A kind of all-solid waste concrete and its preparation method and application

Abstract

The present invention relates to the technical field of solid waste utilization, and specifically discloses a full-solid waste concrete and a preparation method and application thereof. The full-solid waste concrete provided by the present invention is prepared by mixing coal gangue of different particle sizes into coal gangue aggregate, using a mixture of modified coal gangue micropowder and steel slag powder after microwave activation as modified coarse aggregate, and further adding waste rubber powder, modified rubber, hydroxypropyl methylcellulose and basalt fiber, so that each component plays a role of composite reinforcement, thereby improving the mechanical strength, high temperature stability, low temperature stability and fatigue resistance of the full-solid waste concrete; the present invention runs through the microwave activation operation in the preparation method, further improving the overall performance of the full-solid waste concrete composite material, thereby achieving a significant effect of 1+1>2.

Description

Technical Field

[0001] The present invention relates to the technical field of solid waste utilization, and in particular to a full-solid waste concrete and a preparation method and application thereof. Background Art

[0002] 3D printing technology, as an emerging manufacturing technology, has shown great application potential in the field of construction with its high precision, high efficiency, high flexibility and customizability. Through 3D printing technology, the shape, size and structure of building materials can be precisely controlled to achieve the rapid construction of complex structures. Especially when preparing building materials such as recycled rubber concrete boards, 3D printing technology can ensure the uniformity and stability of materials and improve the quality and performance of products. At present, there have been research reports on 3D printing concrete. Some researchers have improved the mechanical properties of 3D printing concrete by introducing carbon fiber into concrete. However, in order to make the concrete of this formula have better fluidity and thixotropy, it is necessary to add expansion agent, defoaming agent and air entraining agent into the formula. The production process is relatively cumbersome and not suitable for practical engineering applications; some researchers have also added nanographene to 3D printing concrete to solve the problem that the existing 3D printing concrete has poor fluidity and is prone to material breaking during the printing process. However, due to the high cost of nanographene, it is not conducive to large-scale application in engineering. Therefore, it is of great significance to provide a low-cost all-solid waste concrete with excellent thermal stability, resistance to low-temperature cracking and fatigue resistance and high strength. Summary of the invention

[0003] In view of this, the present invention provides a full-solid waste concrete and a preparation method and application thereof.

[0004] In order to solve the above technical problems, the technical solution provided by the present invention is:

[0005] The first aspect of the present invention provides a method for preparing all-solid waste concrete, comprising the following steps:

[0006] Step 1, mixing coal gangue with a particle size of 0.038 mm to 4.5 mm and coal gangue with a particle size of 5 mm to 15 mm to obtain coal gangue aggregate;

[0007] Step 2, grinding the coal gangue, and then performing microwave activation at a power of 600W to 700W to obtain modified coal gangue micropowder;

[0008] Step 3, uniformly mixing the modified coal gangue powder and steel slag powder to obtain a mixture, and subjecting the mixture to microwave activation at a power of 950 W to 1050 W to obtain a modified coarse aggregate;

[0009] Step 4, uniformly mixing the coal gangue aggregate, modified coarse aggregate and waste rubber powder to obtain a first mixed ore;

[0010] Step 5, heating the modified rubber at 150° C. to 170° C., and then adding the modified rubber to the first mixed mineral material to obtain a second mixed mineral material;

[0011] Step 6: uniformly mix the second mixed mineral material, hydroxypropyl methylcellulose and basalt fiber, and perform microwave activation at a power of 1150 W to 1250 W to obtain all-solid waste concrete;

[0012] Wherein, in step 5, the modified rubber is obtained by sequentially irradiating waste rubber powder with ultraviolet light and modifying it with alkali, and then coating it with epoxy resin and polyamide resin.

[0013] Compared with the prior art, in the all-solid waste concrete provided by the present invention, the coarse-grained coal gangue in step 1 serves as a skeleton structure, so that the concrete can withstand a larger load, and the fine-grained coal gangue can fill the gaps between the particles in the concrete. The present invention can significantly improve the compressive strength of the concrete by selecting coal gangue of different particle sizes as coal gangue aggregate, and the dense concrete structure also helps to resist the stress caused by temperature changes, further improving the high temperature stability, low temperature stability and fatigue resistance of the concrete.

[0014] In step 2, the gangue is mechanically ground to increase the specific surface area of ​​the gangue, and the crystal structure of the gangue is changed through microwave activation, so that the chemical bonds inside the gangue are changed and more active sites are generated, which is conducive to better combination of the modified gangue powder with other components in the concrete, thereby improving the compressive strength and fatigue resistance of the concrete. In addition, the modified gangue powder can fill the tiny pores in the concrete, reduce the heat conduction inside the concrete, and improve the high temperature stability and low temperature stability of the concrete.

