Expressway ditch cover plate and preparation method and application thereof

Abstract

The application belongs to the technical field of engineering materials, and particularly relates to a highway ditch cover plate and a preparation method and application thereof. The preparation method comprises the following steps: S1. raw material preparation; S2. crushing peach gum and passing the peach gum through an 80-100 mesh sieve, adding the peach gum into base pitch, and simultaneously adding nano silicon dioxide, polyvinyl acetate and water to obtain a mixed system; S3. high-speed stirring the mixed system at 110-115 DEG C for 30-45 min to obtain modified pitch; S4. mixing cement, silica fume, river sand, rice stone, basalt fiber and carboxylic acid water reducing agent, and adding the modified pitch while stirring until the mixture is uniform to obtain a concrete slurry; and S5. pouring the concrete slurry into a ditch cover plate mold, vibrating uniformly, and performing a curing and demolding step to obtain the highway ditch cover plate. The modified pitch is added into the concrete, and the toughness and mechanical properties of the cover plate are simultaneously improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of engineering materials, and particularly relates to a highway ditch cover plate and a preparation method and application thereof. BACKGROUND

[0002] Traditional cement concrete is a kind of rigid material, which has the characteristics of strong bearing capacity, good high-temperature stability, excellent weather resistance and durability, etc., but has poor resistance to impact, cracking and fatigue damage. The highway ditch cover plate is applied to the drainage ditch on both sides of the highway, generally has a large span, and is subjected to impact from various vehicles driving at high speed at any time, so damage is prone to occur, and it is difficult to maintain after cracking, and driving comfort is poor. Asphalt is a kind of elastic-plastic viscous material, and the concrete prepared by using asphalt as a binder has the characteristics of solid texture, strong bearing capacity, high flatness, vibration reduction function, high skid resistance and good driving comfort.

[0003] After the traditional cement concrete cover plate is mixed with asphalt, the concrete has the characteristics of both flexible material and rigid material, so that the use performance of the cover plate is improved, and the cover plate has a wide application prospect. However, due to the poor compatibility of asphalt and concrete, asphalt cannot be directly added, and generally needs to be emulsified and modified to improve the flowability and wettability of asphalt, so as to improve the compatibility. However, the existing emulsified asphalt generally has the problem of adhesion to stone, and the improvement of the mechanical properties of the concrete is not obvious. SUMMARY

[0004] Therefore, the purpose of the present application is to overcome the shortcomings of the prior art, and to provide a highway ditch cover plate and a preparation method and application thereof, so as to improve the toughness and mechanical strength of the cover plate.

[0005] The purpose of the present application is achieved by the following technical solutions:

[0006] A preparation method of a highway ditch cover plate, comprising the following steps:

[0007] S1. Preparing cement, silica fume, river sand, gravel, basalt fiber, polycarboxylate superplasticizer, water, matrix asphalt, peach gum, nano-silicon dioxide and polyvinyl acetate for standby;

[0008] S2. The peach gum is crushed and then sieved through an 80-100 mesh sieve, and is added to the matrix asphalt, while the nano-silicon dioxide, polyvinyl acetate and water are added, to obtain a mixed system;

[0009] S3. The mixed system is stirred at a high speed at 110-115 DEG C for 30-45 min to obtain modified asphalt;

[0010] S4. Mix the cement, silica fume, river sand, gravel, basalt fiber and polycarboxylic acid water reducing agent, and add the modified asphalt while stirring until the mixture is uniform, to obtain a concrete slurry;

[0011] S5. Pour the concrete slurry into a trench cover plate mold, vibrate uniformly, and perform curing and demolding steps to obtain the highway trench cover plate.

[0012] The curing is performed according to the description in Q / CR 2.1-2014 Railway Cable Trough Cover Plate and Sidewalk Step Plate Part 1: Active Powder Concrete Type.

[0013] Further, in step S1, the cement is 130-170 parts by weight, the silica fume is 10-15 parts by weight, the river sand is 270-280 parts by weight, the gravel is 400-420 parts by weight, the basalt fiber is 2-3 parts by weight, the polycarboxylic acid water reducing agent is 15-20 parts by weight, the water is 60-70 parts by weight, the matrix asphalt is 30-35 parts by weight, the peach gum is 3-5 parts by weight, the nano silicon dioxide is 10-15 parts by weight, and the polyvinyl acetate is 3-4 parts by weight.

