Toughening type resin thin layer repairing material for cement pavement as well as preparation method and application of toughening type resin thin layer repairing material

Abstract

The invention provides a toughened resin thin layer repair material for a cement pavement as well as a preparation method and application thereof. The repair material comprises a main material, a modifier and a filler, wherein the main materials comprise the following components in parts by mass: 100 parts of unsaturated polyester resin, 5-20 parts of a diluent, 1 part of an initiator and 1 part of an accelerant; the modifier is prepared from 5 to 10 parts of polyurethane, 1 to 4 parts of nano silicon dioxide and 1 to 2 parts of plasticizer. The repairing material overcomes the defect that traditional polyester resin is poor in toughness, and meanwhile has the advantages of being high in strength, good in abrasion resistance, rapid in hardening, high in bonding strength and low in manufacturing cost.

Description

Technical Field

[0001] The invention belongs to the field of cement pavement repair materials, and in particular relates to a toughened resin thin layer repair material for cement pavement, a preparation method and an application thereof. Background Art

[0002] Cement concrete pavement is one of the main structural forms of pavement in my country, with the advantages of high strength, good stability and good durability. However, the pavement structure will be subjected to the rolling and impact of traffic loads for a long time. Under the combined effect of other factors such as the environment, it is easy to have various diseases such as peeling, exposure, roughness, joint material damage and potholes, which greatly reduces the smoothness of the pavement and seriously affects the driving comfort and safety of vehicles. And because concrete is a rigid material, it is difficult to repair. At present, the solutions to the surface layer diseases of cement pavements mainly include local replacement of the plate, additional paving repair after appropriate surface treatment, and thin layer repair. Among them, thin layer repair can make full use of the residual strength and modulus of the lower layer of old concrete road slabs, reduce the paving thickness of the surface repair, and thus reduce the project cost; on the other hand, this method is fast in repair and maintenance, and can open traffic early, which can meet the requirements of rapid pavement repair, so it is widely used in cement pavement surface repair.

[0003] The main materials for repairing thin layers of cement pavement currently include special cement mortar, polymer mortar and polymer modified cement mortar. Cement-based repair materials have poor wear resistance, require long-term maintenance, and are slow to open to traffic; polymer repair materials such as epoxy resin and acrylic resin have the advantages of excellent mechanical properties, fast opening to traffic, and high interlayer bonding strength, but due to their high prices, the overall cost of the repair project is high and is not suitable for large-scale use. Unsaturated polyester resin has the advantages of high early strength, excellent durability and outstanding interlayer bonding strength, and is relatively cheap compared to epoxy resin and acrylic resin, but unsaturated polyester resin is brittle and has poor toughness after curing, and is prone to cracking after repeated traffic loads. Summary of the invention

[0004] In view of the problems existing in the above-mentioned prior art, the present invention provides a toughened resin thin layer repair material for cement pavement, a preparation method and application thereof, which overcomes the shortcomings of poor toughness of traditional polyester resins and has the characteristics of high strength, good wear resistance, fast hardening, high bonding strength and low cost.

[0005] The present invention is achieved through the following technical solutions: In the first aspect, the present invention provides a toughened resin thin layer repair material for cement pavement, comprising: a main material, a modifier and a filler; wherein, in terms of weight parts, the main material comprises: 100 parts of unsaturated polyester resin, 5-20 parts of diluent, 1 part of initiator, and 1 part of accelerator; the modifier comprises: 5-10 parts of polyurethane, 1-4 parts of nano-silicon dioxide, and 1-2 parts of plasticizer.

[0006] Preferably, the unsaturated polyester resin is bisphenol A type unsaturated polyester resin, and the solid content is 62%-68%.

[0007] Preferably, the diluent is styrene; the initiator is benzoyl peroxide; and the accelerator is N,N-dimethylaniline.

[0008] Preferably, the nano-silica is oleophilic nano-silica.

[0009] Furthermore, the nano-silica is nano-silica modified by a silane coupling agent.

[0010] Preferably, the plasticizer is dibutyl phthalate, and the ester content is greater than 99.5%.

[0011] Preferably, the filler is river sand.

[0012] Furthermore, the gradation of the river sand is n1 or n2, and the particle size ratio of the n1 gradation and the n2 gradation is shown in Table 1: Table 1n1, n2 grading

[0014] In a second aspect, the present invention provides a method for preparing the toughened resin thin layer repair material for cement pavement, comprising the following steps: a. The unsaturated polyester resin, diluent, initiator and accelerator are stirred and mixed to obtain the main material; b. The polyurethane, nano-silica and plasticizer are stirred and mixed to obtain a modifier; c. Add the modifier to the main material and mix evenly, add the resulting mixture to the filler, stir evenly, and obtain the toughened resin thin layer repair material.