[0015] In step 3, the mixture of coal gangue powder and steel slag powder is modified by microwave activation. The selective heating effect of microwave can accelerate the active The ion migration and interfacial reaction with free CaO and MgO in the steel slag powder promote the formation of CSH gel and ettringite (AFt) during the hydration process; at the same time, the local high temperature induced by microwaves causes the glassy silicate network in the steel slag powder to depolymerize, releasing more active and , further strengthening the cross-linking density and microstructure compactness of the hydration products, thereby significantly improving the compressive strength of the concrete. At the same time, microwave activation causes the atoms or molecules on the surface of the modified coal gangue powder and steel slag powder particles to break and rearrange, changing their surface energy, and enhancing the bonding between the two and other components in the concrete, thereby improving the compressive capacity of the concrete; in addition, improving the bonding between the various components in the concrete is conducive to improving the compactness of the concrete, reducing the volume change of the prepared concrete under temperature changes, and improving high temperature stability and low temperature stability.

[0016] In step 5, ultraviolet irradiation can cause the molecular chains on the surface of the waste rubber powder to break and reorganize, generate more active functional groups, and the alkali modification further improves the activity of the functional groups in the modified rubber. The rubber powder after ultraviolet irradiation and alkali modification can avoid the agglomeration phenomenon in the concrete, and can also greatly improve the binding force between the modified rubber and other substances in the concrete, so that it can be evenly dispersed in the concrete, and enhance the compressive strength of the concrete; the ultraviolet irradiation and alkali modification process further improves the adsorption capacity of the modified rubber for epoxy resin and polyamide resin, and the epoxy resin and polyamide resin adhere to the surface of the modified rubber, further improving the tensile strength of the waste rubber powder, and can also make the modified rubber firmly bonded to the coal gangue aggregate and the modified coarse aggregate, improve the integrity of the concrete, and then improve its mechanical strength. Moreover, the epoxy resin and polyamide resin are coated on the surface of the rubber powder, which can prevent the modified rubber from aging, deformation and other problems in a high temperature environment, and prevent the modified rubber from becoming brittle in a low temperature environment, thereby improving the high temperature stability and low temperature stability of the concrete; in addition, the epoxy resin and polyamide resin can also fix the relative position of the modified rubber in the concrete, so that it can fully play the role of buffering and dispersing stress, thereby improving the fatigue resistance of the concrete; heating the modified rubber at a specific temperature can make the modified rubber and other components better integrated, thereby further improving the mechanical strength of the concrete.

[0017] In step 6, hydroxypropyl methylcellulose can form a network structure in the concrete system to limit excessive shrinkage of the concrete under low temperature conditions, and the gangue aggregate and modified coarse aggregate in the concrete can be adsorbed on the hydroxypropyl methylcellulose, so that the gangue aggregate and the modified coarse aggregate are not easily displaced under high temperature conditions, thereby improving the compactness, high temperature stability and low temperature stability of the concrete; the basalt fiber can further enhance the mechanical strength of the concrete, and under the action of external force, it can also share part of the stress and improve the fatigue resistance of the concrete; the two fibers play a synergistic role and can greatly improve the mechanical strength, high temperature and low temperature stability and fatigue resistance of the concrete; the present invention adds hydroxypropyl methylcellulose and basalt fiber to the second mixed mineral material, and further microwaves to activate it, so that the reaction between the components in the concrete is more sufficient, and the comprehensive performance of the concrete is improved to the greatest extent, so that the concrete has excellent mechanical strength, high temperature stability, low temperature stability and fatigue resistance.

[0018] In the preparation method of all-solid waste concrete provided by the present invention, coal gangue of different particle sizes is mixed to prepare coal gangue aggregate, a mixture of modified coal gangue powder and steel slag powder activated by microwave is used as modified coarse aggregate, and waste rubber powder, modified rubber, hydroxypropyl methylcellulose and basalt fiber are further added, and the various components play a role in composite reinforcement, thereby improving the mechanical strength, high temperature stability, low temperature stability and fatigue resistance of the all-solid waste concrete; the operation of microwave activation is carried out throughout the preparation method, thereby further improving the overall performance of the all-solid waste concrete composite material, thereby achieving a significant effect of 1+1>2.

[0019] Preferably, in step 1, taking the total mass of the gangue aggregate as 100%, the mass percentage of the gangue with a particle size of 0.038 mm to 4.5 mm in the gangue aggregate is 58% to 62%, and the mass percentage of the gangue with a particle size of 5 mm to 15 mm in the gangue aggregate is 38% to 42%.

[0020] The present invention further limits the ratio of coarse-grained gangue to fine-grained gangue in the gangue aggregate, which can make the prepared all-solid waste concrete more compact and improve the compressive strength of the all-solid waste concrete.

[0021] Preferably, in step 1, the apparent density of the gangue aggregate is 1800 kg / m 3 ~2200kg / m 3 The water absorption rate is 5%~10%, and the moisture content is 2%~6%.

[0022] Preferably, in step 2, the grinding conditions are: grinding the coal gangue at a rate of 380 r / min~420 r / min for 60 min~90 min, and passing through a sieve with 200~600 meshes.