[0014] Further, the basalt fiber includes 19mm long fibers and 3mm short fibers, wherein the 3mm short fibers can control the development of capillary cracks in the concrete, and the 19mm long fibers can form a three-dimensional network structure to strengthen the connection between the aggregates, and under the synergistic action of the two, the mechanical properties of the cover plate can be further improved.

[0015] Further, the weight ratio of the long fibers to the short fibers is 2-2.5:1.

[0016] Further, in step S1, the cement is P·O 42.5R cement.

[0017] Further, in step S1, the particle size of the gravel is 5-10mm.

[0018] Further, in step S1, the basalt fiber is a general-purpose basalt fiber.

[0019] Further, in step S3, the rotation speed of the high-speed stirring is 500-800 r / min.

[0020] The application also provides a highway trench cover plate prepared by the above preparation method.

[0021] The application also provides the use of the above highway trench cover plate in construction engineering.

[0022] The peach gum is a gum substance secreted from the bark of a peach tree, and the main component of the peach gum is peach gum polysaccharide, which has sufficient water solubility and proper viscosity. The peach gum is used as an emulsifier of modified base asphalt in the application. While being emulsified, polyvinyl acetate is added to the base asphalt, which becomes an emulsion under the action of the peach gum after being contacted with water. Under high-speed stirring, the polyvinyl acetate emulsion reacts with the asphalt, which has the effects of increasing the softening point of the asphalt, improving the low-temperature flexibility of the asphalt, increasing the ductility of the asphalt, and increasing the anti-aging property of the asphalt. Subsequently, the polyvinyl acetate emulsion gradually dries and loses water in the process of hardening of the concrete, and part of the polyvinyl acetate emulsion is separated from the asphalt to form a polyvinyl acetate film between the asphalt and the concrete aggregate, which can effectively improve the adhesion between the asphalt and the aggregate. As a modification aid, nano-silicon dioxide forms a paste with the asphalt in the early stage of modification, which can improve the stability of the mixture and avoid the polyvinyl acetate molecules from being separated too early. In the later stage of hardening of the concrete, the nano-silicon dioxide can also fill the pores in the concrete to improve the self-compacting property of the concrete.

[0023] The application has the following beneficial effects:

[0024] The highway cover plate prepared by the application has good adhesion between the asphalt and the aggregate, and the toughness of the cover plate is improved while the other mechanical properties are also effectively improved. The peach gum is selected as the emulsifier of the modified asphalt, which is natural, non-polluting and low in cost. DETAILED DESCRIPTION

[0025] The technical solutions of the application will be further described in detail below with reference to the examples, but the protection scope of the application is not limited to the following description.

[0026] Example 1

[0027] A preparation method of a highway trench cover plate, comprising the following steps:

[0028] S1. Prepare, by weight parts, P.O 42.5R cement 145 parts, silica ash 12 parts, river sand 270 parts, 5-10 mm rice stone 400 parts, 3 mm basalt fiber 1 part, 19 mm basalt fiber 2.2 parts, polycarboxylic acid water reducer 18 parts, water 60 parts, base asphalt 35 parts, peach gum 4 parts, nano-silicon dioxide 15 parts, and polyvinyl acetate 28 parts for standby;

[0029] S2. Crush the peach gum and pass it through an 80-100 mesh sieve, and then add the base asphalt, the nano-silicon dioxide, the polyvinyl acetate and the water to obtain a mixed system;

[0030] S3. Stir the mixed system at a speed of 800 r / min at 110-115 DEG C for 30 min to obtain modified asphalt;

[0031] S4. Mix the cement, silica fume, river sand, rice stone, basalt fiber and carboxylic acid water reducing agent, add the modified asphalt while stirring until the mixture is uniform, to obtain a concrete slurry;

[0032] S5. Pour the concrete slurry into a trench cover plate mold, vibrate uniformly, and perform curing and demolding steps to obtain the highway trench cover plate.

[0033] The basalt fiber is a general-purpose basalt fiber, and the basalt fiber and the polycarboxylic acid water reducing agent are purchased from the market; the size of the highway trench cover plate provided in this embodiment is 490*590*50mm, which is suitable for highways in China. Before step S5, reinforcement is provided in the mold according to general methods in the art. The curing in step S5 is performed according to the description in “Q / CR2.1-2014 Railway Cable Trough Cover Plate and Sidewalk Step Plate Part 1: Active Powder Concrete Type”.

