Splicing interface agent for non-same-layer equal-thickness asphalt surface layers of extension project and preparation method of splicing interface agent

Abstract

The invention relates to the technical field of pavement splicing structures, in particular to an extension project non-same-layer equal-thickness asphalt surface layer splicing interface agent and a preparation method thereof. The technical key points are as follows: after the interface agent is formed, one surface is combined with an asphalt material, and the other surface is combined with a cement stabilizing material; the interface agent comprises a geopolymer and emulsified asphalt; the water in the emulsified asphalt and the geopolymer are subjected to hydration reaction. The invention provides an extension project non-same-layer equal-thickness asphalt surface layer splicing interface agent and a preparation method thereof, belongs to a rigid-flexible composite material, and has a good transition effect between a flexible structure and a rigid structure, so that the modulus of the flexible structure and the modulus of the rigid structure are coordinated, and the flexible structure and the rigid structure work cooperatively; the occurrence of cracks at the splicing part is delayed or even prevented.

Description

Technical Field

[0001] The present invention relates to the technical field of pavement splicing structures, and in particular to an interfacial agent for splicing non-homogeneous and equal-thickness asphalt surface layers in an expansion project and a preparation method thereof. Background Art

[0002] The reconstruction and expansion project is a systematic project involving multiple aspects such as pavement evaluation, old road reconstruction, pavement structure, splicing of new and old structures, recycling, traffic organization, and safety management. Among them, the splicing quality of the new and old roadbeds and pavements is an important prerequisite for ensuring the driving comfort and durability of the highway after expansion, which will directly affect the overall stability of the pavement structure of the reconstruction and expansion project. Improper treatment of the splicing part is likely to cause diseases such as differential settlement, deformation, and longitudinal cracking. The splicing of the new and old roadbeds and pavements includes multiple dimensions in the spatial sense. Horizontally, it includes the splicing between the old road lanes and the expanded lanes and the splicing of the new and old roadbeds at the old roadside slope position. Vertically, it includes the splicing between the surface layer, base layer, and subgrade, as well as the reinforcement of the top surface of the subgrade in the third lane considering heavy traffic. In addition, an easily overlooked point is that whether it is milling and paving during the old road reconstruction process or the paving overlay of the temporary traffic structure, there are problems with the interlayer bonding of the new and old asphalt mixtures, which should also be regarded as part of the splicing project. However, existing research has not involved the splicing of the old road asphalt surface layer and the new road cement stabilized base layer, and there is no relevant engineering application at home and abroad for reference, while the high-speed expansion project has a relatively large demand for this.

[0003] Therefore, there is an urgent need to develop an interfacial agent for splicing non-homogeneous and equal-thickness asphalt surface layers in an expansion project to fill the domestic gap, enhance the durability of the splicing part, and improve the quality of the expansion project. Summary of the Invention

[0004] The purpose of the present invention is to provide an interfacial agent for splicing non-homogeneous and equal-thickness asphalt surface layers in an expansion project and a preparation method thereof, which belongs to a composite material combining rigidity and flexibility, plays a good transitional role between the flexible structure and the rigid structure, coordinates the moduli of the flexible structure and the rigid structure, enables the two to work together, and delays or even prevents the occurrence of cracks at the splicing part.

[0005] The above technical purpose of the present invention is achieved through the following technical solutions:

[0006] An interfacial agent for splicing non-homogeneous and equal-thickness asphalt surface layers in an expansion project provided by the present invention is characterized in that after the interfacial agent is formed, one side is combined with the asphalt material and the other side is combined with the cement stabilized material;

[0007] The interfacial agent includes geopolymer and emulsified asphalt;

[0008] The water in the emulsified asphalt undergoes a hydration reaction with the geopolymer.

[0009] Further, the geopolymer includes a powder and a liquid activator, and the weight ratio of the powder to the liquid activator is 5:(3.0 - 3.5).

[0010] Further, the powder and the liquid activator undergo a polymerization reaction to form a three-dimensional networked three-dimensional structure with silicon-oxygen tetrahedrons and aluminum-oxygen tetrahedrons.

[0011] Further, the powder includes fly ash, cement, and mineral powder;

[0012] Among them, the weight ratio of the fly ash, cement, and mineral powder is 1:(0.5 - 1):(1 - 1.5).

[0013] Further, the liquid activator includes sodium hydroxide and sodium silicate; among them, the weight ratio of the sodium hydroxide to the sodium silicate is 1:(1 - 1.5).

