Design and construction method of non-compaction normal temperature mixing and pouring type resin mixture

Abstract

The application provides a design and construction method of a non-compaction normal-temperature mixing pouring type resin mixture, which comprises raw material selection, mixture mixing ratio design, mixture performance detection, mixture mixing, transportation, paving and resin premixed gravel spreading. The application utilizes the characteristics of high strength, fast curing, high temperature resistance and fatigue resistance of the modified epoxy resin to prepare a high durability steel bridge deck paving material with excellent high and low temperature performance and excellent fatigue performance, and meanwhile, the non-compaction pouring type construction process effectively improves the construction workability and saves the economic cost by utilizing the characteristics of self-flow forming and no need of rolling. The application solves the technical problems of complicated steel bridge deck paving construction process, difficult construction quality control, rut and crack diseases of the steel bridge deck paving during service period and the like, and is a low-carbon, green, environment-friendly, simple-to-construct, excellent road performance and long service life new road material technology.

Description

Technical Field

[0001] This invention relates to a steel bridge deck paving material and a steel bridge deck paving construction method, specifically to a design and construction method for a non-compacting, room-temperature mixing and casting resin mixture. Background Technology

[0002] Due to the relatively large deformation and relatively low stiffness of long-span steel bridge decks, steel bridge deck pavement is easily affected by factors such as vehicle loads, temperature, humidity, and the structure of the steel bridge deck. The stress and deformation are complex, requiring high standards in terms of strength, flexibility, high-temperature stability, low-temperature crack resistance, and fatigue durability. Steel bridge deck pavement remains a global technical challenge. Due to the special location and function of steel bridge deck pavement, the pavement layer structure also requires lightweight, good adhesion, and waterproofing. The most widely used steel bridge deck pavement materials in the world are mainly divided into the following categories: 1) cast-in-place asphalt concrete; 2) modified dense-graded asphalt concrete; 3) modified asphalt SMA; and 4) epoxy asphalt concrete. These pavement materials are used in long-span steel bridges in my country, but many bridges have developed early defects such as rutting, cracking, shoving, and fatigue failure shortly after opening to traffic, as well as steel structure damage such as steel plate corrosion. The problem of defects in steel bridge deck pavement in my country remains quite serious.

[0003] Mainstream steel bridge deck paving materials and construction technologies all have obvious drawbacks. For example, cast-in-place asphalt concrete has excellent waterproof performance but insufficient high-temperature stability; modified dense-graded asphalt concrete has poor high-temperature stability and fatigue resistance; modified asphalt SMA has insufficient fatigue resistance; and epoxy asphalt concrete has excellent high-temperature stability but insufficient low-temperature crack resistance. The key to the success of steel bridge deck paving is to enable paving materials and structures to simultaneously possess high high-temperature stability, low-temperature crack resistance, fatigue durability, water damage resistance, and simple construction technology under heavy traffic loads and harsh environmental conditions, so as to effectively prevent or delay the occurrence of rutting and cracking in the paving layer.

[0004] Currently, the construction of steel bridge deck paving materials, both domestically and internationally, mainly employs high-temperature construction methods. This requires heating aggregates and asphalt to 160-240℃, which not only consumes a large amount of energy but also emits a large amount of harmful gases and dust, severely polluting the environment. This is inconsistent with the current national recommended green development concept and the development goals of "carbon peaking" and "carbon neutrality".

[0005] Epoxy resin is a commonly used polymer material, mainly composed of epoxy resin and a curing agent. After reacting with the curing agent, the epoxy resin forms a three-dimensional cross-linked network, giving the material its insoluble and infusible properties, i.e., thermosetting. Therefore, unlike thermoplastic asphalt, epoxy resin road materials have excellent high-temperature resistance. Simultaneously, epoxy resin road materials also possess excellent mechanical properties, corrosion resistance, and fatigue resistance. However, this highly cross-linked network structure also determines that traditional epoxy resin cured products have poor toughness. At low temperatures, epoxy resin cured products are even more brittle, which affects the low-temperature crack resistance of epoxy resin concrete pavements. Furthermore, under the influence of heat and ultraviolet light, the epoxy resin molecules absorb radiation energy, and the bond energy breaks to generate free radicals (Ro). These free radicals then combine with oxygen molecules, causing changes in the epoxy resin structure and a decrease in relative molecular mass or cross-linking, ultimately leading to a significant reduction or even loss of the epoxy resin's anti-aging properties.

[0006] Patent document CN113214661A discloses a design and construction method for castable epoxy rubber powder composite modified asphalt mixtures. This technology combines the adjustable and controllable elastic modulus of epoxy resin with the high viscosity and high elasticity of rubber-modified asphalt to prepare a high-durability steel bridge deck pavement material with adjustable and controllable modulus and excellent high and low temperature performance. It solves the problem of insufficient flexibility in general epoxy composite asphalt, which easily leads to brittle failure under cold climate conditions. However, it does not consider optimizing the anti-aging performance of the mixture in environments with ample sunlight and strong ultraviolet radiation. The construction method provided in this application optimizes the mixing, transportation, and paving processes of the mixture, but its construction temperature is based on a high-energy-consuming mode of 220-240℃, which is inadequate in terms of economic and environmental considerations.

