A decorative concrete with photosensitive color-changing properties and its preparation method

Abstract

This application relates to the field of decorative concrete, specifically disclosing a photosensitive color-changing decorative concrete and its preparation method, comprising the following raw materials in parts by weight: 40-60 parts cement, 90-135 parts color-changing sand, 40-70 parts crushed stone, 25-45 parts waste fiber, 5-12 parts silica fume, 5-8 parts heat-conducting liquid, and 15-35 parts water. The preparation method includes the following steps: Step 1, treating the waste fiber in a constant-temperature water bath using an agar solution; Step 2, heating and stirring the treated waste fiber with the heat-conducting liquid to react, followed by crushing to obtain heat-conducting fibers; Step 3, uniformly mixing the cement, color-changing sand, crushed stone, silica fume, water-reducing agent, water, and the heat-conducting fibers obtained in Step 2 to obtain the decorative concrete. The resulting concrete can change color under natural light, exhibiting excellent decorative properties and good thermal conductivity with rapid heat dissipation from the concrete surface.

Description

Technical Field

[0001] This application relates to the field of decorative concrete, and more specifically, to a type of decorative concrete with photosensitive color-changing properties and a method for its preparation. Background Technology

[0002] Traditionally, concrete has been used primarily as a structural material in construction, with load-bearing being its main function. However, with the rapid development of modern concrete, decorative concrete, as a decorative material, has gained increasing application and attention in recent years due to its plasticity in appearance and shape design and its beautiful decorative effect.

[0003] For example, Chinese patent CN108033731A discloses a decorative stone-like concrete and its preparation process. The key technical points include the following components by weight: 320-370 parts cement, 150-200 parts water, 850-890 parts medium sand, 150-200 parts crushed stone with a particle size of 5-25mm, 800-820 parts crushed stone with a particle size of 5-10mm, and 5-7 parts water-reducing agent. The cement, medium sand, crushed stone, and water, when mixed, form self-compacting concrete. Furthermore, the 800-820 parts of 5-10mm crushed stone, combined with the concrete, create a stone-like material with excellent decorative effects.

[0004] However, in practical applications, it has been found that although the above-mentioned imitation stone concrete has a certain decorative effect, when used in outdoor environments, the decorative effect is monotonous, and the concrete easily accumulates heat from sunlight, leading to damage to the internal structure of the concrete and the appearance of cracks. Summary of the Invention

[0005] This application provides a decorative concrete with photosensitive color change and a preparation method thereof. The resulting concrete can change colors under natural light, has excellent decorative properties, good thermal conductivity, and fast heat dissipation from the concrete surface, which can effectively reduce the occurrence of cracks.

[0006] In the first aspect, the decorative concrete with photosensitive color change provided in this application adopts the following technical solution: A decorative concrete with photosensitive color change includes the following raw materials in parts by weight: 40-60 parts of cement, 90-135 parts of color-changing sand, 40-70 parts of crushed stone, 25-45 parts of waste fiber, 5-12 parts of silica fume, 5-8 parts of heat-conducting liquid, and 15-35 parts of water.

[0007] The color-changing sand is prepared by the following steps: adding dopamine solution and water-reducing agent to manufactured sand, stirring evenly, heating and adjusting to an alkaline environment, adding color-changing material, and reacting to obtain color-changing sand.

[0008] By employing the above technical solutions, color-changing sand can impart excellent light-sensitive properties to concrete, achieving different color changes under sunlight, thus giving the concrete good decorative properties. The dopamine solution, under heating and alkaline conditions, can rapidly self-polymerize to form polydopamine, improving the effective adhesion between the manufactured sand and the color-changing material. It also enhances the compatibility and bonding force between the manufactured sand and other components such as crushed stone, making the concrete more compact and improving its mechanical properties. Water-reducing agents, generally surfactants, can promote the interfacial bonding force between the color-changing material and the manufactured sand, and also promote the uniform dispersion of the color-changing sand in the concrete system, resulting in a uniform color-changing effect and improving the decorative properties of the concrete. Adding water-reducing agents to the color-changing sand treatment can both assist the color-changing sand in improving the decorative properties of the concrete and enhance its mechanical properties.