[0014] Further, the modulus of the liquid alkaline activator is 1.1 - 1.3.

[0015] Further, the emulsified asphalt is anionic emulsified asphalt.

[0016] Further, calculated by weight parts, the interfacial agent includes the following components: 70 - 75 parts of geopolymer and 25 - 30 parts of emulsified asphalt.

[0017] The present invention also provides a preparation method for the splicing interfacial agent of non - same - layer equal - thickness asphalt surface layer in an expansion project, including the following steps:

[0018] Mix sodium hydroxide and sodium silicate evenly to obtain a liquid alkaline activator;

[0019] Mix fly ash, cement, and mineral powder evenly to obtain a powder;

[0020] Add the liquid alkaline activator to the powder and stir evenly to obtain a geopolymer;

[0021] Add the emulsified asphalt to the geopolymer and stir evenly to obtain the splicing interfacial agent.

[0022] In summary, the present invention has the following beneficial effects:

[0023] The interfacial agent provided by the present invention belongs to a composite material combining rigidity and flexibility, plays a very good transitional role between the flexible structure and the rigid structure, coordinates the moduli of the flexible structure and the rigid structure, enables the two to work together, and delays or even prevents the occurrence of cracks at the splicing part. Specific embodiments

[0024] To further elaborate on the technical means and effects adopted by the present invention to achieve the intended invention purpose, a splicing interface agent for non - same - layer and equal - thickness asphalt surface layers in an expansion project and its preparation method proposed according to the present invention, their specific implementation manners, characteristics and effects are described in detail as follows.

[0025] In this specific implementation manner, the sources of commercially available materials are as follows:

[0026] Anionic emulsified asphalt: Jiangsu Zhonglu New Material Technology Development Co., Ltd.

[0027] Fly ash: Pengze Honghao Mashan Mining Co., Ltd.

[0028] Mineral powder: Pengze Honghao Mashan Mining Co., Ltd.

[0029] Sodium silicate: Jiangsu Zhonglu New Material Technology Development Co., Ltd.

[0030] Sodium hydroxide: Jiangsu Zhonglu New Material Technology Development Co., Ltd. [[ID=2,0]]

[0031] Cement: Pengze Honghao Mashan Mining Co., Ltd.

[0032] In previous highway expansion projects, the splicing conditions involved were all the splicing of the same - layer and equal - thickness of the old asphalt layer and the new asphalt layer, and the old water - stable layer and the new water - stable layer, that is, the splicing of flexible structures with flexible structures, and the splicing of rigid structures with rigid structures. The developed materials were also for the same - layer and equal - thickness; the splicing condition of the old asphalt layer and the new water - stable layer was not involved, that is, the splicing of a flexible structure with a rigid structure. The modulus gap between the flexible structure and the rigid structure is very large, and stress concentration will occur under heavy loads, resulting in cracking at the splicing part.

[0033] However, traditional flexible splicing materials for flexible structures with flexible structures and rigid splicing materials for rigid structures with rigid structures are not applicable to the splicing of flexible structures with rigid structures. They cannot play a role in coordinating flexible structures and rigid structures, and cannot enable the two to work together. Under heavy loads, the splicing part is very prone to cracking.

[0034] The interface agent provided in this specific implementation manner belongs to a composite material that combines rigidity and flexibility. It plays a very good transitional role between flexible structures and rigid structures, coordinates the moduli of flexible structures and rigid structures, enables the two to work together, and delays or even prevents the occurrence of cracks at the splicing part.

[0035] This specific implementation manner provides a splicing interface agent for non - same - layer and equal - thickness asphalt surface layers in an expansion project. After the interface agent is formed, one side is combined with asphalt materials, and the other side is combined with cement - stabilized materials;

[0036] The interface agent includes geopolymers and emulsified asphalt;

[0037] The water in the emulsified asphalt undergoes a hydration reaction with the geopolymer.

[0038] It can be understood that the asphalt materials involved in this specific embodiment mainly include the following layers. The surface layer is the uppermost asphalt concrete layer, directly bearing traffic loads and the influence of the external environment; it is responsible for providing a waterproof, smooth, and wear-resistant surface. The middle layer is located below the surface layer and mainly plays a buffering role, transmitting and dispersing the loads from the surface layer to ensure the overall strength of the structure. The bottom layer is the lowermost asphalt concrete layer, usually having larger aggregates and a lower asphalt content, responsible for bearing most of the loads from the upper layer and transmitting them to the underlying base course or subgrade.

