Composite modified fiber for polyurethane concrete, high-toughness macadam polyurethane concrete and method for preparing same
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANDONG JIANZHU UNIV
- Filing Date
- 2026-02-05
- Publication Date
- 2026-06-09
Smart Images
Figure CN122169344A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of road engineering, specifically providing a composite modified fiber for polyurethane concrete, high-toughness multi-crushed stone polyurethane concrete, and its preparation method. Background Technology
[0002] In the current field of road engineering paving, polyurethane mixtures have become an important candidate material for heavy-duty roads, bridge decks and other scenarios due to their advantages such as high bonding strength, strong high-temperature stability, corrosion resistance, long service life and low maintenance cost. However, they face significant problems of insufficient toughness in actual service. When subjected to repeated vehicle dynamic loads, low-temperature freeze-thaw cycles or slight settlement and deformation of the base layer, they are prone to cracking, spalling of mineral materials and potholes due to stress concentration, making it difficult to meet the crack resistance and deformation resistance requirements of high-grade roads for long-term service.
[0003] To address the aforementioned technical issues, existing technologies often improve the toughness of polyurethane blends through physical means such as adding fibers and rubber particles, or through chemical means such as adding liquid toughening agents. However, these methods often suffer from high material costs, cumbersome manufacturing processes, or toughness regression due to toughening agent migration after long-term service. Summary of the Invention
[0004] The present invention addresses the shortcomings of the prior art by providing a composite modified fiber for polyurethane concrete, which can delay local failure of the matrix and improve the overall strength and ductility of the composite material.
[0005] The technical solution adopted by the present invention to solve its technical problem is: the composite modified fiber for polyurethane concrete is a PVA fiber modified by a combination of silane coupling agent and diethylene glycol.
[0006] Preferably, the method for preparing the composite modified fiber of the present invention includes: S1. Place the PVA fiber in a silane coupling agent alcohol solution and immerse it for an appropriate time to ensure that the fiber is evenly wetted; S2. After impregnation, the fibers are dried to remove the solvent, and at the same time, the silane coupling agent is condensed into a film on the fiber surface. S3. The fiber treated with silane coupling agent is placed in a diethylene glycol aqueous solution, impregnated for an appropriate time, and then dried to a slightly dry state to retain the infiltrated diethylene glycol component, thus obtaining a composite modified fiber.
[0007] Preferably, the immersion time of the PVA fiber in the silane coupling agent alcohol solution in step S1 is 30-60 min, and more preferably 35-45 min.
[0008] Preferably, the mass ratio of PVA fiber to silane coupling agent alcohol solution is 100:(102-520), more preferably 100:(102-315), and particularly preferably 100:(202-215).
[0009] Preferably, the mass ratio of silane coupling agent to alcohol solution in the silane coupling agent alcohol solution is (2-20):(100-500), more preferably (2-15):(100-300), and particularly preferably (2-15):200.
[0010] Preferably, the volume percentage concentration of the alcohol solution is 90% to 95%. Under this concentration condition, the alcohol solution can control the hydrolysis rate of the silane coupling agent while diluting the concentration of the silane coupling agent, avoiding excessively fast hydrolysis rate that could lead to self-polymerization of silane hydrolysis products, and reducing the risk of gelation or precipitation.
[0011] Preferably, the pH value of the silane coupling agent alcohol solution is 4 to 5, and the pH value can be adjusted by adding dilute hydrochloric acid to the solution.
[0012] Preferably, the silane coupling agent is KH-550 (γ-aminopropyltriethoxysilane), KH-792 (N-β-aminoethyl-γ-aminopropyltrimethoxysilane), or Z-6040 (γ-glycidyl ether propyltrimethoxysilane). After hydrolysis, the products of these silane coupling agents can form Si–O–PVA bonds on the surface of PVA fibers and chemically bond with subsequent polyurethane binders, strengthening the adhesion between the fibers and the polyurethane interface and enhancing the water stability of the multi-aggregate polyurethane concrete.
[0013] Preferably, in step S2, the impregnated fibers are first allowed to evaporate the solvent naturally, and then placed in an oven at 80-90°C to dry for 1-2 hours, so that the silane coupling agent can condense into a film on the fiber surface and completely remove the residual solvent.
[0014] Preferably, the mass ratio of PVA fiber to diethylene glycol aqueous solution in step S3 is 100:(102-525) based on the mass of PVA fiber, more preferably 100:(102-315), and particularly preferably 100:(202-215).
