Recycled aggregate concrete light partition board and manufacturing method thereof

Abstract

The invention discloses a recycled aggregate concrete lightweight partition board and a manufacturing method thereof, cement, coarse aggregate, fine aggregate, pearl grains and fibers are subjected to dry mixing together to form a mixture; mixing an adhesive and a first part of water, and adding the mixture into the mixture to form a first mixture; after CaCl2 and NaCl are mixed with a second part of water, a plasticizer and a foaming agent are added, and after foaming is completed, a second mixture is formed; performing dry mixing on the second mixture and the first mixture to obtain a concrete mixture, and curing to obtain the partition board. According to the invention, the biological waste shells are applied to the concrete, and the construction waste aggregate is used for replacing the natural gravel aggregate in the traditional cement-based partition wall board, so that the renewable and environment-friendly concrete partition wall board is prepared, meanwhile, the material ratio and the preparation method are simple, solid wastes are effectively utilized, the consumption of non-renewable resources is reduced, and the cost is reduced. Popularization and application are facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of building materials, and particularly relates to a lightweight partition board made of recycled aggregate concrete and a manufacturing method thereof. Background Art

[0002] With the continuous development of the construction industry in China, the demand for building materials is increasing, the consumption of natural aggregates is increasing day by day, and the reserves are decreasing; moreover, with the urbanization construction and economic development, there are more and more construction wastes generated by demolitions, and the total amount of construction wastes is increasing day by day, with nowhere to stack, bringing problems of pollution and land occupation to the city.

[0003] Wallboards are an important part of prefabricated buildings. Lightweight interior partition boards are a unique and representative type among wallboards, with characteristics such as light weight, portability, and low strength requirements for non-load-bearing structures. With the promotion of prefabricated buildings, the demand for lightweight interior partition boards is also increasing.

[0004] Currently, the widely used lightweight interior partition boards mainly include concrete hollow wallboards, glass fiber reinforced cement (GRC) hollow wallboards, ceramsite concrete hollow wallboards, autoclaved aerated concrete wallboards (ALC), foamed ceramic lightweight wallboards, polystyrene granule cement sandwich composite wallboards, light steel keel calcium silicate wallboards (filled with rock wool), and steel wire mesh cement polystyrene sandwich wallboards.

[0005] Existing lightweight partition boards have many disadvantages. For hollow wallboards, the quality of concrete hollow wallboards is unstable and the flexural strength is insufficient; glass fiber reinforced cement hollow wallboards have large dry shrinkage and high prices; currently, the more widely used in the market is ceramsite concrete hollow wallboards, but with the increasingly strict requirements for green and low-carbon development in China, the development of ceramsite concrete hollow wallboards is increasingly restricted. For solid wallboards, autoclaved aerated concrete wallboards must be cured using an autoclave, with high energy consumption and certain risks, and China is gradually restricting the use of boilers and autoclaves; foamed ceramic lightweight wallboards are brittle and are easily broken during transportation and construction. For composite wallboards, the polystyrene granules inside the polystyrene granule cement sandwich composite wallboards are easily pulverized and have poor durability. At the same time, the industry is gradually increasing the requirements for the fire resistance of wall materials, and polystyrene materials are restricted; light steel keel calcium silicate wallboards have poor sound insulation, and the rock wool filled inside is harmful to the human respiratory tract and is currently restricted; steel wire mesh cement polystyrene sandwich wallboards have poor fire resistance and do not meet the fire protection grade. Generally speaking, lightweight concrete interior partition boards are ideal substitutes for traditional partition materials.

[0006] In the existing small amount of research and application on interior partition walls containing construction waste, there are generally problems such as complex material ratios, low usage of construction waste aggregates, and high raw material costs. At the same time, since biological wastes such as oyster shells and shellfish shells discarded in the food industry are also an important part of urban waste, if they can be turned from waste into treasure and recycled into the preparation of partition boards, then the two major problems of construction waste and biological shell waste can be solved. Therefore, how to break through the utilization of construction waste aggregates and biological waste, as well as the design of the formulation process of lightweight interior partition boards, are all technical problems that urgently need to be solved in the current industry.

