High-toughness polyurethane concrete and preparation method thereof

Abstract

The invention relates to the technical field of road engineering materials, in particular to high-toughness polyurethane concrete and a preparation method thereof. The high-toughness polyurethane concrete is prepared from the following raw materials in parts by weight: 100 parts of mineral aggregates, 10-18 parts of polyurethane, 0.02-0.08 part of carbon nanotubes, 5-10 parts of rubber particles, 0.2-0.3 part of fibers, 0.1-0.5 part of an improving agent and 0.02-0.05 part of a coupling agent. The carbon nano tubes, the rubber particles and the polyurethane are connected in the mixture to form a net-shaped connection structure through the coupling effect of the coupling agent when the carbon nano tubes, the rubber particles and the polyurethane are mixed, so that the impact resistance and the stability of the mixture are enhanced; the high-temperature performance, the low-temperature performance and the anti-cracking performance of the mixture can be remarkably improved through the cooperation effect of the carbon nano tubes and the rubber particles, meanwhile, based on the cooperation effect of the polyurethane, the carbon nano tubes and the rubber particles, under the high-temperature condition, the curing reaction between the polyurethane and the mixture is accelerated, the polyurethane has good bonding force with aggregate, and the coating force on the aggregate is enhanced.

Description

Technical Field

[0001] The invention relates to the technical field of road engineering materials, and in particular to a high-toughness polyurethane concrete and a preparation method thereof. Background Art

[0002] Polyurethane concrete is a new type of composite material made by mixing ordinary concrete with high molecular polymer material polyurethane. Compared with traditional concrete, polyurethane concrete has significant advantages in mechanical properties and durability, such as higher compressive strength, better chemical corrosion resistance and better impact resistance. These characteristics make it have broad application prospects in road engineering, bridge paving and other fields.

[0003] However, existing polyurethane concrete still has some technical problems in practical applications. First, its water resistance is poor, especially in humid or rainy environments, and it is prone to performance degradation after long-term use. Secondly, the high-temperature stability is insufficient. Under high temperature conditions in summer, polyurethane concrete is prone to softening and deformation, leading to road rutting problems. In addition, the low-temperature crack resistance needs to be improved. At low temperatures in winter, the material is prone to cracks due to shrinkage, affecting the integrity and service life of the road surface. Finally, the fatigue resistance is insufficient. After bearing vehicle loads for a long time, polyurethane concrete is prone to fatigue damage, shortening the maintenance cycle of the road surface.

[0004] In summary, the water resistance, high temperature stability, low temperature crack resistance and fatigue resistance of existing polyurethane concrete still need to be improved. Summary of the invention

[0005] The purpose of the present invention is to provide a high-toughness polyurethane concrete and a preparation method thereof, so as to solve the problem that the water resistance, high-temperature stability, low-temperature crack resistance and fatigue resistance of the existing polyurethane concrete still need to be improved.

[0006] To achieve the above-mentioned purpose, the present invention provides a high-toughness polyurethane concrete, which is made of the following raw materials in parts by weight: 100 parts of mineral material, 10-18 parts of polyurethane, 0.02-0.08 parts of carbon nanotubes, 5-10 parts of rubber particles, 0.2-0.3 parts of fibers, 0.1-0.5 parts of improvers and 0.02-0.05 parts of coupling agents, wherein the mineral material is natural pebbles, the polyurethane is a polyester-polyether composite polyurethane, the carbon nanotube is one of single-walled carbon nanotubes or multi-walled carbon nanotubes or a mixture thereof, the improver is NTADDAS3228, and the coupling agent is isopropyl tri(dioctyl pyrophosphate) titanate.

[0007] Wherein, the particle size of the natural pebbles is 0-10 mm, and the particle size of the rubber particles is 1-3 mm.