[0007] Patent document CN106927723B discloses a large-void cold-mix epoxy resin mixture and its preparation method. This technology utilizes the high strength and stiffness of epoxy resin, while replacing 0-3mm particle size mineral aggregates with an equal amount of 1-3mm rubber particles. This ensures the overall structure of the mixture maintains strength while exhibiting a certain degree of flexibility, resulting in good high-temperature deformation resistance and good low-temperature crack resistance. However, the control of the rubber powder content is not detailed. Excessive rubber powder content can lead to varying degrees of decrease in the compressive strength, flexural strength, and splitting tensile strength of the epoxy resin concrete. Furthermore, the larger voids allow water and air to penetrate the cold-mix resin mixture, accelerating the wet-heat aging process and reducing its service life.

[0008] Patent document CN110847035A discloses a method for constructing roller-compacted asphalt concrete for steel bridge decks. This method employs an overlay of pre-coated material, effectively improving the high-temperature stability of the bridge deck pavement, reducing rutting, and enhancing driving comfort and durability. However, this method does not fundamentally solve the problem of steel bridge deck pavement defects. Under prolonged heavy loads and harsh environments, rutting and cracking are still prone to occur. Furthermore, this method does not consider the economic and environmental issues under high-temperature construction conditions. Summary of the Invention

[0009] To address the aforementioned shortcomings, this invention provides a design and construction method for non-compacted, room-temperature mixed, castable resin mixtures. Building upon castable asphalt mixture paving technology, this method overcomes the limitations of high-temperature stability while retaining excellent waterproofing, crack resistance, deformation coordination, durability, and ease of construction. It changes the high-energy-consuming construction mode of castable asphalt concrete, which operates at temperatures as high as 220–240°C, significantly reducing energy consumption and carbon emissions. This green and environmentally friendly approach simplifies the construction process and lowers economic costs.

[0010] The technical solution to achieve the above objectives is as follows:

[0011] A design method for non-compacting, room-temperature mixing and casting resin mixtures includes the following steps:

[0012] Step 1: Select raw materials: including coarse aggregate, fine aggregate, mineral powder, modified epoxy resin, curing agent, polyester fiber, and epoxy resin anti-aging modifier;

[0013] Step 2: Mix design of aggregate: Select three gradations (fine, medium, and coarse) and preliminarily determine the asphalt-aggregate ratio. Use Leuer flowability test to preliminarily determine the gradation type and the mass ratio of each aggregate. If the estimated asphalt-aggregate ratio is within the predetermined range, take multiple different asphalt-aggregate ratios to conduct Leuer flowability test and semicircular bending fracture (SCB) test. Determine the optimal asphalt-aggregate ratio based on the fracture toughness and Leuer value obtained from the test.

[0014] Step 3: Performance testing of the mixture: The performance of the cast resin mixture is tested through water damage resistance test, low temperature crack resistance test, high temperature rutting test and fatigue test.

[0015] Furthermore, in step 1, the coarse aggregate is rolled from basalt and has a particle size of 5-10 mm; the fine aggregate is made from basalt rock and has a particle size of 0-5 mm; and the mineral powder is ground from limestone.

[0016] Further, in step 1, the tensile strength of the modified epoxy resin at 23°C ranges from 0.5 to 3.0 MPa, the elongation at break at 23°C is not less than 150%, and the curing time at 23°C is not more than 24 hours and not less than 1 hour. The modified epoxy resin is cured at room temperature and consists of two components, A and B. Component A is epoxy resin and component B is curing agent. The mass ratio of components A to B is 2:1 to 1:1. The tensile strength of the polyester fiber is not less than 500 MPa, and the elongation at break is not less than 30%. The anti-aging modifier is a hindered amine light stabilizer and an ultraviolet absorber, UV-X.

[0017] Furthermore, in step 2, the relationship between the particle size of the cast resin mixture and the passing rate of each sieve aperture is as follows:

[0018] 9.5mm 95-100%

[0019] 4.75mm 65-85%

[0020] 2.36mm 45-62%

[0021] 0.6mm 35-50%

[0022] 0.3mm 28-42%

[0023] 0.15mm 25-34%

[0024] 0.075mm² 20-27%.

[0025] Furthermore, in step 2, the optimal asphalt-aggregate ratio of the cast resin mixture is 8.0–10.0%; the dynamic stability of the cast resin mixture at 70°C is not less than 10,000 cycles / mm; and the ultimate bending strain of the cast resin mixture at -10°C is not less than 10,000 με.