[0007] After retrieval, there are patent literatures publicly available on using construction waste to prepare partition boards in the prior art. For example, Patent CN115304342A discloses a recycled lightweight interior partition board made of construction waste and its preparation method. This invention uses waste EPS particles and waste foam concrete particles selected by pre-treating construction waste, and adds gypsum slurry to prepare a gypsum-based recycled lightweight aggregate sandwich layer, which can effectively reduce the density of the lightweight interior partition board and improve the sound insulation efficiency; it also provides a new method for the resource utilization of waste lightweight particles collected from the dust collection of construction waste treatment. However, the partition board prepared by this invention is a gypsum board partition. Although it is light in weight and high in strength, its load-bearing capacity is insufficient, it is easy to be affected by moisture and deformed, and problems such as discoloration and yellowing may occur after long-term use. Another example is Patent CN111170691A, which discloses a recycled sound insulation and heat insulation core material slurry and its application in lightweight partition boards and a recycled lightweight partition board. This invention uses waste autoclaved aerated concrete blocks to replace polymer materials to obtain a recycled sound insulation and heat insulation core material slurry, which can make the lightweight partition board have better fire resistance, high strength, heat insulation, and sound insulation effects, and the cost is low, and it can effectively recycle construction waste. This invention is mainly aimed at the recycling and reuse of waste autoclaved aerated concrete blocks, and the prepared recycled sound insulation and heat insulation core material slurry is used as the heat insulation core material inside the partition board, which is essentially different from the recycled aggregate concrete lightweight partition board prepared in this application.

[0008] There are also some invention concept solutions that mostly remain in the conceptual or preliminary experimental stage. When put into practical application, many difficult problems will arise. For example, Patent CN101041578A discloses lightweight aggregate concrete and a formwork wall member made of the lightweight aggregate concrete. The various dust powders generated after crushing plant fibers will affect the workability of the concrete. Patent CN1603271A discloses an eco-friendly recycled aggregate functional wallboard and its manufacturing method, which contains multi-parameter hybrid fibers (complex parameters of more than two types), and the obtained product cannot meet the requirements of mechanical properties. Another example is that Patent CN109836097A discloses an ecological ultra-high performance concrete, which uses steel fibers mixed with other fibers for hybridization. The steel fibers are ultra-high strength and toughness fibers, while the plant fibers contain polysaccharides and bases, and polysaccharides will be released through the mixing of cement to corrode the steel fibers. Once the internal steel fibers of the concrete slab are corroded, brittle fracture of the concrete slab will occur immediately; and due to the strong toughness and flexural aggregation of the fibers, the phenomenon of fiber aggregation often occurs when two fibers are mixed, and it is almost impossible to mix when three fibers are mixed, resulting in a very serious flexural aggregation phenomenon. Patent CN111574177A discloses a straw cement thermal insulation partition board and its preparation method. The reed straw is woven to obtain a grid-shaped reed straw net, multiple layers of straw nets are stacked in a mold, and the cereal crop straw is crushed and then mixed and stirred evenly with powder A and a flame retardant adhesive and then transported to the mold for molding to obtain a straw cement wallboard blank. This solution has complex processes and is difficult to control the quality uniformity, which is not conducive to practical application. Patent CN110423066A discloses a full brick waste recycled aggregate concrete lightweight partition board and its manufacturing method. The main material of the partition board uses dry-hard or semi-dry-hard concrete and is internally provided with a steel bar skeleton and an anti-cracking net. On the basis of designing the steel bar mesh, fibers are used to enhance the strength of the concrete board. It not only cannot reduce the weight of the concrete board, but also causes great difficulties in casting production for the construction technology. Especially, the flexural aggregation and pollution of polypropylene fibers, glass fibers and polyester fibers are extremely large, and it is extremely easy to be inhaled into the mouth and cause health problems. Moreover, the concrete containing steel bars in this solution cannot be transported to a recycling device such as a jaw crusher as filling stones, making it difficult to achieve recycling and reuse. Summary of the Invention

[0009] In order to overcome the defects and deficiencies existing in the prior art, at least one object of the present invention is to provide a recycled aggregate concrete lightweight partition board and its manufacturing method, which applies biological waste shell-like materials to concrete, uses construction waste aggregates to replace natural sand and gravel aggregates in traditional cement-based partition boards, prepares a renewable and environmentally friendly concrete partition board, and at the same time has a simple material ratio and preparation method, effectively utilizes solid waste, reduces the consumption of non-renewable resources, and is suitable for popularization and application.