[0008] The present invention also provides a method for preparing high-toughness polyurethane concrete for preparing the high-toughness polyurethane concrete as described above, comprising the following steps:

[0009] Modifier preparation: Mix the carbon nanotubes and the coupling agent evenly at a ratio of 1:1 to obtain a carbon nanotube modifier, and mix the rubber particles and the coupling agent evenly at a ratio of 1:0.005 to obtain a rubber particle modifier;

[0010] Compound-modified polyurethane preparation: Add the prepared carbon nanotube modifier and the improver to the polyurethane, stir evenly, and then shear-treat with a high-speed shearer to obtain a compound-modified polyurethane;

[0011] Compound-modified polyurethane concrete preparation: Stir the prepared rubber particle modifier, the mineral aggregate, and the fiber for 1 to 2 minutes, then add the compound-modified polyurethane and continue to mix and stir evenly to obtain the high-toughness polyurethane concrete.

[0012] A high-toughness polyurethane concrete and a preparation method thereof according to the present invention are made of the following raw materials in parts by weight: 100 parts of mineral aggregate, 10 to 18 parts of polyurethane, 0.02 to 0.08 parts of carbon nanotubes, 5 to 10 parts of rubber particles, 0.2 to 0.3 parts of fiber, 0.1 to 0.5 parts of improver, and 0.02 to 0.05 parts of coupling agent. The polyurethane concrete is compound-modified by using the carbon nanotubes, the rubber particles, and the fiber, and has better high-temperature stability, low-temperature crack resistance, and fatigue resistance than ordinary polyurethane concrete; the raw materials of the polyurethane, the carbon nanotubes, the rubber particles, and the fiber are non-toxic and harmless, and the production process of the mixture is pollution-free. Moreover, by adding isopropyltris(dioctylpyrophosphato)titanate, the carbon nanotubes, the rubber particles, and the polyurethane are connected to form a network connection structure inside the mixture through the coupling action of the coupling agent during mixing, thereby enhancing the impact resistance and stability of the mixture; at the same time, isopropyltris(dioctylpyrophosphato)titanate can improve the fatigue performance of the mixture; the combined action of the carbon nanotubes and the rubber particles can significantly improve the high-temperature and low-temperature performance of the mixture. Meanwhile, based on the synergistic effect of the polyurethane, the carbon nanotubes, and the rubber particles, at high temperatures, the polyurethane accelerates the curing reaction with the mixture, has good adhesion to the aggregate, and at the same time enhances the coating force on the aggregate. The addition of the carbon nanotubes and the rubber particles endows the mixture with very good ability to resist load deformation; at low temperatures, it has excellent viscoelastic properties, and the addition of the carbon nanotubes and the rubber particles makes the mixture have better crack resistance. Brief Description of the Drawings

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0014] Figure 1 It is a flowchart of the steps of the preparation method of the high-toughness polyurethane concrete provided by the present invention. Specific embodiments

[0015] The following will describe in detail the embodiments of the present invention. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present invention, and should not be construed as a limitation of the present invention.

[0016] The present invention provides a high-toughness polyurethane concrete, which is made from the following raw materials in parts by weight: 100 parts of mineral aggregate, 10 - 18 parts of polyurethane, 0.02 - 0.08 parts of carbon nanotubes, 5 - 10 parts of rubber particles, 0.2 - 0.3 parts of fibers, 0.1 - 0.5 parts of improver, and 0.02 - 0.05 parts of coupling agent. The mineral aggregate is natural pebbles, the polyurethane is a polyester polyether composite polyurethane, the carbon nanotubes are either single-walled carbon nanotubes or multi-walled carbon nanotubes or a mixture of them, the improver is NT ADDAS3228, and the coupling agent is isopropyl tri(dioctylpyrophosphate acyloxy) titanate.

[0017] Furthermore, the particle size of the natural pebbles is 0 - 10 mm, and the particle size of the rubber particles is 1 - 3 mm.