[0015] In a third aspect, the present invention provides the use of the toughened resin thin layer repair material for cement pavement in the repair of cement pavement.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention performs a synergistic toughening treatment of nano-silicon dioxide and polyurethane on the unsaturated polyester resin, wherein the polyurethane and the unsaturated polyester resin are integrated during the curing process to form an interpenetrating or semi-interpenetrating structure, so that the high elasticity of the polyurethane is integrated with the good heat resistance and adhesion of the unsaturated polyester resin, and an excellent toughening effect is obtained; and the addition of nano-silicon dioxide can not only achieve the reinforcement effect of the unsaturated polyester resin cured product, but also take into account the properties such as toughness; in particular, this type of inorganic rigid particles can also improve the dimensional shrinkage rate, corrosion resistance and other characteristics of the unsaturated polyester resin. Moreover, the unsaturated polyester resin and styrene are used as the main materials, and the curing reaction can start quickly under the action of the initiator and the accelerator, so that the repair material quickly forms strength, greatly reducing the traffic pressure caused by the road repair and traffic blockage. In addition, the repair material of the present invention has higher dimensional stability and durability than other ordinary resin materials, and has stronger bonding strength with the original concrete road surface; and while ensuring the repair ability, the repair material of the present invention has a lower cost, and the cost of the same amount of materials is about 0.4-0.7 times that of epoxy resin repair materials and acrylic resin repair materials.

[0017] Furthermore, the present invention preferably uses bisphenol A type unsaturated polyester resin as the main ingredient. Compared with ortho-phthalic unsaturated polyester resin or isophthalic unsaturated polyester resin, the distance between ester bonds in the molecular chain that are easily hydrolyzed and destroyed is increased, so that the ester bond density is reduced, the hydrolysis of the ester bonds is hindered, and the ability of the repair material to resist water damage is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is the lipophilicity of nano-silica before and after modification; Figure 2 Schematic diagram of the bending tensile strength test of the repair material of Example 1 and Comparative Examples 1-3 of the present invention; Figure 3 Schematic diagram of the pull-out strength test of the repair material of Example 1 of the present invention and Comparative Examples 1-3. DETAILED DESCRIPTION

[0019] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0020] It should be noted that the process equipment or devices not specifically specified in the following embodiments are all conventional equipment or devices in the art.

[0021] It should be noted that the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices. Moreover, unless otherwise specified, the numbering of each method step is only a convenient tool for identifying each method step, and is not intended to limit the order of arrangement of each method step or to define the scope of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the present invention without substantially changing the technical content.

[0022] The toughened resin thin layer repair material for cement pavement of the present invention comprises: a main material, a modifier and a filler; wherein, in terms of weight percentage, the main material comprises: 100 parts of unsaturated polyester resin, 5-20 parts of diluent, 1 part of initiator, and 1 part of accelerator; the modifier comprises: 5-10 parts of polyurethane, 1-4 parts of nano-silicon dioxide, and 1-2 parts of plasticizer.

[0023] The present invention uses nano-silicon dioxide and polyurethane to perform synergistic toughening treatment on unsaturated polyester resin, wherein the polyurethane and the unsaturated polyester resin are integrated during the curing process to form an interpenetrating or semi-interpenetrating structure, so that the high elasticity of the polyurethane is integrated with the good heat resistance and adhesion of the unsaturated polyester resin to obtain an excellent toughening effect; and the addition of nano-silicon dioxide can not only achieve the reinforcement effect of the unsaturated polyester resin cured product, but also take into account the toughness and other properties; in particular, this type of inorganic rigid particles can also improve the thixotropy, wear resistance, heat resistance and other properties of the unsaturated polyester resin.

[0024] In some embodiments of the present invention, the unsaturated polyester resin is preferably a bisphenol A type unsaturated polyester resin, and the solid content is 62%-68%. Compared with the orthophthalic unsaturated polyester resin or the isophthalic unsaturated polyester resin, the bisphenol A type unsaturated polyester resin has a larger spacing between ester bonds in the molecular chain that are easily hydrolyzed and damaged, so that the ester bond density is reduced, which has a hindering effect on the hydrolysis of the ester bond and improves the ability of the repair material to resist water damage.