[0010] To achieve the above object, the present invention provides the following technical solutions:

[0011] The first object of the present invention is to provide a lightweight partition board made of recycled aggregate concrete, comprising the following components in parts by mass:

[0012]

[0013] Among them, the coarse aggregate is recycled concrete stone powder, which is derived from construction waste; the fine aggregate is obtained by crushing the treated biological shell waste.

[0014] In an implementable embodiment of the first aspect, the hydrophobic plant fiber is any one of reed fiber, coconut shell fiber, and sisal fiber.

[0015] In an implementable embodiment of the first aspect, the calculated content of the hydrophobic plant fiber is 2.6% - 4.7%. Preferably, the content of the hydrophobic plant fiber is 3%.

[0016] In an implementable embodiment of the first aspect, the length of the reed fiber is 20 mm - 30 mm, and the width is 1.0 mm - 1.5 mm.

[0017] In an implementable embodiment of the first aspect, the foaming agent is anhydrous gypsum;

[0018] And / or, the plasticizer adopts Стахемент - 2000 superplasticizer;

[0019] And / or, the binder adopts diphenylmethane diisocyanate binder.

[0020] In an implementable embodiment of the first aspect, the partition board is an assembled wallboard structure. A connecting portion is provided on one side in the width direction of the partition board, and a connecting hole is provided in the connecting portion;

[0021] And / or, the size of the lightweight partition board is: the width is 0.8 - 0.95 m, the height is 2.8 m - 3.2 m, and the thickness is 0.20 - 0.22 m;

[0022] And / or, a number of transverse steel bars and longitudinal steel bars are arranged inside the lightweight partition board.

[0023] In an implementable embodiment of the first aspect, mating tenons and grooves are respectively provided on both side surfaces in the height direction of the partition board, and the tenons and grooves match;

[0024] And / or, the tenons and grooves are respectively located at the central position in the thickness direction of the partition board and extend along the width direction;

[0025] And / or, the width of the tenon is 4 cm to 8 cm smaller than the thickness of the partition board, and the depth of the groove is 3 cm to 10 cm;

[0026] And / or, mounting holes are provided in the groove.

[0027] The second object of the present invention is to provide a manufacturing method of a lightweight partition board made of recycled aggregate concrete, comprising the following steps:

[0028] S1: Dry mix cement with coarse aggregate, fine aggregate, pearl grains, and hydrophobic plant fibers to form a mixture.

[0029] S2: After mixing the binder and the first part of water, add them to the mixture in the above step S1 to form a first mixture.

[0030] S3: Mix CaCl2 and NaCl with the second part of water to form a mixed solution. At this time, the water temperature range is 38°C to 45°C. Then, add a plasticizer and a foaming agent to the mixed solution and perform foaming treatment. After the foaming is completed, a second mixture is formed.

[0031] S4: Dry mix the second mixture after the foaming is completed in step S3 with the first mixture in step S2 to obtain a concrete mixture.

[0032] S5: Add the above concrete mixture into a mold, and obtain a lightweight partition board made of recycled aggregate concrete after curing.

[0033] In an implementable embodiment of the second aspect, in step S1, the hydrophobic plant fibers are subjected to roll pressing and cutting treatment to make their sizes meet the usage requirements. Then, the dust on the fiber surface is removed, and the fibers are immersed in an alkali solution and taken out and drained for standby after a certain period of time.

