Setting method for curb ramp zero-height difference reconstruction and road surface durability improvement

Abstract

This invention relates to the field of municipal engineering technology and discloses a method for improving the durability of curb ramps with zero elevation difference. The specific implementation stages are as follows: Stage 1: Precise demolition and foundation treatment; Stage 2: Fine aggregate concrete pouring; Stage 3: Laying of spiral-wound spring pipes; Stage 4: Asphalt concrete surface paving. This invention addresses the zero elevation difference reconstruction of curb ramps at urban road intersections. Within a limited space of 300mm width and only 100-120mm thickness, it systematically solves the three major technical problems faced by the reconstructed road surface: insufficient base strength, insufficient surface layer strength, and interlayer water leakage through scientific design and innovative technical means. It is scientific, reasonable, and economical, significantly improving the overall durability and service life of asphalt concrete pavement. The use of spiral-wound spring pipes ensures the surface layer strength while forming a channel around the pipe material in the asphalt concrete layer to collect and discharge seepage water.

Description

Technical Field

[0001] This invention relates to the field of municipal engineering technology, specifically to a method for improving road surface durability through zero-elevation modification of curb ramps. Background Technology

[0002] Currently, in accordance with the requirement of zero height difference for curb ramps, the existing curb ramps in important areas and key road sections are being rectified according to the current specifications. At present, the renovation of zero height difference curb ramps at municipal road intersections generally involves directly laying asphalt concrete on the top surface of the curb to fill the height difference. However, the renovation of zero height difference curb ramps at road intersections needs to strive for scientific and economical approaches to improve the durability of asphalt concrete pavement. Currently, the direct laying of asphalt concrete has revealed issues with the interlayer bond failure law and shear failure mode of asphalt concrete in the 0-30mm thickness range, and it is also impossible to simultaneously meet the structural strength and drainage requirements within a 100mm thickness. Current technology directly uses asphalt concrete for overlay, filling the height difference with asphalt concrete. The minimum thickness of asphalt concrete is 0, and the maximum thickness is generally only 30mm. It is prone to peeling and detachment, which does not meet the requirements of standard construction. Moreover, in the current zero-height-difference reconstruction of curb ramps, it is impossible to solve the problems of insufficient base load-bearing capacity, thin asphalt surface layer that is easy to peel off, and reduced durability caused by water accumulation between layers in the limited space of no more than 320mm in width and no more than 120mm in thickness through layered structure design and functional material composite. This can easily lead to the problem of insufficient base strength, insufficient surface strength, and water leakage between layers after reconstruction. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a method for improving the durability of curb ramps with zero elevation difference. This method solves the problem of current technologies that directly use asphalt concrete overlays to fill the elevation difference. However, the minimum thickness of asphalt concrete is 0 mm, and the maximum thickness is generally only 30 mm, making it prone to peeling and detachment, failing to meet the requirements of standard construction. Furthermore, current methods for curb ramp zero elevation difference reconstruction cannot simultaneously address the issues of insufficient base course bearing capacity, thin asphalt surface layer prone to peeling, and reduced durability due to water accumulation between layers within a limited space of no more than 320 mm in width and no more than 120 mm in thickness. This often results in the reconstructed pavement facing problems such as insufficient base course strength, insufficient surface layer strength, and water leakage between layers.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a method for improving the durability of a curb ramp by modifying it to a zero-height-difference structure. The modification is carried out in four stages. Zero height difference refers to a height difference of 0-5mm between the ramp and the roadway surface. First, the existing curb structure is removed through a fine-grained demolition operation. Then, high-strength fine-aggregate concrete is poured to form a reliable base structure. Next, spiral-wound wire-reinforced spring pipes are laid to achieve the dual functions of drainage channels and structural reinforcement. The spiral-wound wire-reinforced spring pipes form lateral drainage channels and bear vertical loads. Finally, a fine-grained modified asphalt concrete surface layer is laid to form a complete road structure. The fine-aggregate concrete base layer and the asphalt concrete surface layer work together to form a zero-height-difference road structure. The spiral-wound wire-reinforced spring pipes are placed between the two layers and connected to the rainwater inlet. The specific implementation phases of the renovation are as follows: Phase 1: Precise removal and basic treatment; Second stage: Fine aggregate concrete pouring; Phase 3: Laying of spiral-wound spring tubes; Phase 4: Asphalt concrete surface layer paving; In the precise demolition and foundation treatment stage, measurement and layout are carried out, while cutting and demolition are performed, and the foundation is cleaned and concrete is prepared. During the fine aggregate concrete pouring stage, while leveling and pouring, curing and strength monitoring are carried out. The strength grade of fine aggregate concrete should not be lower than C30, and the thickness should be 50-70mm. During the laying stage of the spiral-wound spring tube, the spiral-wound spring tube is customized and its layout scheme is simulated so that the spiral-wound spring tube is laid according to the optimized layout scheme. Finally, its end is connected to the rainwater inlet and sealed. During the asphalt concrete pavement stage, tack coat is applied and modified asphalt concrete is prepared, while paving and compaction are carried out simultaneously, and long-term monitoring is conducted after the road is opened to traffic.

[0005] As a preferred technical solution of the present invention, the precise breaking and basic processing stage includes the following implementation steps: Step 11, Digital Measurement and Precise Layout; Step 12, Silent cutting and fine breaking; Step 13, substrate refinement; Step 14: Prepare high-strength, fast-hardening concrete.

