main pressure in the normal direction; after completing the current compaction stage, the pavement layer's state data is reacquired, and the compaction effect of the pavement layer is evaluated based on the pavement layer's state data; if the evaluation result still does not meet the preset compaction standard, the compaction is repeated until two consecutive evaluation results meet the preset compaction standard.

[0101] The density difference is determined by the difference between the actual compacted density of the pavement layer and the preset compacted density standard. The preset density difference threshold can be set to 0.03 g / cm³. 3 When the density difference is greater than or equal to the threshold, the compaction procedure is initiated. During the compaction stage, to expedite the process and ensure effective compaction, load-enhanced compaction is performed in the dominant direction of each zone. Radial static pressure is applied to the core zone, and normal static pressure is applied to the transition zone. The load is 1.3 times or more than double that of the initial main compaction stage, and the number of compaction passes is increased by 1 to 2. After compaction, the rebound modulus and density data are re-collected. If the density difference in two consecutive test results is less than 0.03 g / cm³, the compaction is considered successful. 3If the compaction is successful, the compaction is deemed qualified, and the final compaction and shaping stage begins.

[0102] In some embodiments, the pavement layer is shaped and compacted to form a shaped pavement layer, including: vibrating the core area at least twice, statically compacting the transition area at least once, and then rolling the entire pavement layer.

[0103] The purpose of the final compaction is to achieve a dense and smooth road surface and eliminate wheel tracks. Final compaction involves at least two passes of vibratory compaction on the core area and at least one pass of static compaction on the transition area using a smooth-drum roller. The compaction speed is controlled at 3-5 km / h, and the temperature is not lower than 70℃. Then, a kneading compaction is performed on the entire road surface. This kneading compaction uses a reciprocating kneading device to perform low-amplitude, high-frequency kneading on the road surface, further densifying the surface and effectively eliminating wheel tracks, improving smoothness and skid resistance. The kneading frequency is controlled at 50-60Hz, and the single action time is not less than 2 seconds, ensuring that the asphalt concrete surface layer forms a uniform texture in its microstructure. After final compaction, the surface smoothness and compaction degree are promptly tested to ensure they meet design requirements, preventing shoving, cracking, and other defects during subsequent use, and ensuring the long-term durability and driving safety of the asphalt around manholes.

[0104] In some embodiments, the state data of the pavement layer after main compaction is obtained, and the compaction effect of the pavement layer is evaluated based on the state data of the pavement layer. Before this, the method further includes: after the main compaction of the pavement layer is completed, the pavement layer is subjected to an appearance quality inspection, the appearance quality inspection includes at least one of crack width, crack density and joint height difference; if the appearance quality inspection fails, the pavement layer is partially repaired until the appearance quality inspection passes.

[0105] Crack width refers to the maximum width of visible cracks on the surface of the pavement layer. Cracks are identified and measured using image acquisition. Crack density is the sum of crack lengths per unit area. Connection height difference refers to the height difference between the newly paved asphalt and the existing pavement or the surrounding structure of the manhole cover, which is detected using a laser scanner.

[0106] When the crack width is greater than 0.2 mm and the crack density exceeds 5 cm / m 2 If the height difference at the joint exceeds 3mm, the appearance quality inspection is deemed unsatisfactory. The area exceeding the standard needs to be milled or locally reinforced and compacted until all indicators meet the appearance benchmark requirements. After the repair is completed, a re-inspection should be conducted to ensure that the crack width is ≤0.2mm, the crack density is ≤5cm / m², and the height difference at the joint is ≤3mm.

[0107] In some embodiments, to further enhance the ability to maintain quality after construction, the method further includes: periodically detecting the apparent damage of the shaped pavement layer and making local repairs to the pavement layer based on the apparent damage.

[0108] The apparent damage refers to the distribution range and severity of apparent defects such as cracks, potholes, looseness, bleeding, and wheel tracks that appear on the pavement layer after construction. Based on the apparent damage and the location of the pavement layer, targeted repairs are carried out on the pavement layer, and stress concentration areas around the storm drain grates are reinforced.

[0109] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for compacting the mixture around a rainwater grate, characterized in that, include: The work area is delineated based on the location of the rainwater grate opening, and the base layer of the work area is cleaned and dehumidified; The pre-prepared asphalt mixture is spread on the base layer of the work area to form a road surface layer; The pavement layer is divided into a core zone and a transition zone from the center of the storm drain grate outlet outwards. Differentiated directional loads are applied to the core zone and the transition zone for initial and main compaction, respectively, including: The road surface layer is divided into a core area and a transition area from the center of the storm drain grate outlet outwards; Initial compaction stage: The road surface layer is statically compacted by a road roller, and then the statically compacted road surface layer is vibrated. Main compaction stage: The core area is compacted sequentially along the radial and normal directions of the core area by a road roller in a manner with progressively increasing load. Then, the transition area is compacted sequentially along the radial and normal directions of the transition area in a manner with progressively increasing load. Obtain the state data of the pavement layer after main compaction, and evaluate the compaction effect of the pavement layer based on the state data of the pavement layer; Based on the evaluation results of the compaction effect of the pavement layer, the pavement layer is further compacted until the compaction effect of the pavement layer reaches the preset compaction standard; After the compaction effect of the road surface layer reaches the preset compaction standard, the road surface layer is shaped and compacted to form a shaped road surface layer.

