Disease treatment method for old airport runway in high heat area

Abstract

The invention discloses a disease treatment method for old airport lanes in a high heat area. The method comprises the following steps: S1, disease evaluation and classification treatment; s2, planning a processing scheme; s3, high-temperature-resistant composite cover surface treatment; and S4, interface reinforcement and drainage optimization. According to the method, the pavement disease type and severity are determined by evaluating and classifying the diseases, the treatment scheme is determined according to the pavement disease type and severity, local structure repair is performed according to the treatment scheme, and compared with an existing cement concrete plate replacement repair mode, the method has the advantages of being short in construction period and low in cost.

Description

Technical Field

[0001] This invention relates to the field of pavement defect treatment technology, specifically to a method for treating pavement defects in old airport runways in high-temperature areas. Background Technology

[0002] Generally, pavement defects include bulging, corner cracks, transverse, longitudinal, and diagonal cracks, durability cracking (D-shaped cracks), old pavement patches, spalling, subsidence, broken slabs, joint fractures, and alkali-aggregate reaction. In high-temperature regions (such as Nasiriyah, Iraq), airport pavements are subjected to long-term high temperatures, heavy loads, and environmental factors, and the main defects fall into the following categories: 1. Cracks and broken plates, including "longitudinal, transverse and oblique cracks", "broken plates or intersecting cracks", "corner fractures", etc. 2. Joint-related issues, including "damaged or ineffective caulking compound", "broken joints", "peeling corners", and "expansion cracks", etc. 3. Vertical displacement of pavement panels, including "mud pumping and voiding at the bottom of the slab" and "settlement or misalignment", etc. 4. Surface-related, including "peeling, cracking and micro-cracks", "durability cracks", "shrinkage cracks" and "pits", etc.

[0003] Currently, common treatment methods for pavement defects in high-temperature areas include: 1. Traditional asphalt overlay repair methods are prone to problems such as rutting, loosening, and insufficient anti-aging ability in high-temperature environments; 2. Cement concrete slab replacement repair method: This method has a long construction period and high cost, and the bonding performance between the old pavement and the new pavement is poor, which may cause new defects. 3. Composite repair methods, such as combining asphalt overlay with cement grouting, still have insufficient adaptability for long-term use in high-temperature areas. Summary of the Invention

[0004] The purpose of this invention is to provide a method for treating defects in the runways of old airports in high-temperature areas, in order to solve the technical problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A method for treating runway defects in old airports in high-temperature areas, characterized by the following steps: S1. Pavement Defect Assessment and Classification: Pavement defects are identified through on-site inspection, radar detection, and ultrasonic testing. Based on the measurement and statistical results, pavement defects are classified into cracked slabs, joint defects, vertical displacement of pavement panels, and surface defects. The severity of defects is classified into mild, moderate, and severe. S2. Treatment Plan: Based on the type of pavement defects, a treatment plan is planned, specifically including treatment strategies for cracked and broken slab defects, joint defects, vertical displacement defects of pavement panels, and surface defects. Specific technical solutions are used to treat the specific defects through joint or crack filling processes, partial thickness repair processes for pavement panels, full thickness repair processes for panels, foundation grouting processes, and slab grinding processes. S3. High-temperature resistant composite overlay treatment: A modified asphalt concrete overlay is laid on the repaired pavement, and a high-temperature stabilizer is added to enhance its high-temperature resistance; a high-temperature anti-aging spray coating is then laid on the modified asphalt concrete overlay to improve its weather resistance and UV resistance. S4 Interface Reinforcement and Drainage Optimization: Interface bonding materials are used to improve the bonding force between the old pavement and the new paving layer, preventing the interface layer from detaching; the drainage system of the pavement is optimized by adjusting the slope and adding drainage channels to reduce the damage to the pavement caused by rainwater retention.

[0006] More preferably, the treatment strategies for cracked slab defects include full-thickness repair, partial-thickness repair, or crack filling repair. In full-thickness repair: If a single slab has multiple longitudinal, transverse, or diagonal cracks, and the length of a single crack exceeds half the length of the slab's shorter side, and the average width of one of the cracks is greater than 10 mm, then the entire slab should be replaced. During the slab restoration process, the original dowel bars or tie bars should be restored. If a "corner fracture" occurs, or there is obvious misalignment between the slabs on both sides of the crack, or obvious mud pumping occurs around the crack, the base layer should be treated first, and then the slabs in the area affected by the crack should be repaired with full-thickness repair techniques. Subsequent repairs should be carried out using full-thickness repair techniques. In partial thickness repair: When there is no obvious misalignment of the slabs around the crack, but there is relatively serious spalling, partial thickness repair is carried out on the slabs in the area affected by the crack; the repair depth is half the thickness of the slab, and the connection between the patch and the original pavement is strengthened by setting connecting nails; subsequent repair is carried out using partial thickness repair technology; In crack filling: cracks should not intersect, there should be no obvious misalignment on both sides of the cracks, the average width of the cracks should be less than 5mm, and there should be no obvious spalling around the cracks. Then, the crack filling process should be used for repair.

[0007] Furthermore, regarding the treatment strategies for joint-related defects: The sections of the added concrete slab should be completely consistent with those of the old slab; the joints of the upper and lower slabs should be aligned, and when misalignment occurs occasionally, the error should not exceed 30mm. When irregularly shaped slabs appear on the old pavement, causing the additional concrete slabs to be inconsistent with the original pavement slabs, the original pavement surface is cut according to the dimensions of the additional slabs, and then the cuts are filled with joint filler. For areas where the old pavement concrete with irregularly shaped slabs is segmented but the overlay layer does not require segmentation, the joints of the old pavement slabs are covered with asphalt felt before the overlay layer concrete is poured.

[0008] Furthermore, regarding countermeasures for vertical displacement defects in pavement panels: Mud pumping and voids at the bottom of the slab: Use foundation grouting and replace the grouting material at the joints; Subsidence or misalignment: The following treatment measures shall be taken according to the magnitude of the misalignment or subsidence: If the misalignment or settlement is less than 5 mm, replace the grouting material at the joint of the misaligned or settled plate. When the misalignment or subsidence is between 5 and 10 mm, the misalignment should be eliminated by grinding the plates. When the misalignment or settlement exceeds 10 mm, partial thickness repair should be carried out, with a repair depth of 5–10 cm. The repair width should be determined by calculating the elevation difference, and the slope i of the repaired surface should not exceed 1%. If the slab bulges, make a full-thickness cut at the joint where the bulge is located, with a cut width of 3-5 cm. Clean out any debris from the joint and replace the grouting material after the stress has been fully released.

[0009] Furthermore, in the treatment strategies for surface-type diseases: Thoroughly remove the mud from the old pavement using pressurized water and a wire brush. For areas with paint markings and rubber residue from aircraft tires, roughen the old pavement to expose the old stone on the horizontal joint surfaces, and then rinse it clean with water. Clean the old concrete pavement, removing sand, gravel, mud, debris, asphalt, and joint filler from the joints; If the old concrete pavement has poor flatness and there is a gap between the bottom of the formwork and the old pavement, use wooden strips, asphalt felt or cement mortar to seal the gap tightly to prevent concrete from leaking out.

