Polymer grouting material for trenchless repair of pavement diseases and preparation method and application thereof

Abstract

The application belongs to the technical field of pavement preventive maintenance, and discloses a high polymer grouting material for non-excavation repair of pavement diseases and a preparation method thereof. The high polymer grouting material is aimed at the problems of conventional two-component polyurethane grouting material, such as water sensitivity, easy foaming, insufficient mechanical properties of foamed polyurethane material, poor bonding effect on a wet interface, and poor universality in disease treatment. Through multi-component regulation of polyurethane, epoxy and plasticizer, the viscosity of the first mixed component and the second mixed component of the pavement high polymer grouting material is low, and the permeability is good. The pavement high polymer grouting material does not foam for dry and wet disease interfaces, has good universality for crack and pumping diseases of the asphalt layer and the base layer, and can achieve the purpose of simultaneously repairing diseases of the asphalt layer and the semi-rigid base layer and prolonging the service life of the pavement. The application also provides application of the high polymer grouting material in non-excavation disease repair technology of the pavement.

Description

Technical Field

[0001] This invention belongs to the field of pavement preventive maintenance technology. Specifically, it relates to a water-insensitive polymer grouting material that has both high adhesion and non-foaming properties under wet interface conditions, its preparation method, and its application in trenchless repair of pavement defects. Background Technology

[0002] As one of the most significant defects in asphalt pavements, structural damage caused by cracking of the semi-rigid base course has always been a key focus of pavement maintenance. In water-damaged environments, cracking of the semi-rigid base course can further lead to asphalt pavement cracking, interlayer delamination, and loosening of the structural layers. Macroscopically, this manifests as pavement cracks and pumping, which can further develop into potholes, severely impacting the pavement's service life.

[0003] Currently, the commonly used crack repair techniques for asphalt pavements mainly include grouting, filling, and sealing. However, these repair methods are not very effective in terms of adhesion and mechanical properties. General grouting treatments can only treat the surface of the crack and cannot address cracks in the semi-rigid base layer, meaning they cannot fundamentally delay or prevent crack development. For repairs where the damage has progressed to pumping, the common method is pavement excavation and patching. This method is not only costly but also has a long construction period, resulting in limited economic and social benefits.

[0004] Trenchless asphalt pavement repair technology is based on research into minimally invasive grouting technology. Compared to conventional excavation repair methods, this technology has less impact on traffic, is simpler to construct, and causes less disturbance to the pavement structure. Trenchless grouting methods mainly include geopolymer grouting and polymer grouting. Geopolymer grouting primarily uses inorganic grouting materials, which can fill and reinforce the base course. However, it has a slow reaction and curing speed, poor bond strength and permeability, and is prone to shrinkage. Most importantly, geopolymer grouting can only treat the base course, requiring milling and repaving of the asphalt layer. Polymer grouting, on the other hand, has significant advantages over geopolymers. It has a fast reaction speed and high bond strength, serving both filling and bonding functions. However, polymer grouting materials are generally prone to foaming, especially in moist cracks and pumping environments, where the foaming ratio is high and uncontrollable. This leads to problems such as low mechanical strength after foaming, easy volume shrinkage, and reduced load-bearing capacity.

[0005] Two-component polyurethane polymer grouting materials are characterized by adjustable performance, fast reaction speed, high mechanical strength, and rapid construction without curing, making them the preferred choice for polymer grouting materials. Polyurethane polymer grouting materials are high-molecular polymers obtained by mixing polyisocyanates and polyether polyols or polyester polyols as raw materials, along with catalysts, chain extenders, and other additives in a specific ratio. During construction, holes are first drilled at the cracks / pumps according to the condition of the damage. Then, the polyurethane polymer grouting material is injected into the damaged area using specialized grouting pressure equipment for filling and repair. However, the situation of pavement cracks / pumps is complex. In particular, moisture, dampness, or standing water at the interface of the cracks / pumps can form a water film between the asphalt concrete / water-stabilized concrete and the polyurethane material, hindering the adhesion between the welding material and the substrate, severely affecting the bonding effect, and failing to achieve long-term waterproofing and resistance to the development of the damage. Furthermore, polyurethane materials are sensitive to water and easily foam and become loose in the presence of water, affecting the bonding strength and mechanical properties of the grouting material. After the crack is filled, the bonded area remains under dynamic service loads and will still be subject to tension, compression, and vertical displacement. The bond strength, tensile shear strength, and other mechanical properties of the grouting material will affect the service performance after crack welding. Furthermore, since the base course of a road typically consists of cement-stabilized crushed stone and lime-fly ash-stabilized crushed stone, polyurethane polymer grouting materials exhibit good adhesion to the asphalt layer but only moderate adhesion to the base course. Therefore, for applications involving road cracks / pumping defects, the grouting material needs to possess characteristics such as rapid reaction speed, non-foaming upon contact with water, high bond strength at wet interfaces, and broad applicability to cracks and pumping defects in both the asphalt layer and base course.