[0009] Reusing waste fibers can further save resources and protect the environment. The heat-conducting fluid can further improve the thermal conductivity of the system, and the concrete surface can dissipate heat quickly, reducing the adverse effects caused by heat accumulation, thereby effectively reducing the occurrence of cracks.

[0010] Furthermore, P.O42.5 cement or P.C32.5R cement can be used; the choice should be made according to actual needs.

[0011] Furthermore, the crushed stone has a continuous gradation of 5-16 mm particle size, wherein the mass ratio of particles with a particle size of 5-10 mm to particles with a particle size of 10-16 mm is (0.4-0.5):1, and more preferably 0.43:1.

[0012] Furthermore, the average particle size of the manufactured sand is 0.3-0.5 mm.

[0013] Furthermore, the water-reducing agent has a water reduction rate of ≥25% and a bleeding rate of ≤60%.

[0014] Furthermore, the waste fiber is one of polyester fiber, polyamide fiber, or cotton fiber. The waste fiber can be polyester fiber, polyamide fiber, or cotton fiber.

[0015] Preferably, the components in the color-changing sand are used in the following amounts: by weight, 72-100 parts of manufactured sand, 10-22 parts of dopamine solution, 8-13 parts of color-changing material, and 1-3 parts of water-reducing agent.

[0016] Preferably, a 35-45 wt% dopamine solution is used.

[0017] Preferably, the color-changing material includes at least two of titanium dioxide, silicon dioxide, diphenylpyran, and dithiophene ethylene.

[0018] As a further preferred option, the color-changing material is preferably titanium dioxide and diphenylpyran in a mass ratio of 1:(0.8-1.5), with a mass ratio of 1:1 being optimal.

[0019] By adopting the above technical solution, the dosage relationship of each component in the color-changing sand is optimized, thereby improving the overall quality of the color-changing sand. For the color-changing materials, a combination of organic and inorganic materials is preferred. Titanium dioxide and silicon dioxide are inorganic color-changing materials, while diphenylpyran and dithiophene are organic color-changing materials. Among them, titanium dioxide and silicon dioxide have different refractive indices. After sunlight is refracted accordingly, under the action of organic color-changing materials, different color-changing effects can be exhibited, further improving the decorative performance of concrete.

[0020] Preferably, the heat-conducting fluid is prepared by the following steps: dissolving phenolic resin in ethanol, adding heat-conducting powder and coupling agent, and dispersing them evenly.

[0021] Preferably, the components in the heat-conducting fluid are used in the following amounts by weight: 1-4 parts phenolic resin, 3-8 parts ethanol, 0.5-1.2 parts thermal conductive powder, and 0.2-0.5 parts coupling agent.

[0022] Further preferred, the coupling agent is silane coupling agent KH550 or silane coupling agent KH560.

[0023] By adopting the above technical solution, phenolic resin has good solubility in ethanol, and thermally conductive powder can also play a certain modifying role in phenolic resin. Coupling agent can not only help the thermally conductive powder to disperse evenly and improve the compatibility of each raw material component, but also further improve the bonding force between the thermally conductive liquid and other raw material components, thereby improving the thermal conductivity of concrete.

[0024] Preferably, the thermally conductive powder is selected from at least one of zinc oxide and silicon carbide.

[0025] By adopting the above technical solutions, both zinc oxide and silicon carbide have excellent thermal conductivity, which can not only improve the thermal conductivity of concrete, accelerate heat dissipation from the concrete surface, reduce the adverse effects caused by heat accumulation, and effectively reduce the occurrence of cracks, but also enhance the density of concrete and improve its compressive strength.