[0025] In some embodiments of the present invention, the diluent is styrene; the initiator is benzoyl peroxide; and the accelerator is N,N-dimethylaniline. With styrene as the diluent, the curing reaction of unsaturated polyester and styrene under the action of the initiator and the accelerator can start quickly, so that the repair material quickly forms strength, greatly reducing the traffic pressure caused by the road repair and traffic blockage.

[0026] In some embodiments of the present invention, the nano-silica is nano-silica modified with a silane coupling agent. Currently commonly used nano-silica generally exhibits great hydrophilicity and oleophobicity. When it is used for polymer modification, its oleophobic nature makes it difficult to infiltrate, disperse, and stably exist in organic systems such as polymers, causing tiny nanoparticles to move in the direction of reducing the surface area in the polymer, and then agglomeration of nanoparticles in the polymer occurs. Therefore, it needs to be modified. The oleophilicity of nano-silica before and after modification is as follows: Figure 1 shown.

[0027] The silane coupling agent-modified nano-silicon dioxide is prepared by the following preparation method: Step 1: Take an appropriate amount of nano-silica powder and pretreat it in an ethanol aqueous solution for 40-60 minutes, then centrifuge and dry; Step 2: Add the dried nano-silica powder to the silane coupling agent solution, stir evenly, then increase the temperature to 100-120°C and introduce nitrogen protection, and continue stirring for 7-9 hours; Step 3: centrifuge the solution, dry the obtained solid, and obtain modified nano-silica.

[0028] In some embodiments of the present invention, the plasticizer is preferably dibutyl phthalate, and the ester content is greater than 99.5%.

[0029] In some embodiments of the present invention, the filler is river sand, and the amount of river sand added is 100-160 parts. According to the maximum density curve theory, two river sand gradations of n1 and n2 are obtained. The two gradations correspond to the maximum void ratio and the minimum void ratio in the gradation range of 0.3-0.7, respectively. A smaller void ratio can provide greater strength, while a structure formed by a larger void ratio has better workability. The appropriate gradation can be selected according to the actual strength of the repair target. The specific particle size ratios are shown in Table 1; Table 1 Two theoretical gradations of n1 and n2

[0030] The present invention provides a method for preparing a toughened resin thin layer repair material for cement pavement, which specifically comprises the following steps: a. The unsaturated polyester resin, diluent, initiator and accelerator are stirred and mixed to obtain the main material; b. The polyurethane, nano-silica and plasticizer are stirred and mixed to obtain a modifier; c. Add the modifier to the main material and mix evenly, add the resulting mixture to the filler, stir evenly, and obtain the toughened resin thin layer repair material.

[0031] Example 1 Step 1: pre-treat the nano-silica powder in an ethanol-water solution (ethanol: water = 10: 1) for 50 min, centrifuge, and dry the resulting solid at 110 °C for 8 h; Step 2: Add the dried nano-silica powder to the KH-550 solution at a uniform speed, and stir the KH-550 solution at a uniform speed for 15 minutes by mechanical stirring until the nano-silica powder is evenly distributed in the KH-550 solution, and then increase the temperature of the stirrer to make the temperature of the KH-550 solution reach 110°C and introduce nitrogen protection, and continue stirring for 8 hours; Step 3: Pour the solution obtained in step 2 into a centrifuge tube, centrifuge the solution at a speed of 3000r / min, repeat 3 times until all particles are taken out, and then dry it in an environment of 120°C for 8h, grind it into powder, and obtain 15g of modified nano-silica, which is sealed and stored; Step 4: Weigh 1000g of bisphenol A type unsaturated polyester resin, add 150g of styrene, and after preliminary stirring, add 10g of benzoyl peroxide and 10g of N,N-dimethylaniline respectively, and stir for about 5min to obtain the main material; Step 5: Weigh 100g of polyurethane, add 10g of modified nano-silica and 10g of dibutyl phthalate thereto, stir thoroughly and perform ultrasonic treatment for about 10min to ensure that the modifier components are evenly mixed to obtain a modifier; Step six: Add the modifier obtained in step five to the main material obtained in step four and mix well. Prepare 1200g of river sand according to the n1 gradation in Table 1, add it in small amounts to the mixture of the main material and the modifier several times, stirring while adding, to obtain a toughened resin thin layer repair material for cement pavement.