[0023] Preferably, in step 2, the conditions for microwave activation are: frequency of 2 GHz to 3 GHz, temperature of 140° C. to 180° C., and time of 3 min to 10 min.

[0024] The preferred microwave activation conditions are conducive to improving the activity of coal gangue, making it more fully combined with other components in concrete, and improving the mechanical strength, high temperature stability, low temperature stability and fatigue resistance of concrete.

[0025] Preferably, in step 2, the particle size of the modified coal gangue powder is 0.025 mm to 0.075 mm.

[0026] Preferably, in step 3, the particle size of the steel slag powder is 10 mm to 30 mm.

[0027] By limiting the particle sizes of modified coal gangue powder and steel slag powder, it is beneficial to make the modified coal gangue powder adhere to the steel slag powder to the greatest extent, further stimulate the active components of the steel slag powder, and improve the strength of the steel slag powder.

[0028] Preferably, in step 3, the conditions for microwave activation are: frequency of 2.4 GHz to 2.5 GHz, temperature of 150° C. to 200° C., and time of 5 min to 10 min.

[0029] The present invention further limits the conditions for microwave activation, which is beneficial to fully react the modified coal gangue powder and the steel slag powder, thereby improving the mechanical strength, high temperature stability and low temperature stability of the concrete.

[0030] Preferably, in step 3, the mass ratio of the modified coal gangue powder to the steel slag powder is (4-6): (98-102).

[0031] The optimal ratio is beneficial to further improve the comprehensive performance of concrete.

[0032] Preferably, in step 4, the tensile strength of the waste rubber powder is 3MPa~5MPa.

[0033] Preferably, in step 4, the particle size of the waste rubber powder is 0.11 mm to 0.13 mm.

[0034] By limiting the tensile strength and particle size of waste rubber powder, the waste rubber powder can share a certain amount of stress under the action of external force, thereby improving the fatigue resistance of concrete.

[0035] Preferably, in step 5, the heating time is 10 min to 15 min.

[0036] Preferably, in step 5, the specific operation of adding to the first mixed mineral material is: spraying the modified glue uniformly on the first mixed mineral material by spraying, and stirring at a suitable rate for 2 minutes to 3 minutes.

[0037] Preferably, in step 6, the hydroxypropyl methylcellulose has a length of 5 mm to 8 mm, a diameter of 0.1 mm to 0.3 mm, and a tensile strength of 2950 MPa to 2960 MPa.

[0038] Preferably, in step 6, the basalt fiber has a length of 9 μm to 18 μm, a diameter of 13 μm to 20 μm, and a tensile strength of 2000 MPa to 3000 MPa.

[0039] The present invention further defines the specific parameters of hydroxypropyl methylcellulose and basalt fiber, which can maximize the effects of the two fibers and greatly improve the mechanical strength, high temperature and low temperature stability and fatigue resistance of concrete.

[0040] Preferably, in step 6, the microwave activation time is 5 min to 7 min.

[0041] Preferably, in step 6, the temperature of the microwave activation is 155°C to 165°C.

[0042] The optimal microwave conditions are conducive to making the reaction between the various components in the concrete more complete and improving the comprehensive performance of the concrete.

[0043] Preferably, based on the total mass of all-solid waste concrete as 100%, the mass percentage of the coal gangue aggregate in the all-solid waste concrete is 50%~60%, the mass percentage of the modified coarse aggregate in the all-solid waste concrete is 25%~35%, the mass percentage of the waste rubber powder in the all-solid waste concrete is 5%~10%, the mass percentage of the modified rubber in the all-solid waste concrete is 3%~5%, the mass percentage of the hydroxypropyl methylcellulose in the all-solid waste concrete is 0.5%~1.5%, and the mass percentage of the basalt fiber in the all-solid waste concrete is 0.5%~1.5%.

[0044] The present invention limits the mass content of each component in the all-solid waste concrete, which is conducive to further exerting the effects between the components and greatly improving the comprehensive performance of the all-solid waste concrete.

[0045] Preferably, in step 5, the method for preparing the modified rubber comprises the following steps:

[0046] S1. irradiating the waste rubber powder with ultraviolet light to obtain irradiated waste rubber powder;

[0047] S2, adding the irradiated waste rubber powder to an alkaline solution, soaking at 50° C. to 60° C., solid-liquid separation, washing, and drying to obtain treated irradiated waste rubber powder;

[0048] S3, mixing the epoxy resin and the polyamide resin evenly, and heating at 80°C to 90°C to obtain a mixed resin;

[0049] S4, adding the treated irradiated waste rubber powder into the mixed resin, heating at 60° C. to 70° C. to obtain modified rubber.

[0050] The preparation method of the modified glue provided by the present invention is simple to operate. The modified glue prepared by the modification method of the present invention has excellent tensile strength and aging resistance. Applying it to concrete can significantly improve the mechanical strength, fatigue resistance, high temperature stability and low temperature stability of the concrete.

