CN110904774A

CN110904774A - Modular self-snow-melting pavement based on graphene

Info

Publication number: CN110904774A
Application number: CN201911216103.0A
Authority: CN
Inventors: 闫慧君; 李莹莹; 白建伟; 姜艳丽
Original assignee: Harbin University
Current assignee: Harbin University
Priority date: 2019-12-02
Filing date: 2019-12-02
Publication date: 2020-03-24
Anticipated expiration: 2039-12-02
Also published as: CN110904774B

Abstract

The invention discloses a graphene-based modular self-snow-melting pavement, which relates to a conductive asphalt pavement and aims to solve the problems that a modular conductive asphalt pavement caulking material cannot meet the damage of an expansion joint caused by the influence of pavement environmental change, cannot adapt to the change of pavement joints and crack widths, cannot realize the formation of a conductive network of an assembled conductive asphalt pavement, and thus has discontinuous conductivity, wastes energy and influences the ice-snow melting effect; the problems of poor high-temperature stability, low-temperature crack resistance, water stability, fatigue resistance and low conductivity of the conductive asphalt pavement are solved. According to the modularized self-snow-melting pavement, the graphene conductive asphalt layer plays a role in conducting and heating, the conductive shape memory composite material is filled in the joints, the width changes of the joints and the cracks of the pavement can be met actively, and the modular self-snow-melting pavement can be better attached to the unit asphalt pavement to realize the joint connection and the conductive continuity according to the change of the pavement environment. The invention is applied to the field of self-snow-melting road surfaces.

Description

Modular self-snow-melting pavement based on graphene

Technical Field

The present invention relates to conductive asphalt pavements; in particular to a modularized self-snow-melting pavement based on graphene.

Background

The climate change in four seasons of China is obvious, particularly in late autumn, winter and early spring, is influenced by cold air, the temperature change is obvious, a large amount of rainfall and snowfall are brought, the road surface is easy to accumulate snow and ice, further, the road traffic is greatly influenced, and the driving performance and the safety of the running vehicles are extremely adverse due to the accumulated ice and snow on the road surface. According to statistics, about 15% -30% of traffic accidents in winter are related to accumulated snow on the road surface, particularly, serious traffic accidents such as continuous rear-end collision and the like are easy to happen on a highway. The serious accumulated snow on the road surface can close the road, thereby bringing serious influence to the smooth road and causing huge economic loss.

The existing snow removing methods mainly comprise manual snow removing, mechanical snow removing and snow melting agent snow removing, but the snow removing methods have aftermath and cannot ensure the timely removal of the accumulated snow. Mechanical snow removal and manual snow removal have the shortcomings of high cost, low efficiency, long traffic sealing time and the like, and snow melting salt is spread to cause long-term damage and pollution to greening vegetation, soil and water on one hand, so that an electric heating snow removal mode is considered to be an active snow removal mode with good comprehensive performance in a plurality of road snow removal technologies, and therefore, the conductive asphalt pavement is gradually adopted at present.

However, the construction period of the conductive asphalt pavement is seriously affected by the weather temperature, the automation of the construction procedure is low, and the construction and maintenance time of the base layer is long, so that the construction period is long. Secondly, in the construction technology of the cast-in-place asphalt pavement, the transportation distance of materials is long, and the construction environment is seriously differentiated, so that the construction process is difficult to accurately control, and the quality uniformity of the asphalt pavement is poor. The assembled asphalt pavement is a novel pavement structure form which is provided aiming at the problems of the traditional cast-in-place asphalt pavement, the block pavement slab is processed on a precast yard, and then the block pavement slab is transported to the site for assembly, thereby realizing the programmed construction of the asphalt pavement, but splicing joints can be reserved in the method, under the action of load, the deformation of two adjacent slabs at the joints is inconsistent, the asphalt surface layer at the joints can receive larger shear stress, thereby causing the damage, which is embodied in macroscopical that the cracks are caused by the existence of the base layer to develop upwards, namely, reflection cracks are generated.

The crack is used as the weakest link of the cement concrete pavement and can generate harm to the pavement in different degrees, so the crack can influence the service life of the cement concrete pavement, meanwhile, the aging and cracking of the conductive asphalt can obviously influence the resistivity, the self heat storage is large, the snow removal and deicing effects are influenced, the existing asphalt-based caulking material can not meet the damage of the expansion joint caused by the influence of the change of the pavement environment, can not adapt to the pavement joint and the change of the crack width, and can not realize the formation of a conductive network of the assembled conductive asphalt pavement, thereby the conduction is discontinuous, the energy is wasted, and the ice and snow melting effects are influenced.