[0032] Example 2 In actual projects with high strength requirements, the amount of diluent, polyurethane and river sand can be reduced, and a gradation with a lower void ratio can be used to improve the strength of the molded repair material. The specific steps are: Referring to steps 1 to 3 in Example 1, prepare an equal amount of modified nano-silicon dioxide for use; Step 4: Weigh 1000g of bisphenol A type unsaturated polyester resin, add 50g of styrene, and after preliminary stirring, add 10g of benzoyl peroxide and 10g of N,N-dimethylaniline respectively, and stir for about 5min to obtain the main material; Step 5: Weigh 50 g of polyurethane, add 10 g of modified nano-silica and 10 g of dibutyl phthalate thereto, stir thoroughly and perform ultrasonic treatment for about 10 minutes to obtain a modifier; Step six: Add the modifier obtained in step five to the main material obtained in step four and mix evenly. Prepare 1000g of river sand according to the n1 gradation in Table 1, and add it to the mixture of the main material and the modifier in small amounts and multiple times, stirring while adding, to obtain a toughened resin thin layer repair material for cement pavement.

[0033] Example 3 In some actual projects that require high fluidity and high workability of materials, the amount of diluent and river sand can be increased, and a gradation with a larger void ratio can be selected. The specific steps are: Referring to steps 1 to 3 in Example 1, prepare an equal amount of modified nano-silicon dioxide for use; Step 4: Weigh 1000g of bisphenol A type unsaturated polyester resin, add 200g of styrene, and after preliminary stirring, add 10g of benzoyl peroxide and 10g of N,N-dimethylaniline respectively, and stir for about 5min to obtain the main material; Step 5: Weigh 100 g of polyurethane, add 10 g of modified nano-silica and 20 g of dibutyl phthalate thereto, stir thoroughly and perform ultrasonic treatment for about 10 minutes to obtain a modifier; Step six: Add the modifier obtained in step five to the main material obtained in step four and mix evenly. Prepare 1600g of river sand according to the n2 gradation in Table 1, and add it to the mixture of the main material and the modifier in small amounts and multiple times, stirring while adding, to obtain a toughened resin thin layer repair material for cement pavement.

[0034] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that no modifier component is added, and other conditions are the same.

[0035] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the unsaturated polyester resin in the main material is replaced by epoxy resin, no diluent is added, the initiator benzoyl peroxide is replaced by phenalkamine epoxy curing agent, and the accelerator N,N-dimethylaniline is replaced by 2, 4, 6-tris(dimethylaminomethyl)phenol. In addition, no modifier is added, and the specific preparation steps are as follows: Weigh 1000g of epoxy resin and heat it in a water bath to reduce its viscosity. After eliminating bubbles, take it out of the water bath, slowly add 7g of 2, 4, 6-tris(dimethylaminomethyl)phenol and stir for 5 minutes, then add 1200g of n1 grade river sand, stir evenly, add 25g of phenolic amine epoxy curing agent, and stir for more than 5 minutes.

[0036] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that the unsaturated polyester resin and styrene in the main material are replaced by acrylic resin, and the mass ratio of each component in the main material is acrylic resin: benzoyl peroxide: N, N-dimethylaniline = 100: 1.5: 0.39, and no modifier is added, and other conditions are the same.

[0037] The dimensional stability and freeze-thaw durability of the materials prepared in Example 1 and Comparative Examples 1-3 were tested with reference to the "Test Method for Drying Shrinkage of Cement Mortar" (JC-T603-2004) and the "Standard for Experimental Methods for Basic Performance of Building Mortar" (JGJ / T70-2009). At the same time, the corrosion resistance of the materials prepared in Example 1 and Comparative Examples 1-3 was evaluated by placing the test pieces in a sulfuric acid solution and an aqueous solution with a pH of 1, respectively, soaking for 7 days, and taking them out. The mass loss rate and strength loss rate of the test pieces were measured. The results are shown in Table 2: Table 2 Dimensional stability, freeze-thaw durability, and corrosion resistance test results

[0038] The bonding strength of the repair materials of Example 1 and Comparative Examples 1-3 was evaluated by flexural tensile strength and pull-out strength, respectively. The test schematic diagram is shown in FIG. Figure 2 and Figure 3 The test results are shown in Table 3: Table 3 Flexural tensile strength and pull-out strength test results

[0039] By comparing the above test results, it can be seen that the various indicators (dimensional stability, freeze-thaw durability, corrosion resistance, flexural tensile strength and pull-out strength) of Example 1 are better than those of Comparative Examples 1 and 3, indicating that the introduction of nano-silicon dioxide and polyurethane can improve the performance of pure unsaturated polyester resin in many aspects. Compared with Comparative Example 2, Example 1 is only slightly lower in corrosion resistance and pull-out strength, indicating that the comprehensive modification of nano-silicon dioxide and polyurethane can make the unsaturated polyester resin have similar or even better performance than epoxy resin. The above results show that the toughened resin thin layer repair material for cement pavement proposed by the present invention has excellent comprehensive performance.

