Epoxy resin concrete for bridge expansion joint and method for preparing the same

Abstract

The application relates to the technical field of concrete, and particularly discloses an epoxy resin concrete for bridge expansion joints and a preparation method thereof. The concrete is composed of an A component and a B component, the A component comprises epoxy resin, polypropylene glycol diglycidyl ether, core-shell polymer, quartz powder, quartz sand, natural crushed stone, steel fiber, active silicon micro powder, fumed silica, wetting dispersant, defoaming agent and ultraviolet absorber, and the B component comprises polyether amine, alicyclic amine, an accelerator, silane coupling agent and benzyl alcohol. The two components are mixed during use. In the application, the epoxy resin is mixed with aggregate and core-shell polymer, and then the concrete is obtained through curing. The shell layer in the core-shell polymer can improve the strength, the compatibility with the epoxy resin and the interfacial force, the core layer is used for absorbing energy and buffering impact, so that the concrete can ensure the strength and improve the toughness.

Description

Technical Field

[0001] This application relates to the field of concrete technology, specifically to an epoxy resin concrete for bridge expansion joints and its preparation method. Background Technology

[0002] Bridge expansion joints are critical connecting components of bridges, ensuring free expansion and contraction on both sides of the main beam and between the bridge and abutments under temperature changes and vehicle loads, preventing stress cracking. They also reinforce connection points and fill gaps, ensuring bridge deck smoothness and traffic safety, and are crucial for maintaining normal bridge operation and extending its service life. The anchorage area of ​​expansion joints is exposed to the outdoors for extended periods, enduring wind, rain, temperature changes, freeze-thaw cycles, and repeated impacts and shear forces from vehicles. Furthermore, with some bridges operating for a long time and experiencing increased loads, damage such as concrete fracture, cracking, and spalling can easily occur. In severe cases, this can lead to the anchorage area separating from the main beam and bridge deck pavement, compromising structural integrity and affecting traffic safety.

[0003] In the repair of expansion joint anchorage zones, traditional cement-based repair materials, while readily available and easy to apply, have significant drawbacks: poor deformation capacity, susceptibility to cracking after repair, low early strength, long curing periods, and impeded traffic flow. Furthermore, they are relatively expensive, have poor adhesion, and their repair effects are not long-lasting. In contrast, epoxy resin concrete, as a new type of high-performance repair material, offers significant advantages. It boasts high early strength, low shrinkage, strong adhesion, water and erosion resistance, excellent ultimate deformation capacity, and rapid setting, making it suitable for expansion joint applications, shortening the curing period, and improving construction efficiency.

[0004] However, due to the inherently high cross-linking structure of epoxy resin, it exhibits high interfacial surface energy and internal stress, as well as high brittleness and poor impact resistance. Existing technologies can toughen epoxy resin concrete by introducing flexible segments and adding elastomers and inorganic fillers, but these methods often lead to a decrease in other properties such as strength and heat resistance. Furthermore, it needs to adapt to the rapid development requirements of engineering projects, achieving high strength as quickly as possible. Therefore, how to improve the flexibility of epoxy resin concrete without reducing strength and adapting to engineering needs has become a crucial issue that needs to be addressed. Summary of the Invention

[0005] To meet the needs of rapid traffic opening and engineering adaptation, this application provides epoxy resin concrete for bridge expansion joints and its preparation method.

[0006] Core-shell polymers, composed of a core and a shell, are typically a combination of hard and soft materials. Introducing core-shell particles into an epoxy resin matrix can simultaneously improve the material's strength and toughness without significantly affecting its thermal properties. However, this physical toughening method usually requires a long initiation time, and the soft core cannot function effectively when the interfacial bonding between the two is weak. This results in a longer mechanical response time for the concrete before it reaches the expected toughness, thus affecting the requirement for rapid traffic opening after construction. In contrast, the shell layer of this invention has epoxy groups that can covalently bond with amino groups during curing, forming chemical bonds. Furthermore, the soft core has formed a complete dual-network structure through free radical copolymerization and rare earth ion-carboxyl ion crosslinking. Under these conditions, this invention can maintain rapid curing while avoiding the lag in toughness development caused by weak interfacial bonding in traditional toughening systems, thereby achieving shorter construction time and faster traffic opening.