[0034] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0035] 1. The present invention is made of lightweight foamed concrete as the main material. This lightweight foamed concrete completely replaces natural aggregate with recycled aggregate, effectively utilizes construction waste and biological shell waste, realizes the maximum resource recycling, saves energy resources, reduces costs, greatly reduces the adverse impact of construction and biological waste on the environment, and at the same time can improve the flexural performance of the wallboard by using the toughness of the fiber.

[0036] 2. The main material of the partition board of the present invention is configured with a foaming agent, a plasticizer and cement. Instead of using a steel bar framework in the main material of the partition board, natural plant fibers such as reed fibers are used for substitution. After reaching the service life, it can be directly crushed into stones, stone powder and fine sand of various particle sizes by a recycling treatment device such as a jaw crusher and then applied to building engineering materials again; moreover, the material ratios adopted in the present invention, such as coarse aggregate, fine aggregate, etc., have been fully studied to enable the product to meet the international industry and Chinese GB national mechanical standards for the secondary structure interior partition wall.

[0037] 3. The solution of this application uses only one kind of plant fiber, which can avoid the generation of agglomeration phenomenon, promote the setting of cement, improve the compactness of the wallboard, and make the concrete lighter, more durable and non-agglomerating during the production process through high-strength and high-plasticity foaming technology; among them, the plant fiber is preferably reed fiber, which has good workability and is easy to disperse and mix; reed fiber has good toughness, which can effectively limit the expansion of cracks, thereby improving the flexural strength of the concrete and enhancing the toughness of the concrete, enabling it to withstand greater deformation and load; the addition of reed fiber can also fill the pores of the concrete, improve its density, and thus increase the compressive strength of the concrete; during the preparation process of the partition board in this application, vibration is not required, which is also because the addition of hydrophobic fibers such as reed fibers fills the voids, has good workability, and can be directly cast into shape, simplifying the construction process.

[0038] 4. In the raw materials of the solution of this application, when the hydrophobic plant fiber added is reed fiber, the size length and width of the reed fiber need to be within a suitable range: if the fiber is too long, it is easy to entangle and agglomerate during the mixing process, resulting in local fiber enrichment, damaging the material homogeneity, and the fibers are easy to pull each other during ramming, hindering the settlement of the aggregate, increasing the porosity, and the agglomerated area may become a stress concentration point, reducing the flexural strength; fibers of appropriate length can enhance the compressive strength and flexural strength of the concrete; if the fiber is too short, it is difficult to form an effective three-dimensional support network in the concrete, reducing the flexural and tensile strength of the material.

[0039] The present invention also studied the addition amount of reed fiber. It was found that when the fiber addition amount was too much, it would affect the overall workability of the foamed fiber concrete, resulting in uneven mixing, too large cured air bubbles, and poor mechanical properties. At the same time, too much fiber would also cause the fibers to tangle and lap inside the concrete, making it impossible to mix better with the foamed concrete and giving full play to the flexural toughness of the reed fiber. When the fiber addition amount was too little, an effective three-dimensional reinforcement network could not be formed, resulting in a decrease in flexural strength, an increased risk of brittle fracture, difficulty in fully exerting the mechanical interlocking effect with the cement matrix, weakening the fiber-matrix interfacial bond strength, inability to improve the cohesiveness of the mixture, easy occurrence of aggregate segregation and bleeding phenomena, and the specimens not being light enough, and also unable to consume more agricultural waste reed fiber, failing to meet the requirements of sustainable development of the building environment. Therefore, only an appropriate fiber addition amount can not only promote the consumption of agricultural waste but also enable the reed foamed concrete to obtain better mechanical properties and meet the national standard. When the reed fiber is added to the foamed concrete in the addition amount described in the present application, the mechanism lap between the reed fiber and the foamed concrete shows good results, with uniform air bubbles, strong density, and no phenomena such as fiber tangling and lapping, fully expressing the flexural toughness of the reed fiber in the specimens of the reed fiber foamed concrete.