[0010] Furthermore, Joint or crack filling processes include: Remove old sealant; Widening the joint; The dimensions of the joints and the cracks after widening should meet the width-to-depth ratio; among them, the width-to-depth ratio of the groove is 1:1 when silicone-based grouting materials are used, and the width-to-depth ratio of the groove is 1:1 to 1:2 when polyester-based, polyurethane-based, or asphalt-based grouting materials are used. Seam cleaning; Install backing strips; the backing strips should be made of elastic materials with good weather resistance that are incompatible with and do not react with the grouting material; the width of the backing strips should be 25% greater than the joint width, tightly attached to the joint groove, with no leaks, and the joint overlaps should be sealed. Prepare the grouting material; Crack sealing operation.

[0011] Furthermore, the thickness repair process for the pavement panel includes: Determine the dimensions of the patch; The minimum repair depth is 5cm, and the maximum repair depth is half the plate thickness (the force transmission rod and tie rod must not be damaged); the maximum side length of the repair block shall not exceed 2m, and the minimum shall not be less than 0.15m. The repair area extends 5-10 cm outward from the affected area. The patch should be a regular rectangle with an aspect ratio of less than 2:1. For patches with irregular dimensions or an aspect ratio greater than 2:1, repairs should be done in multiple stages to ensure each patch meets the dimensional requirements. Alternatively, a single repair can be performed, with immediate cutting after pouring. After cutting, the patch should meet the aspect ratio requirement of less than 2:1, and the cut should be filled. When the repair location is at a corner of the board and the short side of the patch is greater than 0.5m, the patch should be polygonal. When the distance between two adjacent patch blocks is less than 30 cm, they should be repaired together; when patch blocks cross joints, effective isolation measures should be taken at the joint location; Cutting of the deck panel Draw boundary lines according to the repair area. The pavement cutting machine cuts along these lines, with the cutting depth as close as possible to the depth of the patch, but the minimum cutting depth should not be less than 5cm. To minimize the impact of pavement breakage on surrounding intact slabs, after boundary cutting, the concrete within the repair area is cut in a grid pattern. The cutting method is as follows: First, make slits along the long side of the patch, with a spacing of 2-6 cm and a depth of 5 cm; Then, cut two slits along the short side at a distance of 4 cm from the repair boundary, with a cutting depth of 5 cm. The pavement is broken; the cement concrete within the broken repair area is repaired from the center outwards; when the broken depth exceeds half the thickness of the slab, full-thickness repair is used. Draw boundary lines according to the repair area. The pavement cutting machine cuts along these lines, with the cutting depth as close as possible to the depth of the patch, but the minimum cutting depth should not be less than 5cm. To reduce the impact of pavement breakage on surrounding intact slabs, after boundary cutting, the concrete within the repair area is cut in a grid pattern. The cutting method is as follows: First, make slits along the long side of the patch, with a spacing of 2-6 cm and a depth of 5 cm; Then, cut two slits along the shorter side, 4 cm from the repair boundary, with a cutting depth of 5 cm; Pit cleaning Remove broken pieces and other debris from the repair pit, then clean it with a high-pressure water gun, and finally clean the repair pit with high-pressure air to ensure that there is no debris or dust in the pit.

[0012] When the patch is located at the edge or corner of the board, the joint adjacent to the patch needs to be treated. During breaking and cleaning, remove the grouting material and backing strip from the joint; before pouring, place a compressible isolation board such as a rubber sheet or foam board at the joint, with the same width as the original joint.

[0013] Concrete mixing and pouring Concrete mixing: After estimating the amount of concrete needed for repairs, calculate the quantities of cement, aggregates, additives, and water, and weigh them accurately. Use forced mixing equipment to mix evenly and pour the concrete immediately after mixing.

[0014] Concrete pouring: Ensure the pit is clean and the walls are free of excessive dust; the pit and its bottom should be moist, but not waterlogged; the concrete should be poured in one go, and for larger areas, it should be poured in one direction. When pouring manually, use a shovel to spread the concrete, and throwing is strictly prohibited.

[0015] Concrete vibration: Vibration at the same location should last no less than 10 seconds, until the concrete stops falling and no longer bubbles or forms a paste-like layer. The distance between moving vibrating devices should not exceed 1.5 times their radius of action. The overlap between two vibration locations should be 10-20 cm.

[0016] Leveling and surface finishing It is strictly forbidden to sprinkle water or roughen the concrete surface during finishing. First, use a long board to roughly level the surface, then use a plastic trowel and a steel trowel to finish the surface. The finishing process should be repeated no less than three times, as follows: The first troweling is done by smoothing back and forth along the transverse slope, with the front and back troweling overlapping by 1 / 2. This is mainly used to knead and press the slurry, press down the exposed stones, eliminate obvious unevenness, and accelerate the evaporation of moisture. After the moisture has slightly evaporated, apply a second layer of sizing along the transverse slope. This is mainly used to squeeze out air bubbles, press sand into the board surface, eliminate sand holes, and make the board surface dense. The final squeegee is used to remove any remaining uneven marks on the board surface and accelerate the evaporation of moisture.

[0017] La Mao To ensure a tighter and stronger bond between the subsequent overlay concrete and the original pavement, roughening is necessary after the surface is smoothed. Roughening should be done sooner rather than later; gently press the concrete surface with your index finger until it feels firm but not yet completely hardened, at which point roughening can begin.

[0018] The texture of the roughened surface should be perpendicular to the wheel track direction. The average texture depth of the roughened surface should be greater than 0.4 mm. Roughening should not cause slurry seepage or loosening. During the roughening process, cement slurry adhering to the roughening tools should be frequently washed with water.

[0019] Maintenance After roughening is completed, before the concrete initially sets, spray a curing agent to keep it moist and maintain its moisture for at least 7 days.

[0020] More preferably, the full-thickness panel repair process includes: Patch Repair Size The shortest side length of the patch should not be less than 60cm. The repair range should extend 5-10cm outward from the affected area. The patch should be full thickness and the shape of the patch should be a regular rectangle with a length-to-width ratio of less than 2:1. For slender strip patches (length-to-width ratio greater than 2:1), repairs should be done in sections according to the length-to-width ratio requirement of 2:1, with tie rods installed between adjacent patches; alternatively, patches can be cut into sections according to the length-to-width ratio requirement after pouring the concrete once, and the cut joints should be filled. Repair both damaged areas together if the distance between two adjacent damaged areas is less than 60cm. When patching across a joint, repair the joint separately along the joint.

[0021] Panel cutting Use a slit cutter to cut along the repair boundary. The deeper the cut, the better, but the minimum depth should not be less than 10 cm.

[0022] panel broken Large slabs are broken with a hydraulic breaker, while small slabs are broken with a pneumatic pick from the center outwards. When breaking the slabs, care should be taken to protect the edges and corners of the slabs. The power of the breaking equipment should not be too high. The dowel bars, tie bars, and reinforcing steel mesh in the original pavement must be removed.

[0023] Grassroots processing If the base layer is found to be loose, muddy, or waterlogged after removing the surface layer, the base layer should be treated and compacted by manual or mechanical tamping depending on the size of the working surface.

