A method for preparing coconut shell bionic reinforced recycled coarse aggregate

Abstract

The invention provides a method for preparing coconut shell bionic reinforced recycled coarse aggregate, which relates to the technical field of coarse aggregate processing, and comprises a sizing machine, a powdering machine, a conveyor belt and recycled coarse aggregate. The recycled coarse aggregate is sprayed with slurry, entangled with fibers, and sprayed with slurry for the second time to form a coconut shell bionic structure, which can improve the strength of the recycled coarse aggregate, reduce the water absorption rate of the recycled coarse aggregate, solve the inherent defects of the recycled coarse aggregate, and promote the large-scale application of the recycled coarse aggregate. General industrial solid wastes such as fly ash, slag powder, phosphorus slag powder and activators are prepared into slurry for strengthening the recycled coarse aggregate. The method not only promotes the consumption of general industrial solid wastes, but also improves the performance of the recycled coarse aggregate and reduces the cost of the reinforced treatment of the recycled coarse aggregate. The rapid coagulation of the alkali-activated material improves the efficiency of the reinforced treatment of the recycled coarse aggregate, and the treated aggregate can be used for production immediately.

Description

Technical Field

[0001] The invention relates to the technical field of coarse aggregate processing, in particular to a method for preparing coconut shell bionic reinforced recycled coarse aggregate. Background Art

[0002] The application of recycled coarse aggregate is an effective way to deal with construction waste. It can not only reduce the pollution of construction waste to the environment, but also reduce the consumption of natural aggregate resources. It is an important way to green and sustainable development and has significant social, economic and environmental benefits.

[0003] Existing recycled coarse aggregates often have disadvantages such as high crushing value and high water absorption, which results in a low replacement rate when recycled coarse aggregates are used to prepare concrete, hindering the large-scale application of recycled coarse aggregates. Summary of the invention

[0004] Technical issues solved:

[0005] In view of the shortcomings of the prior art, the present invention provides a method for preparing coconut shell bionic reinforced recycled coarse aggregate, which solves the shortcomings of high crushing value and water absorption rate of recycled coarse aggregate.

[0006] Technical solution:

[0007] To achieve the above objectives, the present invention is implemented by the following technical scheme: a method for preparing coconut shell bionic reinforced recycled coarse aggregate, comprising a sizing machine, a powdering machine, a conveyor belt and recycled coarse aggregate, and the production line structure composed of the sizing machine, the powdering machine and the conveyor belt is as follows:

[0008] Sp1: ingredients and equipment preparation, the ingredients and equipment preparation is to clean the sizing machine, powder machine and conveyor belt in sequence and then connect them, and prepare a certain amount of recycled coarse aggregate, sodium silicate aqueous solution, fly ash, slag powder, and phosphorus slag powder for standby;

[0009] Sp2: slurry preparation, wherein the slurry preparation is to use a sodium silicate aqueous solution as an activator, and fly ash, slag powder and phosphorus slag powder are mixed in sequence to form a slurry;

[0010] Sp3: spraying slurry, wherein the spraying slurry is to place the recycled coarse aggregate inside the slurry coating machine, and evenly spray the slurry in step Sp2 on the surface of the recycled coarse aggregate;

[0011] Sp4: entangled fibers, wherein the entangled fibers are obtained by transferring the recycled coarse aggregate with the slurry attached to the surface in step Sp3 to a powder loading machine through a conveyor belt, and placing fibers in the powder loading machine, and the recycled coarse aggregate is entangled with the fibers through the powder loading machine;

[0012] Sp5: secondary spraying slurry, wherein the secondary spraying slurry is prepared by mixing fly ash, slag powder, phosphorus slag powder and sodium silicate aqueous solution into slurry, and conveying the fiber-entangled recycled coarse aggregate in step Sp4 to a sizing machine through a conveyor belt to be evenly sprayed with the newly prepared slurry;

[0013] Sp6: air-drying and discharging, wherein the air-drying and discharging is to air-dry the surface of the recycled coarse aggregate after being sprayed with the slurry in step Sp5 to form a film, thereby completing the preparation of the recycled coarse aggregate.

[0014] Preferably, the mass proportions of the components in the slurry in the slurry preparation are 30%-45% fly ash, 15%-25% slag powder, 10%-20% phosphorus slag powder, and 25%-35% sodium silicate aqueous solution.