[0051] Preferably, in S1, the particle size of the waste rubber powder is 0.11 mm to 0.13 mm.

[0052] Preferably, in S1, the tensile strength of the waste rubber powder is 3 MPa~5 MPa.

[0053] Preferably, in S1, the ultraviolet wavelength of the ultraviolet irradiation is 250nm~280nm.

[0054] Preferably, in S1, the irradiation intensity of the ultraviolet radiation is 15 mW / cm 2 ~25mW / cm 2 .

[0055] Preferably, in S1, the ultraviolet irradiation time is 5 min to 8 min.

[0056] Preferably, in S2, the alkaline solution is an aqueous solution containing sodium hydroxide and sodium silicate, wherein the mass content of the sodium hydroxide in the alkaline solution is 3% to 5%, and the mass content of the sodium silicate in the alkaline solution is 1% to 2%.

[0057] Preferably, in S2, the soaking time is 20 min to 40 min.

[0058] Preferably, in S2, the mass ratio of the irradiated waste rubber powder to the alkaline solution is 1:(1.5-3).

[0059] Preferably, in S3, the mass ratio of the epoxy resin to the polyamide resin is 3:(1.5~2.5).

[0060] Preferably, in S3, the model of the epoxy resin is E-51.

[0061] Preferably, in S3, the model of the polyamide resin is PA66.

[0062] Preferably, in S3, the heating condition is: stirring is required during heating until the two substances are evenly mixed.

[0063] Preferably, in S4, the mass ratio of the treated irradiated waste rubber powder and the mixed resin is (4-4.2):1.

[0064] Preferably, in S4, the heating time is 8h~10h.

[0065] A second aspect of the present invention provides an all-solid waste concrete prepared by the above-mentioned method for preparing all-solid waste concrete.

[0066] The third aspect of the present invention provides the application of the above-mentioned all-solid waste concrete in 3D printing concrete.

[0067] The present invention obtains an all-solid waste concrete material with high mechanical strength, high temperature resistance and low temperature stability, and excellent fatigue resistance by precisely controlling the proportion of each component in the all-solid waste concrete and optimizing the preparation process. The use of 3D printing technology to print all-solid waste concrete can quickly and accurately print out prefabricated concrete components according to a preset model, greatly shortening the construction period. Compared with the traditional asphalt concrete construction method, there is no need to wait for the long-term transportation and paving and rolling of concrete, and continuous printing can be achieved, which improves construction efficiency and is particularly suitable for emergency repairs and rapid construction projects. 3D printing can easily realize the manufacture of components of various complex shapes and structures, breaking through the limitations of traditional construction methods in shape and structure, providing greater freedom for engineering design, and being able to meet personalized and innovative engineering needs.

[0068] Preferably, when 3D printing concrete, the diameter of the nozzle is 3 cm to 5 cm.

[0069] Preferably, when the 3D printing concrete is performed, the extrusion speed is 0.32 m / s. 3 / h~0.4m 3 / h.

[0070] Preferably, when 3D printing concrete, the extrusion pressure is 5MPa~5.5MPa.

[0071] Preferably, when 3D printing concrete, the horizontal printing speed is 250m / h~290m / h. DETAILED DESCRIPTION

[0072] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0073] In order to better illustrate the present invention, further examples are given below.

[0074] Example 1

[0075] This embodiment provides a method for preparing all-solid waste concrete, comprising the following steps:

[0076] Step 1: Mix coal gangue with a particle size of 0.038 mm and coal gangue with a particle size of 5 mm to obtain coal gangue aggregate; wherein, based on the total mass of the coal gangue aggregate as 100%, the mass content of the coal gangue with a particle size of 0.038 mm is 58%, and the mass content of the coal gangue with a particle size of 5 mm is 42%; the apparent density of the coal gangue aggregate is 2000 kg / m 3 , water absorption is 10%, moisture content is 2%;

[0077] Step 2, grinding the gangue at 380 r / min for 90 min, passing through a 600-mesh sieve, and then microwave activating at 700 W power, 2 GHz frequency and 180° C. for 10 min to obtain modified gangue micropowder with a particle size of 0.025 mm;

[0078] Step 3, uniformly mixing the modified coal gangue powder and the steel slag powder with a particle size of 10 mm to obtain a mixture, and subjecting the mixture to microwave activation for 5 minutes at a power of 950 W, a frequency of 2.5 GHz and a temperature of 150° C. to obtain a modified coarse aggregate; wherein the mass ratio of the modified coal gangue powder to the steel slag powder is 4:98;

[0079] Step 4, mixing the gangue aggregate, modified coarse aggregate and waste rubber powder evenly to obtain a first mixed mineral material; wherein the waste rubber powder has a tensile strength of 3 MPa and a particle size of 0.11 mm;

[0080] Step 5, heating the modified rubber at 170° C. for 15 min, and then spraying it onto the first mixed mineral material, stirring it evenly, to obtain a second mixed mineral material;