[0006] In the existing technology, water glass polyurethane grouting materials have the characteristics of being insensitive to water and not foaming. However, water glass polyurethane materials have poor mechanical properties and low shear strength. They can be used for roadbed voids and other defects, but they are still difficult to apply to cracks / pumping defects that require high bonding strength. Currently, there are some research reports on water glass polyurethane grouting materials. For example, Chinese patent CN 105566593A discloses a highly compatible water glass modified polyurethane grouting material and its preparation method. Although it can improve the compatibility of the system and reduce the foaming and cost problems of pure polyurethane to a certain extent, it is mainly applicable to coal mine reinforcement and does not focus on the adhesion and shear resistance of polyurethane materials to damp substrates. Another example is Chinese patent CN106046761A, which discloses a high-adhesion two-component epoxy-polyurethane blend material and its preparation method. Although it can achieve adhesion at damp interfaces, the adhesion effect at damp interfaces is limited. In addition, the material foams and is mainly used for road void bearing, without considering the uncontrollable influence of moisture in cracks / pumping defects on the foaming and performance of the blend material, and lacks application performance research in crack / pumping bonding application scenarios.

[0007] In summary, further research is needed on polyurethane grouting materials to address the challenges of polymer grouting technology in terms of adhesion, foaming properties, and moisture sensitivity. Ultimately, the goal is to achieve simultaneous bonding and filling of pumped-out / cracked / interlayer defects in asphalt layers and semi-rigid water-stabilized layers through polymer grouting, thereby achieving structural repair and extending pavement service life. Summary of the Invention

[0008] To address the technical drawbacks of existing polyurethane grouting materials used in trenchless pavement repair, this invention provides a novel polymer grouting material for pavement repair that combines high adhesion with water-insensitive and non-foaming properties. This polymer grouting material does not foam at both dry and wet crack / pumping interfaces, exhibits broad applicability to crack / pumping defects in asphalt layers and base courses, and possesses excellent mechanical and adhesive properties, thus demonstrating superior bonding performance at both dry and wet interfaces.

[0009] The present invention specifically adopts the following technical solution: In a first aspect, the present invention provides a polymer grouting material for trenchless repair of road surface defects, comprising a first mixed component and a second mixed component mixed in equal volumes.

[0010] The first mixing component comprises the following components that are uniformly mixed: 60-100 parts of polyether polyol; 1-5 parts coupling agent; 0.3~0.8 parts of organometallic polyurethane catalyst; 10-15 parts of phenolic amine epoxy curing agent; The second mixing component comprises the following components that are uniformly mixed: 30-60 parts of isocyanate; 20-40 parts of isocyanate-terminated polyurethane prepolymer; 10-15 parts epoxy resin; Plasticizer 2-8 parts; All figures above are by weight (parts).

[0011] Optionally, the polyether polyol is selected from one of polyether diol, polyether triol, polyether tetraol, polyoxyethylene polypropylene block polyether, bisphenol A polyether, or a mixture of at least two in any proportion.

[0012] Optionally, the coupling agent is selected from silane coupling agents and / or titanate coupling agents.

[0013] Optionally, the organometallic polyurethane catalyst is selected from one of the environmentally friendly non-foaming catalysts CUCAT-6 and CUCAT-K6, or a mixture of the two in any proportion.

[0014] Optionally, the phenolic amine epoxy curing agent is a mixture of T31 and NX-5653 in equal mass.

[0015] It should be noted that T31 and NX-5653 are different models of phenolic amine epoxy curing agents.

[0016] Optionally, the isocyanate is a mixture of polymethylene polyphenyl polyisocyanate and diphenylmethane diisocyanate in a mass ratio of 3:1.

[0017] Optionally, the isocyanate-terminated polyurethane prepolymer is prepared by reacting diphenylmethane diisocyanate and dehydrated polyether diol in an inert atmosphere at 80°C to 90°C at a mass ratio of 2.5:2 to 3.5:2 for 3 to 4 hours.

[0018] Furthermore, dehydrated polyether diols can be obtained by vacuum dehydration.

[0019] Furthermore, the polyether glycol is PPG-400.

[0020] Generally, an inert atmosphere can be a conventional inert gas atmosphere such as N2 or Ar, without being specifically limited here.

[0021] Optionally, the epoxy resin is E44 and / or E51.

[0022] Optionally, the plasticizer is selected from any one of epoxidized soybean oil, epoxidized fatty acid triester, epoxidized tetrahydrophthalic acid ester, or a mixture of at least two in any proportion.

[0023] The polymer grouting material for trenchless repair of road surface defects provided by this invention features, firstly, an organometallic polyurethane catalyst with high catalytic activity for the NCO / OH reaction, particularly exhibiting a stronger targeted inhibition effect on the reaction between water and isocyanate. This effectively suppresses the catalytic effect of conventional polyurethane catalysts on isocyanate and water, preventing the generation of CO2 bubbles. This ensures that the two-component polyurethane material does not foam in either damp or water-containing defects, thereby reducing the impact of environmental moisture on the foaming rate and mechanical properties of the polyurethane grouting material. Furthermore, this catalyst does not promote the cross-linking side reaction of isocyanate. Combined with the introduced polyurethane prepolymer, it controls the reaction rate, reduces stress defects caused by excessively rapid reactions, resulting in higher toughness after curing, greater resistance to deformation, and increased bond strength. Additionally, the organometallic polyurethane catalyst has high activity, allowing the curing time of the road surface grouting material to be controlled at around 60 seconds at relatively low dosages, achieving rapid penetration and rapid strength development. Compared to conventional alkyl metal catalysts, this organometallic polyurethane catalyst has the advantages of good stability and resistance to hydrolysis.