[0040] 5. In the present application, the reed fiber was pretreated by rolling and cutting, removing dust, and immersing it in an alkali solution before application. By rolling and cutting and removing dust, the reed fiber can be better dispersed in the concrete, avoiding agglomeration and improving the uniformity of the fiber reinforcement effect. Since the surface of the reed is relatively smooth and has strong toughness, its own form has relatively poor adhesion to cement. After being treated by immersing in an alkali solution, not only the gelatinous layer on the surface of the reed fiber is removed, making the fiber surface rougher and enhancing the adhesion to cement, but also the polysaccharides in the fiber can be effectively reduced, avoiding its influence on the water-cement ratio, thereby ensuring the compactness of the wallboard structure.

[0041] 6. In the present application, the treated bio-shell waste was used as fine aggregate after being crushed. Through a large number of experimental verifications, it was found that after specific treatment, the bio-shell waste used as fine aggregate can not only effectively fill the voids in the concrete and improve the compactness of the wallboard, but also bring an additional strength enhancement effect to the wallboard due to its own characteristics such as certain hardness and microstructure. The concrete partition wallboard made by the present invention has the characteristic of being significantly lighter than standard concrete, and this significantly lighter characteristic is based on meeting the mechanical properties specified by the industry.

[0042] 7. During the production process of the concrete partition wall panel of the present invention, vibration is not required. However, if a standard and dense concrete wall panel structure is to be obtained, a superplasticizer needs to be used to improve the plasticity of the concrete partition wall panel and enhance the density of the wall panel. The present invention selects a special superplasticizer, Стахемент-2000, which can significantly improve the crack resistance and frost resistance of concrete, reduce shrinkage, and increase waterproof performance. Especially for the solution of the present application containing aggregates and hydrophobic plant fibers, it can ensure high-quality finished products.

[0043] The binder of the present invention uses diphenylmethane diisocyanate binder, which can better fuse the microscopic interfaces of concrete and hydrophobic plant fibers, making their adhesion closer, effectively improving the density of the concrete partition wall panel, and is used in combination with CaCl2 and NaCl. CaCl2 plays a role in reducing water and accelerating setting, while NaCl has a solidifying effect, enabling faster plastic deformation. The specific ratio of CaCl2 and NaCl not only plays an early strength role but also jointly regulates the setting time, hydration process, and microscopic structure of concrete with other admixtures and raw materials, improving the workability and durability of concrete, and comprehensively improving the influence of recycled aggregates, including construction waste coarse aggregates and biowaste fine aggregates, on the performance of concrete. Since hydrophobic plant fibers need to be used in the solution of the present invention, the performance of concrete will affect the performance quality of the partition wall panel containing hydrophobic plant fibers, such as dry shrinkage deformation, etc. Therefore, the combination of CaCl2 and NaCl and the selection of their respective proportions are also very important. The synergistic effect of CaCl2 and NaCl optimizes the setting time and microscopic structure of concrete.

[0044] Each additive material in the present application plays a key role in improving the foaming structure of the wall panel, enhancing plasticity, and increasing density. Their mutual interactions jointly achieve a complex synergistic optimization effect in multiple aspects of the wall panel performance. By being used in combination with the main raw material of the present invention, the prepared partition wall panel is not only lightweight but also has high compressive strength, flexural strength, and good toughness, making it suitable as an interior partition wall and exterior wall enclosure material for buildings. The raw material ratio of the present application has undergone scientific practical tests, and a lightweight partition wall panel that is significantly lighter than standard concrete but can meet the mechanical performance requirements of the industry can be obtained.

[0045] 8. In the production method of the present application, the order of raw material input (such as first dry-mixing cement with coarse aggregates, fine aggregates, pearl particles, and hydrophobic plant fibers, then adding an aqueous solution containing a binder, and finally adding a plasticizer and a foaming agent) and the mixing conditions (such as mixing temperature) can ensure that each raw material is fully and evenly mixed at different stages, avoiding problems such as agglomeration and incomplete reaction. For example, prior dry-mixing is beneficial to the uniform dispersion of hydrophobic plant fibers in the aggregates, laying a foundation for their full reaction with other raw materials in the subsequent process. The control of the mixing temperature can affect the chemical reaction rate and foaming effect, achieving the best performance of the concrete.