[0018] In this embodiment, using the carbon nanotubes, the rubber particles and the fibers to compound and modify polyurethane concrete has better high-temperature stability, low-temperature crack resistance and fatigue resistance than ordinary polyurethane concrete; the polyurethane, the carbon nanotubes, the rubber particles and the fiber raw materials are non-toxic and harmless, and there is no pollution in the production process of the mixture. Moreover, by adding isopropyl tris(dioctylpyrophosphate acyloxy) titanate, when the carbon nanotubes, the rubber particles and the polyurethane are mixed, a network connection structure is formed inside the mixture through the coupling action of the coupling agent, thereby enhancing the impact resistance and stability of the mixture; at the same time, isopropyl tris(dioctylpyrophosphate acyloxy) titanate can improve the fatigue performance of the mixture; the combined action of the carbon nanotubes and the rubber particles can significantly improve the high-temperature and low-temperature performance of the mixture. Meanwhile, based on the synergistic effect of the polyurethane, the carbon nanotubes and the rubber particles, under high-temperature conditions, the polyurethane accelerates the curing reaction with the mixture, has a good bonding force with the aggregate, and at the same time enhances the coating force on the aggregate. The addition of the carbon nanotubes and the rubber particles endows the mixture with a very good ability to resist load deformation; at low temperature, it has excellent viscoelastic properties, and the addition of the carbon nanotubes and the rubber particles makes the mixture have better crack resistance.

[0019] Please refer to Figure 1 , the present invention also provides a preparation method of high-toughness polyurethane concrete for preparing the high-toughness polyurethane concrete as described above, including the following steps:

[0020] S1. Modifier preparation: Mix the carbon nanotubes and the coupling agent evenly at a ratio of 1:1 to obtain a carbon nanotube modifier, and mix the rubber particles and the coupling agent evenly at a ratio of 1:0.005 to obtain a rubber particle modifier;

[0021] S2. Compound modified polyurethane preparation: Add the prepared carbon nanotube modifier and the improver to the polyurethane, stir evenly and then perform shear treatment with a high-speed shear machine to obtain a compound modified polyurethane;

[0022] S3. Compound modified polyurethane concrete preparation: Stir the prepared rubber particle modifier with the mineral aggregate and the fibers for 1 to 2 minutes, and then add the compound modified polyurethane and continue to mix and stir evenly to obtain the high-toughness polyurethane concrete.

[0023] In this embodiment, first, the carbon nanotubes and the coupling agent are mixed evenly at a ratio of 1:1 to obtain a carbon nanotube modifier, and the rubber particles and the coupling agent are mixed evenly at a ratio of 1:0.005 to obtain a rubber particle modifier. Then, the prepared carbon nanotube modifier and the improver are added to the polyurethane, and after stirring evenly, they are sheared by a high-speed shearing machine to obtain a composite-modified polyurethane. Finally, the prepared rubber particle modifier is stirred with the mineral aggregate and the fiber for 1 to 2 minutes, and then the composite-modified polyurethane is added and stirred continuously until evenly mixed, thus obtaining the high-toughness polyurethane concrete.

[0024] Example 1:

[0025] The present invention also provides a preparation method of high-toughness polyurethane concrete for preparing the high-toughness polyurethane concrete as described above, which includes the following steps:

[0026] Modifier preparation: 5 g of the carbon nanotubes and 5 g of the coupling agent are mixed evenly to obtain a carbon nanotube modifier, and 100 g of the rubber particles and 5 g of the coupling agent are mixed evenly to obtain a rubber particle modifier;

[0027] Composite-modified polyurethane preparation: The prepared carbon nanotube modifier and 20 g of the improver are added to 2000 g of the polyurethane, and after stirring evenly, they are sheared by a high-speed shearing machine to obtain a composite-modified polyurethane;

[0028] Composite-modified polyurethane concrete preparation: The prepared rubber particle modifier is stirred with 20000 g of the mineral aggregate and 40 g of the fiber for 1 to 2 minutes, and then the composite-modified polyurethane is added and stirred continuously for 3 min, thus obtaining the high-toughness polyurethane concrete.