[0039] The cement-stabilized materials involved in this specific embodiment mainly include: the cement-stabilized crushed stone layer, which uses crushed stone or gravel as aggregates, adds a certain proportion of cement and water, and is mixed and spread into layers. This material has high strength and durability and is a commonly used base material in highway engineering; the cement-stabilized sand and gravel layer, which uses natural sand and gravel or artificial sand and gravel, adds cement and water for mixing and compaction. This material is usually used for the base course of sections with lower strength requirements or secondary roads; the cement-stabilized soil layer, which directly mixes soil with cement and water and is used as the base course of low-grade pavements. This material has low strength but is suitable for areas with good soil quality; other stabilizer-stabilized layers, which use lime, fly ash, industrial waste residues, etc. as stabilizers in addition to cement.

[0040] When joining new and old road surfaces, due to the different material compositions and moduli of the asphalt layer and the cement-stabilized layer, using the jointing agent provided by the existing technology cannot coordinate the moduli of the two materials, resulting in problems such as cracking and settlement. However, the interfacial agent provided in this specific embodiment, through the reaction of the geopolymer with the water in the emulsified asphalt, while the geopolymer reacts with water through an alkaline activator to generate a network-structured material with good chemical corrosion resistance, causes the emulsified asphalt to demulsify, binds the asphalt in the network-structured material, and the two combine to form a composite material, having the strength and durability of the geopolymer, as well as the waterproof and flexible characteristics of the asphalt. It can not only take into account the flexibility of the asphalt layer but also connect to the rigidity of the water-stabilized layer, closely combine the new and old road surfaces, enable the two to work together, and delay or even prevent the occurrence of cracks at the joint.

[0041] In some preferred embodiments, the geopolymer includes a powder and a liquid activator, and the weight ratio of the powder to the liquid activator is 5:(3.0 - 3.5).

[0042] It can be understood that the structure of geopolymers is mainly composed of a network of silicates and aluminates. In emulsified asphalt, asphalt particles are suspended in water through emulsifiers. After the water evaporates, the asphalt particles recombine to form a thin film. In order to effectively combine geopolymers with emulsified asphalt, it is necessary to consider the interfacial bonding mechanism of the two materials. Therefore, the content of the liquid activator plays an important role in the bonding process of geopolymers and emulsified asphalt, helping to form a uniform and high-density gel-like structure. Under the action of an appropriate proportion of the liquid activator, the gelation reaction inside the geopolymers is more uniform. The gel-like geopolymers can penetrate into the tiny voids in the emulsified asphalt and form a strong physical bond at the interface. This physical interaction at the interface makes the asphalt particles and the geopolymer matrix bind more tightly, forming a composite material with good structural integrity and mechanical properties. At the same time, the appropriate proportion of the liquid activator can help control the initial fluidity and the final setting state of the geopolymers. When the geopolymers are combined with emulsified asphalt, the optimized ratio of the activator makes the geopolymers have an appropriate viscosity, ensuring that they can effectively cover and wrap the surface of the asphalt film. This can enhance the adhesiveness of the material, reduce the risk of interfacial separation, and improve the durability and crack resistance of the composite material.

[0043] In some preferred embodiments, the powder reacts with the liquid activator to generate a three-dimensional networked three-dimensional structure with silicon-oxygen tetrahedrons and aluminum-oxygen tetrahedrons.

[0044] It can be understood that this structure of geopolymers acts as the skeleton of emulsified asphalt, bearing and dispersing mechanical stress. Although emulsified asphalt has good flexibility, its mechanical strength is relatively low. The three-dimensional network structure of geopolymers can effectively improve the overall strength of the composite material and prevent excessive deformation or rupture under high load conditions. The bond energy of covalent bonds is higher than that of general physical bonding forces. Therefore, this silicon-oxygen - aluminum-oxygen network has higher compressive and tensile strengths. This strong network of geopolymers compensates for the lack of strength in emulsified asphalt and endows the composite material with better load-bearing capacity and crack resistance.