[0015] Preferably, the modulus of the sodium silicate aqueous solution in the slurry preparation and the secondary spraying slurry is 3.1-3.4, the sodium oxide content is greater than 8.2%, the silicon dioxide content is greater than 26%, and the insoluble matter in water is less than 0.4%.

[0016] Preferably, the slurry preparation and the secondary slurry spraying are both carried out by successively putting materials into a vertical axis planetary mixer and stirring them to form a slurry.

[0017] Preferably, the mass proportions of the various components in the slurry formed by the secondary spraying slurry are 20%-35% fly ash, 20%-30% slag powder, 10%-20% phosphorus slag powder, and 30%-40% sodium silicate aqueous solution.

[0018] Preferably, the recycled coarse aggregate passes through a sizing machine, a powdering machine, and a sizing machine in sequence, and is transmitted between the sizing machine and the powdering machine by a conveyor belt, and the conveyor belt runs at a speed of 10 m / min.

[0019] Preferably, the fiber used for the bonded fiber is polypropylene fiber, with a fiber diameter of 0.1 mm-0.2 mm, a fiber length of 10 mm-20 mm, a linear density of 2.4 dtex-2.6 dtex, and an elongation of 16%-18%.

[0020] Beneficial effects:

[0021] The present invention provides a method for preparing coconut shell bionic reinforced recycled coarse aggregate, which has the following beneficial effects:

[0022] 1. The present invention forms a coconut shell bionic structure by spraying recycled coarse aggregate with slurry, binding fibers, and spraying slurry for the second time, which can improve the strength of the recycled coarse aggregate, reduce the water absorption rate of the recycled coarse aggregate, solve the inherent defects of the recycled coarse aggregate, and promote the large-scale application of the recycled coarse aggregate.

[0023] 2. The present invention uses fly ash, slag powder, phosphorus slag powder and other general industrial solid wastes and activators to prepare slurry for strengthening recycled coarse aggregate. This method not only promotes the disposal of general industrial solid wastes, but also improves the performance of recycled coarse aggregate and reduces the cost of strengthening treatment of recycled coarse aggregate. The rapid coagulation of alkali-activated materials improves the efficiency of strengthening treatment of recycled coarse aggregate, and the treated aggregate can be used for production immediately. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a diagram of the preparation method of the present invention. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Specific embodiment one:

[0027] like Figure 1 As shown, a method for preparing coconut shell bionic reinforced recycled coarse aggregate includes a sizing machine, a powdering machine, a conveyor belt and recycled coarse aggregate. The production line structure composed of the sizing machine, the powdering machine and the conveyor belt is as follows:

[0028] Sp1: Ingredients and equipment preparation, the ingredients and equipment preparation are to clean the sizing machine, powdering machine and conveyor belt in sequence and connect them, and prepare a certain amount of recycled coarse aggregate, sodium silicate aqueous solution, fly ash, slag powder and phosphorus slag powder for standby;

[0029] Sp2: slurry preparation, which is to use sodium silicate aqueous solution as an activator, and then mix fly ash, slag powder and phosphorus slag powder in sequence to form a slurry;

[0030] Sp3: spraying slurry, the spraying slurry is to place the recycled coarse aggregate inside the slurry coating machine, and evenly spray the slurry in step Sp2 on the surface of the recycled coarse aggregate;

[0031] Sp4: Fiber bonding, the fiber bonding is to transfer the recycled coarse aggregate with slurry attached to the surface in step Sp3 to a powder loading machine through a conveyor belt, and place fibers in the powder loading machine, and the recycled coarse aggregate is bonded to the fibers through the powder loading machine;

[0032] Sp5: Secondary spraying slurry, the secondary spraying slurry is to mix fly ash, slag powder, phosphorus slag powder and sodium silicate aqueous solution into slurry, and transport the recycled coarse aggregate with bonded fibers in step Sp4 to a sizing machine through a conveyor belt to be evenly sprayed with the newly prepared slurry;

[0033] Sp6: air-drying and discharging. The air-drying and discharging is to air-dry the surface of the recycled coarse aggregate after being sprayed with the slurry in step Sp5 to form a film, thereby completing the preparation of the recycled coarse aggregate. Specific embodiment 2:

[0035] like Figure 1 As shown, the mass proportions of each component in the slurry in the slurry preparation are 30%-45% fly ash, 15%-25% slag powder, 10%-20% phosphorus slag powder, and 25%-35% sodium silicate aqueous solution. The mass proportions of each component in the slurry formed by the secondary spraying slurry are 20%-35% fly ash, 20%-30% slag powder, 10%-20% phosphorus slag powder, and 30%-40% sodium silicate aqueous solution. The preparation of the slurry in the spraying slurry and the secondary spraying slurry can be completed together in step Sp2 to achieve the simultaneous proportioning of the two slurries. Alternatively, the slurry proportioning for the spraying slurry can be carried out first according to needs, and then the slurry proportioning for the secondary spraying slurry can be carried out. The order can be selected according to actual usage needs and operability. Specific embodiment three:

[0037] like Figure 1 As shown, in order to facilitate the control of the slurry on the surface of recycled coarse aggregate and improve the performance of the finished product, the following restrictions are made on the industrial waste used in the slurry, among which, the modulus of the sodium silicate aqueous solution in the slurry and the secondary spraying slurry is 3.1-3.4, the sodium oxide content is greater than 8.2%, the silicon dioxide content is greater than 26%, and the insoluble matter in water is less than 0.4%. The slurry and the secondary spraying slurry are both made by successively putting the materials into a vertical shaft planetary mixer and stirring them to form a slurry.

[0038] Phosphorus slag powder is mainly made of granulated electric furnace phosphorus slag, which is ground together with a small amount of gypsum to form a powder of a certain fineness; its main components include SiO2, P2O5, Al2O3, CaO, and MgO, among which the ratio of the sum of the mass fractions of Al2O3, CaO, and MgO to the sum of the mass fractions of SiO2 and P2O5 is greater than 1.1, and the mass fraction of P2O5 is less than or equal to 3.4%, and the 28d activity index should be greater than 75%.

[0039] Slag powder is made of granulated blast furnace slag as the main raw material, mixed with a small amount of gypsum and ground into a powder of a certain fineness; its main components include Al2O3, CaO, MgO, SiO2, TiO2, and MnO, among which the ratio of the sum of the mass fractions of Al2O3, CaO, and MgO to the sum of the mass fractions of SiO2, TiO2, and MnO is greater than 1.2%, and the MnO content is less than 2.3%, and the 28d activity index should be greater than 80%.

[0040] Fly ash is the powder collected from the flue gas of the pulverized coal furnace in power plants, which can be of Class F and Class C. Its fineness is less than 25%, water requirement ratio is less than 105%, loss on ignition is less than 8%, and sulfur trioxide content is less than 3%.

[0041] The fiber used for the entangled fiber is polypropylene fiber, and its fiber diameter is 0.1mm-0.2mm, the fiber length is 10mm-20mm, the linear density is 2.4dtex-2.6dtex, and the elongation is 16%-18%. Specific embodiment four:

[0043] like Figure 1 As shown, the recycled coarse aggregate passes through the sizing machine, powdering machine and sizing machine in turn, and the sizing machine and powdering machine are transmitted by a conveyor belt, and the conveyor belt runs at a speed of 10m / min. In order to facilitate the stable operation of the entire device, the sizing machine, powdering machine and conveyor belt are selected to be a component of the existing XKJ600 production line produced by Bokang Company. The overall production line processes are sizing machine, powdering machine, and sizing machine. Specific embodiment five:

[0045] like Figure 1 As shown, the crushing value and water absorption rate of the recycled coarse aggregate produced by the method of the present application are compared before and after as shown in Table 1. It can be seen that the water absorption rate and crushing value of the coconut shell bionic reinforced regenerated coarse aggregate of the present application are greatly reduced.

[0046] Aggregate Type Crushing value / % Water absorption / % Recycled coarse aggregate 15.6 3.2 Coconut shell bionic reinforced recycled coarse aggregate 6.2 1.6

[0047] Table 1

[0048] Ordinary recycled coarse aggregate and coconut shell bionic recycled coarse aggregate were used to prepare C30 and C60 concrete respectively. The concrete mix ratios are shown in Table 2:

[0049] Test No. Label <![CDATA[Water (kg / m 3 )]]> <![CDATA[Cement (kg / m 3 )]]> <![CDATA[Fly ash (kg / m 3 )]]> <![CDATA[Mineral powder (kg / m 3 )]]> <![CDATA[Recycled coarse aggregate (kg / m 3 )]]> <![CDATA[Recycled coarse aggregate after strengthening treatment (kg / m 3 )]]> <![CDATA[Sand (kg / m 3 )]]> <![CDATA[Admixture (kg / m 3 )]]> 1 C30 153 185 70 75 153 870 6 2 C60 148 400 50 100 148 620 10 3 C30 153 185 70 75 153 870 6 4 C60 148 400 50 100 148 620 10