[0040] The shrinkage rates of the repair materials in Examples 2 and 3 of the present invention are 0.07‰ and 0.16‰ respectively.

[0041] In addition, the present invention also tests the flexural strength and compressive strength of the repair materials of Examples 1-3. The specific results are shown in Tables 4 and 5.

[0042] Table 4 Flexural strength

[0043] Table 5 Compressive strength

[0044] Based on the current market price of materials, the unit price of Example 1 and Comparative Examples 1-3 was calculated, and the results were shown in Table 6, based on the preparation of 5 kg of repair materials: Table 6 Calculation results of prices of different resin restoration materials

[0045] From the above results, it can be seen that Example 1 is 63.35% and 45.36% of the price of other resin (Comparative Example 2, Comparative Example 3) repair materials, which greatly reduces the cost of cement pavement repair. Although the price of Comparative Example 1 is lower, it can be seen from the above performance comparison results that its performance is relatively poor, and the unsaturated polyester resin alone cannot usually be used as a cement pavement repair material due to its own excessive brittleness.

[0046] In summary, the repair material of the present invention overcomes the shortcomings of poor toughness of traditional polyester resins by means of synergistic modification, and has the characteristics of high strength, good wear resistance, fast hardening and high bonding strength. In addition, compared with other resin mortar thin layers, it also has the advantage of lower cost, which extends the service life of the concrete pavement while also reducing the maintenance cost of the pavement. This kind of material not only has good adhesion to the cement concrete pavement, but also has excellent stability and durability, and exhibits outstanding performance under environmental and load effects. In addition, this kind of thin layer repair material has a short time to form strength, and after repairing the cement pavement, it can be opened to traffic within 3 hours, and compared with other resin materials, this kind of material has a low cost, which extends the service life of the cement concrete pavement, and also reduces the construction cost of the cement pavement from the perspective of the full life cycle.

[0047] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention rather than all the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A toughened resin thin layer repair material for cement pavement, characterized in that: include: Main material, modifier and filler; wherein, by weight, the main material comprises: 100 parts of unsaturated polyester resin, 5-20 parts of diluent, 1 part of initiator, 1 part of accelerator; the modifier comprises: 5-10 parts of polyurethane, 1-4 parts of nano silicon dioxide, 1-2 parts of plasticizer.

2. The toughened resin thin layer repair material for cement pavement according to claim 1, characterized in that: The unsaturated polyester resin is a bisphenol A type unsaturated polyester resin with a solid content of 62%-68%.

3. The toughened resin thin layer repair material for cement pavement according to claim 1, characterized in that: The diluent is styrene; the initiator is benzoyl peroxide; and the accelerator is N,N-dimethylaniline.

4. The toughened resin thin layer repair material for cement pavement according to claim 1, characterized in that: The nano silicon dioxide is oleophilic nano silicon dioxide.

5. The toughened resin thin layer repair material for cement pavement according to claim 4, characterized in that: The nano silicon dioxide is nano silicon dioxide modified by a silane coupling agent.

6. The toughened resin thin layer repair material for cement pavement according to claim 1, characterized in that: The plasticizer is dibutyl phthalate, and the ester content is greater than 99.5%.

7. The toughened resin thin layer repair material for cement pavement according to claim 1, characterized in that: The filler is river sand.

8. The toughened resin thin layer repair material for cement pavement according to claim 7, characterized in that: The gradation of the river sand is n1 or n2, and the particle size ratio of n1 gradation and n2 gradation is shown in Table 1: Table 1n1, n2 grading 9. The method for preparing the toughened resin thin layer repair material for cement pavement according to any one of claims 1 to 8, characterized in that: The following steps are involved: a. The unsaturated polyester resin, diluent, initiator and accelerator are stirred and mixed to obtain the main material; b. The polyurethane, nano-silica and plasticizer are stirred and mixed to obtain a modifier; c. Add the modifier to the main material and mix evenly, add the resulting mixture to the filler, stir evenly, and obtain the toughened resin thin layer repair material.

10. Use of the toughened resin thin layer repair material for cement pavement according to any one of claims 1 to 8 in cement pavement repair.

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