[0007] In this invention, a soft core based on butyl acrylate and other materials can induce crazing and absorb impact energy, while a hard shell composed of a copolymer of styrene and glycidyl methacrylate provides rigid support. The epoxy groups on the shell surface can undergo a ring-opening reaction with the epoxy resin matrix during curing, forming covalent bonds and solving the interfacial bonding problem. Secondly, the covalent network formed by divinylbenzene within the soft core provides an elastic framework. Under near-neutral conditions of weak acidity, the carboxyl groups dissociate into carboxylate ions, which coordinate with lanthanum ions, undergoing ionic crosslinking polymerization. Due to the high coordination number of lanthanum ions, one ion can connect multiple polymer chains, forming a robust ionic cluster network that interpenetrates with the covalent network of divinylbenzene, thus forming a double-crosslinked network. The ionic clusters formed by lanthanum ions and carboxylate ions act as reversible sacrificial bonds; under external forces, the ionic bonds preferentially break to dissipate energy, and can reorganize after the external force is removed, endowing the material with elastic recovery and fatigue resistance.

[0008] Furthermore, this invention forms an inner and outer core structure through a two-step pre-emulsion addition. A denser core results in greater rigidity and less deformation under compressive stress. A lower crosslinking density in the outer core leads to fewer crosslinking points and greater freedom of movement for the outer polymer chain segments. In a low-crosslinking environment, carboxyl groups more easily approach lanthanum ions to form multi-coordinate ion clusters, and dynamic breakage and recombination of these ion clusters are more likely to occur. This rigid-flexible gradient structure achieves significant improvements in toughness and vibration damping performance while maintaining high strength.

[0009] This invention produces concrete by mixing epoxy resin with aggregates and core-shell polymers, followed by curing with an amine curing agent. The shell layer forms covalent bonds with the matrix during curing through epoxy groups, significantly improving interfacial bonding and thus enhancing toughness while maintaining strength. The core layer absorbs energy and buffers impacts, enabling the concrete to improve toughness while ensuring strength. It is simple to construct, has good durability, and possesses high strength, high toughness, and good elastic recovery ability. It can also improve the smoothness and comfort of vehicle passage.

[0010] In a first aspect, the present invention provides an epoxy resin concrete for bridge expansion joints, comprising component A and component B. Component A comprises the following raw materials in parts by weight: 80-120 parts epoxy resin, 10-15 parts polypropylene glycol diglycidyl ether, 15-20 parts core-shell polymer, 40-55 parts quartz powder, 15-25 parts quartz sand, 15-25 parts natural crushed stone, 10-20 parts activated silica powder, 4-6 parts steel fiber, 1-2 parts fumed silica, 0.5-1.5 parts wetting and dispersing agent, 0.1-0.5 parts defoamer, and 0.1-1 parts ultraviolet absorber. Component B comprises the following raw materials in parts by weight: 25-35 parts polyetheramine, 8-12 parts alicyclic amine, 0.5-1 part accelerator, 1-3 parts silane coupling agent, and 3-5 parts benzyl alcohol. The core-shell polymer is initially polymerized by an initiator to form a seed emulsion, and then the remaining monomers and rare earth ions are added to construct a double cross-linked soft core. The surface is coated with a hard shell polymerized from styrene and glycidyl methacrylate, and finally post-processed to obtain the final product.

[0011] Furthermore, the wetting and dispersing agent is BYK-163.

[0012] Furthermore, the defoamer is BYK-A530.

[0013] Furthermore, the accelerator is 2,4,6-tris(dimethylaminomethyl)phenol.

[0014] Furthermore, the silane coupling agent is γ-glycidoxypropyltrimethoxysilane.

[0015] Furthermore, the ultraviolet absorber is UV-531.