[0006] As a preferred technical solution of the present invention, in step 11, a three-dimensional laser scanner is used to perform a comprehensive scan of the intersection curb ramp, accurately identify the location, size and elevation information of the curb, calculate the specific range to be removed, determine the removal width X, removal thickness Y and removal length Z, and accurately locate and lay out according to the range, and mark the removal boundary line. The breaking width X is determined based on the actual width of the curbstone, ranging from 280 to 320 mm; the breaking thickness Y is determined based on the actual thickness of the curbstone, ranging from 70 to 110 mm; and the breaking length Z is determined based on the actual length of the curbstone, ranging from 600 to 1000 mm. Step 12: Move the cutting equipment along the breaking boundary line to cut, and set up rubber isolation pads to achieve sound insulation. After cutting, use a small hydraulic breaker to break it up. Step 13: Use a high-pressure water gun to rinse the base of the demolition area. For loose mortar layers in the base, use a small milling machine for fine milling and use a roughness measuring instrument to detect the roughness of the base. For base areas with cracks, low-viscosity epoxy resin is required for grouting. After the base treatment and before pouring, the base is pre-wetted with water spraying equipment, and then moistened again 2 hours before pouring. A special concrete interface agent is then applied to the base. Step 14: The main materials include cement, coarse aggregate and fine aggregate. The cement is ordinary Portland cement, the coarse aggregate is continuous graded crushed stone with a particle size of 5-10mm, the fine aggregate is medium and coarse sand, and polycarboxylate high-performance water-reducing agent is added.

[0007] As a preferred embodiment of the present invention, the fine aggregate concrete pouring stage includes the following steps: Step 21, three-dimensional leveling and precise pouring; Step 22, Intelligent Maintenance and Intensity Monitoring; Step 21: Before pouring, the paving thickness H1 of the fine aggregate concrete needs to be calculated and determined. When calculating the paving thickness H1, the breaking thickness Y and the actual total thickness H (total) on site need to be measured. H1 (min) needs to meet the strength requirements and geometric filling requirements. Based on the calculated dimensions, a three-dimensional model of the pouring area is created using BIM software. The model is then output to a 3D printing device to produce a personalized leveling screed. An ultrasonic thickness sensor is installed on the template to monitor the concrete pouring thickness in real time. A variable frequency high-frequency vibrator is used for vibration treatment. After vibration, a power trowel is used to finish the surface, and a manual scraper is used for fine leveling. Step 22: After pouring, cover with plastic film to retain water, and then cover the film with geotextile for insulation. Simultaneously, temperature and maturity sensors are pre-embedded inside the concrete. The curing parameters are automatically adjusted based on the data collected by the sensors. Specifically, the equivalent age of the concrete is calculated in real time according to the maturity method to predict the current strength value. Once the predicted strength value reaches the design requirements, a notification is sent to proceed to the next process.

[0008] As a preferred technical solution of the present invention, the following implementation steps are included in the spiral-wound spring tube laying stage: Step 31, Customized processing and pretreatment; Step 32: CFD simulation to optimize the layout; Step 33, precise positioning and laying; Step 34, end connection and sealing treatment.

[0009] As a preferred technical solution of the present invention, in step 31, the specifications of the spiral-wound spring tube need to be calculated before processing. The inner diameter of the spiral-wound spring tube is not less than 30mm, the diameter of the spring wire is not less than 2.5mm, and the gap between the spring wires is 2mm. The specifications include the number of spiral-wound spring tubes S, the inner diameter d of the spiral-wound spring tube, the length L of the spiral-wound spring tube, and the compressive strength σ of the spiral-wound spring tube. The number of spiral-wound spring tubes S needs to take into account the catchment area of ​​the intersection, the road width, and the drainage distance. The number of spiral-wound spring tubes S is directly related to the reliability and service life of the drainage system. The number of spiral-wound spring tubes S is limited to 2-3 tubes. In actual processing, alloy square steel is used to make spiral wound spring tubes, and square wire is used for the spring wire. The spring wire is continuously wound and formed using a special spring coiling machine, and the pitch accuracy is controlled within ±0.2mm.

[0010] As a preferred technical solution of the present invention, step 32 involves establishing a three-dimensional CAD model of the intersection, marking the road slope, the location of the storm drain, and the water catchment boundary, using CFD software to simulate the surface runoff under different return periods of rainstorms, analyzing the flow direction, velocity distribution, and water accumulation area, and designing an optimized layout scheme for the spiral-wound spring tube based on the simulation results. Step 33: Pop up bidirectional control lines on the surface of fine stone concrete. The spacing of the control lines is evenly distributed according to the number of spiral wire-wound spring tubes. Set up a laser line projector at the intersection of the control lines and use the laser plane as the reference plane. Cut the spiral wire-wound spring tubes to the designed length and lay them one by one according to the designed position. Step 34: Drill holes in the side wall of the rainwater inlet, connect the end of the spiral-wound spring tube to the rainwater inlet using a special connector, and install a self-expanding rubber sealing ring at the interface. For the end that cannot be connected to the rainwater inlet, use wire wrapping to seal it.

[0011] As a preferred embodiment of the present invention, the asphalt concrete pavement stage includes the following implementation steps: Step 41, apply tack coat; Step 42, preparation of modified asphalt concrete; Step 43, 3D paving control; Step 44, Intelligent compaction control; Step 45: Open traffic and conduct long-term monitoring.

[0012] As a preferred technical solution of the present invention, in step 41, a cleaning machine is used to remove the floating dust and debris on the surface of fine stone concrete. The tack coat oil is made of SBS modified emulsified asphalt and is evenly sprayed by a sprayer. At the same time, a fluorescent tracer is added to the tack coat oil. Based on the fluorescent tracer detection, the uniformity of the tack coat oil distribution is detected by ultraviolet light irradiation. Step 42: SBS modified asphalt is used as the asphalt, basalt is used as the aggregate, AC-13C type gradation is used, and warm mix agent is added to reduce the discharge temperature. Before asphalt paving, it is necessary to calculate the paving thickness H2 of the modified asphalt concrete. The determination of the paving thickness H2 needs to take into account both the structural design specifications of asphalt pavement and the actual construction feasibility.