[0046] 9. The solution of the present invention has been put into actual research and development and production. See the photos of the on-site construction progress at the end. Compared with various existing technologies in the same field, it solves the current research situation where various solutions are difficult to be used in practice, and it is a green environmental protection technology that can be truly implemented and widely promoted on a large scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a schematic diagram of the mixture in step S1 in the embodiment of the present invention.

[0048] Figure 2 It is a schematic diagram of the concrete mixture prepared in the embodiment of the present invention.

[0049] Figure 3 It is a schematic diagram of the compression failure of the partition board specimen prepared in the embodiment of the present invention, where (a) is a schematic diagram of the surface structure of the specimen under compression failure, (b) is a schematic diagram of the internal structure of the specimen under compression failure, (c) is a schematic diagram of the surface structure of the specimen under tension failure, and (d) is a schematic diagram of the internal structure of the specimen under tension failure.

[0050] Figure 4 It is a schematic diagram of the structure of the partition board prepared in the embodiment of the present invention.

[0051] Figure 5 It is a schematic diagram of the structure of the partition board from another perspective prepared in the embodiment of the present invention.

[0052] Figure 6 It is a schematic diagram of the steel bar distribution inside the partition board prepared in the embodiment of the present invention.

[0053] Figure 7 It is a schematic diagram of the splicing structure of the partition board prepared in the embodiment of the present invention.

[0054] Figure 8 It is the surface microstructure in the SEM electron microscope of the partition board specimen prepared with 1% - 6% reed fibers in the embodiment of the present invention. Figure 8 a shows the microstructural diagram of the concrete containing 1% reed fiber. Figure 8 b shows the microstructural diagram of the concrete containing 2% reed fiber. Figure 8 c shows the microstructural diagram of the concrete containing 3% reed fiber. Figure 8 d shows the microstructural diagram of the concrete containing 4% reed fiber. Figure 8 e shows the microstructural diagram of the concrete containing 5% reed fiber. Figure 8 f shows the microstructural diagram of the concrete containing 6% reed fiber.

[0055] Figure 9 It is the microstructural diagram of the concrete test blocks prepared with different contents of shell aggregate in the embodiment of the present invention.Figure 9 Figure a shows the microstructure diagram of concrete without shell aggregate. Figure 9 Figure b shows the microstructure diagram of concrete containing 10% shell aggregate. Figure 9 Figure c shows the microstructure diagram of concrete containing 30% shell aggregate. Figure 9 Figure d shows the microstructure diagram of concrete with a 50% shell replacement rate.

[0056] Figure 10 This is the structure diagram of the concrete test block prepared under the condition of excessive CaCl2 content in the present invention. It can be seen that there are many bubbles on the surface of the test block and the mechanical properties are poor.

[0057] Figure 11 This is the structure diagram of the concrete test block prepared under the condition of too little CaCl2 content in the present invention. It can be seen that there are many bubbles inside the test block and it cannot be plastically formed completely.

[0058] Figure 12 This is the weight comparison after complete drying of the test blocks of the embodiment of the present invention and the standard concrete test blocks of the same size. Among them, (a) and (b) are standard concrete test blocks, and (c) and (d) are the test blocks prepared according to the embodiment of the present invention.

[0059] Reference numerals:

[0060] 100, partition panel; 110, connecting part; 111, connecting hole; 120, tenon; 130, groove.

[0061] Figure 13 Photos of the on-site construction progress of the present invention. Detailed implementation manners

[0062] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0063] Embodiment 1

[0064] First, a lightweight partition panel made of recycled aggregate concrete is provided in the embodiments of the present application, including the following components in parts by mass:

[0065]

[0066] Among them, the coarse aggregate uses recycled concrete stone powder with a particle size of 0.5 mm, which is sourced from construction waste. This particle size range forms a dense packing with the cement matrix slurry, avoiding defects such as pitted surfaces and holes in the wall panels. The fine aggregate is obtained by crushing the treated biological shell waste. In some realizable embodiments, the fine aggregate can be taken from charred oyster shells or shell casings, etc., and is obtained after treatment.