[0015] Preferably, the mass ratio of diethylene glycol to water in the diethylene glycol aqueous solution is (2-25):(100-500), more preferably (2-15):(100-300), and particularly preferably (2-15):200.
[0016] Preferably, the fibers treated with the silane coupling agent are immersed in a diethylene glycol solution for 2–8 min, particularly preferably 4–6 min.
[0017] Preferably, the fibers impregnated with diethylene glycol solution are dried at 40–50°C to a moisture content of 10 wt%–20 wt%, and more preferably to a moisture content of 10 wt%–15 wt%.
[0018] Preferably, the DEG is industrial-grade diethylene glycol (purity ≥99%). Its function is as follows: (1) DEG penetrates the surface of PVA fiber, reduces its crystallinity, increases the proportion of amorphous region and chain segment mobility, thereby improving the breaking elongation of PVA fiber, enhancing the toughness of PVA fiber, and making it easier to consume energy without brittle fracture during the pull-out process. (2) After composite modification, the DEG on the surface of PVA fiber reacts with the isocyanate in the polyurethane binder to generate urethane bonds, which consumes some of the -NCO that should have been used to generate urea bonds in the water reaction. The cured product contains both urea bonds and urethane bonds, which reduces the hardness and modulus of the adhesive layer and has a plasticizing effect. (3) DEG molecules contain two hydroxyl groups, which can form new hydrogen bonds with the hydroxyl groups on the surface of PVA fibers, weakening the original PVA–PVA hydrogen bond effect, making the fiber surface more "lubricated" by being covered by DEG, and reducing fiber agglomeration.
[0019] Preferably, the PVA fiber is a short-cut PVA fiber with a length of 6-8 mm.
[0020] A further technical objective of this invention is to provide a high-toughness polyurethane concrete with multiple aggregates, characterized by comprising the aforementioned composite modified fibers.
[0021] Preferably, the high-toughness multi-aggregate polyurethane concrete is prepared from the following component raw materials in parts by weight: 1000 parts of ore 50-80 parts of polyurethane 5-20 parts of composite modified fiber 0.05–0.4 parts of polyurethane dispersant 1 to 3 parts of curing agent.
[0022] As a preferred option, the weight proportions of the raw materials in the high-toughness multi-aggregate polyurethane concrete are as follows: 1000 parts of ore 50-65 parts of polyurethane 7-12 parts of composite modified fiber 0.1 to 0.2 parts of polyurethane dispersant 2-3 parts of curing agent.
[0023] As a preferred option, the passing percentage of the key control screen apertures for the mineral material should meet the following requirements: 100% passing percentage for the nominal maximum particle size, 30-40% passing percentage for the 4.75mm screen aperture, and 8-10% passing percentage for the 0.075mm screen aperture.
[0024] Preferably, the percentage of the ore passing through the screen apertures should meet the following requirements: The gradation ranges are as follows: 100% passing rate for a standard sieve aperture of 13.2mm; 67-75% passing rate for a standard sieve aperture of 9.5mm; 33-38% passing rate for a standard sieve aperture of 4.75mm; 24-29% passing rate for a standard sieve aperture of 2.36mm; 19-22% passing rate for a standard sieve aperture of 1.18mm; 15-20% passing rate for a standard sieve aperture of 0.6mm; 12-16% passing rate for a standard sieve aperture of 0.3mm; 9-12% passing rate for a standard sieve aperture of 0.15mm; and 8-9% passing rate for a standard sieve aperture of 0.075mm.
[0025] Preferably, the polyurethane is a single-component moisture-curing polyurethane adhesive, such as Wanhua 6170, Wanhua 6170F, Wanhua 6179, etc.
[0026] Preferably, the polyurethane dispersant is BYK-163, HCD-802, or SRE-43025. These polyurethane dispersants can be adsorbed onto the fiber surface, and when adjacent PVA particles approach each other, repulsive forces are generated between the molecular chains, which counteract the van der Waals forces between the particles, thereby inhibiting agglomeration and sedimentation.
[0027] Preferably, the curing agent is water, which can react with -NCO to generate unstable carbamic acid, which rapidly decomposes into amine and CO2. The amine then reacts with excess -NCO to form urea bonds for cross-linking, ultimately constructing a high-strength three-dimensional cross-linked network structure.