[0024] Secondly, the organometallic polyurethane catalyst used is an environmentally friendly organometallic polyurethane catalyst. The product does not contain restricted heavy metals such as mercury, lead, and tin, and complies with environmental regulations. It is an ideal replacement for conventional polyurethane catalysts such as organomercury, lead, and tin, avoiding the disadvantage that conventional polyurethane industrial catalysts have a strong catalytic effect on the reaction of isocyanates and water, making them difficult to apply to products that do not foam in humid and water-rich environments. At the same time, it also overcomes the problem that organobismuth, which is currently considered to be the closest to organomercury, still cannot avoid foaming, bulging, and cracking even when using a more stringent water control process than mercury.

[0025] Thirdly, while organometallic polyurethane catalysts can prevent foaming of two-component polyurethane at damp interfaces, the presence of moisture at the interface still results in a two-layer structure between the polyurethane material and the substrate with a water film barrier. Although this can fill cracks and other defects, the bonding strength is poor. To address this, this invention introduces epoxy resin and a special phenolic amine epoxy curing agent into the polymer grouting material. This allows the phenolic hydroxyl groups on the curing agent to form hydrogen bonds, coordination bonds, or physicochemical crosslinks with the active sites on the damp defect interface, significantly increasing the adhesion and shear strength to damp substrates. Furthermore, the combined use of different types of phenolic amine epoxy curing agents achieves a synergistic effect, balancing reaction speed and adhesion to damp interfaces. The introduction of the epoxy system also improves the universality of the grouting material's adhesion to different substrates, meeting the diverse bonding needs of asphalt layers, water-stabilized layers, and lime-stabilized crushed stone.

[0026] Fourth, in this polymer grouting material, the epoxy system (mainly referring to the epoxy resin in the second mixed component) and the polyurethane system (mainly referring to the isocyanate-terminated polyurethane prepolymer in the second mixed component) not only undergo cross-linking reactions separately, but also, in the presence of an organometallic polyurethane catalyst, the epoxy resin reacts with some isocyanates to form a multi-element network structure, enhancing the adhesion between the polymer grouting material and the substrate. Furthermore, the introduction of the coupling agent can improve the compatibility between the epoxy system and the polyurethane system, and can also synergize with the epoxy system to increase the adhesion between the polymer grouting material and the damp concrete substrate.

[0027] Fifth, based on the purpose of controlling the reaction rate and adjusting the water insensitivity and toughness of the material, considering that the reaction rate of a single isocyanate is too fast, it will cause the polymer grouting material to have poor injection effect, be easily affected by moisture in the environment, and produce mechanical defects. This invention combines isocyanate with a polyurethane prepolymer with reduced isocyanate content, which can effectively control the reaction rate, reduce foaming, and increase the toughness of the polymer grouting material.

[0028] A second aspect of the present invention provides a method for preparing the above-mentioned polymer grouting material for trenchless repair of road surface defects, comprising the following steps: Preparation of the first mixed component: Add 1-5 parts of coupling agent, 0.3-0.8 parts of organometallic polyurethane catalyst and 10-15 parts of phenolic amine epoxy curing agent to 60-100 parts of polyether polyol and stir to mix evenly. After dehydration treatment, the first mixed component is obtained and sealed for storage. Preparation of the second mixed component: Dehydrate the mixture of 10-15 parts epoxy resin and 2-8 parts plasticizer, then add 30-60 parts isocyanate and 20-40 parts terminal isocyanate polyurethane prepolymer, stir and mix evenly to obtain the second mixed component, and seal and store. Preparation of polymer grouting material: Mix equal volumes of the first mixing component and the second mixing component evenly to obtain a polymer grouting material for trenchless repair of road surface defects.

[0029] All of the above are by weight.

[0030] Optionally, in the formulation of the first mixed component, the organometallic polyurethane catalyst is selected from one of the environmentally friendly non-foaming catalysts CUCAT-6 and CUCAT-K6, or a mixture of the two in any proportion.

[0031] Optionally, in the formulation of the first mixed component, the coupling agent is selected from silane coupling agents and / or titanate coupling agents.

[0032] Optionally, in the formulation of the first mixture, the phenolic amine epoxy curing agent is prepared by mixing T31 and NX-5653 in equal mass.

[0033] Optionally, in the formulation of the first mixed component, the polyether polyol is selected from one of polyether diol, polyether triol, polyether tetraol, polyoxyethylene polypropylene block polyether, bisphenol A polyether, or a mixture of at least two in any proportion.

[0034] Optionally, in the formulation of the second mixture, the epoxy resin is E44 and / or E51.

[0035] Optionally, in the formulation of the second mixture, the plasticizer is selected from any one of epoxidized soybean oil, epoxidized fatty acid triester, and epoxidized tetrahydrophthalic acid ester, or a mixture of at least two in any proportion.

[0036] Optionally, in the preparation of the second mixture, the isocyanate is a mixture of polymethylene polyphenyl polyisocyanate and diphenylmethane diisocyanate in a mass ratio of 3:1.

[0037] Optionally, in the preparation of the second mixed component, the isocyanate-terminated polyurethane prepolymer is prepared by reacting diphenylmethane diisocyanate and dehydrated polyether diol in an inert atmosphere at 80°C to 90°C for 3 to 4 hours at a mass ratio of 2.5:2 to 3.5:2.