[0050] Table 2

[0051] The compressive strength, machine expansion and collapse bucket time test data of ordinary recycled coarse aggregate and coconut shell bionic recycled coarse aggregate are shown in Table 3:

[0052] Test No. Label Expansion / mm Slump time / s 28 days compressive strength / Mpa 1 C30 455 11.4 31.2 2 C60 520 15.6 56.5 3 C30 550 4.2 38.2 4 C60 635 6.3 68.5

[0053] Table 3

[0054] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprising a reference structure" do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0055] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing coconut shell bionic reinforced recycled coarse aggregate, comprising a sizing machine, a powdering machine, a conveyor belt and recycled coarse aggregate, characterized in that: The production line structure composed of the sizing machine, the powdering machine and the conveyor belt is used to prepare the recycled coarse aggregate as follows: Sp1: ingredients and equipment preparation, the ingredients and equipment preparation is to clean the sizing machine, powder machine and conveyor belt in sequence and then connect them, and prepare a certain amount of recycled coarse aggregate, sodium silicate aqueous solution, fly ash, slag powder, and phosphorus slag powder for standby; Sp2: slurry preparation, wherein the slurry preparation is prepared by mixing fly ash, slag powder and phosphorus slag powder in sequence with sodium silicate aqueous solution as an activator to form a slurry, wherein the mass proportions of the components in the slurry are 30%-45% fly ash, 15%-25% slag powder, 10%-20% phosphorus slag powder and 25%-35% sodium silicate aqueous solution; Sp3: spraying slurry, wherein the spraying slurry is to place the recycled coarse aggregate inside the slurry coating machine, and evenly spray the slurry in step Sp2 on the surface of the recycled coarse aggregate; Sp4: entangled fibers, wherein the entangled fibers are obtained by transferring the recycled coarse aggregate with the slurry attached to the surface in step Sp3 to a powder loading machine through a conveyor belt, and placing fibers in the powder loading machine, and the recycled coarse aggregate is entangled with the fibers through the powder loading machine; Sp5: secondary spraying slurry, wherein the secondary spraying slurry is prepared by mixing fly ash, slag powder, phosphorus slag powder and sodium silicate aqueous solution into slurry, and conveying the fiber-entangled recycled coarse aggregate in step Sp4 to a sizing machine through a conveyor belt to be evenly sprayed with the newly prepared slurry, wherein the mass proportions of the components in the slurry formed by the secondary spraying slurry are 20%-35% fly ash, 20%-30% slag powder, 10%-20% phosphorus slag powder and 30%-40% sodium silicate aqueous solution; Sp6: air-drying and discharging, wherein the air-drying and discharging is to air-dry the surface of the recycled coarse aggregate after being sprayed with the slurry in step Sp5 to form a film, thereby completing the preparation of the recycled coarse aggregate.

2. The method for preparing coconut shell bionic reinforced recycled coarse aggregate according to claim 1, characterized in that: The modulus of the sodium silicate aqueous solution in the slurry preparation and the secondary spraying slurry is 3.1-3.4, the sodium oxide content is greater than 8.2%, the silicon dioxide content is greater than 26%, and the insoluble matter in water is less than 0.4%.

3. The method for preparing coconut shell bionic reinforced recycled coarse aggregate according to claim 1, characterized in that: The slurry preparation and the secondary slurry spraying are both carried out by successively putting materials into a vertical axis planetary mixer and stirring them to form slurry.

4. The method for preparing coconut shell bionic reinforced recycled coarse aggregate according to claim 1, characterized in that: The recycled coarse aggregate passes through a sizing machine, a powdering machine, and a sizing machine in sequence, and the sizing machine and the powdering machine are transmitted by a conveyor belt, and the conveyor belt runs at a speed of 10 m / min.

5. The method for preparing coconut shell bionic reinforced recycled coarse aggregate according to claim 1, characterized in that: The fibers used for the entangled fibers are polypropylene fibers, with a fiber diameter of 0.1 mm to 0.2 mm, a fiber length of 10 mm to 20 mm, a linear density of 2.4 dtex to 2.6 dtex, and an elongation of 16% to 18%.

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