2. The method for compacting the mixture around a rainwater grate according to claim 1, characterized in that, The pre-prepared asphalt mixture includes a load-bearing layer mixture, a transition layer mixture, and a sealing layer mixture. The load-bearing layer mixture comprises, by weight, 5-6 parts asphalt, 4-5 parts polymer modifier, 0.4 parts high modulus agent, 1.3-1.8 parts steel fiber, 0.5-1 parts basalt fiber, 3-5 parts mineral powder, 60-65 parts basalt, 20-25 parts limestone, and 0.2-0.3 parts first additive. The first additive is a mixture of antioxidant and tackifier. The transition layer mixture comprises, by weight, 12-15 parts of polyurethane adhesive and 85-88 parts of aggregate skeleton, wherein the polyurethane adhesive comprises, by weight, 7-8 parts of polyether polyol, 5-6 parts of isocyanate, 0.1-0.2 parts of catalyst, 0.5-1 parts of toughening agent and 0.3-0.5 parts of silica filler; the aggregate skeleton comprises, by weight, 60-65 parts of graded crushed stone, 20-25 parts of stone chips, 5-8 parts of limestone mineral powder filler and 0.5-1 parts of chopped fiber; The sealing layer mixture comprises, by weight, 6-7 parts polymer-modified asphalt, 0.3-0.5 parts high-viscosity agent, 0.05-0.1 parts fiber stabilizer, 4-6 parts limestone, 50-55 parts basalt, 30-35 parts manufactured sand, and 0.2-0.3 parts second additive; wherein the second additive is a mixture of anti-stripping agent and ultraviolet absorber.

3. The method for compacting the mixture around the rainwater grate according to claim 2, characterized in that, The step of spreading the pre-prepared asphalt mixture onto the base layer of the work area to form a road surface layer includes: The load-bearing layer mixture, the transition layer mixture, and the sealing layer mixture are sequentially spread on the base layer of the work area, and each layer is coated with a pre-prepared interface treatment agent; wherein, the pre-prepared interface treatment agent comprises, by weight, 3-4 parts of thermoplastic elastomer, 0.5-1 parts of silane coupling agent, 1-2 parts of tackifying resin, 3-4 parts of diluent, and 0.1-0.2 parts of stabilizer.

4. The method for compacting the mixture around a rainwater grate according to claim 1, characterized in that, The initial load ratio between the radial and normal directions of the core area is 7:3, and the initial load ratio between the radial and normal directions of the transition area is 3:

7.

5. The method for compacting the mixture around a rainwater grate according to claim 1, characterized in that, The condition data of the pavement layer includes rebound values; The process of acquiring the state data of the pavement layer after main compaction and evaluating the compaction effect of the pavement layer based on the state data includes: The rebound value is measured at multiple preset measurement points on the core area and the transition area using the drop hammer rebound method. The rebound values ​​at multiple preset measurement points on the core area and the transition area are obtained, and the measured rebound values ​​are averaged to obtain the average rebound value corresponding to the core area and the transition area respectively. Based on the average rebound values ​​corresponding to the core area and the transition area respectively, determine the rebound modulus corresponding to the core area and the transition area respectively; The resilient modulus of the pavement layer is obtained by weighting the resilient modulus corresponding to the core area and the transition area respectively; wherein the weight value of the core area is greater than the weight value of the transition area. Based on the resilient modulus of the pavement layer, combined with the preset standard resilient modulus and the preset compaction standard, the compaction degree of the pavement layer is determined, and based on the compaction degree of the pavement layer and the preset compaction density standard, the actual compaction density of the pavement layer is determined. The compaction effect of the pavement layer is evaluated using the actual compaction density of the pavement layer.

6. The method for compacting the mixture around a rainwater grate according to claim 5, characterized in that, The step of further compacting the pavement layer based on the evaluation results of the compaction effect of the pavement layer until the compaction effect of the pavement layer reaches the preset compaction standard includes: Compare the actual compaction density of the pavement layer with the density difference of the preset compaction density standard. If the density difference is greater than or equal to the preset density difference threshold, then the pavement layer is compacted. In the current compaction stage, the core area is statically compacted with a load more than one times the initial load when the main pressure is applied radially, and then the transition area is statically compacted with a load more than one times the initial load when the main pressure is applied in the normal direction. After completing the current compaction stage, the state data of the pavement layer is reacquired, and the compaction effect of the pavement layer is evaluated based on the state data. If the evaluation result still does not meet the preset compaction standard, the compaction is repeated until the preset compaction standard is met in two consecutive evaluations.

7. The method for compacting the mixture around a rainwater grate according to claim 1, characterized in that, The step of shaping and compacting the pavement layer to form a shaped pavement layer includes: The core area is subjected to at least two rounds of vibratory compaction, the transition area is subjected to at least one round of static compaction, and the entire surface layer is subjected to kneading compaction.

8. The method for compacting the mixture around a rainwater grate according to claim 1, characterized in that, The step of acquiring the state data of the pavement layer after main compaction and evaluating the compaction effect of the pavement layer based on the state data of the pavement layer also includes: After the main compaction of the pavement layer is completed, the pavement layer is subjected to an appearance quality inspection. The appearance quality inspection includes at least one of the following: crack width, crack density, and joint height difference. If the appearance quality inspection fails, the pavement layer shall be partially repaired until the appearance quality inspection passes.

9. The method for compacting the mixture around a rainwater grate according to claim 1, characterized in that, Also includes: The apparent damage of the shaped pavement layer is periodically inspected, and the pavement layer is locally repaired according to the apparent damage.

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