In addition, the conductive asphalt pavement has good impact resistance, fatigue resistance, toughness after cracking, durability and the like in the case of doping steel fibers. Although the doped steel fiber can improve the conductive performance, the specific resistance of the steel fiber asphalt is obviously increased along with the prolonging of the service time due to the thicker diameter of the steel fiber, and the conductive performance of the conductive asphalt doped with the steel fiber is reduced mainly due to the oxidation passivation layer generated on the surface of the steel fiber in the alkaline environment. How to improve the conductive asphalt doped with steel fiber is the problem to be solved at present.

Disclosure of Invention

The invention aims to solve the problems that the modularized conductive asphalt pavement caulking material can not meet the damage of an expansion joint caused by the influence of the change of a pavement environment, can not adapt to the change of pavement joints and crack widths, and can not realize the formation of a conductive network of an assembled conductive asphalt pavement, so that the conduction is discontinuous, the energy is wasted, and the ice and snow melting effect is influenced;

the problems of poor high-temperature stability, low-temperature crack resistance, water stability, fatigue resistance and low conductivity of the conductive asphalt pavement are solved.

And provides a modular self-snow-melting pavement based on graphene.

The self-snow-melting pavement made of the modular multiphase material is formed by splicing a plurality of modular self-snow-melting pavement units, each modular self-snow-melting pavement unit comprises a substrate, a lower asphalt layer, a graphene conductive asphalt layer, electrodes, an insulating asphalt layer and a surface layer, the substrate is made of lean concrete, continuous grooves are formed in the substrate along the transverse direction or the longitudinal direction, the lower asphalt layer is poured in the grooves and is bonded through an emulsified asphalt adhesive, the graphene conductive asphalt layer is arranged on the surface of the lower asphalt layer and is bonded through the emulsified asphalt adhesive, the electrodes are distributed in the graphene conductive asphalt layer at intervals, the electrodes are arranged in the thickness direction of the graphene conductive asphalt layer, the insulating asphalt layer is bonded on the upper surface of the graphene conductive asphalt layer, and the surface layer is laid on the insulating asphalt layer;

a joint exists at the joint of the graphene conductive asphalt layers in the two adjacent modular self-snow-melting pavement units, and a conductive phase-change joint is poured in the joint;

the graphene conductive asphalt layer is prepared from 4-10 parts of asphalt, 70-125 parts of aggregate, 12-18 parts of mineral powder and a conductive material in parts by weight; the conductive material is composed of a graphene oxide-carbon fiber composite material and steel fibers;

wherein, the addition of the graphene oxide-carbon fiber composite material is 5.3-15.8% of the mass of the asphalt, and the addition of the steel fiber is 1.5-3% of the mass of the asphalt.

The invention has the following beneficial effects:

the conductive shape memory composite material prepared by the invention has obvious shape memory effect, and because the invention adopts a modularized conductive asphalt pavement paving mode, gaps exist between adjacent modularized pavements in the paving process, the conductive shape memory composite material can be filled and the gaps can actively meet the width change of pavement joints and cracks, and can be better attached between modularized self-snow-melting pavement unit asphalt pavements according to the change of pavement environment, so that the problems of crack, water seepage, easy aging, poor crack resistance, poor shape memory effect, small shape restoring force and the like of the existing asphalt pavement caulking materials are solved, and the service performance and durability of cement pavements are prolonged; meanwhile, conductive materials such as graphene and polypyrrole are added, and after the width change of joints and cracks of the road surface is actively met, the conductivity between two adjacent road surfaces is realized, so that the problem that the conductivity of the whole conductive asphalt road surface is reduced due to the existence of gaps between the modularized road surfaces or the expansion of the gaps along with the increase of the service cycle is solved, and therefore, in the snow melting process, the voltage needs to be increased for each road surface, the snow melting effect is improved, and the energy waste is caused.

Secondly, the conductivity of the conductive shape memory composite material can be obviously increased by using AOT in the preparation of the conductive shape memory composite material, and the CMP-410 epoxy resin active toughening agent can be crosslinked with epoxy resin and a curing agent, so that the obtained conductive shape memory composite material has excellent toughness, crack resistance and good conductivity;

thirdly, the elastic modulus of the conductive shape memory composite material prepared by the invention is 1 Ga-3.2 Ga, the resistivity is 0.1 omega-0.5 omega-m, the conductive shape memory composite material has obvious shape memory effect, the recoverable stress is large, the recoverable strain is 80% -100% at most, and meanwhile, the conductive shape memory composite material prepared by the invention can realize the driving of the electro-thermotropic shape memory effect of the shape memory polymer.