[0081] Step 6: Evenly mix the second mixed mineral material, hydroxypropyl methylcellulose and basalt fiber, and activate them by microwave at 1150 W power and 155 ° C for 7 minutes to obtain all-solid waste concrete; wherein the hydroxypropyl methylcellulose has a length of 5 mm, a diameter of 0.3 mm, and a tensile strength of 2960 MPa; the basalt fiber has a length of 18 μm, a diameter of 20 μm, and a tensile strength of 2000 MPa;

[0082] Taking the total mass of all-solid waste concrete as 100%, the mass percentage of the coal gangue aggregate is 58%, the mass percentage of the modified coarse aggregate is 30%, the mass percentage of the waste rubber powder is 5%, the mass percentage of the modified rubber is 5%, the mass percentage of the hydroxypropyl methylcellulose is 0.5%, and the mass percentage of the basalt fiber is 1.5%;

[0083] In step 5, the preparation method of the modified rubber comprises the following steps:

[0084] S1, waste rubber powder with a particle size of 0.11mm and a tensile strength of 3MPa was irradiated with an ultraviolet wavelength of 250nm and an irradiation intensity of 15mW / cm 2 The ultraviolet rays are irradiated for 5 minutes to obtain irradiated waste rubber powder;

[0085] S2. Add the irradiated waste rubber powder to an alkaline solution, soak at 60° C. for 20 min, separate the solid from the liquid, wash, and dry to obtain treated irradiated waste rubber powder; wherein the alkaline solution is an aqueous solution containing sodium hydroxide and sodium silicate, the mass content of sodium hydroxide in the alkaline solution is 5%, and the mass content of sodium silicate in the alkaline solution is 1%; the mass ratio of the irradiated waste rubber powder to the alkaline solution is 1:1.5;

[0086] S3, the epoxy resin and the polyamide resin are mixed uniformly, and heated at 90 ° C., and stirred during heating until the two substances are uniformly mixed to obtain a mixed resin; wherein the mass ratio of the epoxy resin to the polyamide resin is 3:1.5, the model of the epoxy resin is E-51, and the model of the polyamide resin is PA66;

[0087] S4. Add the treated irradiated waste rubber powder to the mixed resin, and heat at 60° C. for 8 hours to obtain a modified rubber; the mass ratio of the treated irradiated waste rubber powder to the mixed resin is 4:1.

[0088] Example 2

[0089] This embodiment provides a method for preparing all-solid waste concrete, comprising the following steps:

[0090] Step 1: Mix coal gangue with a particle size of 4.5 mm and coal gangue with a particle size of 15 mm to obtain coal gangue aggregate; wherein, based on the total mass of the coal gangue aggregate as 100%, the mass content of the coal gangue with a particle size of 4.5 mm is 62%, and the mass content of the coal gangue with a particle size of 15 mm is 38%; the apparent density of the coal gangue aggregate is 2200 kg / m 3 , water absorption is 5%, moisture content is 6%;

[0091] Step 2, grinding the coal gangue at 420 r / min for 60 min, passing through a 200-mesh sieve, and then microwave-activating for 3 min at 600 W power, 3 GHz frequency and 140° C. to obtain modified coal gangue micropowder with a particle size of 0.075 mm;

[0092] Step 3, uniformly mixing the modified coal gangue powder and the steel slag powder with a particle size of 30 mm to obtain a mixture, and subjecting the mixture to microwave activation for 10 minutes at a power of 1050 W, a frequency of 2.4 GHz, and a temperature of 200° C. to obtain a modified coarse aggregate; wherein the mass ratio of the modified coal gangue powder to the steel slag powder is 6:102;

[0093] Step 4, uniformly mixing the gangue aggregate, modified coarse aggregate and waste rubber powder to obtain a first mixed mineral material; wherein the waste rubber powder has a tensile strength of 5 MPa and a particle size of 0.13 mm;

[0094] Step 5, heating the modified rubber at 150° C. for 10 min, then spraying it onto the first mixed mineral material, stirring evenly, to obtain a second mixed mineral material;

[0095] Step 6: Evenly mix the second mixed mineral material, hydroxypropyl methylcellulose and basalt fiber, and activate them by microwave at 1250 W power and 165 ° C for 5 minutes to obtain all-solid waste concrete; wherein the hydroxypropyl methylcellulose has a length of 8 mm, a diameter of 0.1 mm, and a tensile strength of 2950 MPa; the basalt fiber has a length of 9 μm, a diameter of 13 μm, and a tensile strength of 3000 MPa;

[0096] Taking the total mass of all-solid waste concrete as 100%, the mass percentage of the coal gangue aggregate is 60%, the mass percentage of the modified coarse aggregate is 25%, the mass percentage of the waste rubber powder is 10%, the mass percentage of the modified rubber is 3%, the mass percentage of hydroxypropyl methylcellulose is 1.5%, and the mass percentage of basalt fiber is 0.5%;