[0026] Secondly, this application provides a method for preparing decorative concrete with photosensitive color change, employing the following technical solution:

[0027] A method for preparing decorative concrete with photosensitive color-changing properties includes the following steps:

[0028] Step 1: Place the waste fibers in an agar solution for constant temperature water bath treatment;

[0029] Step 2: The waste fibers processed in Step 1 are heated and stirred with the heat-conducting liquid to react. After the reaction is completed, the fibers are crushed to obtain heat-conducting fibers.

[0030] Step 3: Mix cement, color-changing sand, crushed stone, silica fume, water-reducing agent, water, and the thermally conductive fiber obtained in Step 2 evenly to obtain decorative concrete.

[0031] Preferably, in step 1, the temperature of the constant temperature water bath treatment is 40-55℃, and the time is 30-45 minutes.

[0032] Preferably, in step 2, the heating and stirring reaction conditions are: heating to 80-105℃ and reaction time of 12-20 min.

[0033] By adopting the above technical solution, the waste fibers are first pretreated with an agar solution, and then heated and stirred with a heat-conducting liquid. During this process, ethanol is gradually evaporated by heat, and the phenolic resin contains a certain amount of phenolic hydroxyl groups, which can further form hydrogen bonds with the polar groups of agar molecules, such as carboxyl groups. This is beneficial to endowing the waste fibers with excellent thermal conductivity and adhesion. As a result, the obtained heat-conducting fibers not only have good dispersibility in the system, significantly improving the thermal conductivity of concrete and reducing the occurrence of cracks, but also effectively improving the mechanical properties of concrete.

[0034] Preferably, the thermally conductive fiber has a length of 12-15 mm and a diameter of 0.2-0.35 mm.

[0035] Adding thermally conductive fibers with a suitable aspect ratio can improve the thermal conductivity of concrete, as well as its workability and mechanical properties.

[0036] In summary, this application has the following beneficial effects:

[0037] 1. Dopamine solution, under heating and alkaline conditions, can rapidly self-polymerize to form polydopamine, improving the effective adhesion between manufactured sand and color-changing materials. It also enhances the compatibility and bonding force between manufactured sand and other components such as crushed stone, resulting in a denser concrete interior and improved mechanical properties. Water-reducing agents, generally surfactants, promote interfacial bonding between color-changing materials and manufactured sand, and also promote the uniform dispersion of color-changing sand in the concrete system, resulting in a uniform color-changing effect and improved decorative properties. Adding water-reducing agents to color-changing sand treatment can both assist in improving the decorative properties of concrete and enhance its mechanical properties.

[0038] 2. First, the waste fibers are pretreated with an agar solution, and then reacted with a heat-conducting liquid by heating and stirring. During this process, the ethanol is gradually evaporated by heating, and the phenolic resin contains a certain amount of phenolic hydroxyl groups, which can further form hydrogen bonds with the polar groups of agar molecules, such as carboxyl groups. This is beneficial to giving the waste fibers excellent thermal conductivity and adhesion, so that the obtained heat-conducting fibers not only have good dispersibility in the system, significantly improving the thermal conductivity of concrete and reducing the occurrence of cracks, but also effectively improving the mechanical properties of concrete. Detailed Implementation

[0039] The embodiments of the present invention will be described in detail below with reference to the examples. However, those skilled in the art will understand that the following examples are only for illustrating the present invention and should not be regarded as limiting the scope of the present invention. Specific conditions not specified in the examples shall be carried out according to conventional conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0040] Example of preparing color-changing sand

[0041] Preparation Example 1

[0042] The color-changing sand is prepared by the following steps: 1 kg of 35 wt% dopamine solution and 0.1 kg of polycarboxylate superplasticizer are added to 7.2 kg of manufactured sand, stirred evenly, heated to 45°C and adjusted to pH 8, 0.8 kg of color-changing material is added, and the mixture is stirred and reacted to obtain the color-changing sand.