[0034] Example 2

[0035] A preparation method of a highway trench cover plate, comprising the following steps:

[0036] S1. Prepare P.O42.5R cement 170 parts, silica fume 10 parts, river sand 280 parts, 5-10mm rice stone 420 parts, 3mm basalt fiber 0.8 parts, 19mm basalt fiber 1.6 parts, polycarboxylic acid water reducing agent 15 parts, water 70 parts, base asphalt 35 parts, peach gum 5 parts, nano silicon dioxide 10 parts and polyvinyl acetate 20 parts by weight for use;

[0037] S2. Crush the peach gum and pass it through an 80-100 mesh sieve, add the base asphalt, and add the nano silicon dioxide, polyvinyl acetate and water to obtain a mixed system;

[0038] S3. Stir the mixed system at 110-115°C at a speed of 500 r / min for 45min to obtain modified asphalt;

[0039] S4. Mix the cement, silica fume, river sand, rice stone, basalt fiber and carboxylic acid water reducing agent, add the modified asphalt while stirring until the mixture is uniform, to obtain a concrete slurry;

[0040] S5. Pour the concrete slurry into a trench cover plate mold, vibrate uniformly, and perform curing and demolding steps to obtain the highway trench cover plate.

[0041] The basalt fiber is a general-purpose basalt fiber, and the basalt fiber and the polycarboxylic acid water reducing agent are purchased from the market; the size of the highway trench cover plate provided in the embodiment is 790*490*70mm, which is suitable for highways in Hunan Province, China, and before step S5, a reinforcement is arranged in the mold according to the general method in the art, and the curing in step S5 is performed according to the description in Q / CR 2.1-2014 Railway Cable Trench Cover Plate and Sidewalk Step Plate Part 1: Active Powder Concrete Type.

[0042] Comparative Example 1

[0043] A preparation method of a highway trench cover plate, which is different from that of Example 1 in that the matrix asphalt is not modified, i.e., step S3 is omitted, the peach gum is crushed to 80-100 mesh, then the components are directly mixed uniformly, and then the steps of pouring, vibrating, curing, demolding and the like are performed.

[0044] Comparative Example 2

[0045] A preparation method of a highway trench cover plate, which is different from that of Example 1 in that the peach gum is omitted from the components, and the nano-silicon dioxide, polyvinyl acetate and water are directly added to the matrix asphalt in step S2 to obtain a mixed system, and the remaining steps are the same.

[0046] Comparative Example 3

[0047] A preparation method of a highway trench cover plate, which is different from that of Example 1 in that the polyvinyl acetate is omitted from the components, and the nano-silicon dioxide, the crushed peach gum and water are directly added to the matrix asphalt in step S2 to obtain a mixed system, and the remaining steps are the same.

[0048] Comparative Example 4

[0049] A preparation method of a highway trench cover plate, which is different from that of Example 1 in that the nano-silicon dioxide is omitted from the components, and the polyvinyl acetate, the crushed peach gum and water are directly added to the matrix asphalt in step S2 to obtain a mixed system, and the remaining steps are the same.

[0050] Comparative Example 5

[0051] A preparation method of a highway trench cover plate, which is different from that of Example 1 in that the matrix asphalt, the peach gum, the nano-silicon dioxide, the polyvinyl acetate are omitted from the components, and the cement, the silica fume, the river sand, the rice stone, the basalt fiber, the carboxylic acid water reducing agent and the water are directly mixed, and then the steps of pouring, vibrating, curing, demolding and the like are performed.

[0052] Due to lack of unified standard, and the reinforcing bars are arranged in the cover plate, the difference of the reinforcing bar structure also causes the difference of the mechanical properties of the cover plate, in order to avoid the error, the mechanical properties of the prepared cover plate are not tested, but the mechanical properties of the concrete test pieces poured by the method of each embodiment and the comparative example are tested by referring to the method in Q / CR 2.1-2014 "Railway Cable Trough Cover Plate and Sidewalk Step Plate Part 1: Reactive Powder Concrete Type", JTJ053-94 "Highway Engineering Cement Concrete Test Regulations", and the test results are shown in Table 1.

[0053] Table 1

[0054]

[0055] The impact toughness of the concrete test pieces poured by the method of each embodiment and the comparative example is tested by using the falling weight impact method, and the specific operation is as follows: a steel ball is used to impact a steel ball placed at the center of the test piece from a certain height, when a crack appears at the lower edge of the test piece, the impact number is recorded, that is, the initial cracking impact number. Then continue to impact cycle, until the crack in the test piece penetrates the whole section, and then record the impact number again, that is, the failure impact number. The size of the test piece is 100 mm x 100 mm x 400 mm.