[0026] A construction method for a non-compacting, room-temperature mixing and casting resin mixture, using the non-compacting, casting resin mixture obtained by the above-mentioned design method, includes the following steps:

[0027] Step 1: First, mix the binder: The binder includes hindered amine light stabilizer and UV absorber UV-X as anti-aging modifiers, epoxy resin of component A, and curing agent of component B. Weigh the hindered amine light stabilizer and UV absorber UV-X, which each account for 0.25-0.45% of the binder mass. First, add the hindered amine light stabilizer and UV absorber UV-X to the curing agent of component B and mix evenly. Then add the epoxy resin of component A and mix evenly for later use. The binder is prepared separately before each batch of mixes. Then, mix the mix: After adding coarse aggregate, fine aggregate, and mineral powder to the mixer, add polyester fiber, which accounts for 1-3‰ of the mix mass. Dry mix for 10-15 seconds, then immediately add the binder and wet mix for 40-50 seconds.

[0028] Step 2: Mixture Transportation: The transportation of cast resin mixtures uses ordinary trucks or specialized transport equipment called Cooker. Cooker mainly consists of two parts: a resin mixture mixing system and a mixing tank. The transportation distance and time should be minimized within the allowable carrying time.

[0029] Step 3: Asphalt Mixture Paving: ① Preparatory work before paving: The paving area should be cleaned in advance. If there is moisture on the surface, it should be thoroughly dried. Oil stains, debris, and dust should be cleaned. Wooden boards or guide rails of the same thickness should be fixed in the specific paving area as a reference for paving; ② Paving: Cast resin mixture is paved at room temperature using a conventional asphalt paver equipped with an automatic screed. The paver does not require heating. Ordinary trucks or cookers should pour the cast resin mixture into the paver hopper via the side feeder; ③ Joint treatment procedures: a. Transverse construction joints: Templates should be erected in advance at the locations where transverse construction joints are to be set before paving. When the machine travels to about 10 meters from the template, slow down the paving speed and finish laying the previously laid material. When it reaches the transverse joint, the paver smoothly lays the remaining material over the joint. Lift the machine on the end template and clean up the remaining material. Then, manually tamp and smooth the mixture at the transverse joint to ensure that the material and template joint are tight. b. Longitudinal joint: Set templates in advance in the longitudinal direction. Apply a release agent to the area where the template side contacts the cast-in-place mixture. After the paver is behind, use a wooden trowel to tamp and treat the surface of the longitudinal joint to ensure that the mixture at the longitudinal joint is tight and the surface is flat. After the mixture is laid and has formed a certain strength, remove the template to keep the joint with a smooth and vertical cross section.

[0030] Step 4: Spreading premixed crushed stone: Use a conventional crushed stone spreader. After the mixture paving process is completed, immediately spread resin premixed crushed stone on the surface so that the premixed crushed stone is embedded in the cast resin mixture.

[0031] Furthermore, in the mixing step, the production process of the cast-in-place resin mixture is all done at room temperature, without the need for any heating equipment.

[0032] Furthermore, in the transportation step, the castable resin mixture is transported from the mixing plant to the construction site by a clean-surfaced ordinary truck or cooker. The inner surface is coated with a thin layer of edible oil to prevent the mixture from sticking to the cargo hold. Each truckload is covered with a tarpaulin or other sufficiently large permitted material to prevent the mixture from being soaked by rain or exposed to direct sunlight, which could cause the temperature to rise.

[0033] Furthermore, in the paving step, the cast-in-place resin mixture is paved in one layer, and the paver's traveling speed is controlled within the range of 2.0 to 5.0 m / min, depending on the mixing production capacity.

[0034] Furthermore, in the step of spreading premixed crushed stone, 0.2% to 0.3% by mass of modified epoxy resin is added to basalt with a particle size of 3 to 5 mm and stirred evenly to serve as the material for spreading premixed crushed stone after paving.

[0035] Compared with the prior art, the advantages of the present invention include:

[0036] (1) The castable resin mixture of the present invention has excellent high-temperature stability, which can effectively improve the high-temperature rutting resistance of the bridge deck pavement layer; it has excellent deformation capacity and good integrity, which can ensure the effective bonding between the pavement layer and the bridge deck; its excellent deformation coordination performance can better adapt to the deformation of the bridge deck steel plate and improve the bonding performance between the pavement layer and the bridge deck; the castable resin mixture is designed with gradation and asphalt-aggregate ratio based on crack resistance performance, which has excellent crack resistance and helps to solve the problem of cracking defects that easily occur in steel bridge deck pavement; the castable resin mixture has a very small porosity and discontinuous internal pores, which has excellent water tightness, so water will not penetrate into the steel bridge deck, effectively protecting the main structure of the bridge from corrosion;

[0037] (2) This invention proposes a pressure-free construction method, which simplifies the construction process, reduces project costs, and reduces the difficulty of quality control;

[0038] (3) Based on room temperature curing modified epoxy resin, this invention proposes a room temperature construction method, which changes the high energy consumption mode of cast-in-place asphalt concrete construction temperature of up to 220-240℃, greatly reduces energy consumption and carbon emissions, is green and environmentally friendly, simplifies the construction process, and also reduces economic costs. Attached Figure Description

[0039] Figure 1 A process flow diagram for the design and construction method of room temperature mixing and casting of resin mixtures to avoid compaction. Detailed Implementation

[0040] The present invention will now be described in detail with reference to specific embodiments, and the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0041] The design method for non-compacting castable resin mixtures in this embodiment includes the following steps:

[0042] Step 1: Select raw materials: including coarse and fine aggregates, mineral powder, modified epoxy resin, curing agent, polyester fiber, and epoxy resin anti-aging modifier.