[0038] Generally, during the preparation of the first and second mixed components, the mixture of each component in the first mixed component and the mixture of epoxy resin and plasticizer in the second mixed component can be dehydrated by vacuum dehydration at about 100°C for about 2 hours to achieve the purpose of almost removing moisture, and then cooled to room temperature for later use.

[0039] A third aspect of the present invention provides the application of the above-mentioned polymer grouting material in trenchless road repair technology.

[0040] This invention addresses the problems of conventional two-component polyurethane grouting materials, such as water sensitivity and easy foaming, insufficient mechanical properties of foamed polyurethane materials, poor adhesion to damp interfaces, and limited applicability to disease treatment. By using a polyurethane-epoxy multi-component system and key component regulation, it synergistically solves the problems of polyurethane's easy foaming in damp environments and poor adhesion at damp interfaces, thus meeting the special technical requirements for repairing cracks and pumping defects in wet or water-containing pavements.

[0041] Compared with the prior art, the present invention has the following beneficial effects: (1) Through the multi-component regulation of polyurethane, epoxy and plasticizer, the viscosity of the first and second mixed components of the polymer grouting material is low and the permeability is good; in addition, the polymer grouting material does not foam for dry and wet disease interfaces, and has good universality for cracks / pumping diseases of asphalt layer and base layer.

[0042] (2) The polymer grouting material has excellent mechanical and bonding properties, with tensile strength greater than 20 MPa, compressive strength greater than 40 MPa, tensile shear strength greater than 10 MPa, and adhesion pull-out strength greater than 5 MPa.

[0043] (3) This polymer grouting material exhibits excellent bonding performance at both dry and wet interfaces, far superior to commercially available two-component polyurethane materials. Compared to the dry interface, the adhesion pull-out strength retention rate is greater than 90% at the wet interface. The splitting tensile strength of the wet crack Marshall specimen after bonding is greater than 1.5 MPa, and the splitting tensile strength ratio of the wet crack specimen to the dry crack specimen is greater than 85%. Detailed Implementation

[0044] The present invention will be further described below with reference to the embodiments, but the implementation of the present invention is not limited thereto.

[0045] It should be noted that phenolic amine epoxy curing agent NX-5653 is a commercially available product of Cardlä Company.

[0046] Example 1 Preparation of isocyanate-terminated polyurethane prepolymer: 55.6 parts by mass of diphenylmethane diisocyanate and 44.4 parts by mass of vacuum-dehydrated polyether diol PPG-400 were placed in a N2 atmosphere and reacted at 80°C for 3 h to obtain isocyanate-terminated polyurethane prepolymer.

[0047] Preparation of the first mixed component: 3 parts by mass of silane coupling agent KH550, 0.5 parts by mass of organometallic polyurethane catalyst CUCAT-6, and 10 parts by mass of phenolic amine epoxy curing agent (5 parts by mass of T31 and 5 parts by mass of NX-5653 mixed) were added to 60 parts by mass of polyether polyol (40 parts by mass of PPG-400 polyether diol and 20 parts by mass of DV125 polyether triol mixed). The mixture was stirred and mixed evenly at 100°C and dehydrated for 2 h. After cooling, it was sealed and stored.

[0048] Preparation of the second mixed component: 10 parts by weight of E51 epoxy resin and 4 parts by weight of epoxy soybean oil plasticizer were vacuum dehydrated at 100°C for 2 h. Then, 30 parts by weight of isocyanate (22.5 parts by weight of polymethylene polyphenyl polyisocyanate and 7.5 parts by weight of diphenylmethane diisocyanate) and 30 parts by weight of terminal isocyanate polyurethane prepolymer were added and stirred evenly at room temperature. The mixture was then sealed and stored.

[0049] Preparation of polymer grouting material: The first and second mixing components are mixed in equal volumes and mechanically mixed for 15 seconds to obtain the polymer grouting material.

[0050] Example 2 Preparation of isocyanate-terminated polyurethane prepolymer: 63.6 parts by mass of diphenylmethane diisocyanate and 36.4 parts by mass of vacuum-dehydrated polyether diol PPG-400 were placed in a N2 atmosphere and reacted at 85°C for 3.5 h to obtain isocyanate-terminated polyurethane prepolymer.

[0051] Preparation of the first mixed component: 1 part by mass of TCA-K55 titanate coupling agent, 0.8 parts by mass of organometallic polyurethane catalyst CUCAT-K6, and 15 parts by mass of phenolic amine epoxy curing agent (7.5 parts by mass of T31 and 7.5 parts by mass of NX-5653 mixed) were added to 80 parts by mass of polyether polyol (40 parts by mass of PPG-200 polyether diol and 40 parts by mass of 403 polyether tetraol). The mixture was stirred and mixed evenly at 100°C and dehydrated for 2 h. After cooling, it was sealed and stored.

[0052] Preparation of the second mixed component: 15 parts by mass of E44 epoxy resin and 2 parts by mass of epoxy fatty acid triester plasticizer were vacuum dehydrated at 100°C for 2 h. Then, 30 parts by mass of isocyanate (22.5 parts by mass of polymethylene polyphenyl polyisocyanate and 7.5 parts by mass of diphenylmethane diisocyanate) and 40 parts by mass of terminal isocyanate polyurethane prepolymer were added and stirred evenly at room temperature. The mixture was then sealed and stored.