[0045] It can be understood that the chemical bonds of silicon-oxygen tetrahedrons and aluminum-oxygen tetrahedrons have high thermal stability. The melting points of silicon dioxide (SiO2) and aluminum oxide (Al2O3) are relatively high, above 1700 °C respectively. This means that the silicon-oxygen and aluminum-oxygen skeletons have excellent thermal stability at high temperatures, while emulsified asphalt is prone to softening or flowing at high temperatures, while geopolymers can maintain their structural integrity at higher temperatures. When the composite material is heated at high temperatures, the presence of geopolymers can effectively inhibit the softening of the asphalt film, thus maintaining the overall structure and performance of the material. Due to the excellent thermal stability of the silicon-oxygen - aluminum-oxygen skeleton of geopolymers, it can effectively slow down the softening rate of emulsified asphalt at high temperatures, help the material maintain its strength and rigidity, and avoid performance degradation due to temperature changes.

[0046] It is understandable that when geopolymers are combined with emulsified asphalt, this network structure can form an effective physical bond with asphalt particles. Through this bond, geopolymers provide good adhesion at the interface, enabling asphalt particles to be firmly embedded in the geopolymer matrix, reducing the risk of peeling and delamination. In addition, the toughness of geopolymers allows the material to release stress through micro-deformation in stress concentration areas, reducing the possibility of crack propagation. The toughness of geopolymers comes from a certain proportion of aluminum-oxygen tetrahedra in their network, which allow a certain degree of structural flexibility while maintaining strength. When combined with emulsified asphalt, geopolymers not only improve adhesion but also enhance the deformation ability of the composite material under tensile and compressive conditions, significantly improving the crack resistance and durability of the material.

[0047] In some preferred embodiments, the powder includes fly ash, cement, and mineral powder;

[0048] Among them, the weight ratio of fly ash, cement, and mineral powder is 1:(0.5 - 1):(1 - 1.5).

[0049] It is understandable that in the powder provided in this specific embodiment, the proportion of mineral powder is the largest. This is because the fine particles of mineral powder have a large specific surface area and good filling ability. When the proportion of mineral powder is high, its fine particles can fill the micro-pores in the emulsified asphalt matrix, reducing the overall porosity of the material. This denser microstructure can effectively enhance the adhesion and stability of the material. The dense interface formed by mineral powder and emulsified asphalt reduces the existence of weak interfaces. At the same time, by increasing the cohesion of the material, it increases the load-bearing capacity and anti-deformation ability of the material under external forces. This tight interface structure enables the material to maintain moderate deformation under load without brittle fracture, thereby improving the flexibility and toughness of the material.

[0050] At the same time, a stable interface is mainly formed between the mineral powder and the asphalt particles in the emulsified asphalt through physical adsorption and mechanical bonding. Due to the small size and high surface activity of the mineral powder particles, it can form a stable bonding layer with the asphalt particles in the emulsified asphalt through adsorption. This adsorption effect of the mineral powder particles can not only enhance adhesion but also slow down the stress concentration at the interface, preventing cracks from propagating inside the material. The physical adsorption between the mineral powder and the asphalt film forms an elastic interface. Under external forces, the interface can slip moderately, allowing local deformation of the material. This deformation mechanism makes the material exhibit high flexibility and ductility and is not prone to brittle fracture at stress concentration points.

[0051] It can be understood that the combination of mineral powder and emulsified asphalt forms a multiphase composite material, where the hard particles of the mineral powder can act as stress dispersants under external loads. Due to the high hardness of the mineral powder, it can play a buffering role in local stress concentration areas, dispersing the concentrated load over a larger area and reducing the risk of crack propagation caused by stress concentration. The introduction of the stress dispersion mechanism significantly improves the crack resistance of the material. The mineral powder particles, as microscopic "support points", can help relieve the stress in the asphalt matrix under load, thereby improving the crack resistance and overall durability of the material. The combination of this crack resistance mechanism with the flexibility of the material enables the composite material to undergo moderate deformation under high stress without sudden failure.

[0052] At the same time, the high proportion of mineral powder helps to improve the deformation recovery ability of the material. After the external force is unloaded, the interface in the mineral powder-emulsified asphalt composite material can achieve a certain degree of self-healing through physical adsorption and particle interaction. This deformation recovery ability helps to slow down the generation and expansion of cracks, thereby improving the overall performance and service life of the material. Although the asphalt part in the composite material may deform due to the load, the fine particles of the mineral powder provide a certain buffer space, enabling the material to recover to a partial original state after unloading. This self-healing ability further enhances the toughness and durability of the material.