[0013] As a preferred technical solution of the present invention, in step 43, elevation points are measured on the surface of the spiral-wound spring tube and the surface of the fine stone concrete to establish a three-dimensional model of the paving reference surface, and the reference surface data is input into the 3D control system of the paver. The paver is a tracked automatic leveling paver. At the same time, multiple infrared temperature measurement points are set up to monitor the paving temperature distribution in real time. When the temperature in a certain place is lower than the lower limit, an automatic warning is issued and the paving process is adjusted in time. Step 44 includes three stages of compaction: initial compaction, intermediate compaction, and final compaction. The initial compaction is performed using a double-drum vibratory roller, the intermediate compaction is performed using a pneumatic tire roller, and the final compaction is performed using a double-drum roller. By installing GPS positioning systems, vibration sensors, and temperature sensors on the road roller, parameter data can be collected in real time and uploaded to the monitoring system to achieve visualization of the compaction trajectory; The compaction degree is detected in real time using a nucleus-free density meter, and the number of rolling passes is dynamically adjusted. Once the compaction degree meets the standard, the next area is entered. Step 45: After compaction, traffic can only be opened after the asphalt concrete temperature drops below 50°C. After traffic is opened, IoT sensors are pre-embedded inside the road surface to monitor road parameters in real time, enabling long-term tracking and predictive maintenance of road performance.

[0014] Compared with the prior art, the present invention provides a method for improving the road surface durability by modifying curb ramps to have zero elevation difference, which has the following beneficial effects: 1. This invention, within a space of 300mm width and only 100-120mm thickness, solves three major technical problems faced by the reconstructed road surface: insufficient base layer strength, insufficient surface layer strength, and water seepage between layers, through scientific design and innovative technical means. It significantly improves the overall durability and service life of asphalt concrete pavement. It is used for the humanized reconstruction of curb ramps in urban roads, and uses spiral-wound spring tubes to solve the strength and drainage problems of zero-height-difference reconstruction of curb ramps at road intersections. It is economical and scientifically sound. First, the existing curbstone structure is removed through meticulous demolition work. Then, high-strength fine aggregate concrete is poured to form a reliable base structure. Next, spiral wire-wound spring tubes are laid to achieve the dual functions of drainage channels and structural reinforcement. Finally, a fine-grained modified asphalt concrete surface layer is laid to form a complete road structure. Together, they constitute a complete technical system to improve pavement durability. The spring tubes, as elastic skeletons, act as stress dispersion paths under vehicle loads, transforming concentrated loads into distributed loads that are transferred to the base layer. The capillary water conduction mechanism and siphon drainage mechanism of the spiral gaps, along with the mechanical interlocking and chemical bonding between the fine aggregate concrete and the asphalt surface layer through the galvanized layer on the surface of the spring tubes, achieve a three-layer collaborative working mechanism of fine aggregate concrete base, spiral wire-wound spring tubes, and asphalt surface layer.

[0015] 2. This invention replaces the traditional method of directly overlaying asphalt concrete, ensuring that the minimum thickness of the asphalt concrete is more than 50mm, meeting the specifications. After removing the original curb stones, C40 fine stone concrete is poured, and the thickness can reach more than 50mm, thus improving the strength of the road base. By using alloy square steel with strong rust resistance and extremely high compressive strength to make spiral-wound spring pipes, and then galvanizing the alloy square steel after treatment, acid and alkali corrosion can be effectively prevented. The spiral structure ensures that the pipe can withstand vehicle pressure, guaranteeing the surface strength. The spiral-wound spring pipe can be bent at will, making it convenient to lay, cut and connect during construction. It is suitable for the planar alignment of intersection curb ramps. At the same time, the spring of the spiral-wound spring pipe forms a channel space, and water can also seep between the pitches. The outer wrapping wire ensures that it will not be blocked. Utilizing capillary action and the siphon principle, it has water permeability and reverse filtration effect, forming a channel around the pipe in the asphalt concrete layer to collect and discharge seepage water.

[0016] In summary, this invention addresses the zero-elevation-difference reconstruction of curb ramps at urban road intersections. Within a limited space of 300mm width and only 100-120mm thickness, it systematically solves three major technical problems faced by the reconstructed road surface: insufficient base layer strength, insufficient surface layer strength, and interlayer water leakage through scientific design and innovative technical means. It is scientifically sound, economical, and significantly improves the overall durability and service life of asphalt concrete pavements. Attached Figure Description

[0017] Figure 1 This is a flowchart of the setting method of the present invention.

[0018] Figure 2 This is a cross-sectional view of the present invention.

[0019] Figure 3 This is a schematic diagram of the intersection of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. However, it should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0021] In the description of this invention, it should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to or indirectly connected to the other element.

[0022] In the description of this invention, it should be noted that the terms "center," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. "Several" means one or more, unless otherwise explicitly specified.