[0053] Preparation of polymer grouting material: The first and second mixing components are mixed in equal volumes and mechanically mixed for 20 seconds to obtain the polymer grouting material.

[0054] Example 3 Preparation of isocyanate-terminated polyurethane prepolymer: 60 parts by mass of diphenylmethane diisocyanate and 40 parts by mass of vacuum-dehydrated polyether diol PPG-400 were placed in a N2 atmosphere and reacted at 90°C for 3 h to obtain isocyanate-terminated polyurethane prepolymer.

[0055] Preparation of the first mixed component: 5 parts by mass of silane coupling agent KH560, 0.3 parts by mass of organometallic polyurethane catalyst CUCAT-6, and 12.5 parts by mass of phenolic amine epoxy curing agent (6.25 parts by mass of T31 and 6.25 parts by mass of NX-5653 mixed) were added to 100 parts by mass of polyether polyol (60 parts by mass of PPG-400 polyether diol and 40 parts by mass of bisphenol A polyether BPE-10 mixed). The mixture was stirred and mixed evenly at 100°C and dehydrated for 2 h. After cooling, it was sealed and stored.

[0056] Preparation of the second mixed component: 12.5 parts by weight of E44 epoxy resin and 8 parts by weight of plasticizer (a mixture of 4 parts by weight of epoxidized soybean oil and 4 parts by weight of epoxidized tetrahydrophthalic acid ester) were vacuum dehydrated at 100°C for 2 h. Then, 60 parts by weight of isocyanate (a mixture of 45 parts by weight of polymethylene polyphenyl polyisocyanate and 15 parts by weight of diphenylmethane diisocyanate) and 30 parts by weight of terminal isocyanate polyurethane prepolymer were added. The mixture was stirred and mixed evenly at room temperature and then sealed and stored.

[0057] Preparation of polymer grouting material: The first and second mixing components are mixed in equal volumes and mechanically mixed for 10 seconds to obtain the polymer grouting material.

[0058] Example 4 Preparation of isocyanate-terminated polyurethane prepolymer: 60 parts by mass of diphenylmethane diisocyanate and 40 parts by mass of vacuum-dehydrated polyether diol PPG-400 were placed in a N2 atmosphere and reacted at 85°C for 3 h to obtain isocyanate-terminated polyurethane prepolymer.

[0059] Preparation of the first mixed component: 2 parts by mass of titanate coupling agent 201, 0.3 parts by mass of organometallic polyurethane catalyst CUCAT-K6, and 12.5 parts by mass of phenolic amine epoxy curing agent (a mixture of 6.25 parts by mass of T31 and 6.25 parts by mass of NX-5653) were added to 75 parts by mass of polyether polyol (a mixture of 45 parts by mass of PPG-400 polyether diol and 30 parts by mass of polyoxyethylene polypropylene block polyether L-35). The mixture was stirred and mixed evenly at 100°C and dehydrated for 2 h before cooling and sealing for storage.

[0060] Preparation of the second mixed component: A mixture of 10 parts by weight of E51 epoxy resin and 5 parts by weight of epoxy fatty acid triester plasticizer was dehydrated under vacuum at 100°C for 2 hours. Then, 45 parts by weight of isocyanate (a mixture of 33.75 parts by weight of polymethylene polyphenyl polyisocyanate and 11.25 parts by weight of diphenylmethane diisocyanate) and 20 parts by weight of terminal isocyanate polyurethane prepolymer were added. The mixture was stirred and mixed evenly at room temperature and then sealed for storage.

[0061] Preparation of polymer grouting material: The first and second mixing components are mixed in equal volumes and mechanically mixed for 15 seconds to obtain the polymer grouting material.

[0062] Example 5 Preparation of isocyanate-terminated polyurethane prepolymer: 60 parts by mass of diphenylmethane diisocyanate and 40 parts by mass of vacuum-dehydrated polyether diol PPG-400 were placed in a N2 atmosphere and reacted at 80°C for 4 h to obtain isocyanate-terminated polyurethane prepolymer.

[0063] Preparation of the first mixed component: 3 parts by mass of silane coupling agent 570, 0.6 parts by mass of organometallic polyurethane catalyst CUCAT-6, and 12 parts by mass of phenolic amine epoxy curing agent (6 parts by mass of T31 and 6 parts by mass of NX-5653 mixed) were added to 80 parts by mass of polyether polyol (50 parts by mass of PPG-200 polyether diol and 30 parts by mass of 4110 polyether tetraol mixed). The mixture was stirred and mixed evenly at 100°C and dehydrated for 2 h. After cooling, it was sealed and stored.

[0064] Preparation of the second mixed component: 15 parts by weight of E44 epoxy resin and 3 parts by weight of epoxy soybean oil plasticizer were vacuum dehydrated at 100°C for 2 h. Then, 40 parts by weight of isocyanate (a mixture of 30 parts by weight of polymethylene polyphenyl polyisocyanate and 10 parts by weight of diphenylmethane diisocyanate) and 40 parts by weight of terminal isocyanate polyurethane prepolymer were added. The mixture was stirred and mixed evenly at room temperature and then sealed and stored.

[0065] Preparation of polymer grouting material: The first and second mixing components are mixed in equal volumes and mechanically mixed for about 15 seconds to obtain the polymer grouting material.

[0066] To verify the influence of the dosage and material selection of each component in the polymer grouting material of the present invention on the final performance, several comparative experiments were conducted.