The interface bonding performance of the carbon fiber is improved through the pretreated carbon fiber in the preparation of the graphene oxide-carbon fiber composite material, the carbon fiber can be used as a supporting framework to effectively avoid excessive stacking of graphene, gaps between the carbon fiber and asphalt are filled on the surface of the graphene-coated carbon fiber, the bonding performance of the modified graphite and the asphalt is improved, and the bonding strength of the graphite and the carbon of the graphite can be improved.

In the research of the conventional conductive heating asphalt pavement, although the conductive asphalt mixture is used as a pavement wearing layer, the asphalt mixture is used for the problem that the surface layer is easy to age, crack and the like, the crack has obvious influence on the conductivity of the asphalt mixture, and meanwhile, the problem is considered to be safety. The lower asphalt layer (lower surface layer) in the modular self-snow-melting pavement based on graphene mainly plays a role of a bearing layer, a dense framework type asphalt mixture is adopted, and the thickness of the lower asphalt layer is 5-10 cm; the graphene conductive asphalt layer plays a role in conducting and heating, and the thickness of the graphene conductive asphalt layer is 3-5 cm; considering that the surface layer (wearing layer) is affected by the high temperature of the lower layer and the low temperature of the environment on the stability of the surface layer in winter, the insulating asphalt layer with a smaller thickness is arranged on the graphene conductive asphalt layer, the thickness is 0.3-1.0 cm, the insulating asphalt layer can adopt heat conduction enhanced asphalt mixture (such as graphite powder doped modified asphalt mixture), and finally the surface layer is paved on the surface of the insulating asphalt layer.

Drawings

Fig. 1 is a schematic structural diagram of a graphene-based modular self-snow-melting pavement according to the present invention;

FIG. 2 is a schematic view of a tongue-and-groove structure on a substrate.

Detailed Description

The specific implementation mode is as follows: the self-snow-melting road surface made of the modularized multi-phase material is formed by splicing a plurality of modularized self-snow-melting road surface units, each modularized self-snow-melting road surface unit comprises a substrate 1, a lower asphalt layer 3, a graphene conductive asphalt layer 4, electrodes 5, an insulating asphalt layer 7 and a surface layer 8, the substrate 1 is made of lean concrete, continuous grooves 2 are transversely or longitudinally formed in the substrate 1, the lower asphalt layer 3 is poured in the grooves 2 and bonded through an emulsified asphalt adhesive, the graphene conductive asphalt layer 4 is arranged on the surface of the lower asphalt layer 3 and bonded through an emulsified asphalt adhesive, a plurality of electrodes 5 are arranged in the graphene conductive asphalt layer 4 at intervals, the electrodes 5 are arranged along the thickness direction of the graphene conductive asphalt layer 4, the insulating asphalt layer 7 is arranged on the upper surface of the graphene conductive asphalt layer 4, the surface layer 8 is laid on the insulating asphalt layer 7;

a joint exists at the joint of the graphene conductive asphalt layers 4 in the two adjacent modular self-snow-melting pavement units, and a conductive phase-change joint 6 is poured in the joint;

The second embodiment is as follows: the first difference between the present embodiment and the specific embodiment is: the thickness of the graphene conductive asphalt layer 4 is 3-5 cm, and the thickness of the insulating asphalt layer 7 is 0.3-1.0 cm. The rest is the same as the first embodiment.

The third concrete implementation mode: the first difference between the present embodiment and the specific embodiment is: a plurality of mortises 9 are formed in the side edge of the base plate 1 along the thickness direction of the base plate 1, the adjacent base plates 1 are spliced to form an H-shaped mortise 9, the tenon joint piece 10 is H-shaped, and the tenon joint piece 10 is inserted into the mortise 9. The rest is the same as the first embodiment.

The fourth concrete implementation mode: the first difference between the present embodiment and the specific embodiment is: the preparation method of the graphene conductive asphalt layer comprises the following steps:

weighing 4-10 parts of asphalt, 70-125 parts of aggregate and 12-18 parts of mineral powder according to parts by weight; stirring and mixing asphalt, aggregate and steel fiber at 170 ℃ for 90s, adding mineral powder, and stirring for 90s to obtain a primary mixed material;

secondly, adding the graphene oxide-carbon fiber composite material into the primary mixed material obtained in the first step, and stirring for 90 seconds at the temperature of 160-170 ℃; and obtaining the graphene conductive asphalt layer by adopting a Marshall compaction method. The rest is the same as the first embodiment.