[0016] Furthermore, the preparation method of the core-shell polymer includes the following steps: X1. Add 2wt% hydroxyethyl cellulose dispersion, sodium dodecyl sulfate, fatty alcohol polyoxyethylene ether, and sodium citrate to water, stir evenly, adjust the pH to 6-7 with acid, then add butyl acrylate, 50wt% sodium acrylate solution, and divinylbenzene. Under nitrogen protection, heat to 65-70℃, add 10wt% potassium persulfate aqueous solution, and stir for 0.5-1.5h to obtain seed emulsion. X2. Homogenize butyl acrylate, 50wt% sodium acrylate solution, divinylbenzene, and fatty alcohol polyoxyethylene ether to obtain a first preemulsion; homogenize butyl acrylate, 50wt% sodium acrylate solution, divinylbenzene, and fatty alcohol polyoxyethylene ether to obtain a second preemulsion; add the first preemulsion dropwise to the seed emulsion and stir for 1-2 hours to form the core; then simultaneously add the second preemulsion, 25wt% lanthanum chloride aqueous solution, and 10wt% potassium persulfate aqueous solution to form the outer core; control the pH throughout the addition; after the addition is complete, continue stirring at 65-70℃ for 1-2 hours to obtain the core layer solution; X3. Add styrene, glycidyl methacrylate, and fatty alcohol polyoxyethylene ether to water and homogenize to obtain a shell pre-emulsion. Cool the core solution to 50-55℃, add a portion of the shell pre-emulsion dropwise, and then simultaneously add 3.33wt% tert-butyl hydrogen peroxide aqueous solution, 10wt% formaldehyde sodium bisulfite aqueous solution, and the remaining shell pre-emulsion. After the addition is complete, stir for 0.5-1.5h, raise the temperature to 60-65℃ and stir for 1-2h, then cool to 35-40℃, add alkali to adjust the pH to 8-9, add 1% (dry weight) of fumed silica, disperse evenly, and spray dry to obtain the core-shell polymer.

[0017] Furthermore, the mass ratio of the hydroxyethyl cellulose dispersion, sodium dodecyl sulfate, fatty alcohol polyoxyethylene ether, sodium citrate, and water is 25:1-5:4-8:0.1-1:500-700.

[0018] Furthermore, in step X1, the mass ratio of butyl acrylate, sodium acrylate solution, divinylbenzene, and potassium persulfate aqueous solution is 23.5:2-4:0.9-1:2-5.

[0019] Furthermore, in step X2, the mass ratio of butyl acrylate, sodium acrylate solution, divinylbenzene, and fatty alcohol polyoxyethylene ether in the first preemulsion is 105.75:8-15:4-8:0.5-1.5; the mass ratio of butyl acrylate, sodium acrylate solution, divinylbenzene, and fatty alcohol polyoxyethylene ether in the second preemulsion is 105.75:8-15:2-8:0.5-1.5; and the mass ratio of the second preemulsion, lanthanum chloride aqueous solution, and potassium persulfate aqueous solution is 100-150:40:0.5-1.

[0020] Furthermore, the mass ratio of styrene, glycidyl methacrylate, fatty alcohol polyoxyethylene ether, water, tert-butyl hydrogen peroxide aqueous solution, and formaldehyde sodium bisulfite aqueous solution is 40:8-12:1-3:25-35:8-12:4-8.

[0021] Secondly, the present invention provides a method for preparing epoxy resin concrete for bridge expansion joints, comprising the following steps: S1. After mixing epoxy resin, polypropylene glycol diglycidyl ether, and wetting and dispersing agent evenly, add core-shell polymer and ultraviolet absorber, stir evenly, then add activated silica powder, quartz powder, quartz sand, natural crushed stone, steel fiber, and fumed silica, disperse evenly, then add defoamer, and vacuum degas to obtain component A. S2. Mix polyetheramine, alicyclic amine, accelerator, silane coupling agent and benzyl alcohol evenly to obtain component B; S3. When using, mix component A and component B at a mass ratio of 100:15-25 to obtain epoxy resin concrete, then pour and smooth it after cleaning the joints.

[0022] Compared with the prior art, the beneficial effects of this application are at least as follows: 1. This invention produces concrete by mixing epoxy resin with aggregates, core-shell polymers, etc., and then curing it with an amine curing agent. It is simple to construct, has good durability, and possesses high strength and high elasticity. It can also improve the smoothness and comfort of vehicle traffic and reduce noise.

[0023] 2. The core-shell polymer in this invention uses polyacrylic acid and rare earth ions-acrylic acid ions as a soft core to initiate crazing, absorb impact energy, and consume energy, while using styrene and glycidyl methacrylate copolymer as a hard shell to provide rigid support. The improved toughness allows the concrete to have a longer service life.

[0024] 3. This invention achieves higher energy dissipation efficiency and coordination efficiency through the rigid-flexible gradient inner and outer cores, thereby improving multiple properties such as toughness and vibration reduction. Detailed Implementation

[0025] The various embodiments or implementation schemes in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments.

[0026] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0028] In this specification, unless otherwise specified, "parts" refers to "parts by weight".

[0029] The following describes embodiments of this application. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0030] Quartz powder, particle size: 400 mesh.