[0067] Comparative Example 1 The similarities between this comparative example and Example 5 will not be repeated here; only the differences from Example 5 will be described. The difference between this comparative example and Example 5 is that, in the preparation of the first mixed component, a mixture of 2.5 parts by weight of T31 and 2.5 parts by weight of NX-5653 was used as the phenolic amine epoxy curing agent; and in the preparation of the second mixed component, the amount of E44 epoxy resin was 5 parts by weight. The rest is the same as described in Example 5, resulting in a comparative polymer grouting material.

[0068] Comparative Example 2 The similarities between this comparative example and Example 3 will not be repeated here; only the differences will be described. The difference between this comparative example and Example 3 is that the commercially available organotin polyurethane catalyst SUL-4 is used in place of the organometallic polyurethane catalyst CUCAT-6. The rest is the same as described in Example 3, resulting in a comparative polymer grouting material.

[0069] Comparative Example 3 The similarities between this comparative example and Example 5 will not be repeated here; only the differences will be described. The difference between this comparative example and Example 5 is that, in the preparation of the second mixed component, the amount of the isocyanate-terminated polyurethane prepolymer is 10 parts by mass. The rest is as described in Example 5, resulting in a comparative polymer grouting material.

[0070] Comparative Example 4 The similarities between this comparative example and Example 5 will not be repeated here; only the differences from Example 5 will be described. The difference between this comparative example and Example 5 is that, in the preparation of the first mixed component, 12 parts by weight of T31 were used as the phenolic amine epoxy curing agent, while NX-5653 phenolic amine epoxy curing agent was not included. The rest is as described in Example 5, resulting in a comparative polymer grouting material.

[0071] Comparative Example 5 The similarities between this comparative example and Example 5 will not be repeated here; only the differences will be described. The difference between this comparative example and Example 5 is that, in the preparation of the first mixed component, the amount of the organometallic polyurethane catalyst CUCAT-6 is 0.2 parts by mass. The rest is as described in Example 5, resulting in a comparative polymer grouting material.

[0072] Comparative Example 6 The similarities between this comparative example and Example 5 will not be repeated here; only the differences from Example 5 will be described. The difference between this comparative example and Example 5 is that, in the preparation of the first mixed component, the phenolic amine epoxy curing agent is removed. In the preparation of the second mixed component, E44 epoxy resin is removed. The rest is the same as described in Example 5, resulting in a comparative polymer grouting material.

[0073] Comparative Example 7 The similarities between this comparative example and Example 5 will not be repeated here; only the differences from Example 5 will be described. The difference between this comparative example and Example 5 is that, in the preparation of the first mixed component, the amount of the organometallic polyurethane catalyst CUCAT-6 is 1.2 parts by mass. In the preparation of the second mixed component, isocyanate is removed. The rest is as described in Example 5, yielding the comparative polymer grouting material.

[0074] Comparative Example 8 By using DK-1 two-component micro-foamed polyurethane grouting material from Shanghai Dongda Chemical Co., Ltd., and mechanically mixing components A and B in equal volumes for about 10 seconds, a comparative polymer grouting material can be obtained.

[0075] The relevant performance tests of the crack welding materials were conducted in accordance with the relevant standards of GB / T2567 "Test Method for Performance of Resin Castings", GB / T7124 "Determination of Tensile Shear Strength of Adhesives", GB / T5210 "Adhesion Test of Paints and Varnishes by Pull-Off Method", JTG E20-2011 "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering", and CJJT260 "Technical Specification for Trenchless Repair of Deep Road Defects".

[0076] First, the viscosity of the first and second mixed components of each embodiment and comparative example was tested. The viscosity of the first and second mixed components of each embodiment was between 200 cp and 300 cp (comparative example 3 was greater than 500 cp). The viscosity was low, the fluidity was good, and the permeability was good.

[0077] The expansion ratio in water was determined by adding 2 / 3 water to a disposable cup, then pouring in a pre-mixed solution of the first and second components. After the welding material solidified, the expansion ratio was observed and tested.

[0078] Table 1 below shows the performance test results of the polymer grouting materials of each embodiment and comparative example.

[0079] Table 1 Performance test results of various polymer grouting materials Application examples The polymer grouting materials provided in the above embodiments of the present invention can be applied to trenchless repair of road surface defects, specifically for the repair of trenchless defects such as cracks in semi-rigid base courses and grout pumping.

[0080] The splitting crack test of Marshall specimens bonded at dry and wet crack interfaces was conducted using a laboratory simulation method. The molded asphalt concrete Marshall specimens were cut in half using a cutting machine. Drying treatment and spraying a thin layer of water mist were performed at the cut interfaces. Then, a pavement polymer grouting material, a mixture of the first and second components, was injected into the cracks and cured to bond as a whole. The next day, a splitting crack test at 15°C was performed. The splitting strength ratio of the Marshall specimens treated with wet and dry cracks was calculated. A higher splitting strength ratio indicates that the welding material is less affected by moisture in the crack.

[0081] Table 2 below shows the performance test results of the polymer grouting materials of each embodiment applied to the trenchless road repair technology on different base surfaces.

[0082] Meanwhile, the same application testing method was used to conduct corresponding tests on each pair of ratios, which are listed in Table 2.