[0043] The color-changing materials are 0.6 kg of titanium dioxide and 0.2 kg of silicon dioxide; the average particle size of the manufactured sand is 0.3-0.5 mm; the water reduction rate of the polycarboxylate superplasticizer is 30%; and the water bleeding rate is 50%.

[0044] Preparation Example 2

[0045] The color-changing sand is prepared by the following steps: 2.2 kg of 45 wt% dopamine solution and 0.3 kg of polycarboxylate superplasticizer are added to 10 kg of manufactured sand, stirred evenly, heated to 45°C and adjusted to pH 8, 1.3 kg of color-changing material is added, and the mixture is stirred and reacted to obtain the color-changing sand.

[0046] The color-changing materials were 1 kg of diphenylpyran and 0.3 kg of dithiophene ethylene; the rest were the same as in Preparation Example 1.

[0047] Preparation Example 3

[0048] The color-changing sand is prepared by the following steps: 2 kg of 40 wt% dopamine solution and 0.2 kg of polycarboxylate superplasticizer are added to 9.4 kg of manufactured sand, stirred evenly, heated to 45°C and adjusted to pH 8, 1 kg of color-changing material is added, and the mixture is stirred and reacted to obtain the color-changing sand.

[0049] The color-changing materials were 0.5 kg of titanium dioxide and 0.5 kg of diphenylpyran; the rest were the same as in Preparation Example 1.

[0050] Preparation Example 4

[0051] The difference from Preparation Example 3 is that the color-changing material includes 0.3 kg of titanium dioxide, 0.1 kg of silicon dioxide, 0.4 kg of diphenylpyran, and 0.2 kg of dithiophene ethylene, while the rest are the same as in Preparation Example 3.

[0052] Example of heat transfer fluid preparation

[0053] Preparation Example 1

[0054] The heat-conducting fluid is prepared by the following steps: 1 kg of phenolic resin is dissolved in 3 kg of ethanol, 1.2 kg of zinc oxide and 0.2 kg of silane coupling agent are added and dispersed evenly.

[0055] Preparation Example 2

[0056] The heat transfer fluid is prepared by the following steps: 4 kg of phenolic resin is dissolved in 8 kg of ethanol, 0.2 kg of silicon carbide, 1 kg of zinc oxide and 0.5 kg of silane coupling agent are added and dispersed evenly.

[0057] Preparation Example 3

[0058] The heat-conducting fluid is prepared by the following steps: 2.6 kg of phenolic resin is dissolved in 6 kg of ethanol, 0.8 kg of silicon carbide and 0.4 kg of silane coupling agent are added and dispersed evenly.

[0059] Example

[0060] Example 1

[0061] A type of decorative concrete with photosensitive color-changing properties comprises the following raw materials: 4 kg of P.O42.5 cement, 9 kg of color-changing sand prepared in Preparation Example 1, 4 kg of crushed stone, 2.5 kg of waste fiber, 1.2 kg of silica fume, 0.5 kg of heat-conducting fluid, and 1.5 kg of water; the crushed stone has a continuous gradation of 5-16 mm particle size, wherein the mass ratio of particles with a particle size of 5-10 mm to particles with a particle size of 10-16 mm is 0.5:1. A method for preparing the photosensitive color-changing decorative concrete includes the following steps:

[0062] Step 1: Place the waste fibers in an agar solution for constant temperature water bath treatment at a temperature of 40°C for 45 minutes.

[0063] Step 2: The waste fibers treated in Step 1 are heated and stirred with the heat-conducting liquid to react. The conditions for heating and stirring reaction are: heating to 80°C and reaction time of 20 minutes. After the reaction is completed, the fibers are crushed to obtain heat-conducting fibers. The length of the heat-conducting fibers is 12-15 mm and the diameter is 0.2-0.35 mm.

[0064] Step 3: Mix cement, color-changing sand, crushed stone, silica fume, water-reducing agent, water, and the thermally conductive fiber obtained in Step 2 evenly to obtain decorative concrete.