[0097] In step 5, the preparation method of the modified rubber comprises the following steps:

[0098] S1, waste rubber powder with a particle size of 0.13mm and a tensile strength of 5MPa was irradiated with an ultraviolet wavelength of 280nm and an irradiation intensity of 25mW / cm 2 The ultraviolet rays are irradiated for 8 minutes to obtain irradiated waste rubber powder;

[0099] S2. Add the irradiated waste rubber powder to an alkaline solution, soak at 50° C. for 40 min, separate the solid from the liquid, wash, and dry to obtain treated irradiated waste rubber powder; wherein the alkaline solution is an aqueous solution containing sodium hydroxide and sodium silicate, the mass content of sodium hydroxide in the alkaline solution is 3%, and the mass content of sodium silicate in the alkaline solution is 2%; the mass ratio of the irradiated waste rubber powder to the alkaline solution is 1:3;

[0100] S3, mixing the epoxy resin and the polyamide resin uniformly, heating at 80° C., stirring during heating, until the two substances are uniformly mixed, to obtain a mixed resin; wherein the mass ratio of the epoxy resin to the polyamide resin is 3:2.5, the model of the epoxy resin is E-51, and the model of the polyamide resin is PA66;

[0101] S4. Add the treated irradiated waste rubber powder to the mixed resin, and heat at 70° C. for 10 hours to obtain a modified rubber; the mass ratio of the treated irradiated waste rubber powder to the mixed resin is 4.2:1.

[0102] Example 3

[0103] This embodiment provides a method for preparing all-solid waste concrete, comprising the following steps:

[0104] Step 1: Mix coal gangue with a particle size of 3 mm and coal gangue with a particle size of 10 mm to obtain coal gangue aggregate; wherein, based on the total mass of the coal gangue aggregate as 100%, the mass content of the coal gangue with a particle size of 3 mm is 60%, and the mass content of the coal gangue with a particle size of 10 mm is 40%; the apparent density of the coal gangue aggregate is 1800 kg / m 3 , water absorption rate is 7%, moisture content is 5%;

[0105] Step 2, grinding the gangue at 400 r / min for 70 min, passing through a 400-mesh sieve, and then microwave-activating for 6 min at 650 W power, 2.5 GHz frequency and 160° C. to obtain modified gangue micropowder with a particle size of 0.038 mm;

[0106] Step 3, uniformly mixing the modified coal gangue powder and the steel slag powder with a particle size of 20 mm to obtain a mixture, and microwave activating the mixture for 8 minutes at a power of 1000 W, a frequency of 2.45 GHz and a temperature of 170° C. to obtain a modified coarse aggregate; wherein the mass ratio of the modified coal gangue powder to the steel slag powder is 5:100;

[0107] Step 4, uniformly mixing the gangue aggregate, modified coarse aggregate and waste rubber powder to obtain a first mixed mineral material; wherein the waste rubber powder has a tensile strength of 4 MPa and a particle size of 0.12 mm;

[0108] Step 5, heating the modified rubber at 160° C. for 12 minutes, and then spraying it onto the first mixed mineral material, stirring it evenly, to obtain a second mixed mineral material;

[0109] Step 6: Evenly mix the second mixed mineral material, hydroxypropyl methylcellulose and basalt fiber, and activate them by microwave at 1200 W power and 160 ° C for 6 minutes to obtain all-solid waste concrete; wherein the hydroxypropyl methylcellulose has a length of 6 mm, a diameter of 0.2 mm, and a tensile strength of 2955 MPa; the basalt fiber has a length of 12 μm, a diameter of 16 μm, and a tensile strength of 2500 MPa;

[0110] Taking the total mass of all-solid waste concrete as 100%, the mass percentage of the coal gangue aggregate is 50%, the mass percentage of the modified coarse aggregate is 35%, the mass percentage of the waste rubber powder is 7%, the mass percentage of the modified rubber is 5%, the mass percentage of hydroxypropyl methylcellulose is 1.5%, and the mass percentage of basalt fiber is 1.5%;

[0111] In step 5, the preparation method of the modified rubber comprises the following steps:

[0112] S1, waste rubber powder with a particle size of 0.12mm and a tensile strength of 4MPa was irradiated with an ultraviolet wavelength of 260nm and an irradiation intensity of 20mW / cm 2 The ultraviolet rays are irradiated for 6 minutes to obtain irradiated waste rubber powder;

[0113] S2. Add the irradiated waste rubber powder to an alkaline solution, soak at 55° C. for 30 min, separate the solid from the liquid, wash, and dry to obtain treated irradiated waste rubber powder; wherein the alkaline solution is an aqueous solution containing sodium hydroxide and sodium silicate, the mass content of sodium hydroxide in the alkaline solution is 4%, and the mass content of sodium silicate in the alkaline solution is 1.5%; the mass ratio of the irradiated waste rubber powder to the alkaline solution is 1:2;

[0114] S3, mixing the epoxy resin and the polyamide resin uniformly, heating at 85° C., stirring during heating, until the two substances are uniformly mixed, to obtain a mixed resin; wherein the mass ratio of the epoxy resin to the polyamide resin is 3:2, the model of the epoxy resin is E-51, and the model of the polyamide resin is PA66;

[0115] S4. Add the treated irradiated waste rubber powder to the mixed resin, and heat at 65° C. for 9 hours to obtain a modified rubber; the mass ratio of the treated irradiated waste rubber powder to the mixed resin is 4.1:1.