[0029] Furthermore, high and low temperature specimens are formed according to (Specimen Preparation Method for Asphalt Mixtures (Wheel Rolling Method) T0703 - 0211) in "Test Procedures for Bitumen and Bituminous Mixtures for Highway Engineering" (JTGE20 - 2011), Marshall specimens are formed according to (Specimen Preparation Method for Asphalt Mixtures (Compaction Method) T0702 - 0211), cube compressive specimens are formed according to "Standard for Test Methods of Mechanical Properties of Ordinary Concrete" GB / T50081 - 2002. The high temperature performance of the high-toughness polyurethane concrete is tested according to the provisions of "Asphalt Mixture Rutting Test T0719" in "Test Procedures for Bitumen and Bituminous Mixtures for Highway Engineering" (JTGE20 - 2011), the water resistance of the high-toughness polyurethane concrete is tested according to the provisions of "Asphalt Mixture Freeze-Thaw Split Test T0729", and the low temperature performance of the high-toughness polyurethane concrete is tested according to the provisions of "Asphalt Mixture Bending Test T0716"; the compressive strength is tested according to the provisions of "Standard for Test Methods of Mechanical Properties of Ordinary Concrete" GB / T50081 - 2002.

[0030] Examples 2 - 5:

[0031] Except for the different raw material ratios, the test piece forming and performance testing of Examples 2 - 5 were carried out according to the steps of Example 1. Table 1 shows the ratios of Examples 2 - 5, and Table 2 shows the test results of Examples 1 - 5:

[0032] Table 1. Ratios of Examples 2 - 5 (unit: g)

[0033] Example 2 Example 3 Example 4 Example 5 Mineral aggregate 20000 20000 20000 20000 Polyurethane 2400 2800 3200 3600 Rubber particles 130 150 170 200 Carbon nanotubes 8 10 13 16 Fibers 45 50 55 60 Improver 40 70 80 100 Coupling agent 12 15 18 20

[0034] Table 2. Performance test results of Examples 1 - 5

[0035]

[0036] Judging from the actual test results in Table 2, the high - toughness polyurethane concrete of the present invention has excellent low - temperature crack resistance and following deformation ability, and can better meet the requirements of ultra - long - span steel bridge deck paving.

[0037] The above - disclosed is only a preferred embodiment of the present invention. Of course, it cannot be used to limit the scope of the rights of the present invention. Those of ordinary skill in the art can understand all or part of the processes of implementing the above - mentioned embodiments, and the equivalent changes made according to the claims of the present invention still fall within the scope covered by the invention.

Claims

1. A high-toughness polyurethane concrete, characterized in that: The invention is prepared from the following raw materials in parts by weight: 100 parts of mineral material, 10-18 parts of polyurethane, 0.02-0.08 parts of carbon nanotubes, 5-10 parts of rubber particles, 0.2-0.3 parts of fiber, 0.1-0.5 parts of improver and 0.02-0.05 parts of coupling agent, wherein the mineral material is natural pebble, the polyurethane is polyester-polyether composite polyurethane, the carbon nanotube is single-walled carbon nanotube or multi-walled carbon nanotube or a mixture thereof, the improver is NTADDAS3228, and the coupling agent is isopropyl tri(dioctyl pyrophosphate acyloxy) titanate.

2. The high-toughness polyurethane concrete according to claim 1, characterized in that: The particle size of the natural pebbles is 0-10 mm, and the particle size of the rubber particles is 1-3 mm.

3. A method for preparing high-toughness polyurethane concrete, used for preparing the high-toughness polyurethane concrete as claimed in claim 1, characterized in that: The steps include: Preparation of the modifier: the carbon nanotubes and the coupling agent are uniformly mixed in a ratio of 1:1 to obtain a carbon nanotube modifier, and the rubber particles and the coupling agent are uniformly mixed in a ratio of 1:0.005 to obtain a rubber particle modifier; Preparation of composite modified polyurethane: adding the prepared carbon nanotube modifier and the improving agent to the polyurethane, stirring evenly and then shearing with a high-speed shearing machine to obtain composite modified polyurethane; Preparation of composite modified polyurethane concrete: stir the prepared rubber particle modifier with the mineral material and the fiber for 1 to 2 minutes, then add the composite modified polyurethane and continue to mix and stir evenly to obtain the high-toughness polyurethane concrete.

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