[0043] ① Coarse aggregate. The test coarse aggregate was rolled from basalt. The various technical indicators of the coarse aggregate were measured in accordance with the "Specifications for Testing Aggregates in Highway Engineering" (JTG E42-2005). The results are shown in Tables 2 and 3.

[0044] Table 2 Results of coarse aggregate screening test

[0045]

[0046] Table 3 Technical test results of coarse aggregates

[0047]

[0048] ② Fine aggregate. Basalt was selected as the aggregate. The technical indicators of the fine aggregate were tested according to the "Specifications for Testing Aggregates in Highway Engineering" (JTG E42-2005). The results are shown in Tables 4 and 5.

[0049] Table 4 Results of fine aggregate screening test

[0050]

[0051]

[0052] Table 5. Technical test results of fine aggregates

[0053]

[0054] ③ Filler. Finely ground limestone powder was selected. Tests were conducted according to the "Specifications for Testing Aggregates in Highway Engineering" (JTG E42-2005), and the results are shown in Table 6.

[0055] Table 6. Results of Technical Testing of Mineral Powder

[0056]

[0057] ④ Polyester fiber. Polyester fiber was added during the mixing process of the cast resin mixture at a dosage of 3‰ (ratio to the mass of the mixture). The performance test results of the polyester fiber are shown in Table 7.

[0058] Table 7 Results of Polyester Fiber Performance Tests

[0059]

[0060] ⑤ Epoxy resin anti-aging agent. Hindered amine light stabilizer and ultraviolet absorber UV-X are added during the binder mixing process, each at a ratio of 0.3% of the binder.

[0061] In this embodiment, the test results of the technical indicators of the modified epoxy resin binder are shown in Table 8.

[0062] Table 8 Test Results of Technical Indicators of Modified Epoxy Resin Binder

[0063]

[0064] Step 2: Mix design of aggregate: Select three gradation forms (fine, medium, and coarse) and preliminarily determine the asphalt-aggregate ratio. Use Leuer flowability test to preliminarily determine the gradation form and the mass ratio of each aggregate. Within the range of ±0.5% of the estimated asphalt-aggregate ratio, take three different asphalt-aggregate ratios to conduct Leuer flowability test and SCB test. Determine the optimal asphalt-aggregate ratio based on the fracture toughness and Leuer value obtained from the test.

[0065] Based on the aggregate screening results, fine, medium, and coarse gradations were selected with a passing rate of 2.36 mm as the gradation control point. Table 9 shows the passing rates of the three composite gradations.

[0066] Table 9. Details of the pass rates for the three synthetic gradations.

[0067]

[0068] Based on the initial proposed oil-aggregate ratio of 8.5%, a mix design test was conducted according to the three initially selected gradations, namely the Liuer flowability test. The test results are shown in Table 10.

[0069] Table 10 Results of Flowability Test

[0070]

[0071]

[0072] The gradation type selected in the embodiment is medium gradation, as shown in Table 11.

[0073] Table 11 Gradation of Mixture

[0074]

[0075] Based on the determined gradation, with an initial oil-aggregate ratio of approximately 8.5%, three different oil-aggregate ratios were selected and subjected to Leuer flowability tests and SCB tests, varying by ±0.5%, to determine the optimal oil-aggregate ratio. The test results are shown in Table 12.

[0076] Table 12 Results of SCB and Liu El tests

[0077]

[0078] Based on both fracture toughness and Liueel value, the optimal asphalt-aggregate ratio in this embodiment was determined to be 8.5%. At this ratio, the mixture achieves a self-flowing and compacted effect. At the optimal asphalt-aggregate ratio, the porosity of the modified epoxy resin mixture is 1.0%, and the Liueel value is 12s.

[0079] Step 3: Performance testing of the mixture: The performance of the cast resin mixture is tested through water damage resistance test, low temperature crack resistance test, high temperature rutting test and fatigue test.

[0080] (1) High-temperature performance. The high-temperature stability was tested using a rutting test. Three specimens were tested. The wheel pressure for the rutting test was 0.7 MPa, and the test temperature was 70℃. The deformation values ​​of the rutting plate were recorded at 45 min and 60 min. The test results are shown in Table 13.