[0024] Add tie rod When the patch area is large (long side greater than 2m, short side greater than 1m), a tie rod should be added between the patch and the original pavement. The tie rod is made of threaded steel bar, 70cm in length, and can be 14 or 16mm in diameter. It is added in the center of the plate thickness and is treated with rust prevention. The tie rods are arranged at equal intervals of 50 cm, and the minimum burial depth on one side is 30 cm. The distance between the outermost tie rod and the edge of the patch or the pavement joint is between 25 and 35 cm; After installation, the vertical and horizontal deviations at both ends of the tie rod should be less than 20mm. Reinforcing steel mesh installation The flexural strength of the patch is improved by setting up a steel mesh. The reinforcing steel mesh can be set in a single layer or double layer. The reinforcing bars should be placed within 1 / 3 to 1 / 2 of the slab thickness below the top surface of the slab, or arranged using a double-layer reinforcing mesh. The outermost reinforcing bar should be approximately 10cm from the edge of the patch, and the concrete cover thickness should be no less than 5cm. Longitudinal and transverse reinforcing bars should be of the same diameter; if they are different, the difference should not exceed 0.4 cm. The minimum clear spacing between reinforcing bars should not be less than twice the maximum aggregate size. While meeting the requirements for rebar spacing, smaller diameter rebars should be used. The minimum diameter and maximum spacing of the rebars must meet the design requirements. The lap length of reinforcing bars should generally be no less than 35 times the diameter of the reinforcing bar, and should be done by binding or welding. The lap positions should be staggered. The steel mesh should be pre-embedded horizontally as much as possible, and the horizontal height difference between the two sides should be controlled within ±1cm.

[0025] Seam treatment When the patch is located at the edge or corner of the pavement, the existing joints of the pavement should be treated: During breaking and cleaning, remove the sealant and backing strip from the joints; Before pouring, place a compressible isolation board such as a rubber sheet or foam board at the joint, with the same width as the original joint. If the original joint had a dowel bar or tie bar, it should be restored to its original state. When restoring, a new hole should be drilled and installed at a position 10-20cm horizontally offset from the original dowel bar (tie bar).

[0026] Force transmission bar setting When the patch area is large (length in the joint direction greater than 2m), the original dowel bar at the joint should be restored: The dowel bars are made of plain round steel bars and are placed in the center of the slab thickness; For dowel bars at general joint locations, half their length plus 5cm should be coated with a thin layer of asphalt or fitted with a plastic sleeve. At the expansion joint, the dowel bar is fitted with a sleeve at the asphalt-coated end, leaving a gap inside which is filled with foam plastic, yarn, etc., and the sleeve ends are arranged alternately. The distance between the outermost load-bearing bar and the joint or free edge of the board should be between 15 and 20 cm.

[0027] 9) Cleaning of pits and grooves Remove broken pieces and other debris from the pit, then clean it with a high-pressure water gun, and finally clean and repair the pit with high-pressure air to ensure that there is no debris or dust in the pit.

[0028] The requirements for concrete pouring, leveling, surface finishing, roughening, and curing are the same as those for partial thickness repairs, and can be found in Section 5.2.

[0029] Furthermore, the basic grouting process includes: Hole Formation; After the grouting holes are laid out on site, they are drilled using drilling equipment. The grouting holes should be perpendicular to the pavement surface. Clean the hole; Monitor slab disturbance; set up a level instrument near the grouting area, 30-40 m away from the grouting area, to monitor the grouting slab jacking in real time. Grouting should be stopped under the following circumstances: the grouting slab rises by 3mm; grout is seen oozing from the transverse or longitudinal joints of the paving slab or other grouting holes; the grouting machine pump pressure suddenly rises rapidly; or there are signs of excessive pressure under the slab, such as grout nozzles spraying out. Secondary grouting; secondary grouting should be carried out 0.5 hours before the initial setting of the previous grouting solution; Sealing holes; Maintenance.

[0030] More preferably, the plate grinding process includes: When grinding the slabs with a grinder, start from the high point of the misalignment and grind outwards gradually. The amount of material ground at one time should not be too large to avoid damaging the pavement. Misalignment should be eliminated through repeated grinding. During the grinding process, a 3m ruler can be used for measurement. The grinding control standard is that the height difference between adjacent boards is less than 3mm. For panels with significant misalignment, a grinding machine with a cutting blade can be used to cut them first, followed by grinding.

[0031] Compared with the prior art, the present invention has the following features and beneficial effects: This application determines the type and severity of pavement defects by assessing and classifying the defects, and then determines the treatment plan accordingly. Based on the treatment plan, local structural repairs are carried out, which has the advantages of shorter construction period and lower cost compared with the existing cement concrete slab replacement repair method.

[0032] This application employs a systematic assessment and classification of defects, targeting different types of defects (cracks, misalignment, pumping, spalling, etc.) and their severity, and utilizes a combination of techniques including foundation grouting, full-thickness / partial-thickness repair, and joint repair. This not only repairs surface defects but also strengthens the base layer and foundation, eliminates the root cause of defects, and prevents recurrence. This application, through interface reinforcement technology (using special interface bonding materials) and scientific joint treatment process, greatly improves the bonding force between the new and old pavement, enabling the overlay layer and the old pavement to work together to form an integral structure, thereby extending the service life of the overall pavement and solving the technical problem of poor durability of traditional repair methods under high temperature environments.

[0033] In the partial structural repair process of this application, high-performance repair materials are used for repair, thereby improving the overall strength of the pavement. For the settlement area, grouting technology is used to fill it, thereby improving the bearing capacity of the foundation and avoiding the occurrence of new defects. In this application, a modified asphalt concrete overlay is used for high-temperature resistant composite overlay treatment, and a high-temperature stabilizer is added to enhance its high-temperature resistance. A high-temperature anti-aging spray coating is used to cover the overlay to improve its weather resistance and UV resistance.

[0034] The method presented in this application systematically solves the problem of pavement defects caused by the combined effects of severe factors such as high heat, strong ultraviolet radiation, and heavy loads. It provides a set of proven and directly applicable technical systems and standard procedures for pavement maintenance and repair work at airports in similar climatic conditions around the world (such as the Middle East, Africa, and Southeast Asia). It solves the technical problem that existing technical methods suffer from diverse defect types and lack targeted treatment solutions.

[0035] This application proposes a scientific and effective approach to the restoration of the old airport, rather than demolition and reconstruction. This method embodies the concept of sustainable development, maximizes the use of existing assets, postpones the time required for massive reconstruction investments, and has significant economic and environmental value. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the repair structure when the height difference H between the sunken plate and the adjacent plate is greater than 10 mm. Figure 2 This is a schematic diagram of the full-thickness panel repair process involved in this application. Figure 1 ; Figure 3 This is a schematic diagram of the full-thickness panel repair process involved in this application. Figure 2 ; Detailed Implementation

[0038] To make the technical means, innovative features, objectives and effects of this invention easier to understand, the invention will be further described below.