[0053] In some preferred embodiments, the liquid activator includes sodium hydroxide and sodium silicate;

[0054] Among them, the weight ratio of sodium hydroxide to sodium silicate is 1:(1 - 1.5).

[0055] It can be understood that the silicon ions in sodium silicate can combine with dissolved aluminum ions and sodium ions to form a more stable silicon-oxygen-aluminum-oxygen framework structure. This structure enhances the adhesiveness and internal toughness of the material. Especially when combined with emulsified asphalt, it can provide a more solid and stable interfacial layer. The enhancement of this silicon-oxygen network helps to improve the crack resistance and flexibility of the material under stress. When the content of sodium silicate is relatively high, the silicon-oxygen tetrahedron structure inside the material is denser, effectively improving the crack resistance and toughening performance of the material, enabling the composite material to withstand greater stress and deformation without brittle fracture.

[0056] In some preferred embodiments, the modulus of the liquid alkaline activator is 1.1 - 1.3.

[0057] It can be understood that when the modulus is relatively low (e.g., below 1.1), the alkalinity in sodium silicate is relatively strong, and the reaction may be too fast, which may lead to insufficient adhesiveness of the material; while when the modulus is too high (above 1.3), the silicon content is too high, which may cause the material to become brittle. When the modulus is 1.1 - 1.3, the ratio of silicon to sodium is appropriate, which can form good adhesiveness at the interface and contribute to the tight combination between the geopolymer and emulsified asphalt.

[0058] In some preferred embodiments, the emulsified asphalt is an anionic emulsified asphalt.

[0059] It is understandable that the asphalt particles of anionic emulsified asphalt have negative charges, and geopolymers are usually formed under alkaline conditions, and alkaline solutions usually contain cations (such as Na + , Ca 2+ This attractive interaction between positive and negative charges allows the anionic emulsified asphalt to better bond with the geopolymer matrix, forming a stronger interface. The anionic emulsified asphalt better matches the alkaline excitation system of the geopolymer, forming a more stable composite material and improving the material's bonding properties and interfacial bonding strength.

[0060] In addition, since the asphalt particles in the anionic emulsified asphalt have negative charges, it can be more easily stabilized and expanded in the alkaline environment with the geopolymer. + ) attracts the negatively charged particles in the anionic emulsified asphalt to form a stable interface layer, thereby enhancing the adhesion between the interfaces. This charge interaction not only increases the interfacial bonding strength of the material, but also improves the overall stability of the composite material and reduces the possibility of material peeling or delamination.

[0061] In some preferred embodiments, the interface agent includes the following components, calculated by weight: 70-75 parts of geopolymer and 25-30 parts of emulsified asphalt.

[0062] As can be understood, geopolymer possesses high mechanical strength and durability, providing a robust structural framework, while emulsified asphalt offers flexibility and ductility. The 7075 parts geopolymer ratio ensures the material's strength, compressive strength, and durability, while the 2530 parts emulsified asphalt enhances its toughness and crack resistance. This ratio achieves a good balance between strength and toughness, ensuring the material's load-bearing capacity under high loads while also adapting to external shocks and temperature fluctuations, reducing brittle fracture.

[0063] Furthermore, the asphalt film in the emulsified asphalt forms a bonding layer within the material, effectively connecting the geopolymer's particle structure. A 25-30 phr emulsified asphalt ratio provides sufficient adhesion to the geopolymer skeleton, ensuring the material's integrity and preventing interfacial delamination or peeling. This ratio not only ensures the geopolymer's strength, but also leverages the emulsified asphalt's adhesive properties to further enhance the composite's cohesion, making it more integrated and stable.

[0064] This specific embodiment also provides a method for preparing an interface agent for splicing asphalt pavements of different thicknesses in an expansion project, comprising the following steps:

[0065] Mix sodium hydroxide and sodium silicate evenly to prepare a liquid alkaline activator;

[0066] Mix fly ash, cement, and mineral powder evenly to prepare a powder;

[0067] Add the liquid alkaline activator to the powder and stir evenly to obtain a geopolymer;

[0068] Add emulsified asphalt to the geopolymer and stir evenly to obtain a splicing interface agent.

[0069] Example 1

[0070] A splicing interface agent for non - same - layer equal - thickness asphalt surface layer in an expansion project provided in this example includes 80 g of geopolymer and 27 g of anionic emulsified asphalt.

[0071] Among them, the geopolymer includes: 15 g of sodium hydroxide, 15 g of sodium silicate, 20 g of fly ash, 10 g of cement, and 20 g of mineral powder.