[0023] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0024] Example: Please refer to Figure 1-3This invention provides the following technical solution: a method for improving the durability of a road surface by modifying a curb ramp with zero elevation difference. The modification is carried out in four stages. First, the existing curb structure is removed through a fine-grained demolition operation. The standard size of the curb is 300mm wide × 100-120mm thick. Then, high-strength fine stone concrete is poured to form a reliable base structure. Next, spiral-wound wire spring pipes are laid to achieve the dual functions of drainage channels and structural reinforcement. The spiral-wound wire spring pipes form lateral drainage channels and bear vertical loads. The spiral-wound wire spring pipes are tubular structures formed by spirally winding rectangular cross-section spring steel wires with a pitch of 2mm to form water seepage gaps. The overall shape is a cylindrical spiral spring. Finally, a fine-grained modified asphalt concrete surface layer is laid to form a complete road structure. The fine stone concrete base layer and the asphalt concrete surface layer work together to form a zero elevation difference road structure. The spiral-wound wire spring pipes are placed between the two layers and connected to the rainwater inlet. The specific implementation phases of the renovation are as follows: Phase 1: Precise removal and basic treatment; Second stage: Fine aggregate concrete pouring; Phase 3: Laying of spiral-wound spring tubes; Phase 4: Asphalt concrete surface layer paving; In the precise demolition and foundation treatment stage, measurement and layout are carried out, while cutting and demolition are performed, and the foundation is cleaned and concrete is prepared. During the fine aggregate concrete pouring stage, while leveling and pouring, curing and strength monitoring are carried out. The strength grade of fine aggregate concrete should not be lower than C30, and the thickness should be 50-70mm. During the laying stage of the spiral-wound spring pipe, the spiral-wound spring pipe is customized and processed. The spiral-wound spring pipe is a spiral-wound permeable spring steel pipe. The layout scheme is simulated so that the spiral-wound spring pipe is laid according to the optimized layout scheme. Finally, the end of the pipe is connected to the rainwater inlet and sealed. During the asphalt concrete pavement stage, tack coat is applied and modified asphalt concrete is prepared, while paving and compaction are carried out simultaneously, and long-term monitoring is conducted after the road is opened to traffic. In the specific implementation of the renovation, parametric calculation is used to accurately calculate and optimize the thickness of each pavement layer. Spiral-wound spring tubes are used to simultaneously address the two major functional requirements of drainage and reinforcement, ensuring the bearing strength of the surface layer while solving the problem of water infiltration between layers and pore water. Digital construction technology is introduced to improve construction accuracy and quality stability, and process monitoring technology is used to achieve long-term tracking and predictive maintenance of pavement performance.

[0025] The precise removal and basic processing phase includes the following implementation steps: Step 11, Digital Measurement and Precise Layout; Step 12, Silent cutting and fine breaking; Step 13, substrate refinement; Step 14: Prepare high-strength, fast-hardening concrete.

[0026] Step 11: Use a 3D laser scanner to perform a comprehensive scan of the intersection curb ramp, accurately identify the location, size and elevation information of the curb, calculate the specific area to be removed, determine the removal width X, removal thickness Y and removal length Z, and accurately locate and lay out according to the area, and mark the removal boundary line. The demolition width X is the transverse demolition range along the road; the demolition thickness Y is the original curbstone thickness; and the demolition length Z is the longitudinal demolition range along the road. The demolition width X is determined based on the actual width measurement of the curbstone, with a baseline value of 300mm and a range of 280-320mm. The demolition thickness Y is determined based on the actual thickness measurement of the curbstone, with a range of 70-110mm. The demolition length Z is determined based on the actual length measurement of the curbstone, with a range of 600-1000mm. Step 12: Move the cutting equipment along the breaking boundary line to cut, and set up rubber isolation pads to achieve sound insulation. The cutting equipment is a water jet cutting equipment. After the cutting is completed, a small hydraulic breaker is used for breaking. Step 13: Use a high-pressure water gun to flush the base of the demolition area. For loose mortar layers in the base, use a small milling machine for fine milling and use a roughness measuring instrument to detect the roughness of the base and measure the Ra value to ensure that Ra=1.5-3.0mm. For base areas with cracks, low-viscosity epoxy resin is required for grouting. Before pouring, the base is pre-wetted with water spraying equipment and then moistened again 2 hours before pouring to ensure that the base is saturated and surface-dry. A special concrete interface agent is then applied to the base, and an acrylic modified cement-based material is selected as the interface agent to improve the interlayer bonding effect. Step 14: The main materials include cement, coarse aggregate and fine aggregate. Ordinary Portland cement is selected for cement, continuous graded crushed stone with a particle size of 5-10mm is selected for coarse aggregate, and medium-coarse sand is selected for fine aggregate. It also incorporates polycarboxylate high-performance water-reducing agent, with a water reduction rate of ≥25%, and has early strength function, significantly accelerating the cement hydration reaction. The water-cement ratio of the concrete is ≤0.35, and the slump is 80-120mm. It can be used to formulate C40 fine aggregate concrete with early strength and fast hardening characteristics, which can significantly shorten the curing time from the traditional 7 days to 2-3 days, greatly reducing the impact of construction on traffic.