[0065] Example 2

[0066] A type of decorative concrete with photosensitive color-changing properties comprises the following raw materials: 6 kg of P.O42.5 cement, 13.5 kg of color-changing sand prepared in Preparation Example 2, 7 kg of crushed stone, 4.5 kg of waste fiber, 0.5 kg of silica fume, 0.8 kg of heat-conducting fluid prepared in Preparation Example 2, and 3.5 kg of water; the crushed stone has a continuous gradation of 5-16 mm particle size, wherein the mass ratio of particles with a particle size of 5-10 mm to particles with a particle size of 10-16 mm is 0.4:1.

[0067] A method for preparing decorative concrete with photosensitive color-changing properties includes the following steps:

[0068] Step 1: Place the waste fibers in an agar solution for constant temperature water bath treatment at a temperature of 55°C for 45 minutes.

[0069] Step 2: The waste fibers processed in Step 1 are heated and stirred with the heat-conducting liquid. The conditions for heating and stirring are: heating to 105℃ and reaction time of 12min. After the reaction is completed, the fibers are crushed to obtain heat-conducting fibers. The length of the heat-conducting fibers is 12-15mm and the diameter is 0.2-0.35mm.

[0070] Step 3: Mix cement, color-changing sand, crushed stone, silica fume, water-reducing agent, water, and the thermally conductive fiber obtained in Step 2 evenly to obtain decorative concrete.

[0071] Example 3

[0072] A decorative concrete with photosensitive color-changing properties comprises the following raw materials: 5.2 kg of cement, 10 kg of color-changing sand prepared in Preparation Example 3, 5.7 kg of crushed stone, 4 kg of waste fiber, 0.8 kg of silica fume, 0.7 kg of heat-conducting liquid prepared in Preparation Example 2, and 2 kg of water; the crushed stone has a continuous gradation of 5-16 mm particle size, wherein the mass ratio of particles with a particle size of 5-10 mm to particles with a particle size of 10-16 mm is 0.43:1;

[0073] The preparation method of the decorative concrete with photosensitive color change is the same as that in Example 1.

[0074] Example 4

[0075] The difference from Example 3 is that the color-changing sand prepared in Preparation Example 4 was used, while the rest were the same as in Example 3.

[0076] Example 5

[0077] The difference from Example 3 is that the preparation method of decorative concrete with photosensitive color change includes the following steps:

[0078] Step 1: Place the waste fibers in an agar solution for constant temperature water bath treatment at a temperature of 50°C for 40 minutes.

[0079] Step 2: The waste fibers treated in Step 1 are heated and stirred with the heat-conducting liquid. The conditions for heating and stirring are: heating to 95°C and reaction time of 15 minutes. After the reaction is completed, the fibers are crushed to obtain heat-conducting fibers. The length of the heat-conducting fibers is 12-14 mm and the diameter is 0.2-0.3 mm.

[0080] Step 3: Mix cement, discolored sand, crushed stone, silica fume, water-reducing agent, water and the thermally conductive fiber obtained in step 2 evenly to obtain decorative concrete.

[0081] The component dosages are the same as in Example 3.

[0082] Example 6

[0083] The difference from Example 5 is that the heat-conducting liquid prepared in Preparation Example 3 was used, while the rest were the same as in Example 5.

[0084] Comparative Example

[0085] Comparative Example 1

[0086] The difference from Example 6 is that the color-changing sand is prepared by the following steps: 9.4 kg of manufactured sand, 0.2 kg of polycarboxylate superplasticizer, 0.5 kg of titanium dioxide and 0.5 kg of diphenylpyran are mixed and stirred evenly;

[0087] Everything else is the same as in Example 6.

[0088] Comparative Example 2

[0089] The difference from Example 6 is that the color-changing sand is a mixture of manufactured sand and polycarboxylate superplasticizer, while the rest is the same as in Example 6.