[0031] Quartz sand, particle size: 80-120 mesh.

[0032] Activated silica micro powder, particle size: 600 mesh.

[0033] The natural crushed stone is composed of basalt and diabase, and its gradation is as follows:

[0034] Steel fiber, diameter: 0.12-0.25mm, length: 6mm.

[0035] The epoxy resin is bisphenol A epoxy resin with an epoxy value of 0.51-0.54 mol / 100g and a model number of NPEL-128.

[0036] Polypropylene glycol diglycidyl ether, model: 217.

[0037] Polyetheramine, model: D230.

[0038] Alicyclic amine, model: Ancamine2280.

[0039] Divinylbenzene, content: 80%.

[0040] Fatty alcohol polyoxyethylene ether, model: AEO-9.

[0041] Fumed silica, type: A200, specific surface area: 200±25m² 2 / g.

[0042] The 2wt% hydroxyethyl cellulose dispersion was obtained by adding 1 part hydroxyethyl cellulose to 49 parts water and allowing it to swell completely.

[0043] A 50wt% sodium acrylate solution is obtained by adding 10 parts acrylic acid and 4.4 parts sodium hydroxide to 6.28 parts water and stirring until homogeneous.

[0044] The 25wt% lanthanum chloride aqueous solution is obtained by adding 10 parts of lanthanum chloride heptahydrate to 16.42 parts of water at 50℃ and stirring until homogeneous.

[0045] The 3.33wt% tert-butyl hydrogen peroxide aqueous solution is obtained by adding 0.5 parts of 70% tert-butyl hydrogen peroxide aqueous solution to 10 parts of water and stirring until homogeneous.

[0046] Example 1 A method for preparing epoxy resin concrete for bridge expansion joints includes the following steps: S1. Mix 100 parts of epoxy resin, 10 parts of polypropylene glycol diglycidyl ether, and 1.2 parts of BYK-163 evenly, then add 18 parts of core-shell polymer and 0.5 parts of UV-531. Stir evenly, then add 15 parts of activated silica powder, 50 parts of quartz powder, 20 parts of quartz sand, 20 parts of natural crushed stone, 5 parts of steel fiber, and 1.5 parts of fumed silica. After evenly dispersing, add 0.4 parts of BYK-A530. Vacuum degassing is performed to obtain component A. S2. Mix 30 parts of polyetheramine, 12 parts of alicyclic amine, 0.8 parts of 2,4,6-tris(dimethylaminomethyl)phenol, 2 parts of γ-glycidyl etheroxypropyltrimethoxysilane, and 4 parts of benzyl alcohol evenly to obtain component B. S3. When using, mix component A and component B at a mass ratio of 100:20 to obtain epoxy resin concrete, then pour and smooth it after cleaning the joints. The method for preparing the core-shell polymer includes the following steps: X1. Add 25 parts of 2wt% hydroxyethyl cellulose dispersion, 4 parts of sodium dodecyl sulfate, 6 parts of fatty alcohol polyoxyethylene ether, and 0.5 parts of sodium citrate to 600 parts of water. After stirring evenly, add 5wt% dilute hydrochloric acid to adjust the pH to 6.5. Then add 23.5 parts of butyl acrylate, 2.88 parts of 50wt% sodium acrylate solution, and 0.94 parts of divinylbenzene. Heat to 70℃ under nitrogen protection, add 2.7 parts of 10wt% potassium persulfate aqueous solution, and stir for 1 hour to obtain seed emulsion. X2. Homogenize 105.75 parts of butyl acrylate, 12.96 parts of 50wt% sodium acrylate solution, 4.23 parts of divinylbenzene, and 0.9 parts of fatty alcohol polyoxyethylene ether to obtain a first preemulsion; homogenize 105.75 parts of butyl acrylate, 12.96 parts of 50wt% sodium acrylate solution, 4.23 parts of divinylbenzene, and 0.9 parts of fatty alcohol polyoxyethylene ether to obtain a second preemulsion; add the first preemulsion dropwise to the seed emulsion and stir for 1.5 h to form the core; then simultaneously add the second preemulsion, 40 parts of 25wt% lanthanum chloride aqueous solution, and 1 part of 10wt% potassium persulfate aqueous solution to form the outer core. The pH is controlled at 6-6.5 throughout the dropwise addition. After the dropwise addition is complete, continue stirring at 70℃ for 2 h to obtain the core layer solution; X3. Add 40 parts of styrene, 10 parts of glycidyl methacrylate, and 2 parts of fatty alcohol polyoxyethylene ether to 30 parts of water, and homogenize to obtain a shell pre-emulsion. Cool the core solution to 50°C, add 20% of the shell pre-emulsion, and then simultaneously add 10.5 parts of 3.33wt% tert-butyl hydrogen peroxide aqueous solution, 6 parts of 10wt% formaldehyde sodium bisulfite aqueous solution, and the remaining shell pre-emulsion. After the addition is complete, stir for 1 hour, heat to 65°C and stir for 1.5 hours, then cool to 35°C, add ammonia to adjust the pH to 8.5, add 1% of dry weight of fumed silica, disperse evenly, and spray dry to obtain the core-shell polymer.