[0027] The following steps are included in the fine aggregate concrete pouring stage: Step 21, three-dimensional leveling and precise pouring; Step 22, Intelligent Maintenance and Intensity Monitoring; Step 21: Before pouring, the paving thickness H1 of the fine aggregate concrete needs to be calculated and determined, in mm, and should not be less than 50 mm. When calculating the paving thickness H1, the demolition thickness Y and the actual total thickness H (total) on site need to be measured. Then, H1 (min) is calculated. H1 (min) must meet the strength requirements and geometric filling requirements. The fine aggregate concrete needs to fill at least half the thickness of the original curbstone to achieve structural transition, while reserving necessary safety margins to ensure interlayer bonding and overall stability. The formula is as follows: H1(min) = Y / 2 + ΔH; Where H1(min) represents the minimum paving thickness of fine aggregate concrete (mm), Y represents the breaking thickness, ΔH represents the safety increment, and ΔH is 20mm. In actual engineering projects, the paving thickness H1 of fine aggregate concrete needs to be comprehensively determined based on the actual total thickness on site, ensuring that the fine aggregate concrete thickness simultaneously meets three conditions: the minimum thickness of 50mm specified in the specifications, the calculated value based on the original curb thickness, and the remaining space after deducting the thickness of the asphalt concrete. H1=max(50,Y / 2+20,H(total)-H2); Where H1 represents the paving thickness of fine aggregate concrete (mm), H(total) represents the actual total thickness on site (mm), which is determined by on-site measurement, and H2 represents the paving thickness of fine-grained modified asphalt concrete (mm). Considering the impact of the width-to-thickness ratio of the breached area on the overall structural strength, a strength correction factor K1 is introduced for correction: K1=1.0+0.05×(X / 300-1)+0.03×(Z / 800-1); H1(adjusted) = H1 × K1; Wherein, K1 represents the dimensionless strength correction coefficient, X represents the breaking width (mm), with a reference value of 300, and Z represents the breaking length (mm), with a reference value of 800; When the demolition width is greater than the reference value, the increased width-to-thickness ratio leads to unfavorable stress distribution, requiring an increase in the thickness of the fine aggregate concrete. When the demolition length is greater than the reference value, the increased length-to-width ratio also requires an increase in thickness to resist bending stress. Based on the calculated dimensions, a three-dimensional model of the pouring area is created using BIM software and output to a 3D printing device to produce a personalized leveling screed. The leveling screed is customized according to the special shape of the area to be broken, and can complete the leveling operation of the entire area in one go. An ultrasonic thickness sensor is installed on the template to monitor the concrete pouring thickness in real time. A variable frequency high-frequency vibrator is used for vibration treatment. After vibration, a power trowel is used to finish the surface, and a manual scraper is used for fine leveling. Step 22: After pouring, cover with plastic film to retain water, and then cover the film with geotextile for insulation. Simultaneously, temperature and maturity sensors are pre-embedded inside the concrete. The curing parameters are automatically adjusted based on the data collected by the sensors. Specifically, the equivalent age of the concrete is calculated in real time according to the maturity method to predict the current strength value. Once the predicted strength value reaches the design requirements, a notification is sent to proceed to the next process. The curing time is shortened by 20%-30% compared to traditional methods, avoiding quality defects such as temperature cracks.

[0028] The equivalent age of the maturity method is te = Σ(Δt × exp[13.65 - 4000 / (273 + T)]), where Δt is the time interval and T is the concrete temperature in °C. The following steps are included in the laying stage of spiral-wound spring tubes: Step 31, Customized processing and pretreatment; Step 32: CFD simulation to optimize the layout; Step 33, precise positioning and laying; Step 34, end connection and sealing treatment.

[0029] Step 31: Before processing, it is necessary to calculate the specifications of the spiral-wound spring tube. The inner diameter of the spiral-wound spring tube should not be less than 30mm, the spring wire diameter should not be less than 2.5mm, and the spring wire gap should be 2mm. The specifications include the number of spiral-wound spring tubes S, the inner diameter d, the length L, and the compressive strength σ. The number of spiral-wound spring tubes S needs to take into account the catchment area of ​​the intersection, the road width, and the drainage distance. The number of spiral-wound spring tubes S is directly related to the reliability and service life of the drainage system. The number of spiral-wound spring tubes S is limited to 2 tubes. When calculating the quantity S of spiral-wound spring tubes, the quantity of spiral-wound spring tube foundations is first determined based on the road width: S(base) = 2 + floor((W-6) / 4); Where S(base) represents the number of spiral wound spring tube foundations (units), W represents the road width (meters), and floor represents the floor function; The standard two-way four-lane road is about 15 meters wide and is equipped with two spiral-wound spring pipes as a basic configuration. As the road width increases, one more spiral-wound spring pipe is added for every 4 meters of width increase to meet the increased drainage capacity requirements. The final determination of the number S of spiral-wound spring tubes needs to take into account the catchment area correction: S=max{2,min[3,S(base)+S(water)]}; Where S represents the final number of spiral-wound spring tubes (units), and S(water) represents the catchment area correction value; Calculation of catchment area correction value: When the catchment area A is less than or equal to 200 square meters, S(water) equals 0; when the catchment area A is between 200 and 500 square meters, S(water) equals 1; when the catchment area A is greater than 500 square meters, S(water) equals 2. A larger catchment area means a larger drainage demand, requiring a corresponding increase in the number of spiral-wound spring tubes to ensure that the drainage capacity matches the catchment volume. Determining the inner diameter d of a spiral-wound spring tube requires consideration of quantity and width factors: d=30+5×(S-2)+2×((X-300) / 100); Where d represents the inner diameter of the spiral wound spring tube (mm), S represents the number of spiral wound spring tubes (pieces), and X represents the breaking width (mm). When the number of spiral-wound spring tubes increases, the drainage volume of each tube decreases, so the pipe diameter can be appropriately reduced. When the width of the tube increases, a larger drainage cross-section is required, so the pipe diameter should be appropriately increased. The length L of the spiral-wound spring tube needs to be determined based on the breaking length and the requirements of the connecting section: L = Z + 2 × L(connector); Where L represents the effective length of the spiral-wound spring tube (mm), Z represents the breaking length (mm), and L(connector) represents the length of the connecting section (mm), with a value of 50-100mm, to ensure that the spiral-wound spring tube can completely cover the breaking area and reserve sufficient connection length to achieve a reliable connection with the rainwater inlet or the sealing end; The compressive strength σ of the helical wire-wound spring tube ensures its structural safety under vehicle loads. σ(max) = (P × D) / (2 × δ × n); Where σ(max) represents the maximum calculated compressive strength (MPa), P represents the vehicle wheel pressure (MPa), with a value of 0.7-1.1, depending on the vehicle type and load level, D represents the outer diameter of the spiral-wound spring tube (mm), δ represents the spring wire diameter (mm), and n represents the safety factor, with a value of 1.5-2.0, to ensure that the stress of the spiral-wound spring tube under the design load does not exceed the allowable strength of the material, thus ensuring structural safety; After the specifications of the spiral-wound spring tube were determined, the actual processing involved using alloy square steel to manufacture the spiral-wound spring tube. The alloy square steel was sandblasted to remove rust, was of Sa2.5 grade, treated with phosphate primer, and then hot-dip galvanized with a zinc layer thickness ≥65μm. The spring wire was made of square wire and spring steel with a yield strength of not less than 350MPa. It was continuously wound and formed using a special spring coiling machine, with the pitch accuracy controlled within ±0.2mm.