[0083] Table 2 Comparison of performance tests of polymer grouting materials on different substrates As shown in Table 1, the polymer grouting material of this invention possesses excellent mechanical properties, exhibiting superior comprehensive performance in tensile strength, compressive strength, elongation at break, and tensile shear strength. It achieves tensile strength greater than 10 MPa, compressive strength greater than 40 MPa, and tensile shear strength greater than 10 MPa, demonstrating superior overall performance compared to the comparative examples. This results in high strength and toughness, as well as excellent tensile and shear resistance, enabling it to withstand tensile and shear failure at the bonding site during service. Furthermore, the gelation time is adjustable (controlled to approximately 60 seconds to meet the requirements of construction and rapid strength development), and it does not foam in either anhydrous or aquatic environments.

[0084] Table 2 shows that, in adhesion pull-out tests conducted on both dry and damp substrates, the adhesion pull-out strength retention rate (>90%) of the embodiments of the present invention is significantly higher than that of the comparative example, indicating that even in damp environments with defects, the polymer grouting material of the present invention still exhibits excellent bonding performance. Similarly, the Marshall splitting strength ratio results for different interface treatments show that the specimens in the application examples of the present invention have higher splitting strengths and splitting strength ratios (>85%) under different interface treatments, which are also significantly higher than those in the comparative example.

[0085] By comprehensively comparing the differences between the comparative examples and the embodiment, comparative examples 1, 3-7 were compared with embodiment 5 in terms of epoxy curing agent / epoxy resin content, polyurethane prepolymer dosage, and organometallic polyurethane catalyst content. Due to the differences in the content and type of each component, the components did not exert a synergistic effect, and the overall performance was not as good as that of embodiment 5. Similarly, comparative example 2 was compared with embodiment 3 in terms of the type of polyurethane catalyst, and the overall performance was not as good as that of embodiment 3.

[0086] Specifically, the epoxy resin and phenolic amine epoxy curing agent content in Comparative Example 1 is lower than that in Example 5. In this invention, the epoxy resin / phenolic amine epoxy curing agent enhances the mechanical strength of the epoxy system and strengthens the interpenetration with the polyurethane network. Furthermore, in the presence of an organometallic polyurethane catalyst, the epoxy groups can also react with isocyanates, enhancing the mechanical properties of the grouting material. Due to the reduced epoxy content, Comparative Example 1 exhibits a decrease in tensile strength, compressive strength, and tensile shear strength. Moreover, the phenolic hydroxyl groups of the special phenolic amine epoxy curing agent used in this invention can form hydrogen bonds, coordination bonds, and physicochemical crosslinks with the active sites on the wet interface, significantly increasing the adhesion and shear strength of the wet substrate. This is reflected in the fact that the adhesion pull-out strength retention rate and Marshall splitting strength ratio of Comparative Example 1 are much lower than those of Example 5.

[0087] Compared to Example 3, Comparative Example 2 primarily used a conventional polyurethane catalyst, which could not achieve the function of the organometallic polyurethane catalyst of this invention. This resulted in the two-component comparative grouting material not foaming in a dry, anhydrous environment, but foaming in a wet environment, further leading to a decrease in the mechanical properties of the comparative grouting material, particularly its tensile shear strength. Furthermore, the water sensitivity and foaming characteristics of this comparative grouting material in humid environments also caused a significant decrease in the adhesion pull-out strength and Marshall splitting tensile strength ratio on wet substrates.

[0088] In Comparative Example 3, the amount of isocyanate-based polyurethane prepolymer used was less than that in Example 5 and was outside the design range. The main function of the polyurethane prepolymer in the system is to increase the toughness of the grouting material and to some extent eliminate performance defects such as foaming caused by excessively fast reaction rates. In addition, due to the reduced amount of polyurethane prepolymer, the ratio of isocyanate and other reactive groups in the polyurethane system changed outside the reasonable range, resulting in a decrease in the overall performance of the grouting material. Specifically, the gel time was shorter, the toughness was worse (elongation at break was reduced), and the adhesion, pull-out strength, and Marshall splitting tensile strength ratio were all somewhat reduced. Compared with other comparative examples, Comparative Example 3 showed slightly better performance.

[0089] The specific composition and ratio of the phenolic amine epoxy curing agent in Comparative Example 4 are not within the specified range; it only contains T31 phenolic amine epoxy curing agent and lacks NX-5653. Since the system design primarily utilizes a combination of two types of phenolic amine epoxy curing agents to achieve a synergistic effect, balancing reaction speed and adhesion to different interfaces, the gel time of the grouting material in Comparative Example 4 is longer, the tensile shear strength is significantly reduced, and the adhesion, pull-out strength, and Marshall splitting strength at both dry and wet interfaces are decreased.

[0090] In Comparative Example 5, the content of the organometallic polyurethane catalyst was reduced compared to the design range, which to some extent led to the foaming phenomenon of the grouting material under humid and water-containing conditions, further affecting the mechanical properties, bond strength and bonding effect on the Marshall specimen. Specifically, the water expansion rate increased from 1 times that of non-foaming to 1.1 times that of microfoaming, the tensile shear strength decreased, and the splitting strength ratio of the Marshall specimen decreased significantly.