[0081] Table 13 Rutting Test Results of Cast Resin Mixtures

[0082]

[0083] (2) Low-temperature performance. The low-temperature performance was tested using a small beam low-temperature bending test, and a total of 6 specimens were tested. The test temperature was set at -10℃ and the loading rate was 50mm / min. The results of the low-temperature bending test of the cast resin mixture small beam are shown in Table 14.

[0084] Table 14 Results of Low-Temperature Bending Test on Beams

[0085]

[0086] (3) Water resistance. The water resistance was tested using a freeze-thaw splitting test. Marshall specimens were prepared and cured according to the Marshall specimen molding method. The specimens were then randomly divided into a reference group and a test group, with 5 specimens in each group. During the test, the specimens were first immersed in water at 25℃ for 20 min, then immersed in water at 0.09 MPa under vacuum for 15 min, then placed in a -18℃ low-temperature chamber for 16 h, then kept at a constant temperature in a 60℃ water bath for 24 h, and finally immersed in water at 25℃ for 2 h before testing. The test results are shown in Table 15.

[0087] Table 15 Results of Freeze-Thaw Splitting Test for Cast Resin Mixtures

[0088]

[0089] (4) Fatigue performance. The fatigue performance was tested using a strain-controlled four-point beam bending fatigue test. Before the test, the specimen was kept at 15±0.1℃ for more than 6 hours. The strain value ε was determined before the test and used to control the test. The test was terminated when the stiffness modulus dropped to half of the initial value. The number of tests at this point is the fatigue life. The results of the strain-controlled four-point beam bending fatigue test are shown in Table 16.

[0090] Table 16 Fatigue Test Results

[0091]

[0092] The construction method for non-compacting cast-in-place resin mixtures in this embodiment includes the following steps:

[0093] Step 1: Mixing of Asphalt Mixtures: Traditional asphalt mixing plants or other equipment such as cement concrete mixing plants can be used. Binder Mixing: Weigh the hindered amine light stabilizer and UV absorber UV-X, and add them to component B (curing agent) at the specified ratio (0.25-0.45% of the binder weight), and mix thoroughly. Then add component A (epoxy resin), mix thoroughly, and set aside. The binder should be prepared separately before each batch of mix. Mixing of Asphalt Mixtures: After adding coarse aggregate, fine aggregate, and mineral powder to the mixer, add polyester fiber (1-3‰ of the mix weight), dry mix for 10-15 seconds, then immediately add the binder and wet mix for 40-50 seconds.

[0094] Key points of the process: (1) Before starting production, the weighing system of each silo, mineral powder silo and resin in the mixing plant should be weighed to confirm the accuracy of the weighing in the mixing plant. Aggregates of different particle sizes should be stored separately. At the same time, ensure that the storage location is hardened and dry, and take measures to prevent rain and moisture. The entire production process of the cast resin mixture is carried out at room temperature and no heating equipment is required.

[0095] Step 2: For transporting injection-type resin mixtures, ordinary trucks or specialized transport equipment (Cooker) can be used. The Cooker mainly consists of two parts: a resin mixture mixing system and a mixing tank. Minimize transport distance and time within permissible carrying time limits.

[0096] Key points of the process: (1) Before loading, clean the ordinary transport truck or Cooker truck and carefully check the mixing system to avoid malfunctions after loading the mixture. Before construction, check the condition of the ordinary transport truck or Cooker truck, the fuel level, and the tarpaulin covering the vehicle.

[0097] (2) Before loading, the inner surface of the cast resin mixture in a regular truck or Cooker should be coated with a thin layer of edible oil to prevent the mixture from sticking to the cargo hold. Each truckload should be covered with a tarpaulin or other sufficiently large permitted material to prevent the mixture from being soaked by rain or exposed to the sun and causing the temperature to rise.

[0098] 6. Asphalt Mixture Paving. Cast resin mixtures can be paved using asphalt pavers. A paver mainly consists of three parts: self-traction, paving, and pre-layout. It should be equipped with an automatic screed. Cast resin mixtures are paved at room temperature, and the paver does not require heating. Ordinary trucks or cookers should pour the cast resin mixture into the paver's hopper via a side feeder.

[0099] Key points of the process: (1) Preparations before paving. The paving area should be carefully cleaned in advance, and any moisture on the surface should be thoroughly dried. Fixed wooden boards or guide rails of the same thickness should be fixed in the specific paving area as a reference for paving.

[0100] (2) The test personnel must conduct a Leuer test on the mixture delivered to the site to ensure that the fluidity of the mixture is within 20 seconds before it can be laid. When laying the surface layer mixture, the machine travel speed should be controlled at 3m / min according to the mixing production capacity.

[0101] (3) It is not permitted to pile the mixture on the ground first and then have it shoveled up by a loader and loaded into the paver hopper. The reason for using a side feeder is to avoid ordinary trucks or cookers traveling on lanes with adhesive.