[0090] Comparative Example 3

[0091] The difference from Example 6 is that the thermal conductive liquid is replaced with an equal amount of thermal conductive silicone grease, while the rest is the same as Example 6.

[0092] Comparative Example 4

[0093] The difference from Example 6 is that the preparation method of decorative concrete with photosensitive color change includes the following steps:

[0094] Step 1: The waste fibers are heated and stirred with the heat-conducting liquid prepared in Example 3. The conditions for heating and stirring are: heating to 95°C and reaction time of 15 min. After the reaction is completed, the fibers are crushed to obtain heat-conducting fibers. The length of the heat-conducting fibers is 12-14 mm and the diameter is 0.2-0.3 mm.

[0095] Step 3: Mix cement, discolored sand, crushed stone, silica fume, water-reducing agent, water and the thermally conductive fiber obtained in step 2 evenly to obtain decorative concrete.

[0096] The amounts of each component were the same as in Example 6.

[0097] Comparative Example 5

[0098] The difference from Example 6 is that the preparation method of decorative concrete with photosensitive color change includes the following steps:

[0099] Step 1: Place the waste fibers in an agar solution for constant temperature water bath treatment at a temperature of 50°C for 40 minutes.

[0100] Step 2: Mix cement, discolored sand, crushed stone, silica fume, water-reducing agent, water, and the waste fiber and heat-conducting liquid treated in Step 1 evenly to obtain decorative concrete.

[0101] The amounts of each component were the same as in Example 6.

[0102] Performance testing

[0103] The 28-day compressive strength of the specimens prepared in Examples 1-6 and Comparative Examples 1-5 was determined according to GB / T 50081-2019 "Standard for Test Methods of Physical and Mechanical Properties of Concrete", and their thermal conductivity was determined according to GB / T10295-2008 "Determination of Steady-State Thermal Resistance and Related Properties of Thermal Insulation Materials - Heat Flow Meter Method".

[0104] The samples prepared in Examples 1-6 and Comparative Examples 1-5 were placed outdoors to be exposed to sunlight. The color change of the samples was observed and recorded, and the results are recorded in Table 1.

[0105] Using a solar simulator, sunlight was simulated to irradiate the samples prepared in Examples 1-6 and Comparative Examples 1-5 for 90 days. The number of cracks appearing on the concrete surface and the maximum crack width were recorded. The results are recorded in Table 1.

[0106] Table 1

[0107] As can be seen from Examples 1-6 and Table 1, the obtained concrete can change colors under natural light, exhibiting excellent decorative properties. The concrete not only has good thermal conductivity and rapid heat dissipation from its surface, effectively reducing cracking, but also possesses high compressive strength and excellent mechanical properties. Regarding the color-changing materials, titanium dioxide and diphenylpyran in a 1:1 mass ratio produce the best color-changing effect for the decorative concrete.

[0108] Combining Example 6 and Comparative Examples 1-2 with Table 1, it can be seen that in Comparative Example 1, the raw material components were simply mixed, while in Comparative Example 2, only manufactured sand and water-reducing agent were mixed and directly prepared. The concrete obtained in Comparative Example 2 not only failed to achieve color change, but also showed a significant decrease in mechanical properties. This is because the dopamine solution in the color-changing sand can rapidly self-polymerize to form polydopamine under heating and alkaline conditions, improving the effective adhesion between the manufactured sand and the color-changing material. Simultaneously, it can enhance the compatibility and bonding force between the manufactured sand and other components such as crushed stone, making the concrete more compact and improving its mechanical properties. Water-reducing agents are generally surfactants, which can promote the interfacial bonding force between the color-changing material and the manufactured sand, and also promote the uniform dispersion of the color-changing sand in the concrete system, resulting in a uniform color-changing effect and improving the decorative properties of the concrete. Adding water-reducing agents to the treatment of color-changing sand can both assist the color-changing sand in improving the decorative properties of the concrete and enhance its mechanical properties.