[0039] The embodiments described herein are specific implementations of the present invention, used to illustrate the concept of the invention, and are illustrative and exemplary, and should not be construed as limiting the implementation or scope of the invention. In addition to the embodiments described herein, those skilled in the art can employ other obvious technical solutions based on the content disclosed in the claims and specification of this application. These technical solutions include those that make any obvious substitutions and modifications to the embodiments described herein. I. Classification of Old Road Surfaces The main diseases include the following types: Cracks and broken plates include "longitudinal, transverse and diagonal cracks", "broken plates or intersecting cracks", "corner fractures", etc. Joint-related issues include "damaged or ineffective caulking compound", "broken joints", "peeling corners", and "cracks". Vertical displacement of pavement panels: including "mud pumping and slab bottom separation" and "settlement or misalignment", etc. Surface-related: including "peeling, cracking and fine cracks", "durability cracks", "shrinkage cracks" and "pits", etc.

[0040] II. Disease Treatment Strategies Full thickness repair If a single plate has multiple longitudinal, transverse, or diagonal cracks, and the length of a single crack exceeds half the length of the short side of the plate, and the average width of one of the cracks is greater than 10 mm, the plate should be replaced entirely, and the original force transmission rods or tie rods should be restored. When "corner fracture" occurs, or there is obvious misalignment of the slabs on both sides of the crack, or obvious mud pumping occurs around the crack, the base layer should be treated first, and then the slabs in the area affected by the crack should be repaired to full thickness.

[0041] Partial thickness repair When there is no obvious misalignment of the slabs around the crack but there is relatively serious spalling, the slabs in the area affected by the crack can be partially repaired with a thickness of half the thickness of the slab. The connection between the repair block and the original pavement can be strengthened by setting connecting nails.

[0042] Crack filling When cracks do not intersect, there is no obvious misalignment on both sides of the cracks, the average width of the cracks is less than 5mm, and there is no obvious spalling around the edges, crack filling can be carried out to prevent further crack expansion and surface water infiltration. Treatment strategies for joint defects; The sections of the overlay concrete slabs should be completely consistent with those of the old slabs. The joints between the upper and lower slabs should be aligned; if misalignment occasionally occurs, the error should not exceed 30mm. When irregularly shaped slabs on the old pavement cause the overlay concrete slabs to be inconsistent with the original slab sections, the following method should be adopted: cut joints in the original pavement surface according to the dimensions of the overlay slab sections, and then fill the joints with joint filler. For areas where irregularly shaped slabs have sections in the old pavement concrete surface but the overlay layer does not require sectioning, cover the joints of the old pavement slabs with asphalt felt before pouring the overlay concrete.

[0043] "Damaged caulking compound" refers to the peeling, extrusion, loss, or other failure of the caulking compound. The main reason is that the caulking compound ages, resulting in decreased elasticity and adhesion, causing it to lose its bonding with the joint walls and thus its sealing function. Damaged caulking compound can easily lead to base layer defects such as pumping and voids. If hard particles enter the joint groove, it can also cause defects such as "joint breakage" and "corner spalling." The caulking compound needs to be cleaned and then refilled.

[0044] "Joint breakage" and "corner spalling" refer to the phenomenon of a small amount of debris appearing at the corners of cement concrete slabs. If the debris is not cleaned up in time, it will pose a safety hazard to aircraft operation.

[0045] If the damage around the joint is minor (the width affected by the damage is less than 25 mm), the damaged parts can be cleaned up and then the joint filler material can be applied. When the degree of breakage around the joint is relatively severe (the width of the breakage is greater than 25mm and the depth of the breakage is less than 15mm), shallow repairs can be carried out on the broken parts of the plate. When the degree of breakage around the joint is very serious (the width of the breakage is greater than 25 mm and the depth of the breakage is greater than 15 mm), it is advisable to repair the broken part of the plate with a partial thickness.

[0046] "Expansion cracks" are caused by improper installation or failure of expansion joints. After an expansion crack occurs, the slabs around the expansion joint are prone to full-thickness fracture, resulting in a near loss of structural load-bearing capacity. The slabs within the affected area of ​​the expansion crack need to be repaired with full-thickness reinforcement.

[0047] Treatment strategies for vertical displacement defects of pavement panels For "mud pumping and slab bottom separation", foundation grouting should be used, and the grouting material at the joints should be replaced; Depending on the magnitude of the subsidence or misalignment, the following treatment measures shall be taken for "subsidence or misalignment": When the misalignment (settlement) is less than 5 mm, replace the grouting material at the joint of the misaligned (settled) slab. When the misalignment (sinking) is between 5 and 10 mm, the misalignment is eliminated by plate grinding. When the misalignment (settlement) is greater than 10 mm, partial thickness repair should be carried out (see...). Figure 1 The repair depth should be 5–10 cm, the repair width should be determined by calculating the elevation difference, and the slope i of the repaired surface should not exceed 1%. That is, when the height difference H between the subsided slab 1 and the adjacent slab 2 is greater than 10 mm, partial thickness repair is adopted, the repair depth is 5-10 cm, the repair width is determined by the height difference H, and the slope i of the repair surface shall not be greater than 1%; Specifically, a repair space with a width of 100H is cut out between the sunken slab 1 and the adjacent slab 2. Concrete is poured into the repair space to form a repair block 3. The slope i of the repair surface of the repair block 3 shall not exceed 1%. The upper part of the repair block 3 and the adjacent slab 2 are filled with caulking material 4. If the slab shows signs of "bulging," make a full-thickness cut at the bulging joint, with a cut width of 3-5 cm. Clean out any debris from the joint. Replace the sealant after the stress has been fully released.

[0048] Treatment strategies for surface-level diseases Thoroughly remove the mud from the old pavement using pressurized water and a wire brush. For areas with painted markings and rubber residue from aircraft tires, roughen the old pavement to expose the old stone on the horizontal joint surfaces, and then rinse it clean with water.

[0049] Clean the old concrete pavement. Remove sand, gravel, mud, debris, asphalt, caulking compound, etc. from the joints according to the treatment methods and processes for joint defects.

[0050] If the old concrete pavement has poor flatness, there will be gaps between the bottom of the formwork and the old pavement. These gaps can be sealed tightly with wooden strips, asphalt felt or cement mortar to prevent concrete from leaking out.

[0051] II. Treatment methods and processes Joint (crack) filling Removal of old sealant Old grout material must be removed. A mechanical removal method should be used: first, use a grout cutter to cut away any remaining damaged grout material in the grout lines, then use a hook tool to clean it completely. Old sealant that is difficult to remove can be removed using solvents, sandblasting, or mechanical grinding. If the above methods still cannot remove the residue completely, clean it by widening the crack.

[0052] The following situations require widening the joint: ① Before filling the cracks; ② Existing sealant material in the joints is difficult to remove; ③ The existing sealant material in the joint is incompatible with the new material.

[0053] A. Polyurethane crack sealants are incompatible with asphalt crack sealants and must be completely removed; B. Polyurethane grouting materials have poor compatibility before and after aging and need to be completely removed; C. Asphalt-based crack sealing materials have good compatibility, and it is not necessary to completely remove any residue from the crack walls; D. Silicone-based grouting materials have good compatibility before and after aging, and it is not necessary to completely remove any residue from the grout walls.

[0054] Dimensions of joints (and cracks after widening) The width-to-depth ratio is a crucial factor affecting the durability of crack sealant. For silicone-based crack sealants, the ratio is 1:1; for other sealants, it ranges from 1:1 to 1:2. The crack width should be between 8 and 10 mm, with a minimum of 6 mm and a maximum of 20 mm. The crack depth should take into account the height of the backing strip at the bottom of the crack.