[0030] Step 32: Establish a 3D CAD model of the intersection, mark the road slope, the location of the storm drain, and the water catchment boundary. Use CFD software to simulate the surface runoff under different return period rainstorm conditions, analyze the flow direction, velocity distribution and water accumulation area. Based on the simulation results, design an optimized layout scheme for the spiral-wound spring pipes, including pipe location, spacing setting and longitudinal slope control, so as to accurately calculate the layout position of each spiral-wound spring pipe and improve the reliability of the drainage system. Step 33: Pop up bidirectional control lines on the surface of fine stone concrete. The spacing of the control lines is evenly distributed according to the number of spiral wire-wound spring tubes. Set up a laser line projector at the intersection of the control lines and use the laser plane as the reference plane. Cut the spiral wire-wound spring tubes to the designed length and lay them one by one according to the designed position. Fix them with pipe clamps to ensure that both ends of the spiral wire-wound spring tubes face the direction of the rainwater inlet. Step 34: Drill holes in the side wall of the rainwater inlet and connect the end of the spiral wire-wound spring tube to the rainwater inlet using a special connector. The special connector is a stainless steel clamp connector with a built-in double-lip self-expanding rubber sealing ring. Install the self-expanding rubber sealing ring at the interface. For the end that cannot be connected to the rainwater inlet, use wire wrapping to seal it.

[0031] The asphalt concrete pavement stage includes the following steps: Step 41, apply tack coat; Step 42, preparation of modified asphalt concrete; Step 43, 3D paving control; Step 44, Intelligent compaction control; Step 45: Open traffic and conduct long-term monitoring.

[0032] Step 41: Use a cleaning machine to remove dust and debris from the surface of fine stone concrete. Use SBS modified emulsified asphalt as the tack coat and spread it evenly using a sprayer. At the same time, add a fluorescent tracer to the tack coat at a rate of 0.1%. Based on the fluorescent tracer detection, use ultraviolet light to detect the uniformity of the tack coat distribution to achieve quality inspection and defect diagnosis. Step 42: SBS modified asphalt is used as the asphalt, basalt is used as the aggregate, AC-13C type gradation is used, asphalt-aggregate ratio is 4.8%-5.2%, target void ratio is 4%-5%, and emulsified warm mix agent is added to reduce the discharge temperature by 20-30℃. Before asphalt paving, the paving thickness H2 of the modified asphalt concrete needs to be calculated. H2 is in mm and should not be less than 50 mm. The determination of the paving thickness H2 needs to consider both the structural design specifications for asphalt pavements and the actual construction feasibility. AC-13C type fine-grained modified asphalt concrete is widely used in road surface layers due to its good skid resistance, water tightness, and durability. The specific calculation is as follows: The minimum paving thickness H2 (min) of asphalt concrete is calculated based on the original curb thickness and the minimum construction thickness requirement of asphalt concrete. The minimum thickness of asphalt concrete should be adjusted appropriately according to changes in the original curb thickness, based on the 50mm specified in the standard. When the original curb thickness is greater than the benchmark value of 90mm, it means that the required leveling height difference is greater, and the minimum thickness of asphalt concrete should be increased accordingly. H2(min) = 50 + 0.1 × (Y - 90); Where H2(min) represents the minimum paving thickness of asphalt concrete (mm), Y represents the demolition thickness (mm), and the benchmark value is 90; The final determination of the asphalt concrete paving thickness needs to take into account the width factor: H2 = max(50, H2(min), X / 6); Where H2 represents the paving thickness of fine-grained modified asphalt concrete (mm), X represents the breaking width (mm), and the benchmark value is 300; Ensure that the thickness of asphalt concrete meets three conditions simultaneously: the minimum thickness of 50mm specified in the standard, the calculated value based on the original curb thickness, and the empirically calculated value based on the width; To ensure the overall performance of the surface layer, a performance optimization factor K2 needs to be introduced. Wider failure zones require thicker surface layers to resist the bending and tensile stresses generated by vehicle loads; longer failure zones also require appropriately increased surface layer thickness to improve overall stiffness. K2=1.0+0.02×(X / 300)+0.01×(Z / 800); H2(optimized) = H2 × K2; Wherein, K2 represents the dimensionless surface layer performance optimization coefficient; Step 43: Measure elevation points on the surface of the spiral-wound spring tube and the fine stone concrete surface to establish a three-dimensional model of the paving reference surface. Input the reference surface data into the 3D control system of the paver. The paver adopts a tracked automatic leveling paver, which automatically calculates the target height of the screed. The paving temperature is strictly controlled at 160-175℃ and the paving speed is 2-3m / min. At the same time, multiple infrared temperature measurement points are set up to monitor the paving temperature distribution in real time. When the temperature in a certain place is lower than the lower limit, an automatic warning is issued and the paving process is adjusted in time. Step 44 includes three stages of compaction: initial compaction, intermediate compaction, and final compaction. The initial compaction uses a double-drum vibratory roller with a compaction temperature of 150-140℃ and 2-3 passes. The intermediate compaction uses a pneumatic tire roller with a compaction temperature of 130-120℃ and 3-4 passes. The final compaction uses a double-drum roller with a compaction temperature of 100-80℃ and 2 passes. By installing GPS positioning system, vibration sensor and temperature sensor on the road roller, the number of compaction passes, rolling speed, vibration frequency and compaction temperature are collected in real time, and the parameter data is uploaded to the monitoring system to realize the visualization of the rolling trajectory, so as to ensure that there is no missed compaction or over-compaction. The compaction degree is detected in real time using a nucleus-free density meter, and the number of rolling passes is dynamically adjusted. Once the compaction degree meets the standard, the next area is entered to ensure uniform and stable rolling quality and avoid over-compaction and under-compaction, thereby reducing the compaction degree dispersion coefficient. Step 45: After compaction, traffic can only be opened after the asphalt concrete temperature drops below 50°C. After traffic is opened, IoT sensors are pre-embedded inside the road surface to monitor the road surface temperature, humidity, and strain in real time, enabling long-term tracking and predictive maintenance of road surface performance. When the monitoring data exceeds the normal range, an early warning will be automatically issued, and maintenance timing and maintenance plan will be recommended.