[0047] Example 2 It is basically the same as Example 1, except that the mass ratio of component A to component B is 100:15.

[0048] Example 3 It is basically the same as Example 1, except that the mass ratio of component A to component B is 100:25.

[0049] Example 4 It is basically the same as Example 1, except that the core-shell polymer is 12 parts.

[0050] Example 5 It is basically the same as Example 1, except that the core-shell polymer is 24 parts.

[0051] Example 6 It is basically the same as Example 1, except that the preparation method of the core-shell polymer is different; The method for preparing the core-shell polymer includes the following steps: X1. Add 25 parts of 2wt% hydroxyethyl cellulose dispersion, 4 parts of sodium dodecyl sulfate, 6 parts of fatty alcohol polyoxyethylene ether, and 0.5 parts of sodium citrate to 600 parts of water. After stirring evenly, add 5wt% dilute hydrochloric acid to adjust the pH to 6.5. Then add 23.5 parts of butyl acrylate, 2.88 parts of 50wt% sodium acrylate solution, and 0.94 parts of divinylbenzene. Heat to 70℃ under nitrogen protection, add 2.7 parts of 10wt% potassium persulfate aqueous solution, and stir for 1 hour to obtain seed emulsion. X2. Homogenize 105.75 parts of butyl acrylate, 12.96 parts of 50wt% sodium acrylate solution, 5.92 parts of divinylbenzene, and 0.9 parts of fatty alcohol polyoxyethylene ether to obtain a first preemulsion; homogenize 105.75 parts of butyl acrylate, 12.96 parts of 50wt% sodium acrylate solution, 2.54 parts of divinylbenzene, and 0.9 parts of fatty alcohol polyoxyethylene ether to obtain a second preemulsion; add the first preemulsion dropwise to the seed emulsion and stir for 1.5 h to form the core; then simultaneously add the second preemulsion, 40 parts of 25wt% lanthanum chloride aqueous solution, and 1 part of 10wt% potassium persulfate aqueous solution to form the outer core. The pH is controlled at 6-6.5 throughout the dropwise addition. After the addition is complete, continue stirring at 70℃ for 2 h to obtain the core layer solution; X3. Add 40 parts of styrene, 10 parts of glycidyl methacrylate, and 2 parts of fatty alcohol polyoxyethylene ether to 30 parts of water, and homogenize to obtain a shell pre-emulsion. Cool the core solution to 50°C, add 20% of the shell pre-emulsion, and then simultaneously add 10.5 parts of 3.33wt% tert-butyl hydrogen peroxide aqueous solution, 6 parts of 10wt% formaldehyde sodium bisulfite aqueous solution, and the remaining shell pre-emulsion. After the addition is complete, stir for 1 hour, heat to 65°C and stir for 1.5 hours, then cool to 35°C, add ammonia to adjust the pH to 8.5, add 1% of dry weight of fumed silica, disperse evenly, and spray dry to obtain the core-shell polymer.

[0052] Comparative Example 1 It is basically the same as Example 1, except that no core-shell polymer is added.

[0053] Comparative Example 2 It is basically the same as Example 1, except that a 25wt% aqueous solution of lanthanum chloride is not added.

[0054] Comparative Example 3 The procedure is essentially the same as in Example 1, except that lanthanum chloride heptahydrate is replaced with an equimolar amount of zinc chloride, and the pH of step X2 is controlled at 5.0-5.5.