The fifth concrete implementation mode: the first difference between the present embodiment and the specific embodiment is: the preparation method of the graphene oxide-carbon fiber composite material in the second step is as follows:

1) preparing a graphene oxide dispersion liquid:

A. mixing graphite, ammonium nitrate and sodium acetate according to the mass ratio of 3-4: 2-3: 1; adding concentrated sulfuric acid, stirring and uniformly mixing at the ambient temperature of-4-0 ℃, then carrying out suction filtration and washing for 3-4 times by using deionized water, carrying out suction filtration and washing, and drying in an oven at 60 ℃ for 18-24 hours; placing the dried substance in a tubular heating furnace, heating the substance from room temperature to 900-1000 ℃ within 20-30 s, preserving the heat for 10-30 s, and cooling to room temperature;

B. adding potassium permanganate into the product which is cooled to room temperature in the previous step, and uniformly stirring; then stirring for 30-60 min under the condition of water bath at 35-50 ℃ to obtain reaction liquid;

C. adding the reaction solution in the previous step into deionized water, stirring while chamfering, and then standing for reaction for 10min at the temperature of 55-60 ℃; adding the graphene oxide dispersion solution into hydrogen peroxide or hydrogen peroxide, filtering the solution after the solution turns golden yellow, washing the solution with dilute hydrochloric acid with the volume percentage of 5-10%, and collecting the washed solution to obtain graphene oxide dispersion liquid;

wherein the mass ratio of the graphite to the potassium permanganate is 1: 3-4; the volume ratio of the reaction liquid to the deionized water is 1: 5-6; the volume mass ratio of the hydrogen peroxide or the hydrogen peroxide to the graphite is 7-9 mL:1 g; the volume-mass ratio of concentrated sulfuric acid to graphite is 20-23 mL:1 g;

2) and (3) carbon fiber pretreatment:

soaking carbon fibers in acetone for 24 hours, then repeatedly cleaning the carbon fibers with deionized water, drying the carbon fibers, refluxing the carbon fibers with concentrated nitric acid at 90-95 ℃ for 2-4 hours after drying, cooling the carbon fibers, cleaning the carbon fibers with deionized water until the pH is neutral, and drying the carbon fibers;

3) placing the pretreated carbon fiber into 0.8 mass percent of carboxymethyl cellulose solution, adding tributyl phosphate, and uniformly stirring to obtain a mixed material; mixing asphalt with toluene according to the mass-to-volume ratio of 1g: 8-12 mL, magnetically stirring for 1h, adding the obtained asphalt mixed solution into the mixed material, stirring for 30-40 min, performing suction filtration, drying at room temperature, adding the graphene oxide dispersion liquid, mixing, performing suction filtration, and drying to obtain the graphene oxide-carbon fiber composite material;

wherein the mixing amount of tributyl phosphate in the mixed material is 0.0004 wt%; 5-7 g of the pretreated carbon fiber and graphene oxide dispersion liquid is 1 mL.

The rest is the same as the first embodiment.

The sixth specific implementation mode: the first difference between the present embodiment and the specific embodiment is: the mass ratio of the asphalt to the carbon fiber in the step 3) is 1: 10 to 15. The rest is the same as the first embodiment.

The seventh embodiment: the first difference between the present embodiment and the specific embodiment is: the conductive phase-change connector 5 is made of a conductive shape memory composite material, and the preparation method of the conductive shape memory composite material is completed according to the following steps:

adding sodium di (2-ethylhexyl) succinate sulfonate into deionized water, stirring uniformly, adding pyrrole, and stirring under the condition of ice water bath for reaction for 10-20 min to obtain a solution I;

the volume ratio of the substance of the sodium di (2-ethylhexyl) succinate sulfonate in the step one to the deionized water is (0.01 mol-0.02 mol):100 mL;

dropwise adding a ferric trichloride solution into the solution I, stirring and reacting for 6 hours under the ice-water bath condition, and then adding acetone to obtain a reaction product;

the mass fraction of the ferric trichloride solution in the second step is 15-20%;

the volume ratio of the ferric trichloride solution to the solution I in the step II is 3 (2-3);

the volume ratio of the ferric trichloride solution to the acetone in the second step is 3 (2-3);

washing the reaction product by using distilled water, finally putting the reaction product into a vacuum drying chamber at the temperature of 60 ℃ for 24 hours, and grinding the reaction product into fine powder to obtain AOT-doped polypyrrole;

adding the AOT-doped polypyrrole and epoxy resin into acetone to obtain a suspension, performing ultrasonic treatment on the suspension, and volatilizing the acetone at the temperature of 60-65 ℃ to obtain an epoxy resin/polypyrrole mixture;

the epoxy resin in the fourth step is one or more of bisphenol A type epoxy resin, bisphenol F type epoxy resin or alicyclic epoxy resin;

and fifthly, adding a curing agent, a CMP-410 epoxy resin active toughening agent and graphene into the epoxy resin/polypyrrole mixture, performing ultrasonic treatment, pouring the mixture into a mold, curing and molding, and demolding to obtain the conductive shape memory composite material.