[0033] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for improving road surface durability through zero-elevation modification of curb ramps, characterized in that: The renovation is carried out in four phases. First, the existing curbstone structure is removed through meticulous demolition work. Then, high-strength fine stone concrete is poured to form a reliable base structure. Next, spiral wire-wound spring pipes are laid to achieve the dual functions of drainage channels and structural reinforcement. The spiral wire-wound spring pipes form lateral drainage channels and bear vertical loads. Finally, fine-grained modified asphalt concrete surface layer is laid to form a complete road structure. The fine stone concrete base and the asphalt concrete surface layer work together to form a zero-elevation pavement structure. The spiral wire-wound spring pipes are placed between the two layers and connected to the rainwater inlet. The specific implementation phases of the renovation are as follows: Phase 1: Precise removal and basic treatment; Second stage: Fine aggregate concrete pouring; Phase 3: Laying of spiral-wound spring tubes; Phase 4: Asphalt concrete surface layer paving; In the precise demolition and foundation treatment stage, measurement and layout are carried out, while cutting and demolition are performed, and the foundation is cleaned and concrete is prepared. During the fine aggregate concrete pouring stage, while leveling and pouring, curing and strength monitoring are carried out. The strength grade of fine aggregate concrete should not be lower than C30, and the thickness should be 50-70mm. During the laying stage of the spiral-wound spring tube, the spiral-wound spring tube is customized and its layout scheme is simulated so that the spiral-wound spring tube is laid according to the optimized layout scheme. Finally, its end is connected to the rainwater inlet and sealed. During the asphalt concrete pavement stage, tack coat is applied and modified asphalt concrete is prepared, while paving and compaction are carried out simultaneously, and long-term monitoring is conducted after the road is opened to traffic.

2. The method for improving road surface durability through zero-elevation modification of curb ramps according to claim 1, characterized in that: The precise removal and basic processing phase includes the following implementation steps: Step 11, Digital Measurement and Precise Layout; Step 12, Silent cutting and fine breaking; Step 13, substrate refinement; Step 14: Prepare high-strength, fast-hardening concrete.

3. The method for improving road surface durability through zero-elevation modification of curb ramps according to claim 2, characterized in that: Step 11: Use a 3D laser scanner to perform a comprehensive scan of the intersection curb ramp, accurately identify the location, size and elevation information of the curb, calculate the specific area to be removed, determine the removal width X, removal thickness Y and removal length Z, and accurately locate and lay out according to the area, and mark the removal boundary line. The breaking width X is determined based on the actual width of the curbstone, ranging from 280 to 320 mm; the breaking thickness Y is determined based on the actual thickness of the curbstone, ranging from 70 to 110 mm; and the breaking length Z is determined based on the actual length of the curbstone, ranging from 600 to 1000 mm. Step 12: Move the cutting equipment along the breaking boundary line to cut, and set up rubber isolation pads to achieve sound insulation. After cutting, use a small hydraulic breaker to break it up. Step 13: Use a high-pressure water gun to rinse the base of the demolition area. For loose mortar layers in the base, use a small milling machine for fine milling and use a roughness measuring instrument to detect the roughness of the base. For base areas with cracks, low-viscosity epoxy resin is required for grouting. After the base treatment and before pouring, the base is pre-wetted with water spraying equipment, and then moistened again 2 hours before pouring. A special concrete interface agent is then applied to the base. Step 14: The main materials include cement, coarse aggregate and fine aggregate. The cement is ordinary Portland cement, the coarse aggregate is continuous graded crushed stone with a particle size of 5-10mm, the fine aggregate is medium and coarse sand, and polycarboxylate high-performance water-reducing agent is added.