[0072] This example also provides a preparation method for the above - mentioned interface agent, and the steps are as follows:

[0073] S1. Prepare a composite alkaline activator: Mix 15 g of sodium hydroxide and 15 g of sodium silicate evenly to prepare 30 g of composite alkaline activator;

[0074] S2. Prepare a powder: Mix 20 g of fly ash, 10 g of cement, and 20 g of mineral powder evenly to prepare 50 g of powder;

[0075] S3. Prepare a geopolymer: Add 30 g of composite alkaline activator to 50 g of powder and stir evenly to obtain 80 g of geopolymer;

[0076] S4. Add 27 g of anionic emulsified asphalt to 80 g of geopolymer and stir evenly to obtain a splicing interface agent.

[0077] The performance test results of the splicing interface agent in Example 1 are shown in Table 1.

[0078] Table 1. Direct shear test results of the splicing interface agent in Example 1

[0079]

[0080] Example 2

[0081] A splicing interface agent for non - same - layer equal - thickness asphalt surface layer in an expansion project provided in this example includes 88 g of geopolymer and 40 g of anionic emulsified asphalt.

[0082] Among them, the geopolymer includes: 15 g of sodium hydroxide, 20 g of sodium silicate, 18 g of fly ash, 10 g of cement, and 25 g of mineral powder.

[0083] This embodiment also provides a preparation method of the above interface agent, and the steps are as follows:

[0084] S1. Prepare a composite alkaline activator: Mix 15 g of sodium hydroxide and 20 g of sodium silicate evenly to obtain 35 g of the composite alkaline activator;

[0085] S2. Prepare a powder: Mix 18 g of fly ash, 10 g of cement, and 25 g of mineral powder evenly to obtain 53 g of the powder;

[0086] S3. Prepare a geopolymer: Add 35 g of the composite alkaline activator to 53 g of the powder and stir evenly to obtain 88 g of the geopolymer;

[0087] S4. Add 40 g of anionic emulsified asphalt to 88 g of the geopolymer and stir evenly to obtain the splicing interface agent.

[0088] The performance test results of the splicing interface agent in Example 2 are shown in Table 2.

[0089] Table 2. Direct shear test results of the splicing interface agent in Example 2

[0090]

[0091] Example 3

[0092] A splicing interface agent for non - same - layer and equal - thickness asphalt surface layer in an expansion project provided in this embodiment includes 96 g of geopolymer and 32 g of anionic emulsified asphalt.

[0093] Among them, the geopolymer includes: 15 g of sodium hydroxide, 22 g of sodium silicate, 17 g of fly ash, 17 g of cement, and 25 g of mineral powder.

[0094] This embodiment also provides a preparation method of the above interface agent, and the steps are as follows:

[0095] S1. Prepare a composite alkaline activator: Mix 15 g of sodium hydroxide and 22 g of sodium silicate evenly to obtain 37 g of the composite alkaline activator;

[0096] S2. Prepare a powder: Mix 17 g of fly ash, 17 g of cement, and 25 g of mineral powder evenly to obtain 59 g of the powder;

[0097] S3. Prepare a geopolymer: Add 37 g of the composite alkaline activator to 59 g of the powder and stir evenly to obtain 96 g of the geopolymer;

[0098] S4. Add 32 g of anionic emulsified asphalt to 96 g of the geopolymer and stir evenly to obtain the splicing interface agent.

[0099] The performance test results of the splicing interface agent in Example 3 are shown in Table 3.

[0100] Table 3. Results of the direct shear test of the splicing interface agent in Example 3

[0101]

[0102] Comparative Example 1

[0103] The materials and preparation method of this example are basically the same as those of Example 1, except that instead of using anionic emulsified asphalt, ordinary asphalt is used.

[0104] The performance test results of the splicing interface agent in Comparative Example 1 are shown in Table 4.

[0105] Table 4. Results of the direct shear test of the splicing interface agent in Comparative Example 1

[0106]

[0107] Comparative Example 2

[0108] The materials and preparation method of this example are basically the same as those of Example 1, except that the powder includes: 25 g of fly ash, 20 g of cement, and 5 g of mineral powder.

[0109] The performance test results of the splicing interface agent in Comparative Example 2 are shown in Table 5.