The rest is the same as the first embodiment.

The specific implementation mode is eight: the first difference between the present embodiment and the specific embodiment is: the molar ratio of the sodium bis (2-ethylhexyl) succinate sulfonate to the pyrrole in the first step is 1 (4-7). The rest is the same as the first embodiment.

The specific implementation method nine: the first difference between the present embodiment and the specific embodiment is: the mass ratio of the AOT-doped polypyrrole to the epoxy resin in the step four is (0.1-0.3): 1. The rest is the same as the first embodiment.

The detailed implementation mode is ten: the first difference between the present embodiment and the specific embodiment is: the curing agent in the fifth step is phthalic anhydride or diethylenetriamine, and the mass ratio of the curing agent to the epoxy resin in the epoxy resin/polypyrrole mixture is (8-60): 100. The rest is the same as the first embodiment.

The beneficial effects of the present invention are verified by the following specific examples:

the exemplary embodiments and descriptions of the present invention are provided to explain the present invention and not to limit the present invention.

Example 1

The graphene conductive asphalt layer of the self-snow-melting pavement of the modular multiphase composite material of the embodiment is prepared as follows:

weighing 4 parts of asphalt, 70 parts of aggregate and 12 parts of mineral powder according to parts by weight; stirring and mixing the aggregate and the steel fibers for 90s at 170 ℃, adding the mineral powder and stirring for 90s to obtain a primary mixed material;

secondly, adding the graphene oxide-carbon fiber composite material into the mixed material obtained in the first step, and stirring for 90 seconds at 160 ℃; adopting a Marshall compaction method to compact two surfaces to obtain the graphene conductive asphalt layer;

the preparation method of the graphene oxide-carbon fiber composite material comprises the following steps:

1) preparing a graphene oxide dispersion liquid:

A. mixing graphite, ammonium nitrate and sodium acetate according to the mass ratio of 3:2: 1; adding concentrated sulfuric acid, stirring and mixing uniformly at the ambient temperature of-4 ℃, performing suction filtration and washing for 4 times by using deionized water, performing suction filtration and washing, and drying in an oven at 60 ℃ for 18 hours; placing the dried substance in a tubular heating furnace, heating the substance from room temperature to 1000 ℃ within 25s, preserving the heat for 20s, and cooling the substance to room temperature;

B. adding potassium permanganate into the product which is cooled to room temperature in the previous step, and uniformly stirring; then stirring the mixture for 30min under the condition of water bath at the temperature of 50 ℃ to obtain reaction liquid;

C. adding the reaction solution in the previous step into deionized water, stirring while pouring, and then standing and reacting for 10min at the temperature of 55 ℃; adding the graphene oxide dispersion solution into hydrogen peroxide or hydrogen peroxide, filtering the solution after the solution turns golden yellow, washing the solution with dilute hydrochloric acid with the volume percentage of 5-10%, and collecting the washed solution to obtain graphene oxide dispersion liquid;

wherein the mass ratio of the graphite to the potassium permanganate is 1: 3; the volume ratio of the reaction liquid to the deionized water is 1: 5; the volume mass ratio of the hydrogen peroxide or the hydrogen peroxide to the graphite is 8mL:1 g; the volume mass ratio of concentrated sulfuric acid to graphite is 20mL:1 g;

2) and (3) carbon fiber pretreatment:

soaking carbon fibers in acetone for 24 hours, then repeatedly cleaning the carbon fibers with deionized water, drying the carbon fibers, refluxing the carbon fibers for 3 hours at 95 ℃ with concentrated nitric acid after drying, cooling the carbon fibers, cleaning the carbon fibers with deionized water until the pH is neutral, and drying the carbon fibers;

3) placing the pretreated carbon fiber into 0.8 mass percent of carboxymethyl cellulose solution, adding tributyl phosphate, and uniformly stirring to obtain a mixed material; mixing the asphalt weighed in the step one with toluene according to the mass-to-volume ratio of 1g to 10mL, magnetically stirring for 1h, then adding the obtained asphalt mixed solution into the mixed material, stirring for 30min, performing suction filtration, drying at room temperature, then adding the graphene oxide dispersion liquid, mixing, performing suction filtration, and drying to obtain the graphene oxide-carbon fiber composite material;

wherein the mixing amount of tributyl phosphate in the mixed material is 0.0004 wt%; 6g:1mL of the pretreated dispersion liquid of the carbon fiber and the graphene oxide.

The graphene conductive asphalt layer of the present example was subjected to water stability, high temperature stability, low temperature crack resistance, and resistivity measurements.