[0102] (4) Jointing Procedures: ① Transverse Construction Joints: A template is erected in advance at the transverse construction joint location. When the paver is about 10 meters away from the template, the paving speed is slowed down to complete the previously laid material. Upon reaching the transverse joint, the paver smoothly carries the remaining material across the joint. The paver is then lifted off the end template and the remaining material is cleared. Manual labor is then used to compact and smooth the mixture at the transverse joint, ensuring a tight joint between the material and the template. ② Longitudinal Joints: A template is pre-set in the longitudinal direction. A release agent is applied to the area where the template contacts the cast-in-place mixture. Workers are then stationed behind the paver to compact and surface-treat the longitudinal joint with a wooden trowel, ensuring a dense and smooth surface. The template can only be removed after the mixture has been laid and reached a certain strength, ensuring a smooth and vertical cross-section at the joint.

[0103] 7. Spreading premixed crushed stone. Immediately after paving, spread premixed crushed stone. Spread 3-5mm premixed crushed stone with 0.2% modified epoxy resin content manually or mechanically. Depending on the flowability of the mixture, use a roller to press the crushed stone into the mixture during spreading, ensuring that 1 / 2 to 2 / 3 of it is submerged. After completion, remove any unbonded crushed stone.

[0104] Benefit analysis of this invention:

[0105] (1) The castable resin mixture provided by the present invention has excellent high-temperature stability, with a dynamic stability of 13358 cycles / mm at 70℃, which can effectively avoid rutting disease in the steel bridge deck pavement layer during the summer high temperature; it has excellent deformation capacity, with an ultimate bending strain of more than 10000με at -10℃, which is 2 to 3 times that of commonly used steel bridge deck pavement materials. The excellent deformation performance can better adapt to the large deformation of the bridge deck steel plate and improve the integrity of the pavement layer and the bridge deck; the castable resin mixture uses a high resin content and is designed with gradation and asphalt-aggregate ratio based on crack resistance, which has excellent crack resistance and helps to solve the problem of cracking disease in steel bridge deck pavement; the castable resin mixture has a very small porosity and discontinuous internal voids, which has excellent water tightness, so water will not penetrate into the steel bridge deck, effectively protecting the main structure of the bridge from corrosion.

[0106] (2) The construction method of castable resin mixture provided by the present invention is carried out at room temperature throughout the entire process, without heating, which is low-carbon and environmentally friendly, and has good construction and workability, avoiding the problem of difficult temperature control in the construction process of conventional castable asphalt mixture.

[0107] (3) The present invention relies on the fluidity of the cast resin mixture to spread and form itself, which simplifies the construction process, reduces the construction difficulty, and saves the personnel and equipment costs required for the compaction process. It is economical, safe and saves project costs.

[0108] (4) The castable resin mixture provided by the present invention is suitable for steel bridge deck paving projects with characteristics such as "high temperature in summer, severe cold in winter, large traffic flow and high heavy load ratio". It effectively avoids the need for large-scale road closures for repairs due to ruts, cracks and potholes during service, greatly reduces maintenance costs during service, and provides strong protection for driving safety, with good social and economic benefits.

[0109] This invention overcomes the shortcomings of cast-in-place asphalt mixture paving technology in terms of its high-temperature stability, while retaining its excellent waterproofness, crack resistance, deformation coordination, durability, and ease of construction. Simultaneously, it optimizes raw materials by selecting modified epoxy resin as the binder, leveraging its advantages of high-temperature resistance and room-temperature construction to solve technical problems such as rutting in cast-in-place asphalt concrete paving technology. Furthermore, the no-compaction, room-temperature mixed, cast-in-place resin mixture prepared using modified epoxy resin exhibits excellent low-temperature deformation and crack resistance, overcoming the drawbacks of ordinary epoxy resin and epoxy asphalt paving materials, such as high low-temperature brittleness and susceptibility to cracking. In addition, to reduce the technical requirements for steel bridge deck paving construction, a room-temperature construction and no-compaction method is proposed. This method changes the high-energy-consuming mode of cast-in-place asphalt concrete construction at temperatures as high as 220-240℃, significantly reducing energy consumption and carbon emissions, making it environmentally friendly, simplifying the construction process, and lowering economic costs.

[0110] Detailed effect analysis:

[0111] (1) Excellent high-temperature rutting resistance: After the epoxy resin reacts with the curing agent, a three-dimensional cross-linked network is formed, giving the material the characteristics of being insoluble and infusible, i.e., thermosetting. This invention uses epoxy resin to replace thermoplastic asphalt materials, completely changing the defects of traditional asphalt pavement materials that are prone to thermal stability problems such as rutting, shoving, and shoving at high temperatures in summer. The castable resin mixture provided by this invention has excellent high-temperature stability, with a dynamic stability of 13358 cycles / mm at 70℃, which is far higher than the standard of 3000 cycles / mm at 60℃ in the specification. This can effectively avoid rutting problems in steel bridge deck pavement layers at high temperatures in summer and improve the durability of the pavement.