[0110] Table 5. Results of the direct shear test of the splicing interface agent in Comparative Example 2

[0111]

[0112]

[0113] Comparative Example 3

[0114] The materials and preparation method of this example are basically the same as those of Example 1, except that it includes 40 g of geopolymer and 67 g of anionic emulsified asphalt.

[0115] Among them, 40 g of geopolymer includes: 7.5 g of sodium hydroxide, 10 g of sodium silicate, 9 g of fly ash, 5 g of cement, and 12.5 g of mineral powder.

[0116] The performance test results of the splicing interface agent in Comparative Example 3 are shown in Table 3.

[0117] Table 6. Results of the direct shear test of the splicing interface agent in Comparative Example 3

[0118]

[0119] It can be seen from the above test data that based on the splicing interface agent provided by the present invention, the shear strength of the material is improved, enabling the old asphalt layer and the newly paved water-stabilized layer to be well bonded, thus effectively improving the bonding effect of the splicing interface, enhancing the water stripping resistance of the overall structure, and ensuring the integrity of the road after expansion.

[0120] This non-homogeneous and equal-thickness asphalt surface layer splicing interface agent is formed by the combination of geopolymers and emulsified asphalt, in which the water in the emulsified asphalt undergoes a hydration reaction with the geopolymers. This interface agent has a strong bonding force between asphalt materials and cement-stabilized materials and has the following advantages:

[0121] 1. The interfacial reaction between geopolymers and emulsified asphalt enhances the bonding force

[0122] The hydration reaction of geopolymers forms a silicon-oxygen and aluminum-oxygen tetrahedral network structure through the reaction of an alkaline activator with silico-aluminum materials such as fly ash and mineral powder. During the forming process of the interface agent, the water in the emulsified asphalt participates in the hydration reaction of the geopolymers, helping the geopolymers to form a dense structure. This structure can effectively fill the tiny pores and irregular surfaces on the interface, enabling the interface agent to form a mechanical locking effect with the upper and lower layers of materials. This reaction enhances the density of the interface agent and forms a strong interfacial bonding force. Through this dense network structure, the interface agent can better embed into the surfaces of the cement-stabilized layer and the asphalt layer, significantly improving the bonding property of the interface.

[0123] 2. The high bonding property and durability of geopolymers

[0124] The silicon-oxygen-aluminum-oxygen framework structure of geopolymers forms a high-strength bonding network after the hydration reaction. This network has excellent shear strength and crack resistance. Its chemical inertness enables geopolymers to exhibit good chemical erosion resistance to cement-stabilized materials, and this high-strength chemical bond enables the interface agent to maintain stable bonding performance under long-term stress and external environmental changes (such as temperature, humidity, etc.). The high bonding force of geopolymers enables them to firmly bond with cement-stabilized materials, enhancing the durability of the material interface. It also provides high crack resistance, reducing the risk of interface cracking caused by uneven material stress.

[0125] 3. The compatibility between emulsified asphalt and the asphalt layer

[0126] After the emulsified asphalt breaks, the asphalt particles will reaggregate to form a dense asphalt film. This asphalt film has a high compatibility with the traditional asphalt surface layer and can adhere well to the surface of the asphalt surface layer. In the interface agent, the presence of emulsified asphalt enables it to form chemical bonding force and physical locking force with the asphalt layer at the interface. Emulsified asphalt has a natural chemical affinity with the asphalt layer, and this strong bonding force ensures the bonding effect between the interface agent and the asphalt layer, providing good sealing and waterproofing properties, and enhancing the durability and anti-aging performance of the interface area.

[0127] 4. Flexibility and crack resistance of the interface agent

[0128] Emulsified asphalt imparts a certain degree of flexibility to the interface agent, enabling it to alleviate the stress mismatch problem caused by the different elastic moduli of the asphalt layer and the cement stabilized layer. Under temperature changes or traffic loads, the flexibility of the interface agent allows it to adapt to the minor deformations in the interface area, thereby preventing cracks caused by stiffness mismatch. In addition, the crack resistance of geopolymers enhances the overall toughness of the interface agent. The flexibility and crack resistance of the interface agent enable it to effectively handle the stress transfer between different materials in the expansion project, reduce the occurrence of cracking and peeling phenomena, and extend the service life of the project.