[0028] A further technical objective of this invention is to provide a method for preparing the aforementioned high-toughness multi-aggregate polyurethane concrete, characterized by comprising: Polyurethane and polyurethane dispersant are added to the dehumidified and cooled mineral material and stirred evenly to obtain polyurethane material with multiple crushed stones. The composite modified fiber was added to the multi-crushed polyurethane material in three parts. After stirring evenly, a high-toughness multi-crushed polyurethane material was obtained. After the first addition, the mixture was stirred slowly for 90 to 120 seconds. After the second addition, the mixture was stirred slowly for 60 to 90 seconds. After the third addition, the mixture was stirred slowly for 60 to 90 seconds. Then, the mixture was stirred quickly for 30 to 60 seconds. A curing agent is sprayed onto a high-toughness polyurethane material with multiple aggregates, and then it is immediately molded to obtain high-toughness polyurethane concrete with multiple aggregates.
[0029] Preferably, the polyurethane, polyurethane dispersant, and minerals are stirred at 45–55°C.
[0030] Preferably, the slow stirring speed is 45-60 rpm, and the fast stirring speed is 70-85 rpm.
[0031] Compared with the prior art, the composite modified fiber for polyurethane concrete, the high-toughness multi-aggregate polyurethane concrete and the preparation method thereof of the present invention have the following outstanding advantages: (I) This invention employs DEG and a silane coupling agent to jointly modify PVA fibers, achieving a synergistic effect of "high-energy pull-out" and "controllable interfacial strength." Specifically: On the one hand, DEG penetrates the fiber surface, significantly improving the fiber's toughness and elongation at break by weakening the hydrogen bonds between PVA molecules and reducing crystallinity, enabling it to fully dissipate energy without brittle fracture during pull-out under stress; simultaneously, the DEG-covered fiber surface is more lubricated, effectively reducing fiber agglomeration. On the other hand, during the molding stage of high-toughness, multi-aggregate polyurethane concrete, the DEG on the composite modified fiber surface can react with the isocyanate (-NCO) of polyurethane to generate urethane bonds, consuming some of the -NCO, ultimately forming a rigid-flexible microstructure in the cementitious layer, playing a significant plasticizing role. Meanwhile, the silane coupling agent constructs a strong Si–O–PVA covalent bridge between the PVA fibers and the polyurethane matrix, greatly enhancing the interfacial bonding strength. Through the synergistic effect of the above mechanisms, the load can be transferred to the fiber more quickly and evenly, which not only delays the local failure of the matrix, but also jointly improves the overall strength and ductility of the composite material. (II) This invention enhances the toughness of multi-crushed polyurethane concrete by introducing a fiber bridging mechanism and using DEG and silane coupling agent to modify PVA fibers. Combined with the aggregate gradation of multi-crushed polyurethane concrete of "skeleton interlocking + dense filling", it significantly improves the shear resistance of polyurethane concrete, reduces stress concentration caused by internal voids, reduces the risk of low-temperature cracking, and significantly improves the performance of the mixture. Attached Figure Description
[0032] Appendix Figure 1 These are Marshall specimens formed from high-toughness polyurethane concrete with multiple crushed stones, as shown in Examples 1 and 2. Appendix Figure 2 These are small beam specimens formed from high-toughness, multi-aggregate polyurethane concrete, as shown in Examples 1 and 2. Appendix Figure 3 This is a Marshall specimen of high-toughness polyurethane concrete after splitting, as shown in Example 1. Appendix Figure 4 Example 1 shows a small beam specimen of high-toughness polyurethane concrete with multiple crushed stones that fractured. Appendix Figure 5 Example 1 is a semi-circular bending specimen of high-toughness polyurethane concrete with multiple crushed stones. Detailed Implementation
[0033] The present invention will be further described below with reference to specific embodiments, but this is not intended to limit the present invention.
[0034] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.
[0035] Example 1
[0036] This embodiment provides a composite modified fiber, which is prepared from the raw materials shown in Table 1.
[0037] Table 1. Composition of Composite Modified Fibers (parts by weight)
[0038] Note: Material 9 modified fiber was modified only with diethylene glycol; Material 10 modified fiber was modified only with silane coupling agent alcohol solution; Material 11 modified fiber was modified only with silane coupling agent aqueous solution.
[0039] The preparation method of the composite modified fiber in this embodiment is as follows: S1. Add the silane coupling agent to the alcohol solution, adjust the pH to 4-5 with dilute hydrochloric acid to obtain the coupling agent solution; then immerse the PVA fiber in the solution for 40 minutes to ensure uniform wetting of the fiber; S2. After soaking, remove the fiber, allow the solvent to evaporate naturally, and then place it in an oven at 85°C for 1.5 hours to allow the silane coupling agent to condense into a film on the fiber surface and completely remove any residual solvent. S3. Add DEG to water to prepare a DEG solution, then immerse the silane-treated fiber in it for 5 minutes to ensure thorough and uniform wetting; after soaking, remove the fiber and dry it in an oven at 45°C until slightly dry to retain the infiltrated DEG component, thus obtaining the composite modified fiber.