By adopting a Superpassive grading design, the graphene conductive asphalt layer grading is as follows:

mesh size/mm	19	16	13.2	9.5	4.75	2.36	1.17	0.6	0.3	0.15
											Composition grade%	100	95.2	73.2	54.2	43	34.1	24.8	12.6	9.7	8.4

。

1. Water stability detection

Referring to the Chinese road engineering asphalt and asphalt mixture test procedure JTG E20-2011), the residual stability MS of a water immersion Marshall test is adopted₀And evaluating the water stability of the mixed material by the ratio of the freeze-thaw splitting strength to the TSR of the freeze-thaw splitting test. Different types of conductive asphalt roadbed mixtures are placed in a constant-temperature water bath box to be soaked for 48 hours, and then a Marshall stability test is carried out to measure the soaking stability, and the results are shown in the following table.

As can be seen from the above table, the conductive material of the combination of graphite, steel fiber and carbon fiber has improved interface bonding performance because the pretreated carbon fiber is subjected to slurry removal and preoxidation treatment to contact with the inert interface thereof, the SBS modified asphalt is used as the adhesive, toluene is used as the solvent to prepare the carbon fiber skeleton, and then graphene oxide is added, so that the prepared graphene oxide-carbon fiber material can form a layer of film, and a large amount of asphalt is dispersed on the surface of the film, thereby effectively blocking the immersion of moisture, and improving the water stability of the graphene conductive asphalt layer.

2. High temperature stability detection

And (3) evaluating the high-temperature stability of the graphene conductive asphalt layer by using the dynamic stability of a 60-degree track test according to road engineering asphalt and asphalt mixture test procedure JTG E20-2011. The high-temperature rutting test is carried out according to the standard formed rutting plate test piece, the test piece size is 300mm multiplied by 50mm, and the result is as follows:

specimen type	Type one	Type two	Type III	Type four
					Dynamic stability times/minutes)	3478	3695	3924	2973
Rut depth mm)	1.5	1.4	1.8	1.21

As can be seen from the above table, the addition of the steel fibers can form a three-dimensional space net structure, the three-dimensional space net structure plays a role in transmission and reinforcement, the three-dimensional space net structure is mutually overlapped and supplemented with the cohesive force of asphalt, the slippage of aggregates is prevented, the deformation resistance is improved, the high-temperature stability of the carbon fibers is poor, the addition of the steel fibers can enable the carbon fibers to be reinforced in the deformation resistance through the grid structure, the surface area of the carbon fibers and the surface area of the steel fibers can be increased, extra interfacial adhesion is generated, the adhesion is improved, and the shearing resistance is improved. In the embodiment, the adding amount of the graphite is 22% of the mass of the asphalt, the adding amount of the steel fiber is 2.5 vol% of the conductive material, and the adding amount of the carbon fiber is 0.5 vol% of the conductive material; a graphene conductive asphalt layer with good performance is obtained;

when the addition amount of the steel fiber is 3.5 vol% and the addition amount of the carbon fiber is 0.8 vol%, the high-temperature stability is obviously reduced.

3. Low temperature crack resistance test

And evaluating the low-temperature performance of the graphene conductive asphalt layer through a low-temperature splitting test, wherein the test temperature is-10 ℃, and the loading speed is 55 mm/min.

The addition of steel fibre and carbon fiber can play the effect that adds the muscle and toughen, the even steel fibre of dispersion and carbon fiber form three-dimensional network structure in the electrically conductive compounding of pitch, the modulus of steel fibre and carbon fiber is higher, the addition of steel fibre and carbon fiber can show intensity and the strength modulus that improves the electrically conductive pitch compounding, play and add the muscle effect, steel fibre and carbon fiber can also play the effect of bridging, do benefit to transmission and the dispersion of stress, improve the load bearing capacity of compounding, and deformability, play toughening. In the embodiment, data of type three is obtained by optimizing the addition amounts of the graphene, the steel fibers and the carbon fibers, so that the low-temperature crack resistance of the graphene conductive asphalt layer is remarkably improved.