[0129] 5. Transitional role of the interface agent between the asphalt layer and the cement stabilized layer

[0130] The combination of geopolymers and emulsified asphalt plays a role of a transition layer between the asphalt layer and the cement stabilized layer. Geopolymers can form a strong chemical bond with the cement stabilized layer, while emulsified asphalt binds tightly to the asphalt layer. Through the transitional nature of this material, the interface agent forms a strong bond between the two different materials, while alleviating the elastic differences between the different materials. This interface agent not only improves the bonding performance between the asphalt surface layer and the cement stabilized layer, but also reduces the elastic modulus difference between the two through the transitional nature of the material, reducing stress concentration and material fatigue caused by elastic differences.

[0131] In summary, the design of the non-homogeneous equal-thickness asphalt surface layer splicing interface agent provided by the present invention utilizes the characteristics of geopolymers and emulsified asphalt to form an interface layer with strong bonding force and high durability between the asphalt material and the cement stabilized material. Through the high strength and bonding force of geopolymers, the flexibility and asphalt affinity of emulsified asphalt, and the chemical interaction between the two, the interface agent shows significant advantages in dealing with stress transfer, crack resistance and waterproof performance of different materials, ensuring the long-term stability and reliability of the splicing part in the expansion project.

[0132] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been shown above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art, within the scope of the technical solution of the present invention, can make some changes or modifications to equivalent embodiments by using the technical content disclosed above. However, as long as it does not depart from the technical content of the present invention, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. An asphalt surface layer splicing interface agent with the same thickness on different floors for an expansion project, characterized in that, After the interface agent is formed, one side is combined with the asphalt material and the other side is combined with the cement stabilized material; The interface agent includes geopolymer and emulsified asphalt; The water in the emulsified asphalt undergoes a hydration reaction with the geopolymer.

2. An interfacial agent for splicing of non - same - layer and equal - thickness asphalt surface layers in an expansion project according to claim 1, characterized in that, The geopolymer includes a powder and a liquid activator, and the weight ratio of the powder to the liquid activator is 5:(3.0 - 3.5).

3. An interface agent for splicing non - same - floor equal - thickness asphalt surface layers in an expansion project according to claim 2, characterized in that, The powder and the liquid activator undergo a polymerization reaction to form a three-dimensional networked three-dimensional structure in which silicon-oxygen tetrahedrons and aluminum-oxygen tetrahedrons are cross-linked with each other through shared oxygen atoms. The metal cations in the liquid activator are distributed in the three-dimensional network to balance the negative charges carried by the aluminum-oxygen tetrahedrons.

4. An interfacial agent for splicing of non - same - layer and equal - thickness asphalt surface layers in an expansion project according to claim 2, characterized in that, The powder includes fly ash, cement and mineral powder; Among them, the weight ratio of the fly ash, cement and mineral powder is 1:(0.5 - 1):(1 - 1.5).

5. An interface agent for splicing the non - same - floor and equal - thickness asphalt surface layer in an expansion project according to claim 2, characterized in that, The liquid activator includes sodium hydroxide and sodium silicate; among them, the weight ratio of the sodium hydroxide to the sodium silicate is 1:(1 - 1.5).

6. The splicing interface agent for non - same - floor and equal - thickness asphalt surface layers in an expansion project according to claim 2, characterized in that, The modulus of the liquid alkaline activator is 1.1 - 1.

3.

7. An interface agent for splicing the same-thickness asphalt surface layers on different floors in an expansion project according to claim 1, characterized in that, The emulsified asphalt is anionic emulsified asphalt.

8. The interface agent for splicing asphalt pavements of different thicknesses in an expansion project according to claim 1 is characterized in that: Calculated by weight parts, the interface agent includes the following components: 70 - 75 parts of geopolymer and 25 - 30 parts of emulsified asphalt.

9. An interfacial agent for splicing the same-thickness asphalt surface layers on different floors in an expansion project according to claim 1, characterized in that The asphalt material includes the asphalt concrete layer of the old road surface, and the cement stabilized material includes a cement stabilized gravel layer, a cement stabilized sand and gravel layer or a cement stabilized soil layer.

10. The preparation method of an interfacial agent for splicing the asphalt surface layers with the same thickness on different floors in an expansion project according to claim 1, wherein, It includes the following steps: Mix sodium hydroxide and sodium silicate evenly to prepare a liquid alkaline activator; Mix fly ash, cement and mineral powder evenly to prepare a powder; Add the liquid alkaline activator to the powder and stir evenly to obtain a geopolymer; Add the emulsified asphalt to the geopolymer and stir evenly to obtain a splicing interface agent.

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