[0112] (2) Good low-temperature crack resistance: General epoxy resin and epoxy asphalt lack flexibility and are prone to brittle cracking failure under cold winter conditions. This invention improves crack resistance from the following three aspects: (1) High-elasticity modified epoxy resin (elongation > 150%) is used, which is much higher than that of ordinary epoxy resin (elongation < 10%); (2) In the mixture gradation design, high asphalt content and high mineral powder content are used. For example, the asphalt content of conventional asphalt mixture is about 4% to 6%, while the resin content of this patent is 8% to 10%; the passing rate of conventional asphalt mixture through a 0.075mm sieve is about 7% to 14%, while this patent uses 20% to 27%; (3) In the design of casting type When mixing resins, a certain amount of light absorber (hindered amine light stabilizer HS-X and ultraviolet absorber UV-X) is added. The ultraviolet absorber has a strong absorption effect on ultraviolet light. It can dissolve in epoxy resin and selectively absorb ultraviolet light bands that are harmful to epoxy resin, converting their energy into vibrational energy or secondary radiation (fluorescence, phosphorescence, etc.) that does not harm epoxy resin, thus protecting it from damage by ultraviolet light and avoiding a series of defects such as cracking and pitting caused by aging of the mixture due to ultraviolet light.

[0113] This approach can significantly improve the low-temperature deformation capacity and crack resistance of epoxy resin mixtures. The ultimate bending strain at -10℃ can reach more than 10,000 με, which is 2 to 3 times that of commonly used steel bridge deck paving materials. The excellent deformation performance can better adapt to the large deformation of the bridge deck steel plate and improve the integrity of the paving layer and the bridge deck.

[0114] (3) Excellent high-temperature and low-temperature performance: Mainstream steel bridge deck paving materials and construction technologies all have obvious drawbacks: Asphalt-based steel bridge deck paving materials, such as cast-in-place asphalt mixtures, modified dense-graded asphalt mixtures, and modified asphalt SMA, have good low-temperature crack resistance but insufficient high-temperature stability; epoxy-based paving materials, such as epoxy asphalt mixtures and epoxy resin mixtures, have excellent high-temperature stability but insufficient low-temperature crack resistance. The cast-in-place resin mixture provided by this invention has both good high-temperature stability and low-temperature crack resistance, and can better adapt to the harsh environmental conditions of steel bridge deck paving.

[0115] (4) Impermeable: The castable resin mixture provided by this invention has a porosity of less than 1% due to the use of high epoxy resin content and high mineral powder content, and there are no interconnected voids inside; at the same time, the castable resin mixture has excellent fatigue resistance and crack resistance, with a fatigue life of more than 1 million cycles at a strain of 1000με and a fracture toughness of 270MPa·m. 0.5 The above features prevent cracks from forming. Therefore, rainwater has no way to seep into the pavement or even onto the surface of the steel plate, effectively protecting the steel plate from rainwater corrosion.

[0116] (5) No need for compaction: The castable resin mixture provided by the present invention uses high epoxy resin content and high mineral powder content, and can be laid and formed by the fluidity of the mixture itself. Unlike ordinary asphalt mixture, it does not need to be compacted by a road roller to remove voids, which simplifies the construction process, reduces the construction difficulty, and saves the cost of personnel and equipment required for the compaction process. It is economical, safe and saves project costs.

[0117] (6) Normal temperature construction: The entire process of the cast-in-place resin mixture construction method provided by the present invention is carried out at normal temperature without heating, which can reduce production costs, and is low-carbon, environmentally friendly, energy-saving and emission-reducing. It has good construction workability and environmental protection, and avoids the problems of high temperature (220~240℃) and difficulty in temperature control during the construction of conventional cast-in-place asphalt mixtures.

[0118] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A design method for a non-compacting, room-temperature mixing and casting resin mixture, characterized in that, Includes the following steps: Step 1: Select raw materials: including coarse aggregate, fine aggregate, mineral powder, modified epoxy resin, curing agent, polyester fiber, and epoxy resin anti-aging modifier; Step 2: Mix design of aggregate: Select three gradations (fine, medium, and coarse) and preliminarily determine the asphalt-aggregate ratio. Use Leuer flowability test to preliminarily determine the gradation type and the mass ratio of each aggregate. If the estimated asphalt-aggregate ratio is within the predetermined range, take multiple different asphalt-aggregate ratios to conduct Leuer flowability test and semicircular bending fracture (SCB) test. Determine the optimal asphalt-aggregate ratio based on the fracture toughness and Leuer value obtained from the test. Step 3: Performance testing of the mixture: The performance of the cast resin mixture is tested through water loss resistance test, low temperature crack resistance test, high temperature rutting test and fatigue test; In step 1, the coarse aggregate is rolled from basalt and has a particle size of 5-10 mm. The fine aggregate is made of basalt with a particle size of 0-5mm; the mineral powder is made from limestone. In step 1, the tensile strength of the modified epoxy resin at 23℃ ranges from 0.5 to 3.0 MPa, the elongation at break at 23℃ is not less than 150%, and the curing time at 23℃ is not more than 24 hours and not less than 1 hour. The modified epoxy resin is cured at room temperature and consists of two components, A and B. Component A is epoxy resin and component B is curing agent. The mass ratio of components A to B is 2:1 to 1:

1. The tensile strength of the polyester fiber is not less than 500 MPa, and the elongation at break is not less than 30%. The anti-aging modifier is a hindered amine light stabilizer and an ultraviolet absorber, UV-X.