4. Resistivity measurement

1) Determination of resistivity of graphene conductive asphalt layer in modular self-snow-melting pavement unit

The resistivity is measured according to a solid insulating material volume resistivity and surface resistivity test method BT 1410-2006, a multimeter is adopted to measure the resistivity, the electric and heat conduction characteristics of the graphene electric conduction asphalt layer in one self-snow-melting pavement module are reflected through the resistivity, and the results are as follows:

specimen type	Resistivity (omega. m)
		Type one	2.74
Type two	2.89
		Type III	2.26
Type four	171

2) After splicing the two modular self-snow-melting pavement units, filling the joints with the conductive shape memory composite material of the invention as in embodiment 2), respectively measuring the resistivity of the graphene conductive asphalt layers of the two modular self-snow-melting pavement units as a whole by adopting a universal meter on the graphene conductive asphalt layers at the two ends of the two modular self-snow-melting pavement units; the resistivity is measured according to a solid insulating material volume resistivity and surface resistivity test method BT 1410-2006, and the result is as follows:

specimen type	Resistivity (omega. m)
		Type one	2.84
Type two	2.92
		Type III	2.36
Type four	189

According to the above, the conductive shape memory composite material provided by the invention can actively meet the width change of the road surface joints and cracks, can be better attached between the asphalt road surfaces of the adjacent modular self-snow-melting road surface units, especially between the graphene conductive asphalt layers, and can well realize the conductive effect between the adjacent modular self-snow-melting road surface units while filling the gaps.

The first type is that the addition amount of the graphene oxide-carbon fiber composite material in the graphene conductive asphalt layer is 5.5% of the mass of the asphalt;

the second type is 15% of graphene oxide-carbon fiber composite material in the graphene conductive asphalt layer, and the adding amount of steel fiber is 2.5% of the mass of asphalt;

the third type is 10% of graphene oxide-carbon fiber composite material in the graphene conductive asphalt layer, and the adding amount of steel fiber is 2.5% of the mass of asphalt;

the type four is a comparative example: the addition amount of the graphene oxide-carbon fiber composite material and the steel fiber in the graphene conductive asphalt layer is 3.5% of the mass of the asphalt.

Example 2

The preparation method of the conductive shape memory composite material of the embodiment is completed according to the following steps:

firstly, adding 0.015mol of sodium bis (2-ethylhexyl) succinate sulfonate (AOT) into 100mL of deionized water, uniformly stirring, adding 0.06mol of pyrrole, and stirring and reacting for 15min under the condition of ice-water bath to obtain a solution I;

the mass fraction of the ferric trichloride solution in the second step is 18 percent;

the volume ratio of the ferric trichloride solution to the solution I in the step II is 1: 1;

the volume ratio of the ferric trichloride solution to the acetone in the step two is 1: 1;

adding the AOT-doped polypyrrole and bisphenol A epoxy resin into acetone to obtain a suspension, performing ultrasonic treatment on the suspension, and volatilizing the acetone at the temperature of 60 ℃ to obtain a bisphenol A epoxy resin/polypyrrole mixture;

the mass ratio of the AOT-doped polypyrrole to the epoxy resin in the step four is 0.3: 1;

the ultrasonic time in the fourth step is 30 min;

fifthly, adding diethylenetriamine, a CMP-410 epoxy resin active toughening agent and graphene into the bisphenol A epoxy resin/polypyrrole mixture, performing ultrasonic treatment, pouring the mixture into a mold for curing and molding, and demolding to obtain the conductive shape memory composite material;

the curing and forming process in the step five comprises the following steps: firstly, curing for 3 hours at the temperature of 65 ℃, then curing for 2.5 hours at the temperature of 95 ℃, then curing for 2 hours at the temperature of 130 ℃, and finally curing for 3 hours at the temperature of 125 ℃;

the mass ratio of the diethylenetriamine to the bisphenol A epoxy resin in the bisphenol A epoxy resin/polypyrrole mixture in the step five is 20: 100;

the mass ratio of the CMP-410 epoxy resin active toughening agent to the bisphenol A epoxy resin in the bisphenol A epoxy resin/polypyrrole mixture in the step five is 20: 100;

the mass ratio of the graphene to the bisphenol A epoxy resin in the bisphenol A epoxy resin/polypyrrole mixture in the step five is 8: 100;

and the ultrasonic time in the step five is 10 min.

The conductive shape memory composite material prepared by the embodiment has the elastic modulus of 2.2Ga, the resistivity of 0.15 omega.m, the glass transition temperature of 63 ℃, has a remarkable shape memory effect, is large in recoverable stress and can maximally recover the strain to 98%, and meanwhile, the conductive shape memory composite material prepared by the embodiment can realize the driving of the electro-thermotropic shape memory effect of the shape memory polymer.

Example 3

Preparing a graphene conductive asphalt layer according to the method of the third embodiment type for a heating test:

the size of a test piece of the graphene conductive asphalt layer is 300mm multiplied by 30mm, copper mesh electrodes are arranged on the left side and the right side of the test piece, the periphery and the bottom of the test piece of the graphene conductive asphalt layer are wrapped by heat preservation asbestos, the test piece of the graphene conductive asphalt layer is placed in an environment box, the environment temperature is set to be-10 ℃, a temperature measurement patch is arranged on the upper surface of the graphene conductive asphalt layer, the voltage of a control electrode is 40V, and the temperature of the upper surface of the graphene conductive asphalt layer reaches 0 ℃ after 52min of test.