[0056] The impact toughness of the concrete is calculated according to the following formula:

[0057] W = Nmgh

[0058] In the formula, W is the impact toughness of the concrete, N.m;

[0059] N is the impact number at failure;

[0060] m is the weight of the steel hammer, 3 kg;

[0061] h is the falling height of the impact hammer, 0.3 m;

[0062] g is 9.80 N / kg.

[0063] The test results are shown in Table 2.

[0064] Table 2

[0065]

[0066] According to Table 1 and Table 2, the highway trench cover plates prepared in Examples 1 and 2 have excellent mechanical properties and impact toughness, and Comparative Example 5 is a general rigid concrete cover plate, which has good mechanical properties but weak impact resistance. In comparison, Comparative Example 1 is not modified with base pitch, and the test results are as expected, that is, the toughness of the concrete is not improved, and the mechanical properties are reduced. The performance of Comparative Examples 2-4 is significantly reduced in all aspects, indicating that omitting any one of the components of nano-silicon dioxide, polyvinyl acetate and peach gum will have a great impact on the performance of the final cover plate, and there is a synergistic effect between the components of the present application.

[0067] The above description is only preferred embodiments of the present application, and it should be understood that the present application is not limited to the forms disclosed herein, and should not be considered as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concepts described herein by the above teachings or related art or knowledge. Any modification and change made by those skilled in the art without departing from the spirit and scope of the present application shall be within the protection scope of the claims of the present application.

Claims

1. A method of manufacturing a highway trench cover, characterized by, The preparation method comprises the following steps: S1. Preparing cement 130-170 parts by weight, silica fume 10-15 parts by weight, river sand 270-280 parts by weight, gravel 400-420 parts by weight, basalt fiber 2-3 parts by weight, polycarboxylic acid water reducer 15-20 parts by weight, water 60-70 parts by weight, matrix asphalt 30-35 parts by weight, peach gum 3-5 parts by weight, nano-silicon dioxide 10-15 parts by weight, and polyvinyl acetate 20-30 parts by weight; S2. Crushing the peach gum and passing it through an 80-100 mesh sieve, then adding the matrix asphalt, nano-silicon dioxide, polyvinyl acetate, and water to obtain a mixed system; S3. High-speed stirring the mixed system at 110-115°C for 30-45 min to obtain modified asphalt; S4. Mixing the cement, silica fume, river sand, gravel, basalt fiber, and polycarboxylic acid water reducer, and adding the modified asphalt while stirring until the mixture is uniform to obtain a concrete slurry; S5. Pouring the concrete slurry into a trench cover plate mold, vibrating it uniformly, and performing curing and demolding steps to obtain the highway trench cover plate. The basalt fiber comprises long fibers and short fibers, and the weight ratio of the long fibers to the short fibers is 2-2.5:

1.

2. The method of claim 1, wherein the highway trench cover is made of a material selected from the group consisting of a metal, a resin, a rubber, a plastic, a glass, a ceramic, a wood, a composite material, and a combination thereof. The basalt fiber comprises 19 mm long fibers and 3 mm short fibers.

3. The method of claim 1, wherein the highway trench cover is made of a material selected from the group consisting of a metal, a resin, a rubber, a plastic, a glass, a ceramic, a wood, a composite material, and a combination thereof. In step S1, the cement is P·O 42.5R cement.

4. The method of claim 1, wherein the highway trench cover is made of a material selected from the group consisting of a metal, a resin, a rubber, a plastic, a glass, a ceramic, a wood, a composite material, and a combination thereof. In step S1, the particle size of the gravel is 5-10 mm.

5. The method of claim 1, wherein the highway trench cover is made of a material selected from the group consisting of: a metal, a plastic, a composite, and a combination thereof. In step S1, the basalt fiber is a general-purpose basalt fiber.

6. The method of claim 1, wherein the highway trench cover is made of a material selected from the group consisting of: a metal, a plastic, a composite, and a combination thereof. In step S3, the stirring speed is 500-800 r / min.

7. The highway trench cover plate obtained by the preparation method according to any one of claims 1-6.

8. The application of the highway trench cover plate according to claim 7 in construction engineering.

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