[0055] Comparative Example 4 It is basically the same as Example 1, except that the preparation method of the core-shell polymer is different; The method for preparing the core-shell polymer includes the following steps: X1. Add 25 parts of 2wt% hydroxyethyl cellulose dispersion, 4 parts of sodium dodecyl sulfate, 6 parts of fatty alcohol polyoxyethylene ether, and 0.5 parts of sodium citrate to 600 parts of water. After stirring evenly, add 5wt% dilute hydrochloric acid to adjust the pH to 6.5. Then add 23.5 parts of butyl acrylate, 2.88 parts of 50wt% sodium acrylate solution, and 0.94 parts of divinylbenzene. Heat to 70℃ under nitrogen protection, add 2.7 parts of 10wt% potassium persulfate aqueous solution, and stir for 1 hour to obtain seed emulsion. X2. After homogenizing 211.5 parts of butyl acrylate, 25.92 parts of 50wt% sodium acrylate solution, 8.46 parts of divinylbenzene, and 1.8 parts of fatty alcohol polyoxyethylene ether, a pre-emulsion was obtained. 40 parts of 25wt% lanthanum chloride aqueous solution and the pre-emulsion were added dropwise to the seed emulsion. The pH was controlled at 6-6.5 throughout the addition. After the addition was completed, the mixture was stirred at 70℃ for 1.5 h to obtain the core layer solution. X3. Add 40 parts of styrene, 10 parts of glycidyl methacrylate, and 2 parts of fatty alcohol polyoxyethylene ether to 30 parts of water, and homogenize to obtain a shell pre-emulsion. Cool the core solution to 50°C, add 20% of the shell pre-emulsion, and then simultaneously add 10.5 parts of 3.33wt% tert-butyl hydrogen peroxide aqueous solution, 6 parts of 10wt% formaldehyde sodium bisulfite aqueous solution, and the remaining shell pre-emulsion. After the addition is complete, stir for 1 hour, heat to 65°C and stir for 1.5 hours, then cool to 35°C, add ammonia to adjust the pH to 8.5, add 1% of dry weight of fumed silica, disperse evenly, and spray dry to obtain the core-shell polymer.

[0056] Test section 1. The compressive strength of the epoxy resin concrete in the examples and comparative examples was tested. Cylindrical specimens with a diameter of 50 mm and a height of 100 mm were prepared and cured under standard conditions to the specified age (4 h and 24 h). Axial loading was applied to the specimens at a rate of 1.0 mm / min until failure. The maximum load was recorded, and the compressive strength (MPa) was calculated as: maximum load / specimen cross-sectional area. At least three specimens were tested in each group, and the average value was taken.

[0057] 2. The flexural strength of the epoxy resin concrete in the examples and comparative examples was tested. 100mm × 100mm × 400mm prism specimens were prepared and cured under standard conditions for 7 days. A compression testing machine was started, and a loading rate of 0.08 MPa / s was applied until the specimen failed. The failure load and the corresponding fracture location of the specimen were recorded. The test was repeated three times, and the average value of the three tests was multiplied by a size conversion factor of 0.85 to obtain the flexural strength. The flexural strength (MPa) was calculated as: Fl / bh 2 F: Ultimate load of specimen (N), l: Span between supports (mm), b: Width of specimen section (mm), h: Height of specimen section (mm).

[0058] 3. At the actual bridge expansion joint location, lay a section (length ≥ 5m) of both the material of this invention (experimental group) and the traditional material (control group). Using a calibrated acoustic analyzer, place a microphone 1m away from the expansion joint and 1.2m high. Record the peak noise level (L) of a vehicle (large vehicle, speed 90km / h) when its tires pass over the expansion joint. Amax Each monitoring session lasts 5 minutes, extracting at least 10 valid vehicle passage data points. Noise reduction (ΔdB) = Traditional material measuring point L Amax Average value - Measurement point L of the material in this invention Amax average value.

[0059] Table 1

[0060] Table 2

[0061] As can be seen from Tables 1 and 2, the epoxy resin concrete in the comparative example exhibited higher early-stage strength, but its flexural strength was poor due to its inferior toughening effect. In contrast, the example concrete showed higher strength and better toughness after only 4 hours of curing. This indicates that the concrete obtained by mixing epoxy resin with aggregates and a core-shell polymer, followed by curing with an amine curing agent, has better elastic recovery. The shell layer of the core-shell polymer enhances strength and compatibility with epoxy resin and improves interfacial forces, while the core layer absorbs energy and buffers impact, thus improving toughness while maintaining strength.