And paving a 0.3cm insulating asphalt layer (heat conduction enhanced asphalt mixture) + a 2.5cm surface layer on the surface of the graphene conductive asphalt layer, setting the environmental temperature to be-10 ℃, controlling the electrode voltage to be 40V, and testing the surface temperature of the layer after 95min to reach more than 0 ℃.

It will be understood by those of ordinary skill in the art that the foregoing embodiments are specific examples for carrying out the invention, and that various changes in form and details may be made therein without departing from the spirit and scope of the invention in practice.

To make the objects, aspects and advantages of the embodiments of the present invention more apparent, the following detailed description clearly illustrates the spirit of the disclosure, and any person skilled in the art, after understanding the embodiments of the disclosure, may make changes and modifications to the technology taught by the disclosure without departing from the spirit and scope of the disclosure.

Claims

1. The utility model provides a modularization is from snow melt road surface based on graphite alkene, its characterized in that this modularization heterogeneous material from snow melt road surface is formed by the concatenation of a plurality of modularization self snow melt road surface units, modularization self snow melt road surface unit include base plate (1), lower asphalt layer (3), graphite alkene electrically conductive asphalt layer (4), electrode (5), insulating asphalt layer (7) and surface course (8), the material of base plate (1) is lean concrete, has seted up continuous recess (2) along horizontal or vertical on base plate (1), lower asphalt layer (3) are pour in recess (2) and are bonded through the emulsified asphalt binder, graphite alkene electrically conductive asphalt layer (4) set up asphalt layer (3) surface under and are bonded through the emulsified asphalt binder, a plurality of electrodes (5) have arranged at intervals in graphite alkene electrically conductive asphalt layer (4), electrode (5) set up along the thickness direction of graphite alkene electrically conductive asphalt layer (4), an insulating asphalt layer (7) is bonded on the upper surface of the graphene conductive asphalt layer (4), and a surface layer (8) is laid on the insulating asphalt layer (7);

a joint exists at the joint of the graphene conductive asphalt layers (4) in the two adjacent modularized self-snow-melting pavement units, and a conductive phase-change joint (6) is poured in the joint;

2. The modular self-snow-melting pavement based on graphene according to claim 1, characterized in that the thickness of the graphene conductive asphalt layer (4) is 3-5 cm, and the thickness of the insulating asphalt layer (7) is 0.3-1.0 cm.

3. The graphene-based modular self-snow-melting pavement according to claim 1, characterized in that a plurality of mortises (9) are formed in the side edge of the substrate (1) along the thickness direction of the substrate (1), the adjacent substrates (1) are spliced to form an H-shaped mortise (9), the tenon joint piece (10) is H-shaped, and the tenon joint piece (10) is inserted into the mortise (9).

4. The modular self-snow-melting pavement based on graphene according to claim 1, characterized in that the preparation method of the graphene conductive asphalt layer is as follows:

secondly, adding the graphene oxide-carbon fiber composite material into the primary mixed material obtained in the first step, and stirring for 90 seconds at the temperature of 160-170 ℃; and obtaining the graphene conductive asphalt layer by adopting a Marshall compaction method.

5. The graphene-based modular self-snow-melting pavement according to claim 1 or 4, wherein the preparation method of the graphene oxide-carbon fiber composite material in the second step is as follows:

1) preparing a graphene oxide dispersion liquid:

2) and (3) carbon fiber pretreatment:

6. The modular graphene-based self-snow-melting pavement according to claim 5, wherein the mass ratio of the asphalt to the carbon fiber in the step 3) is 1: 10 to 15.

7. The graphene-based modular self-snow-melting pavement according to claim 1, characterized in that the conductive phase change connector (5) is made of a conductive shape memory composite material, and the preparation method of the conductive shape memory composite material is completed according to the following steps:

8. The graphene-based modular self-snow-melting pavement according to claim 7, wherein the molar ratio of sodium bis (2-ethylhexyl) succinate sulfonate to pyrrole in the first step is 1 (4-7).

9. The modular graphene-based self-snow-melting pavement according to claim 7, wherein the mass ratio of the AOT-doped polypyrrole to the epoxy resin in the fourth step is (0.1-0.3): 1.

10. The graphene-based modular self-snowmelt pavement according to claim 7, characterized in that the curing agent in the fifth step is phthalic anhydride or diethylenetriamine, and the mass ratio of the curing agent to the epoxy resin in the epoxy resin/polypyrrole mixture is (8-60): 100.