[0067] Since shellfish biological waste is composed of calcium carbonate, glycoprotein, proteoglycan, polysaccharide, and chitin. During the hydration reaction of cement, the four main clinker minerals react with water: Tricalcium silicate undergoes a hydration reaction at room temperature to form calcium silicate hydrate (C-S-H gel) and calcium hydroxide,

[0068] 3CaO·SiO2 + nH2O = xCaO·SiO2·(n - 3 + x)H2O + (3 - x)Ca(OH)2;

[0069] Dicalcium silicate (β-C2S) hydrates, 2CaO·SiO2 + nH2O = xCaO·SiO2·(n - 2 + x)H2O + (2 - x)Ca(OH)2.

[0070] In this embodiment, it is made of lightweight foamed concrete as the main material. This lightweight foamed concrete uses recycled aggregate to completely replace natural aggregate, effectively utilizes construction waste and biological shell waste, achieves the maximum resource recycling, saves energy resources, reduces costs, and greatly reduces the adverse impact of building and biological waste on the environment. At the same time, it can also use the toughness of the fiber to improve the flexural strength of the wall panel.

[0071] In this embodiment, the mass fraction of the hydrophobic plant fiber is 0.1 part to 0.15 part. The hydrophobic plant fiber is any single fiber among reed fiber, coconut shell fiber, and sisal fiber, and has good waterproofness, corrosion resistance, and alkali resistance, and can effectively improve the corrosion resistance, alkali resistance, and waterproofness of the partition wall panel.

[0072] Since the strength requirements for general interior partition wall panels are not high, the national standard stipulates that the compressive strength of GRC round-hole lightweight partition wall panels should not be less than 2.5 MPa, and the flexural strength of the wall panels should not be less than 10 MPa. Therefore, designing the concrete partition wall panel in this embodiment according to the design standard of C25 concrete strength can fully meet the usage requirements. In some other application scenarios, if the strength requirements of the used concrete partition wall panels are different, other concrete strength design standards can also be used for design, such as C20, C30, C35, etc. Through comparative research experiments, the preferred content of the hydrophobic plant fiber is 2.65% to 4.73%. Among them, the more preferred scheme of the fiber content calculated according to the design standard of C25 concrete strength is 2.65% to 3%. The test process includes:

[0073] By collecting the experimental samples after crushing, in order to further analyze the influence of reed fibers on the mechanical properties of concrete from a microscopic perspective, SEM electron microscopy scans were conducted on concrete containing 1%, 2%, 3%, 4%, 5%, and 6% reed fibers, and the surface microstructure of the concrete in the SEM electron microscope under different reed fiber replacement rates was observed. Refer to Figure 8 as shown Figure 8 a shows the microstructural diagram of the concrete containing 1% reed fibers, Figure 8 b shows the microstructural diagram of the concrete containing 2% reed fibers, Figure 8 c shows the microstructural diagram of the concrete containing 3% reed fibers, Figure 8 d shows the microstructural diagram of the concrete containing 4% reed fibers, Figure 8 e shows the microstructural diagram of the concrete containing 5% reed fibers, Figure 8 f shows the microstructural diagram of the concrete containing 6% reed fibers.

[0074] The microstructure shows that reed fibers can better combine with concrete. With an addition amount of 2.65% - 4.73%, the workability of the concrete is better, the combination between reed fibers and aggregates is tighter. The addition amount of reed fibers within this range can enhance the flexural and compressive mechanical properties of the concrete. And after the concrete is damaged under high load pressure, the reed fibers have sufficient toughness, the fiber surface is intact, there are no direct damage marks, and they still maintain the combination with shell and recycled aggregate concrete, with a spacing of only 2 - 3μm, directly compensating for the cracking defect of shell concrete after high load pressure. And through the microscopic interface expression of SEM, the medium of cement paste better integrates with the concrete, which also greatly improves the mechanical properties of the concrete.