[0062] Compared to Comparative Examples 1-3, Comparative Example 1, due to the direct reinforcement by high-modulus inorganic fillers, exhibits high strength but also high brittleness. Comparative Example 2, using polyacrylate as a soft core, reduces brittleness to some extent, but its early strength performance is weaker. However, the high-modulus La in Example 1... 3+ Cross-linked particles act as reinforcing points, raising the stress threshold for crack initiation. Furthermore, when the material is subjected to impact or tension, the soft core undergoes large deformation to absorb energy. The internal lanthanum ion cross-linking bonds preferentially undergo reversible breakage, dissipating a large amount of energy, while the covalent cross-linked network maintains structural integrity, preventing permanent damage. After the external force is removed, the ionic bonds can realign, and the material returns to its original state. This gives the concrete high toughness and elasticity, and allows it to achieve high strength in the early stages of curing. In Comparative Example 3, the use of zinc ions for cross-linking did not improve toughness as effectively as lanthanum ions; this is not only due to the strength of the ionic bonds but may also be related to differences in coordination ability.

[0063] Compared with Comparative Example 4, Example 1 adds divinylbenzene and lanthanum chloride separately, so that the ion clusters are concentrated in the low cross-linked outer layer. This avoids the constraint of the highly cross-linked network of divinylbenzene on the reversible ion breakage-recombination mechanism. At the same time, the core is not disturbed by lanthanum ions, and the cross-linking is more compact.

[0064] In the embodiments, the ion clusters undergo reversible fracture and recombination under the vibration of passing wheels. Each fracture-recombination cycle triggers energy conversion, absorbing vibrational energy and reducing the structural vibration of the expansion joint material. Consequently, the sound waves radiated into the air by the vibration are also reduced, thus achieving noise reduction. In contrast, the zinc ion in Comparative Example 3 has a bond energy and coordination crosslinking strength far lower than that of trivalent lanthanum ions, absorbing and dissipating less mechanical energy during dynamic fracture, resulting in a poorer noise reduction effect.

[0065] Compared to Examples 2 and 3, Example 1 uses a different amount of curing agent, which directly affects the curing effect. When the curing agent dosage is low, curing is incomplete, crosslinking density is low, and network strength is insufficient. When the curing agent dosage is excessive, unreacted amine molecules plasticize, thus reducing the final strength. Compared to Examples 4 and 5, Example 1, with a lower content of the core-shell polymer as a toughening agent, although there are fewer energy dissipation units and the strength is high, the toughness improvement is limited. A higher dosage dilutes the matrix, affecting its load-bearing and stress transfer capabilities, preventing all newly added ion clusters from being converted into effective dissipation sites. As the core-shell polymer is key to energy dissipation, the distribution of its energy dissipation points directly affects the noise reduction effect. The results in Tables 1 and 2 show that the dosage in Example 1 achieves a better balance between energy dissipation capability and matrix continuity.