[0109] Combining Example 6 and Comparative Examples 3-5 with Table 1, it can be seen that in Comparative Example 3, the heat-conducting liquid was replaced with heat-conducting silicone grease; in Comparative Example 4, the pretreatment of waste fibers was omitted; and in Comparative Example 5, neither the waste fibers nor the heat-conducting liquid were treated, but were directly mixed with other raw materials later. The overall performance of the concrete obtained in Comparative Examples 3-5 was poor. This is because phenolic resin has good solubility in ethanol, and the heat-conducting powder can also play a certain modifying role on phenolic resin. The coupling agent can not only assist in the uniform dispersion of the heat-conducting powder and improve the compatibility of each raw material component, but also... To improve the bonding force between the heat-conducting fluid and other raw material components, the waste fibers are first pretreated with an agar solution, and then reacted with the heat-conducting fluid under heating and stirring. During this process, ethanol is gradually evaporated upon heating, and the phenolic resin contains a certain amount of phenolic hydroxyl groups, which can further form hydrogen bonds with the polar groups of agar molecules, such as carboxyl groups. This is beneficial for imparting excellent thermal conductivity and adhesion to the waste fibers, resulting in heat-conducting fibers that not only have good dispersibility in the system, significantly improving the thermal conductivity of concrete and reducing cracking, but also effectively improving the mechanical properties of concrete. Therefore, it is evident that only by using the specific raw material components and preparation method described in this application can decorative concrete with excellent decorative effect and superior mechanical properties be obtained.

[0110] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A decorative concrete having a photochromic color change, characterized in that The raw materials include cement 40-60 parts, color-changing sand 90-135 parts, gravel 40-70 parts, waste fiber 25-45 parts, silica fume 5-12 parts, heat-conducting liquid 5-8 parts, water reducing agent 1-3 parts, and water 15-35 parts by weight; The color-changing sand is prepared by adding dopamine solution and water reducing agent to machine-made sand, stirring uniformly, heating and adjusting to an alkaline environment, and adding color-changing material, and obtaining the color-changing sand after reaction; The component dosage in the color-changing sand is as follows: machine-made sand 72-100 parts, dopamine solution 10-22 parts, color-changing material 8-13 parts, and water reducing agent 1-3 parts by weight; the color-changing material includes at least two of titanium dioxide, silicon dioxide, diphenyl pyran, and dithiophene ethylene; the heat-conducting liquid is prepared by dissolving phenolic resin in ethanol, adding heat-conducting powder and coupling agent and dispersing uniformly; the heat-conducting powder is selected from at least one of zinc oxide and silicon carbide; The preparation method of the decorative concrete with light-sensitive color change includes the following steps: Step 1: placing waste fiber in agar solution for constant temperature water bath treatment; Step 2: heating and stirring the waste fiber treated in step 1 and heat-conducting liquid for reaction, and crushing the heat-conducting fiber after reaction to obtain the heat-conducting fiber; Step 3: mixing cement, color-changing sand, gravel, silica fume, water reducing agent, water, and the heat-conducting fiber prepared in step 2 uniformly to obtain the decorative concrete.

2. Decorative concrete with photochromic coloration according to claim 1, characterized by the fact that: The component dosage in the heat-conducting liquid is as follows: phenolic resin 1-4 parts, ethanol 3-8 parts, heat-conducting powder 0.5-1.2 parts, and coupling agent 0.2-0.5 parts by weight.

3. The photochromic decorative concrete according to claim 1, characterized in that: In step 1, the temperature of the constant temperature water bath treatment is 40-55℃, and the time is 30-45 min.

4. The photochromic decorative concrete according to claim 1, characterized in that: In step 2, the heating and stirring reaction conditions are as follows: heating to 80-105℃, and reaction time is 12-20 min.

5. Decorative concrete with photochromic effect according to claim 4, characterized by the fact that: In step 2, the length of the heat-conducting fiber is 12-15 mm, and the diameter is 0.2-0.35 mm.

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