[0116] Comparative Example 1

[0117] This comparative example is different from Example 1 in that:

[0118] Step 2, grinding the coal gangue at 380 r / min for 90 min, passing through a 600-mesh sieve to obtain modified coal gangue powder with a particle size of 0.025 mm;

[0119] The other components and operations were the same as in Example 1.

[0120] Comparative Example 2

[0121] This comparative example is different from Example 1 in that:

[0122] Step 3, uniformly mixing the modified coal gangue powder and the steel slag powder with a particle size of 10 mm to obtain a coarse aggregate; wherein the mass ratio of the modified coal gangue powder to the steel slag powder is 4:98;

[0123] The other components and operations were the same as in Example 1.

[0124] Comparative Example 3

[0125] This comparative example is different from Example 1 in that:

[0126] Step 6: Evenly mix the second mixed mineral material, hydroxypropyl methylcellulose and basalt fiber to obtain all-solid waste concrete; wherein the hydroxypropyl methylcellulose has a length of 5 mm, a diameter of 0.3 mm, and a tensile strength of 2960 MPa; the basalt fiber has a length of 18 μm, a diameter of 20 μm, and a tensile strength of 2000 MPa;

[0127] The other components and operations were the same as in Example 1.

[0128] Comparative Example 4

[0129] This comparative example is different from Example 1 in that:

[0130] Replace the hydroxypropyl methylcellulose with an equal amount of basalt fiber;

[0131] The other components and operations were the same as in Example 1.

[0132] Comparative Example 5

[0133] This comparative example is different from Example 1 in that:

[0134] Replace the basalt fiber with an equal amount of hydroxypropyl methylcellulose;

[0135] The other components and operations were the same as in Example 1.

[0136] Comparative Example 6

[0137] This comparative example is different from Example 1 in that:

[0138] In step 5, the modified rubber is waste rubber powder coated with epoxy resin and polyamide resin;

[0139] The other components and operations were the same as in Example 1.

[0140] Comparative Example 7

[0141] This comparative example is different from Example 1 in that:

[0142] Replace the polyamide resin with an equal amount of epoxy resin;

[0143] The other components and operations were the same as in Example 1.

[0144] Comparative Example 8

[0145] This comparative example is different from Example 1 in that:

[0146] The polyamide resin is replaced by an equal amount of polybutylene terephthalate;

[0147] The other components and operations were the same as in Example 1.

[0148] Comparative Example 9

[0149] This comparative example is different from Example 1 in that:

[0150] Replace the epoxy resin with an equal amount of polyamide resin;

[0151] The other components and operations were the same as in Example 1.

[0152] Comparative Example 10

[0153] This comparative example is different from Example 1 in that:

[0154] Replace the epoxy resin with an equal amount of vinyl resin;

[0155] The other components and operations were the same as in Example 1.

[0156] The all-solid waste concrete prepared in Examples 1 to 3 and Comparative Examples 1 to 10 was subjected to relevant mechanical property tests according to GB / T50784-2013 standard, fatigue resistance was tested according to GB / T50082-2009 in the Standard for Test Methods for Long-term Performance and Durability of Ordinary Concrete, and Marshall stability and dynamic stability were tested according to T 0709-2011 and T0719 in the Test Procedure for Asphalt and Asphalt Mixtures for Highway Engineering (JTGE20-2011). The specific test results are shown in Table 1:

[0157] Table 1

[0158]

[0159] As shown in Table 1, when the all-solid waste concrete provided by the embodiment of the present invention is tested, the Marshall stability reaches 18.5KN, the 60℃ dynamic stability reaches 4800 times / mm, the compressive strength is as high as 45.2MPa, the splitting tensile strength reaches 4.8MPa, the fatigue life reaches 523,000 times, and the fatigue strength retention rate reaches 82.5%. It can be seen that the all-solid waste concrete provided by the embodiment of the present invention has excellent mechanical strength, high temperature stability, low temperature stability and fatigue resistance; the comparative examples 1 to 10 of the present invention replace the key components and key processes in the preparation method of the all-solid waste concrete, and the results show that its Marshall stability, 60℃ dynamic stability, compressive strength, splitting tensile strength and fatigue resistance are significantly lower than the test data of the all-solid waste concrete prepared by the embodiment of the present invention.