[0055] Seam cleaning To improve the adhesion between the sealant and the joint wall, after cutting and widening the joint, use an air compressor to spray compressed air into the joint to remove fine sand, dust, and other impurities. If these cannot be completely removed, use high-pressure water to rinse the joint, and then seal the joint after the water has dried.

[0056] Install backing strips After cleaning the joint (the crack after widening), install the backing strip and fill the crack as soon as possible. The main purpose of installing the backing strip is to ensure the width-to-depth ratio of the filling material meets requirements and to prevent the filling material from seeping down the joint (the crack after widening). If installation must be done the following day, the groove must be cleaned again before installing the backing strip. The backing strip should be made of a weather-resistant, non-reactive, and incompatible elastic material (generally foam strips, such as polyethylene foam). The width of the backing strip should be 25% greater than the joint width, tightly attached to the groove, with no leaks, and the overlapping joints should be sealed.

[0057] Preparation before grouting ① Heated construction type of crack sealing material: Put the crack sealing material into the crack sealing equipment, set the heat melting temperature and the size of the discharge port, and then seal the crack when the temperature of the crack sealing material reaches the required level; ② Normal temperature construction type of crack filling material: After mixing and stirring the crack filling material according to the instructions, it can be used for crack filling.

[0058] Crack sealing operation A specialized joint filling machine is used to fill the longitudinal joints first, followed by the transverse joints.

[0059] Heated construction grouting material During the grouting process, the mixture must be continuously stirred and kept warm. Crack filling should be carried out immediately after the crack cleaning process. The filling material should be used to fully fill the crack groove from bottom to top to avoid air pockets. The filling work of each joint should be continuous, and any joints that are not fully filled should be filled in time. Keep the joint dry and clean during grouting. The construction temperature should be between 4 and 40 ℃. When the temperature is below 4 ℃, the groove must be heated before grouting.

[0060] Normal temperature construction crack sealing material Insert the caulking nozzle at a 45° angle into the bottom of the groove, ensuring that the caulking material fills the groove from bottom to top without leaving any air bubbles; The grouting process should be continuous and at a uniform speed; For non-self-leveling grouting materials, use a flattening tool to press and level the adhesive surface from top to bottom, so that the grouting material is compressed and fully adheres to the joint wall; After the grouting is completed, check the grouting condition of the groove. There should be no bubbling, bulging or other phenomena.

[0061] Repair of pavement panel thickness Patch Repair Size The minimum repair depth is 5cm, and the maximum repair depth is half the plate thickness (the force transmission rod and tie rod must not be damaged); the maximum side length of the repair block shall not exceed 2m, and the minimum shall not be less than 0.15m. The repair area extends 5-10 cm outward from the affected area, and the patch is a regular rectangle with an aspect ratio of less than 2:1. For patch blocks with irregular planar dimensions or an aspect ratio greater than 2:1, repair in multiple stages to ensure that each patch block meets the dimensional requirements; alternatively, repair in one go, cut promptly after pouring, and ensure that the cut patch blocks meet the requirement of an aspect ratio less than 2:1, and fill the cut seams. When the repair location is at the corner of the board and the short side dimension of the repair block is greater than 0.5m, the repair block should be set as a polygon.

[0062] When the distance between two adjacent patch blocks is less than 30 cm, they should be repaired together; when a patch block spans a joint, effective isolation measures should be taken at the joint location.

[0063] Cutting of the deck panel Draw boundary lines according to the repair area. The pavement cutting machine cuts along these lines, with the cutting depth as close as possible to the depth of the patch, but the minimum cutting depth should not be less than 5cm. To minimize the impact of pavement breakage on surrounding intact slabs, after boundary cutting, the concrete within the repair area is cut in a grid pattern. The cutting method is as follows: First, make slits along the long side of the patch, with a spacing of 2-6 cm and a depth of 5 cm; Then, cut two slits along the short side at a distance of 4 cm from the repair boundary, with a cutting depth of 5 cm.

[0064] broken pavement The cement concrete within the repair area should be broken and repaired from the center outwards. The power of the breaking equipment should not be too high, and care should be taken to protect the edges and corners of the repair blocks during breaking. The depth of pavement breaking should be greater than the depth affected by the pavement defects, and the bottom surface of the pothole should be roughly flat after breaking.

[0065] When the fracture depth exceeds half the slab thickness, full-thickness repair should be used. During the demolition process, minimize damage to the dowel bars (tension bars) and clean the surface of the reinforcing bars. When encountering reinforced steel mesh, the following two methods can be used: Cut the reinforcing bars, leaving a 5-7 cm long rebar end, and then weld it to new reinforcing bars to form a new reinforcing mesh. The new reinforcing bars should be the same size as the original bars, and the intersections of the new bars should be firmly welded together. Cut the reinforcing bars and add new reinforcing mesh to the patch. The shape and size of the reinforcing mesh are roughly the same as the patch. Tie the reinforcing bars at intersections with a spacing of 10-15 cm. Place the reinforcing mesh at the same height as the original reinforcing mesh.

[0066] Pit cleaning Remove broken pieces and other debris from the repair pit, then clean it with a high-pressure water gun, and finally clean the repair pit with high-pressure air to ensure that there is no debris or dust in the pit.

[0067] When the patch is located at the edge or corner of the board, the joint adjacent to the patch needs to be treated. During breaking and cleaning, remove the grouting material and backing strip from the joint; before pouring, place a compressible isolation board such as a rubber sheet or foam board at the joint, with the same width as the original joint.

[0068] Concrete mixing and pouring Concrete mixing: After estimating the amount of concrete needed for repairs, calculate the quantities of cement, aggregates, additives, and water, and weigh them accurately. Use forced mixing equipment to mix evenly and pour the concrete immediately after mixing.

[0069] Concrete pouring: Ensure the pit is clean and the walls are free of excessive dust; the pit and its bottom should be moist, but not waterlogged; the concrete should be poured in one go, and for larger areas, it should be poured in one direction. When pouring manually, use a shovel to spread the concrete, and throwing is strictly prohibited.

[0070] Concrete vibration: Vibration at the same location should last no less than 10 seconds, until the concrete stops falling and no longer bubbles or forms a paste-like layer. The distance between moving vibrating devices should not exceed 1.5 times their radius of action. The overlap between two vibration locations should be 10-20 cm.

[0071] Leveling and surface finishing It is strictly forbidden to sprinkle water or roughen the concrete surface during finishing. First, use a long board to roughly level the surface, then use a plastic trowel and a steel trowel to finish the surface. The finishing process should be repeated no less than three times, as follows: The first troweling is done by smoothing back and forth along the transverse slope, with the front and back troweling overlapping by 1 / 2. This is mainly used to knead and press the slurry, press down the exposed stones, eliminate obvious unevenness, and accelerate the evaporation of moisture. After the moisture has slightly evaporated, apply a second layer of sizing along the transverse slope. This is mainly used to squeeze out air bubbles, press sand into the board surface, eliminate sand holes, and make the board surface dense. The final squeegee is used to remove any remaining uneven marks on the board surface and accelerate the evaporation of moisture.