2. The method according to claim 1, characterized in that, In step 2, the relationship between the particle size of the cast resin mixture and the passing rate of each sieve aperture is as follows: 9.5mm 95-100% 4.75mm 65-85% 2.36mm 45-62% 0.6mm 35-50% 0.3mm 28-42% 0.15mm 25-34% 0.075mm 20-27%.

3. The method according to claim 1, characterized in that, In step 2, the optimal asphalt-aggregate ratio range for the castable resin mixture is 8.0–10.0%; the dynamic stability of the castable resin mixture at 70°C is not less than 10,000 cycles / mm; and the ultimate bending strain of the castable resin mixture at -10°C is not less than 10,000 με.

4. A construction method for a non-compacted, room-temperature mixed and castable resin mixture, characterized in that, Construction using the non-compacting castable resin mixture obtained by the design method described in any one of claims 1-3 includes the following steps: Step 1: First, mix the binder: The binder includes hindered amine light stabilizer and UV absorber UV-X as anti-aging modifiers, epoxy resin of component A, and curing agent of component B. Weigh the hindered amine light stabilizer and UV absorber UV-X, which each account for 0.25-0.45% of the binder mass. First, add the hindered amine light stabilizer and UV absorber UV-X to the curing agent of component B and mix evenly. Then add the epoxy resin of component A and mix evenly for later use. The binder is prepared separately before each batch of mixes. Then, mix the mix: After adding coarse aggregate, fine aggregate, and mineral powder to the mixer, add polyester fiber, which accounts for 1-3‰ of the mix mass. Dry mix for 10-15 seconds, then immediately add the binder and wet mix for 40-50 seconds. Step 2: Mixture Transportation: The transportation of cast resin mixtures uses ordinary trucks or specialized transport equipment called Cooker. Cooker mainly consists of two parts: a resin mixture mixing system and a mixing tank. The transportation distance and time should be minimized within the allowable carrying time. Step 3: Asphalt Mixture Paving: ① Preparatory work before paving: The paving area should be cleaned in advance, and any moisture on the surface should be thoroughly dried. Oil, debris, and dust should be cleaned. Wooden boards or guide rails of the same thickness should be fixed in the specific paving area as a reference for paving; ② Paving: Cast resin mixture is paved at room temperature using a conventional asphalt paver equipped with an automatic screed. The paver does not require heating. Ordinary trucks or cookers should pour the cast resin mixture into the paver hopper via the side feeder; ③ Joint treatment procedures: a. Transverse construction joints: Formwork should be erected in advance at the locations where transverse construction joints are to be set. When the paver is 10 meters away from the template, slow down the paving speed and finish laying the previously laid material. When it reaches the transverse joint, the paver smoothly lays the material with the remaining material through the joint. Lift the paver on the end template and clean up the remaining material. Then, manually tamp and smooth the mixture at the transverse joint to ensure that the material and the template joint are tight. b. Longitudinal joint: Set templates in advance in the longitudinal direction. Apply a release agent to the area where the template side contacts the cast-in-place mixture. After the paver is behind, use a wooden trowel to tamp and treat the surface of the longitudinal joint to ensure that the mixture at the longitudinal joint is tight and the surface is flat. After the mixture is laid and has formed strength, remove the template to keep the joint with a smooth and vertical cross section. Step 4: Spreading premixed crushed stone: Use a conventional crushed stone spreader. After the mixture paving process is completed, immediately spread resin premixed crushed stone on the surface so that the premixed crushed stone is embedded in the cast resin mixture.

5. The method according to claim 4, characterized in that, In the mixing step, the production process of the cast-in-place resin mixture is carried out at room temperature and no heating equipment is required.

6. The method according to claim 4, characterized in that, In the transportation process, the castable resin mixture is transported from the mixing plant to the construction site by a clean-surfaced ordinary truck or cooker. The inner surface is coated with a thin layer of edible oil to prevent the mixture from sticking to the cargo hold. Each truckload is covered with a tarpaulin or other sufficiently large permitted material to prevent the mixture from being soaked by rain or exposed to direct sunlight, which could cause the temperature to rise.

7. The method according to claim 4, characterized in that, In the paving step, the cast-in-place resin mixture is paved in one layer, and the paver's traveling speed is controlled within the range of 2.0 to 5.0 m / min, depending on the mixing production capacity.

8. The method according to claim 4, characterized in that, In the step of spreading premixed crushed stone, 0.2% to 0.3% of modified epoxy resin is added to basalt with a particle size of 3 to 5 mm and stirred evenly to serve as the material for spreading premixed crushed stone after paving.

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