[0091] Comparative Example 6 did not contain epoxy resin or phenolic amine epoxy curing agent systems, but only a two-component polyurethane system. Due to the difficulty in leveraging the synergistic effect of the polyurethane-epoxy multi-component system, the overall performance of the grouting material was significantly reduced compared to other comparative examples (except Comparative Example 8). Specifically, although the grouting material did not foam when exposed to water, it had the lowest tensile shear strength, the lowest adhesion pull-out strength retention rate on damp substrates, and the lowest Marshall splitting strength ratio.

[0092] In Comparative Example 7, the content of the organometallic polyurethane catalyst was outside the acceptable range (higher catalyst content results in a shorter gel time for the grouting material), and it contained no isocyanate. Since isocyanate primarily functions as the hard segment component of the polyurethane three-dimensional network in the grouting material, it mainly contributes to the material's mechanical and adhesive properties. Furthermore, the complete absence of isocyanate led to an inaccurate reaction composition ratio in the grouting material. Specifically, this manifested as a decrease in the tensile, compressive, and tensile shear strengths of the grouting material, as well as a reduction in the adhesion pull-out strength retention rate and splitting strength ratio.

[0093] Comparative Example 8 uses commercially available grouting material, which exhibits significant foaming and expansion in water. The performance of the grouting material is greatly affected by the moisture in the environment, and its applicability to crack treatment is not strong. Its overall performance is far lower than that of the present invention and other comparative examples.

[0094] In summary, the polymer grouting material of the present invention has the characteristics of low viscosity, good permeability, non-sensitivity to water and non-foaming, strong adhesion and excellent bonding effect. It has good universality for dry and wet diseased base surfaces, and can simultaneously repair cracks and pumping defects in asphalt layers and semi-rigid base layers, thereby extending the service life of the pavement.

[0095] The embodiments described above are for illustrative purposes only and do not constitute a specific limitation on the present invention. Any modifications made without departing from the basic concept of the present invention, as well as any obvious modifications derived therefrom, are within the scope of protection of the present invention.

Claims

1. A polymer grouting material for trenchless repair of road surface defects, characterized in that, Includes a first and a second mixture of equal volumes; The first mixed component comprises the following components that are uniformly mixed: 60-100 parts of polyether polyol; 1-5 parts coupling agent; 0.3~0.8 parts of organometallic polyurethane catalyst; 10-15 parts of phenolic amine epoxy curing agent; The second mixture comprises the following components that are uniformly mixed: 30-60 parts of isocyanate; 20-40 parts of isocyanate-terminated polyurethane prepolymer; 10-15 parts epoxy resin; Plasticizer 2-8 parts; All figures above are by weight (parts). The organometallic polyurethane catalyst is selected from one of the following: Yurun Environmental Protection non-foaming catalysts CUCAT-6 and CUCAT-K6, or a mixture of the two in any proportion. The phenolic amine epoxy curing agent is composed of T31 and NX-5653 mixed in equal mass. The terminal isocyanate polyurethane prepolymer is prepared by reacting diphenylmethane diisocyanate and dehydrated polyether diol in an inert atmosphere at 80°C to 90°C at a mass ratio of 2.5:2 to 3.5:2 for 3 to 4 hours.

2. The polymer grouting material according to claim 1, characterized in that, The isocyanate is a mixture of polymethylene polyphenyl polyisocyanate and diphenylmethane diisocyanate in a mass ratio of 3:

1.

3. The polymer grouting material according to claim 1, characterized in that, The polyether polyol is selected from one of polyether diol, polyether triol, polyether tetraol, polyoxyethylene polypropylene block polyether, and bisphenol A polyether, or a mixture of at least two in any proportion; The coupling agent is selected from silane coupling agents and / or titanate coupling agents; The epoxy resin is E44 and / or E51; The plasticizer is selected from any one of epoxidized soybean oil, epoxidized fatty acid triester, and epoxidized tetrahydrophthalic acid ester, or a mixture of at least two in any proportion.

4. A method for preparing a polymer grouting material for trenchless repair of road surface defects as described in any one of claims 1 to 3, characterized in that, Includes the following steps: Preparation of the first mixed component: Add 1-5 parts of coupling agent, 0.3-0.8 parts of organometallic polyurethane catalyst and 10-15 parts of phenolic amine epoxy curing agent to 60-100 parts of polyether polyol and stir to mix evenly. After dehydration treatment, the first mixed component is obtained and sealed for storage; wherein, the phenolic amine epoxy curing agent is composed of T31 and NX-5653 mixed in equal mass. Preparation of the second mixed component: Dehydrate a mixture of 10-15 parts epoxy resin and 2-8 parts plasticizer, then add 30-60 parts isocyanate and 20-40 parts isocyanate-terminated polyurethane prepolymer, stir and mix evenly to obtain the second mixed component, and store it in a sealed container; wherein, the preparation method of the isocyanate-terminated polyurethane prepolymer is as follows: react diphenylmethane diisocyanate and dehydrated polyether diol in an inert atmosphere at 80℃-90℃ at a mass ratio of 2.5:2-3.5:2 for 3h-4h. Preparation of polymer grouting material: Equal volumes of the first mixed component and the second mixed component are mixed evenly to obtain the polymer grouting material; All of the above are by weight.

5. The preparation method according to claim 4, characterized in that, The dehydrated polyether diol is obtained by vacuum dehydration of polyether diol.

6. The preparation method according to claim 5, characterized in that, The polyether diol is PPG-400.

7. The application of the polymer grouting material as described in any one of claims 1 to 3 in the non-excavation repair technology of road surface defects.

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