[0040] The tensile strength, elastic modulus, elongation at break and interfacial shear strength of the composite modified fiber material obtained in this embodiment were tested according to the "Synthetic Fibers for Cement Concrete and Mortar" (GB / T 21120-2018) and the monofilament pull-out test. The test results are shown in Table 2.
[0041] Table 2. Test results of modified fiber properties
[0042] Example 2
[0043] This embodiment provides a high-toughness polyurethane concrete with multiple crushed stones, which is made from mineral aggregates, polyurethane, composite modified fibers, polyurethane dispersant, and curing agent.
[0044] The ore used is basalt, and the gradation is shown in Table 3.
[0045] Table 3. Mineral Gradation
[0046] The polyurethane is a single-component moisture-curing polyurethane adhesive 6170F produced by Wanhua Chemical Group Co., Ltd.
[0047] The composite modified fiber uses the material described in Example 1.
[0048] The polyurethane dispersant used is BYK-163.
[0049] The curing agent is water.
[0050] The raw material proportions for high-toughness polyurethane concrete with multiple crushed stones are shown in Table 4.
[0051] Table 4. Composition of polyurethane concrete raw materials (parts by weight)
[0052] The preparation method of high-toughness polyurethane concrete with multiple crushed stones is as follows: (1) After drying the ore to a dry state, cool it to 50°C and put it into a mixing pot. Adjust the mixing pot to 50°C and stir for 2-3 minutes. (2) After the mineral material is stirred evenly, the polyurethane and polyurethane dispersant are poured into the mixing pot. The mixing pot is stirred at 50°C for 100 seconds. After stirring evenly, the polyurethane material with multiple crushed stones is obtained. (3) The composite modified fiber (or chopped PVA fiber) is poured into the mixing pot in three batches. After the first batch is poured in, it is slowly stirred for 100 seconds. After the second batch is poured in, it is slowly stirred for 80 seconds. After the third batch is poured in, it is slowly stirred for 80 seconds. Then it is quickly stirred for 50 seconds. After the mixture is evenly stirred, high-toughness polyurethane concrete is obtained. The slow stirring speed is 50 rpm and the fast stirring speed is 80 rpm. (4) Spray curing agent onto high-toughness polyurethane concrete with multiple crushed stones, and then immediately form it.
[0053] Example 3
[0054] Compared with Example 2, the raw materials and preparation methods of the high-toughness multi-crushed stone polyurethane concrete in this example are basically the same, the only difference being the different aggregate gradation.
[0055] The ore used is basalt, and the gradation is shown in Table 5.
[0056] Table 5. Mineral Gradation
[0057] The raw material proportions for high-toughness polyurethane concrete with multiple crushed stones are shown in Table 6.
[0058] Table 6. Composition of polyurethane concrete raw materials (parts by weight)
[0059] Detection example
[0060] Marshall specimens were prepared according to the specifications in T0702-2025 of the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG 3410-2025), specifically the method for preparing asphalt mixture specimens (compaction method) (Example 1, Example 2). Figure 1 As shown.
[0061] Low-temperature specimens (Examples 1 and 2) were prepared according to the specifications for asphalt and asphalt mixture test methods in the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG 3410-2025) T 0703-2025, specifically the method for preparing asphalt mixture specimens (wheel rolling method). Figure 2 As shown.
[0062] The splitting strength of high-toughness polyurethane mixtures was tested according to the provisions of T 0716-2025 of the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG 3410-2025) (Example 1). Figure 3 As shown.
[0063] The low-temperature bending test of multi-aggregate polyurethane mixture was conducted according to the provisions of T 0715-2025 of the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG 3410-2025) (Example 1). Figure 4 As shown.
[0064] According to the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG 3410-2025), specifically T 0747-2025, the low-temperature performance test of asphalt mixtures (semi-circular bending method) was conducted on multi-aggregate polyurethane mixtures (Example 1). Figure 5 As shown.
[0065] The specific test results are shown in Table 7.