[0066] Compared with Example 6, when the proportion of inner DVB increases to 70%, the core rigidity is further improved and the cross-linking density of outer layer is further reduced, which increases the energy dissipation efficiency of lanthanum ion and carboxyl coordination network. This rigid-flexible gradient structure achieves a significant improvement in toughness and vibration reduction performance while maintaining high strength.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. An epoxy resin concrete for bridge expansion joints, characterized in that, The product comprises two components, A and B. Component A includes the following raw materials in parts by weight: 80-120 parts epoxy resin, 10-15 parts polypropylene glycol diglycidyl ether, 15-20 parts core-shell polymer, 40-55 parts quartz powder, 15-25 parts quartz sand, 15-25 parts natural crushed stone, 10-20 parts activated silica powder, 4-6 parts steel fiber, 1-2 parts fumed silica, 0.5-1.5 parts wetting and dispersing agent, 0.1-0.5 parts defoamer, and 0.1-1 parts ultraviolet absorber. Component B includes the following raw materials in parts by weight: 25-35 parts polyetheramine, 8-12 parts alicyclic amine, 0.5-1 part accelerator, 1-3 parts silane coupling agent, and 3-5 parts benzyl alcohol. The method for preparing the core-shell polymer includes the following steps: X1. Add 2wt% hydroxyethyl cellulose dispersion, sodium dodecyl sulfate, fatty alcohol polyoxyethylene ether, and sodium citrate to water, stir evenly, adjust the pH to 6-7 with acid, then add butyl acrylate, 50wt% sodium acrylate solution, and divinylbenzene. Under nitrogen protection, heat to 65-70℃, add 10wt% potassium persulfate aqueous solution, and stir for 0.5-1.5h to obtain seed emulsion. X2. Homogenize butyl acrylate, 50wt% sodium acrylate solution, divinylbenzene, and fatty alcohol polyoxyethylene ether to obtain a first preemulsion; homogenize butyl acrylate, 50wt% sodium acrylate solution, divinylbenzene, and fatty alcohol polyoxyethylene ether to obtain a second preemulsion; add the first preemulsion dropwise to the seed emulsion and stir for 1-2 hours to form the core; then simultaneously add the second preemulsion, 25wt% lanthanum chloride aqueous solution, and 10wt% potassium persulfate aqueous solution to form the outer core; control the pH throughout the addition; after the addition is complete, continue stirring at 65-70℃ for 1-2 hours to obtain the core layer solution; X3. Add styrene, glycidyl methacrylate, and fatty alcohol polyoxyethylene ether to water and homogenize to obtain a shell pre-emulsion. Cool the core solution to 50-55℃, add a portion of the shell pre-emulsion dropwise, and then simultaneously add 3.33wt% tert-butyl hydrogen peroxide aqueous solution, 10wt% formaldehyde sodium bisulfite aqueous solution, and the remaining shell pre-emulsion. After the addition is complete, stir for 0.5-1.5h, raise the temperature to 60-65℃ and stir for 1-2h, then cool to 35-40℃, add alkali to adjust the pH to 8-9, add 1% (dry weight) of fumed silica, disperse evenly, and spray dry to obtain the core-shell polymer.

2. The epoxy resin concrete for bridge expansion joints as described in claim 1, characterized in that, The wetting and dispersing agent is BYK-163.

3. The epoxy resin concrete for bridge expansion joints as described in claim 1, characterized in that, The defoamer is BYK-A530.

4. The epoxy resin concrete for bridge expansion joints as described in claim 1, characterized in that, The accelerator is 2,4,6-tris(dimethylaminomethyl)phenol.

5. The epoxy resin concrete for bridge expansion joints as described in claim 1, characterized in that, The mass ratio of the hydroxyethyl cellulose dispersion, sodium dodecyl sulfate, fatty alcohol polyoxyethylene ether, sodium citrate, and water is 25:1-5:4-8:0.1-1:500-700.

6. The epoxy resin concrete for bridge expansion joints as described in claim 1, characterized in that, In step X1, the mass ratio of butyl acrylate, sodium acrylate solution, divinylbenzene, and potassium persulfate aqueous solution is 23.5:2-4:0.9-1:2-5.

7. The epoxy resin concrete for bridge expansion joints as described in claim 1, characterized in that, In step X2, the mass ratio of butyl acrylate, sodium acrylate solution, divinylbenzene, and fatty alcohol polyoxyethylene ether in the first preemulsion is 105.75:8-15:4-8:0.5-1.5; the mass ratio of butyl acrylate, sodium acrylate solution, divinylbenzene, and fatty alcohol polyoxyethylene ether in the second preemulsion is 105.75:8-15:2-8:0.5-1.5; and the mass ratio of the second preemulsion to lanthanum chloride aqueous solution and potassium persulfate aqueous solution is 100-150:40:0.5-1.

8. The epoxy resin concrete for bridge expansion joints as described in claim 1, characterized in that, The mass ratio of styrene, glycidyl methacrylate, fatty alcohol polyoxyethylene ether, water, tert-butyl hydrogen peroxide aqueous solution, and formaldehyde sodium bisulfite aqueous solution is 40:8-12:1-3:25-35:8-12:4-8.

9. The method for preparing epoxy resin concrete for bridge expansion joints according to any one of claims 1-8, characterized in that, Includes the following steps: S1. After mixing epoxy resin, polypropylene glycol diglycidyl ether, and wetting and dispersing agent evenly, add core-shell polymer and ultraviolet absorber, stir evenly, then add activated silica powder, quartz powder, quartz sand, natural crushed stone, steel fiber, and fumed silica, disperse evenly, then add defoamer, and vacuum degas to obtain component A. S2. Mix polyetheramine, alicyclic amine, accelerator, silane coupling agent and benzyl alcohol evenly to obtain component B; S3. When using, mix component A and component B at a mass ratio of 100:15-25 to obtain epoxy resin concrete, then pour and smooth it after cleaning the joints.

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