[0072] La Mao To ensure a tighter and stronger bond between the subsequent overlay concrete and the original pavement, roughening is necessary after the surface is smoothed. Roughening should be done sooner rather than later; gently press the concrete surface with your index finger until it feels firm but not yet completely hardened, at which point roughening can begin.

[0073] The texture of the roughened surface should be perpendicular to the wheel track direction. The average texture depth of the roughened surface should be greater than 0.4 mm. Roughening should not cause slurry seepage or loosening. During the roughening process, cement slurry adhering to the roughening tools should be frequently washed with water.

[0074] Maintenance After roughening is completed, before the concrete initially sets, spray a curing agent to keep it moist and maintain its moisture for at least 7 days.

[0075] Full thickness panel repair Repair size of patch 5 The shortest side length of patch 5 should not be less than 60cm. The repair range extends 5-10cm outward from the affected area. The patch should be full thickness and the shape of patch 5 should be a regular rectangle with a length-to-width ratio of less than 2:1. For slender strip patches with a length-to-width ratio greater than 2:1, repair should be done in sections according to the length-to-width ratio of 2:1, with tie rods installed between adjacent patches; alternatively, patches can be cut into sections according to the length-to-width ratio of 2:1 after pouring the concrete once, and the cut joints should be filled. Repair both damaged areas together if the distance between two adjacent damaged areas is less than 60cm. When patching across a joint, repair the joint separately along the joint.

[0076] Panel cutting Use a slit cutter to cut along the repair boundary. The deeper the cut, the better, but the minimum depth should not be less than 10 cm.

[0077] panel broken Large slabs are broken with a hydraulic breaker, while small slabs are broken with a pneumatic pick from the center outwards. When breaking the slabs, care should be taken to protect the edges and corners of the slabs. The power of the breaking equipment should not be too high. The dowel bars, tie bars, and reinforcing steel mesh in the original pavement must be removed.

[0078] Grassroots processing If the base layer is found to be loose, muddy, or waterlogged after removing the surface layer, the base layer should be treated and compacted by manual or mechanical tamping depending on the size of the working surface.

[0079] Add tie rod When the patch area is large, that is, the long side is greater than 2m and the short side is greater than 1m, an additional tie rod 8 is installed between the patch and the adjacent slab of the original pavement. The tie rod 8 is made of threaded steel bar, with a length of 70cm and a diameter of 14 or 16. It is installed in the center of the slab thickness and is treated with rust prevention. Eight tie rods are added at equal intervals of 50 cm, with a minimum burial depth of 30 cm on each side. The outermost tie rod 8 is installed at a distance of 25-35cm from the edge of the patch block or the pavement joint; After installation, the vertical and horizontal deviations at both ends of the additional tie rod 8 should be less than 20mm; Reinforcing steel mesh installation The flexural strength of the patch is improved by setting up a steel mesh. The reinforcing steel mesh can be set in a single layer or double layer. The reinforcing bars should be placed within 1 / 3 to 1 / 2 of the slab thickness below the top surface of the slab, or arranged using a double-layer reinforcing mesh. The outermost reinforcing bar should be approximately 10cm from the edge of the patch, and the concrete cover thickness should be no less than 5cm. Longitudinal and transverse reinforcing bars should be of the same diameter; if they are different, the difference should not exceed 0.4 cm. The minimum clear spacing between reinforcing bars should not be less than twice the maximum aggregate size. While meeting the requirements for rebar spacing, smaller diameter rebars should be used. The minimum diameter and maximum spacing of the rebars must meet the design requirements. The lap length of reinforcing bars should generally be no less than 35 times the diameter of the reinforcing bar, and should be done by binding or welding. The lap positions should be staggered. The steel mesh should be pre-embedded horizontally as much as possible, and the horizontal height difference between the two sides should be controlled within ±1cm.

[0080] Seam treatment When the patch is located at the edge or corner of the pavement, the existing joints of the pavement should be treated: During breaking and cleaning, remove the sealant and backing strip from the joints; Before pouring, a compressible isolation plate 10 is placed at the joint. The compressible isolation plate 10 is a rubber plate or a foam board with the same width as the original joint. After pouring, a backing strip 11 and a grouting material 4 are filled on the top of the compressible isolation plate 10, such as a rubber plate or a foam board, at the joint.

[0081] If the original joint has the original dowel bar 6 or tie bar 7, it should be restored to its original state. When restoring, drill new holes and reinstall at a position 10-20cm horizontally offset from the original dowel bar 6 or tie bar 7.

[0082] If the original joint has the original dowel bar 6 or tie bar 7, it should be restored to its original state. When restoring, drill new holes and reinstall at a position 10-20cm horizontally offset from the original dowel bar 6 or tie bar 7.

[0083] Pit cleaning Remove broken pieces and other debris from the pit, then clean it with a high-pressure water gun, and finally clean and repair the pit with high-pressure air to ensure that there is no debris or dust in the pit.

[0084] The requirements for concrete pouring, leveling, surface finishing, roughening, and curing are the same as those for partial thickness repairs, and can be found in Section 5.2.

[0085] III. Basic Grouting For voids at the bottom of the slab, grouting is required to fill the voids. This process removes air, water, and slurry from the voids in the foundation (or / and base layer), fills the voids with grout, bonds and solidifies the material, increases the reaction modulus of the top surface of the foundation (or / and base layer), seals moisture, and stabilizes the foundation (mainly for crushed stone or granular foundations), thereby eliminating the voids. This ensures the safety of the subsequent concrete overlay.

[0086] 1) Hole formation After the grouting holes are laid out on site, they are drilled using drilling equipment. The grouting holes should be perpendicular to the pavement surface.

[0087] 2) Cleaning the hole After the grouting hole is formed, use compressed air to remove debris from the hole. The grouting hole should be kept dry. If grouting cannot be performed immediately after the hole is formed, the hole should be temporarily plugged.

[0088] 3) Monitor plate disturbances A level instrument is set up near the grouting area, usually 30 to 40 meters away, to monitor the lifting of the grouting slab in real time.

[0089] 4) Grouting should be stopped under the following circumstances: ① The grouting slab was lifted by 3mm; ② Grout is seeping out from the horizontal and vertical joints or other grouting holes of the paving panel; ③ The grouting machine pump pressure suddenly rises rapidly; ④ Situations such as excessive pressure under the grouting nozzle or grout spraying out indicate that the pressure is too high.

[0090] 5) Secondary grouting Secondary grouting can effectively improve grouting quality, especially the uniformity of the under-slab support. Secondary grouting should be carried out 0.5 hours before the initial setting of the previous grout.

[0091] 6) Sealing the holes After grouting stops, the grouting holes should be temporarily sealed with materials such as wooden plugs and cotton yarn; after the grout has initially set, the temporary sealing materials can be removed, and the grouting holes can be sealed with quick-repair material.

[0092] 2) Maintenance The curing time is determined based on the properties of the grout, and traffic can only be opened after the grout has initially set.

[0093] IV. Plate Grinding 1) For plates with a misalignment height difference of no more than 10mm, the misalignment can be eliminated by plate grinding. Use a grinding machine to grind the plate, starting from the highest misalignment point and gradually grinding outwards. 2) The amount of material ground at one time should not be too large to avoid damaging the pavement. Misalignment should be eliminated through repeated grinding. 3) A 3m ruler can be used for measurement during the grinding process. The grinding control standard is that the height difference between adjacent boards is less than 3mm. 4) For plates with large misalignment, a grinding machine with a cutting blade can be used to cut them first, and then they can be ground.