[0066] Table 7 Performance Test Results
[0067] As the test results show, this invention, relying on the effect of composite modified fibers, not only significantly improves the splitting tensile strength, -10℃ flexural tensile strength and -10℃ maximum flexural tensile strain of polyurethane concrete, but also enhances its fracture toughness, successfully optimizing the low-temperature mechanical properties, crack resistance and toughness of polyurethane concrete in all aspects.
[0068] The embodiments described above are merely preferred embodiments of the present invention. Ordinary variations and substitutions made by those skilled in the art within the scope of the technical solutions of the present invention should be included within the protection scope of the present invention.
Claims
1. A composite modifying fiber for polyurethane concrete, characterized by, The composite modified fiber is a PVA fiber modified by a combination of silane coupling agent and diethylene glycol.
2. The composite modified fiber according to claim 1, characterized by, Its preparation methods include: S1. Place the PVA fiber in a silane coupling agent alcohol solution and immerse it for an appropriate time to ensure that the fiber is evenly wetted; S2. After impregnation, the fibers are dried to remove the solvent, and at the same time, the silane coupling agent is condensed into a film on the fiber surface. S3. The fiber treated with silane coupling agent is placed in a diethylene glycol aqueous solution, impregnated for an appropriate time, and then dried to a slightly dry state to retain the infiltrated diethylene glycol component, thus obtaining a composite modified fiber.
3. The composite modified fiber according to claim 2, characterized by, In step S1, the PVA fibers are impregnated in the silane coupling agent alcohol solution for 30–60 minutes, and the mass ratio of PVA fibers to the silane coupling agent alcohol solution is 100:(102–520). Preferably, the mass ratio of silane coupling agent to alcohol solution in the silane coupling agent alcohol solution is (2-20):(100-500), and the pH value is 4-5. Preferably, the silane coupling agent is γ-aminopropyltriethoxysilane, N-β-aminoethyl-γ-aminopropyltrimethoxysilane, or γ-glycidyl etherpropyltrimethoxysilane.
4. The composite modified fiber according to claim 2, wherein In step S2, the impregnated fibers are first allowed to evaporate the solvent naturally, and then dried in an oven at 80-90°C for 1-2 hours.
5. The composite modified fiber according to claim 2, wherein In step S3, Based on the mass of PVA fibers, the mass ratio of PVA fibers to diethylene glycol aqueous solution is 100:(105~525). As a preferred embodiment, the mass ratio of diethylene glycol to water in the diethylene glycol aqueous solution is (5-25):(100-500); After treatment with silane coupling agent, the fiber is immersed in diethylene glycol solution for 2-8 minutes and then dried at 40-50°C to a moisture content of 10 wt%-20 wt%.
6. The composite modified fiber according to claim 1 or 2, wherein The PVA fiber is a short-cut PVA fiber with a length of 6-8 mm.
7. High-ductility macadamic polyurethane concrete, characterized in that, Including components by weight: 1000 parts of ore 50-80 parts of polyurethane 5-20 parts fiber 0.05–0.4 parts of polyurethane dispersant 1-3 parts of curing agent The fiber is the composite modified fiber as described in any one of claims 1-6.
8. The high-ductility polyurethane concrete of claim 7, wherein the polyurethane is a polyurea. The passing percentage of the key control screen openings for mineral materials should meet the following requirements: 100% passing percentage for the nominal maximum particle size, 30-40% passing percentage for the 4.75mm screen opening, and 8-10% passing percentage for the 0.075mm screen opening.
9. The high-toughness multi-aggregate polyurethane concrete according to claim 7 or 8, characterized in that, The polyurethane is a one-component, moisture-curing polyurethane adhesive.
10. The method for preparing high-toughness multi-aggregate polyurethane concrete according to any one of claims 7, 8, or 9, characterized in that, include: Polyurethane and polyurethane dispersant are added to the dehumidified and cooled mineral material and stirred evenly to obtain polyurethane material with multiple crushed stones. The composite modified fiber was added to the multi-crushed polyurethane material in three parts. After stirring evenly, a high-toughness multi-crushed polyurethane material was obtained. After the first addition, the mixture was stirred slowly for 90 to 120 seconds. After the second addition, the mixture was stirred slowly for 60 to 90 seconds. After the third addition, the mixture was stirred slowly for 60 to 90 seconds. Then, the mixture was stirred quickly for 30 to 60 seconds. A curing agent is sprayed onto a high-toughness polyurethane material with multiple aggregates, and then it is immediately molded to obtain high-toughness polyurethane concrete with multiple aggregates. Preferably, the slow stirring speed is 45-60 rpm, and the fast stirring speed is 70-85 rpm.