[0160] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing all-solid waste concrete, characterized in that: The steps include: Step 1, mixing coal gangue with a particle size of 0.038 mm to 4.5 mm and coal gangue with a particle size of 5 mm to 15 mm to obtain coal gangue aggregate; Step 2, grinding the coal gangue, and then performing microwave activation at a power of 600W to 700W to obtain modified coal gangue micropowder; Step 3, uniformly mixing the modified coal gangue powder and steel slag powder to obtain a mixture, and subjecting the mixture to microwave activation at a power of 950 W to 1050 W to obtain a modified coarse aggregate; Step 4, uniformly mixing the coal gangue aggregate, modified coarse aggregate and waste rubber powder to obtain a first mixed ore; Step 5, heating the modified rubber at 150° C. to 170° C., and then adding the modified rubber to the first mixed mineral material to obtain a second mixed mineral material; Step 6: uniformly mix the second mixed mineral material, hydroxypropyl methylcellulose and basalt fiber, and perform microwave activation at a power of 1150 W to 1250 W to obtain all-solid waste concrete; Wherein, in step 5, the modified rubber is obtained by sequentially irradiating waste rubber powder with ultraviolet light and modifying it with alkali, and then coating it with epoxy resin and polyamide resin.

2. The method for preparing all-solid waste concrete according to claim 1, characterized in that: Taking the total mass of the gangue aggregate as 100%, the mass percentage of the gangue with a particle size of 0.038 mm to 4.5 mm in the gangue aggregate is 58% to 62%, and the mass percentage of the gangue with a particle size of 5 mm to 15 mm in the gangue aggregate is 38% to 42%; and / or In step 1, the apparent density of the gangue aggregate is 1800 kg / m 3 ~2200kg / m 3 The water absorption rate is 5%~10%, and the moisture content is 2%~6%.

3. The method for preparing all-solid waste concrete according to claim 1, characterized in that: In step 2, the microwave activation conditions are: frequency of 2 GHz to 3 GHz, temperature of 140° C. to 180° C., and time of 3 min to 10 min; and / or In step 2, the particle size of the modified coal gangue powder is 0.025 mm to 0.075 mm.

4. The method for preparing all-solid waste concrete according to claim 1, characterized in that: In step 3, the particle size of the steel slag powder is 10 mm to 30 mm; and / or In step 3, the microwave activation conditions are: frequency of 2.4 GHz to 2.5 GHz, temperature of 150° C. to 200° C., and time of 5 min to 10 min; and / or In step 3, the mass ratio of the modified coal gangue powder to the steel slag powder is (4-6): (98-102).

5. The method for preparing all-solid waste concrete according to claim 1, characterized in that: In step 4, the tensile strength of the waste rubber powder is 3MPa~5MPa; and / or In step 4, the particle size of the waste rubber powder is 0.11 mm to 0.13 mm.

6. The method for preparing all-solid waste concrete according to claim 1, characterized in that: In step 5, the heating time is 10 min to 15 min; and / or In step 6, the length of the hydroxypropyl methylcellulose is 5 mm to 8 mm, the diameter is 0.1 mm to 0.3 mm, and the tensile strength is 2950 MPa to 2960 MPa; and / or In step 6, the basalt fiber has a length of 9 μm to 18 μm, a diameter of 13 μm to 20 μm, and a tensile strength of 2000 MPa to 3000 MPa; and / or In step 6, the microwave activation time is 5 min to 7 min.

7. The method for preparing all-solid waste concrete according to claim 1, characterized in that: Taking the total mass of all-solid waste concrete as 100%, the mass percentage of the coal gangue aggregate in the all-solid waste concrete is 50%~60%, the mass percentage of the modified coarse aggregate in the all-solid waste concrete is 25%~35%, the mass percentage of the waste rubber powder in the all-solid waste concrete is 5%~10%, the mass percentage of the modified rubber in the all-solid waste concrete is 3%~5%, the mass percentage of the hydroxypropyl methylcellulose in the all-solid waste concrete is 0.5%~1.5%, and the mass percentage of the basalt fiber in the all-solid waste concrete is 0.5%~1.5%.

8. The method for preparing all-solid waste concrete according to claim 1, characterized in that: In step 5, the preparation method of the modified rubber comprises the following steps: S1. irradiating the waste rubber powder with ultraviolet light to obtain irradiated waste rubber powder; S2, adding the irradiated waste rubber powder to an alkaline solution, soaking at 50° C. to 60° C., solid-liquid separation, washing, and drying to obtain treated irradiated waste rubber powder; S3, mixing the epoxy resin and the polyamide resin evenly, and heating at 80°C to 90°C to obtain a mixed resin; S4, adding the treated irradiated waste rubber powder into the mixed resin, heating at 60° C. to 70° C. to obtain modified rubber.

9. A full solid waste concrete, characterized in that: The concrete is prepared by the method for preparing all-solid waste concrete according to any one of claims 1 to 8.

10. Use of the all-solid waste concrete according to claim 9 in 3D printing concrete.

Images