[0094] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, substitutions, or improvements 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 treating runway defects in old airports located in high-temperature areas, characterized in that: Includes the following steps: S1. Pavement Defect Assessment and Classification: Pavement defects are identified through on-site inspection, radar detection, and ultrasonic testing. Based on the measurement and statistical results, pavement defects are classified into cracked slabs, joint defects, vertical displacement of pavement panels, and surface defects. The severity of defects is classified into mild, moderate, and severe. S2. Treatment Plan: Based on the type of pavement defects, a treatment plan is planned, specifically including treatment strategies for cracked and broken slab defects, joint defects, vertical displacement defects of pavement panels, and surface defects. Specific technical solutions are used to treat the specific defects through joint or crack filling processes, partial thickness repair processes for pavement panels, full thickness repair processes for panels, foundation grouting processes, and slab grinding processes. S3. High-temperature resistant composite overlay treatment: A modified asphalt concrete overlay is laid on the repaired pavement, and a high-temperature stabilizer is added to enhance its high-temperature resistance; a high-temperature anti-aging spray coating is then laid on the modified asphalt concrete overlay to improve its weather resistance and UV resistance. S4 Interface Reinforcement and Drainage Optimization: Interface bonding materials are used to improve the bonding force between the old pavement and the new paving layer, preventing the interface layer from detaching; the drainage system of the pavement is optimized by adjusting the slope and adding drainage channels to reduce the damage to the pavement caused by rainwater retention.

2. The method for treating runway defects in high-heat areas as described in claim 1, characterized in that: Treatment strategies for cracked or broken slabs include full-thickness repair, partial-thickness repair, or crack filling. In full-thickness repair: If a single slab has multiple longitudinal, transverse, or diagonal cracks, and the length of a single crack exceeds half the length of the short side of the slab, and the average width of one of the cracks is greater than 10 mm, then the entire slab should be replaced. During the slab restoration process, the original dowel bars or tie bars should be restored. If corner fractures occur, or there is obvious misalignment between the slabs on both sides of the crack, or obvious mud pumping occurs around the crack, the base layer should be treated first, and then the slabs in the area affected by the crack should be repaired using the full-thickness repair process. In partial thickness repair: When there is no obvious misalignment of the slabs around the crack, but there is relatively serious spalling, partial thickness repair is carried out on the slabs in the area affected by the crack; the repair depth is half the thickness of the slab, and the connection between the patch and the original pavement is strengthened by setting connecting nails; subsequent repair is carried out using partial thickness repair technology; In crack filling: when cracks do not intersect, there is no obvious misalignment on both sides of the cracks, the average width of the cracks is less than 5mm, and there is no obvious spalling around the cracks, the crack filling process is used for repair.

3. The method for treating runway defects in old airports in high-temperature areas as described in claim 1, characterized in that: In the treatment strategies for joint defects: The sections of the added concrete slab should be completely consistent with those of the old slab; the joints of the upper and lower slabs should be aligned, and when misalignment occurs occasionally, the error should not exceed 30mm. When irregularly shaped slabs appear on the old pavement, causing the additional concrete slabs to be inconsistent with the original pavement slabs, the original pavement surface is cut according to the dimensions of the additional slabs, and then the cuts are filled with joint filler. For areas where the old pavement concrete with irregularly shaped slabs is segmented but the overlay layer does not require segmentation, the joints of the old pavement slabs are covered with asphalt felt before the overlay layer concrete is poured.

4. The method for treating runway defects in high-heat areas as described in claim 1, characterized in that: In the countermeasures for vertical displacement defects of pavement panels: Pumping and voids at the bottom of the slab: Use foundation grouting and replace the grouting material at the joints; Settlement or misalignment: Take the following remedial measures according to the amount of misalignment or settlement: If the misalignment or settlement is less than 5 mm, replace the grouting material at the joint of the misaligned or settled plate. When the misalignment or subsidence is between 5 and 10 mm, the misalignment should be eliminated by grinding the plates. When the misalignment or subsidence, that is, when the height difference H between the subsided slab (1) and the adjacent slab (2) is greater than 10 mm, partial thickness repair shall be carried out. The repair depth shall be 5 to 10 cm, the repair width shall be determined by the height difference H, and the slope i of the repair surface shall not be greater than 1%. Specifically, a repair space with a width of 100H is cut out in the sunken plate (1) and the adjacent plate (2). Concrete is poured in the repair space to form a repair block (3). The slope of the repair surface of the repair block (3) shall not be greater than 1%. The upper part of the repair block (3) and the adjacent plate (2) are filled with grouting material (4). If the slab bulges, make a full-thickness cut at the joint where the bulge is located, with a cut width of 3-5 cm. Clean out any debris from the joint and replace the grouting material after the stress has been fully released.

5. A method for treating runway defects in high-heat areas as described in claim 1, characterized in that: The repair process for the thickness of the deck panel includes: 1) Determine the size of the patch; The minimum repair depth is 5cm, and the maximum repair depth is half the plate thickness. The force transmission rod and tie rod must not be damaged. The maximum side length of the repair block shall not exceed 2m, and the minimum shall not be less than 0.15m. The repair area extends 5-10 cm outward from the affected area. The repair block should be a regular rectangle with an aspect ratio of less than 2:

1. For repair blocks with irregular dimensions or an aspect ratio greater than 2:1, repair should be done in multiple stages to ensure that each block meets the dimensional requirements. Alternatively, a single repair can be performed, with the block cut immediately after pouring. After cutting, the block should meet the aspect ratio requirement of less than 2:1, and the cut should be filled. When the repair location is at a corner of the board and the short side dimension of the repair block is greater than 0.5m, the repair block should be polygonal. When the distance between two adjacent patch blocks is less than 30 cm, they should be repaired together; when patch blocks cross joints, effective isolation measures should be taken at the joint location; 2) Slab cutting Draw boundary lines according to the repair area. The pavement cutting machine cuts along these lines, with the cutting depth as close as possible to the depth of the patch, but the minimum cutting depth should not be less than 5cm. To reduce the impact of pavement breakage on surrounding intact slabs, after boundary cutting, the concrete within the repair area is cut in a grid pattern, as follows: First, make slits along the long side of the patch, with a spacing of 2-6 cm and a depth of 5 cm; Then, cut two slits along the short side at a distance of 4 cm from the repair boundary, with a cutting depth of 5 cm. 3) Pavement breakage; repair the cement concrete within the breakage area from the center outwards; when the breakage depth exceeds half the slab thickness, use full-thickness repair; Draw boundary lines according to the repair area. The pavement cutting machine cuts along the drawn lines, and the cutting depth should be as similar as possible to the depth of the patch, with a minimum cutting depth of 5cm. To reduce the impact of pavement breakage on surrounding intact slabs, the concrete within the repair area is then cut in a grid pattern after the boundary cutting. The cutting method is as follows: First, make slits along the long side of the patch, with a spacing of 2-6 cm and a depth of 5 cm; Then, cut two slits along the short side at a distance of 4 cm from the repair boundary, with a cutting depth of 5 cm. 4) Cleaning of pits and grooves When the patch is located at the edge or corner of the board, the joint adjacent to the patch needs to be treated. When breaking and cleaning, remove the grouting material and backing strip in the joint. Before pouring, place a compressible isolation plate at the joint. The compressible isolation plate includes a rubber plate or a foam plate, and its width is the same as the original joint width. 5) Concrete mixing and pouring Concrete mixing: After estimating the amount of concrete needed for repair, calculate the amounts of cement, aggregates, additives, and water, and weigh them accurately; use forced mixing equipment, mix evenly, and pour immediately. Concrete pouring: Ensure the pit is clean and the walls are free of dust; the pit and bottom should be moist but not waterlogged; the concrete should be poured in one go, and for larger areas, it should be poured in one direction. When pouring manually, use a shovel to spread the concrete and do not throw it. Concrete vibration: Vibration at the same location should not be less than 10 seconds, until the concrete stops falling and no more bubbles or slurry appear; the moving distance of the vibration equipment should not be greater than 1.5 times its radius of action; the overlap between two vibration locations should be 10~20cm; 6) Leveling and surface finishing It is strictly forbidden to sprinkle water or roughen the concrete surface during finishing; first use a long board to roughly level it, then use a plastic trowel and a steel trowel to finish the surface, applying the trowel at least three times, following the procedure below: The first troweling is done by smoothing back and forth along the transverse slope, with the front and back troweling overlapping by 1 / 2. This is mainly used to knead and press the slurry, press down the exposed stones, eliminate obvious unevenness, and accelerate the evaporation of moisture. After the moisture has slightly evaporated, apply a second layer of sizing along the transverse slope. This is mainly used to squeeze out air bubbles, press sand into the board surface, eliminate sand holes, and make the board surface dense. The final squeegee is used to remove any remaining uneven marks on the board surface and accelerate the evaporation of moisture from the board surface; 7) Laying the hair After the surface is smoothed, it needs to be roughened. The roughening time should be earlier rather than later. You can use your index finger to press the concrete surface slightly. When you feel that the concrete has a certain strength but is not completely hard, you can roughen it. The texture of the roughening process should be perpendicular to the wheel track direction; the average texture depth of the roughened surface should be greater than 0.4 mm; roughening should not cause slurry heaving or loosening; during the roughening process, cement slurry adhering to the roughening tool should be frequently washed with water. 8) Maintenance After roughening is completed, before the concrete initially sets, spray a curing agent to keep it moist and maintain its moisture for at least 7 days.

6. A method for treating runway defects in high-heat areas as described in claim 1, characterized in that: Full-thickness panel repair process includes: 1) Patch (5) Repair size The shortest side length of the patch (5) should not be less than 60cm. The repair range extends 5-10cm outward from the area affected by the disease. The patch (5) should be full thickness repaired. The shape of the patch (5) should be a regular rectangle with a length-to-width ratio of less than 2:

1. Slender strips with an aspect ratio greater than 2:1 - Repair in sections according to the requirement of an aspect ratio of 2:1, and add tie rods (8) between adjacent strips; Alternatively, after pouring once, cut the strips according to the requirement of an aspect ratio of 2:1, and fill the cut joints; Repair both damaged areas together if the distance between two adjacent damaged areas is less than 60cm. When patching (5) across a joint, separate the patch along the joint for repair; 2) Panel cutting Use a slit cutter to cut along the repair boundary, the deeper the cut the better, the minimum depth should not be less than 10 cm; 3) Panel broken Large slabs are broken with a hydraulic breaker, and small slabs are broken with a pneumatic pick from the center outwards. When breaking, care should be taken to protect the corners of the patch blocks. The power of the breaking equipment should not be too high. The original force transmission rod (6), original tie rod (7) and reinforcing steel mesh in the original pavement need to be removed. 4) Grassroots processing 5) Add tie rods When the patch area is large, that is, the long side is greater than 2m and the short side is greater than 1m, a tie rod (8) is added between the patch and the adjacent slab of the original pavement. The tie rod (8) is made of threaded steel bar with a length of 70cm and a diameter of 14 or 16. It is added in the center of the slab thickness and is treated with rust prevention. Add tie rods (8) at equal intervals, with a spacing of 50 cm and a minimum burial depth of 30 cm on one side; The outermost tie rod (8) is installed at a distance of 25-35cm from the edge of the patch block or the pavement joint; After installation, the vertical and horizontal deviations of the two ends of the added tie rod (8) should be less than 20mm; 6) Installation of reinforcing steel mesh The flexural strength of the patch is improved by setting up a steel mesh. The reinforcing steel mesh can be set in a single layer or double layer. The reinforcing bars are placed within 1 / 3 to 1 / 2 of the slab thickness below the upper surface of the slab, or a double-layer reinforcing mesh is used; The outermost reinforcing bar is about 10cm away from the edge of the patch, and the thickness of the concrete cover for the reinforcing bar is not less than 5cm. Longitudinal and transverse reinforcing bars shall be of the same diameter. If they are different, the difference shall not exceed 0.4 cm. The minimum clear spacing between reinforcing bars shall not be less than twice the maximum particle size of the aggregate. While meeting the requirements for rebar spacing, smaller diameter rebars should be used, and the minimum diameter and maximum spacing of the rebars must meet the design requirements. The lap length of the reinforcing bars shall not be less than 35 times the diameter of the reinforcing bars, and shall be obtained by binding or welding. The lap positions should be staggered. The steel mesh should be pre-embedded horizontally as much as possible, and the horizontal height difference between the two sides should be controlled within ±1cm. 7) Joint treatment When the patch is located at the edge or corner of the pavement, the existing joints of the pavement should be treated: During breaking and cleaning, remove the sealant and backing strip from the joints; Before pouring, a compressible isolation board (10) is placed at the joint. The compressible isolation board (10) is a rubber board or a foam board with the same width as the original joint. After pouring, a backing strip (11) and a grouting material (4) are filled on the top of the compressible isolation board (10) such as the rubber board or foam board at the joint. If the original joint has the original force transmission rod (6) or the original tie rod (7), it should be restored to its original state. When restoring, drill holes and reinstall at a position 10~20cm horizontally offset from the original force transmission rod (6) or the original tie rod (7); 8) Add a force transmission rod (9) Set When the length of the joint direction is greater than 2m, that is, when the patch area is large, the original force transmission bar at the joint is restored, that is, an additional force transmission bar is installed (9): Add a force transmission bar (9) using plain round steel bars and set in the center of the slab thickness; A dowel bar (9) is usually added at the joint, with half its length plus 5cm, and coated with a thin layer of asphalt or a plastic sleeve. (9) Add a sleeve to the asphalt-coated end, leaving a gap inside, and fill it with foam plastic and yarn. The sleeve ends are arranged alternately. The distance between the outermost force transmission rod (9) and the joint or sliding end should be between 15 and 20 cm; 9) Cleaning of pits and grooves Remove broken pieces and other debris from the pit, then clean it with a high-pressure water gun, and finally clean and repair the pit with high-pressure air to ensure that there is no debris or dust in the pit. 10) The requirements for concrete pouring, leveling, surface finishing, roughening, and curing are the same as those for partial thickness repairs.

Images