4. The method for improving road surface durability through zero-elevation modification of curb ramps according to claim 3, characterized in that: The following steps are included in the fine aggregate concrete pouring stage: Step 21, three-dimensional leveling and precise pouring; Step 22, Intelligent Maintenance and Intensity Monitoring; Step 21: Before pouring, the paving thickness H1 of the fine aggregate concrete needs to be calculated and determined. When calculating the paving thickness H1, the breaking thickness Y and the actual total thickness H (total) on site need to be measured. H1 (min) needs to meet the strength requirements and geometric filling requirements. Based on the calculated dimensions, a three-dimensional model of the pouring area is created using BIM software. The model is then output to a 3D printing device to produce a personalized leveling screed. An ultrasonic thickness sensor is installed on the template to monitor the concrete pouring thickness in real time. A variable frequency high-frequency vibrator is used for vibration treatment. After vibration, a power trowel is used to finish the surface, and a manual scraper is used for fine leveling. Step 22: After pouring, cover with plastic film to retain water, and then cover the film with geotextile for insulation. Simultaneously, temperature and maturity sensors are pre-embedded inside the concrete. The curing parameters are automatically adjusted based on the data collected by the sensors. Specifically, the equivalent age of the concrete is calculated in real time according to the maturity method to predict the current strength value. Once the predicted strength value reaches the design requirements, a notification is sent to proceed to the next process.

5. The method for improving road surface durability through zero-elevation modification of curb ramps according to claim 1, characterized in that: The following steps are included in the laying stage of spiral-wound spring tubes: Step 31, Customized processing and pretreatment; Step 32: CFD simulation to optimize the layout; Step 33, precise positioning and laying; Step 34, end connection and sealing treatment.

6. The method for improving road surface durability through zero-elevation modification of curb ramps according to claim 5, characterized in that: Step 31: Before processing, it is necessary to calculate the specifications of the spiral-wound spring tube. The inner diameter of the spiral-wound spring tube should not be less than 30mm, the spring wire diameter should not be less than 2.5mm, and the spring wire gap should be 2mm. The specifications include the number of spiral-wound spring tubes S, the inner diameter d, the length L, and the compressive strength σ. The number of spiral-wound spring tubes S needs to take into account the catchment area of ​​the intersection, the road width, and the drainage distance. The number of spiral-wound spring tubes S is directly related to the reliability and service life of the drainage system. The number of spiral-wound spring tubes S is limited to 2-3 tubes. In actual processing, alloy square steel is used to make spiral wound spring tubes, and square wire is used for the spring wire. The spring wire is continuously wound and formed using a special spring coiling machine, and the pitch accuracy is controlled within ±0.2mm.

7. The method for improving road surface durability through zero-elevation modification of curb ramps according to claim 5, characterized in that: Step 32: Establish a 3D CAD model of the intersection, mark the road slope, the location of the storm drain, and the water catchment boundary. Use CFD software to simulate the surface runoff under different return period rainstorm conditions, analyze the flow direction, velocity distribution and water accumulation area, and design an optimized layout scheme for the spiral-wound spring tube based on the simulation results. Step 33: Pop up bidirectional control lines on the surface of fine stone concrete. The spacing of the control lines is evenly distributed according to the number of spiral wire-wound spring tubes. Set up a laser line projector at the intersection of the control lines and use the laser plane as the reference plane. Cut the spiral wire-wound spring tubes to the designed length and lay them one by one according to the designed position. Step 34: Drill holes in the side wall of the rainwater inlet, connect the end of the spiral-wound spring tube to the rainwater inlet using a special connector, and install a self-expanding rubber sealing ring at the interface. For the end that cannot be connected to the rainwater inlet, use wire wrapping to seal it.

8. The method for improving road surface durability through zero-elevation modification of curb ramps according to claim 1, characterized in that: The asphalt concrete pavement stage includes the following steps: Step 41, apply tack coat; Step 42, preparation of modified asphalt concrete; Step 43, 3D paving control; Step 44, Intelligent compaction control; Step 45: Open traffic and conduct long-term monitoring.

9. A method for improving road surface durability through zero-elevation modification of curb ramps according to claim 8, characterized in that: Step 41: Use a cleaning machine to remove dust and debris from the surface of fine stone concrete. Use SBS modified emulsified asphalt as the tack coat and spread it evenly using a sprayer. At the same time, add a fluorescent tracer to the tack coat and use ultraviolet light to detect the uniformity of the tack coat distribution based on the fluorescent tracer detection. Step 42: SBS modified asphalt is used as the asphalt, basalt is used as the aggregate, AC-13C type gradation is used, and warm mix agent is added to reduce the discharge temperature. Before asphalt paving, it is necessary to calculate the paving thickness H2 of the modified asphalt concrete. The determination of the paving thickness H2 needs to take into account both the structural design specifications of asphalt pavement and the actual construction feasibility.

10. A method for improving road surface durability through zero-elevation modification of curb ramps according to claim 8, characterized in that: Step 43: Measure elevation points on the surface of the spiral-wound spring tube and the fine stone concrete surface, establish a three-dimensional model of the paving reference surface, and input the reference surface data into the 3D control system of the paver. The paver adopts a tracked automatic leveling paver. At the same time, multiple infrared temperature measurement points are set up to monitor the paving temperature distribution in real time. When the temperature in a certain place is lower than the lower limit, an automatic warning is issued and the paving process is adjusted in time. Step 44 includes three stages of compaction: initial compaction, intermediate compaction, and final compaction. The initial compaction is performed using a double-drum vibratory roller, the intermediate compaction is performed using a pneumatic tire roller, and the final compaction is performed using a double-drum roller. By installing GPS positioning systems, vibration sensors, and temperature sensors on the road roller, parameter data can be collected in real time and uploaded to the monitoring system to achieve visualization of the compaction trajectory; The compaction degree is detected in real time using a nucleus-free density meter, and the number of rolling passes is dynamically adjusted. Once the compaction degree meets the standard, the next area is entered. Step 45: After compaction, traffic can only be opened after the asphalt concrete temperature drops below 50°C. After traffic is opened, IoT sensors are pre-embedded inside the road surface to monitor road parameters in real time, enabling long-term tracking and predictive maintenance of road performance.

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