[0075] At an addition amount of 3% reed fibers, the reed fibers can be evenly distributed in the concrete specimens without fiber agglomeration; and in the flexural failure, the pulling effect of the reed fibers is very strong and not easy to break, so it can be considered for use in structural concrete. However, in the compressive failure, the compressive coefficient of the reed fibers is not high. It is recommended to develop green fiber concrete as a non-load-bearing material (such as interior partition boards, etc.) to promote the economic sustainable development of green concrete materials.

[0076] Refer to Figure 1 and Figure 2As shown, in some feasible embodiments, when the hydrophobic plant fiber is reed fiber, the size of the reed fiber added to the raw material is: the length is 20 mm to 30 mm, and the width is 1.0 mm to 1.5 mm. Long fibers can enhance the flexural strength of concrete, but if the fibers are too long, the compressive strength will decrease; conversely, short fibers can enhance the compressive strength of concrete, but the flexural strength will decrease. After repeated experiments, it is considered that when the length of the reed fiber is in the range of 20 mm to 30 mm and the width of the reed fiber is in the range of 1.0 mm to 1.5 mm, the flexural strength and compressive strength of the prepared concrete can meet the usage requirements of the partition board.

[0077] Regarding the fine aggregate and its dosage used in the recycled aggregate concrete lightweight partition board, in the research and comparative tests, the applicant prepared concretes containing 0%, 10%, 30%, 50%, etc. of shell aggregate for shell aggregate, carried out SEM electron microscopy scans, and simultaneously observed the surface structure of the concrete in the SEM electron microscopy under different shell replacement rates. Figure 9 a shows the concrete without shell aggregate, Figure 9 b shows the concrete containing 10% shell aggregate, Figure 9 c shows the concrete containing 30% shell aggregate, Figure 9 d shows 4 groups of comparison pictures of the concrete with a 50% shell replacement rate. It can be found that: the concrete with added shell aggregate can promote smaller gaps between the concrete structures, making the concrete have higher stress performance; it can avoid the defect points of compressive cracking and improve the workability of the concrete. However, due to the small flexural stress of the carbonized shell, and the reed fiber can just make up for this flexural stress defect. It is determined that using shell aggregate as the fine aggregate to make the recycled aggregate concrete lightweight partition board has a good effect, and the ratio in the above components of the recycled aggregate concrete lightweight partition board is optimized (0.55 to 0.75 parts of fine aggregate, and the mass fraction accounts for 17.5% to 25.4%).

[0078] In some feasible embodiments, the foaming agent is anhydrous gypsum, which plays a foaming role, making the prepared concrete partition board lighter and meeting the usage requirements. The plasticizer uses Стахемент-2000 superplasticizer. In the production process of the concrete partition board in this embodiment, vibration is not required, but if a standard and dense concrete wallboard structure is to be obtained, the superplasticizer is needed to improve the plasticity of the concrete partition board and the compactness of the wallboard.

[0079] Staxament-2000 superplasticizer is a new generation of plasticizer based on polycarboxylate (Group I). This additive is released in liquid form under TU 800013176.004-2011. This plasticizer has been certified by a laboratory recognized by the European Union, complies with the European standard EN 934-2:2010, meets the requirements statement of TR 2009 / 013 / BY "Buildings and structures, building materials and products, safety", and the requirements of the technical certificate of TC 05.0235.12. It also has a national registration certificate (number BY.50.51.01.008.E.000915.05.13) issued by the Minsk Regional Center for Hygiene, Epidemiology and Public Health.

[0080] In some achievable embodiments, the binder uses diphenylmethane diisocyanate binder, which can better fuse the microscopic interfaces of concrete and hydrophobic plant fibers, making their adhesion tighter and effectively improving the compactness of concrete partition boards.

[0081] In the raw material components of this embodiment, the mass fraction of CaCl2 is 0.026 - 0.033 parts. Selecting a suitable CaCl2 ratio can play an effective role in water reduction and rapid setting. Through experimental analysis, it can be seen that too much CaCl2 will cause the concrete to reduce water and solidify too quickly, which is not conducive to foaming and mixing. At the same time, too rapid water reduction will lead to insufficient reaction of the cementitious matrix, many plastic mold bubbles, poor aesthetics, and poor mechanical properties of the finished product, failing to meet the specification requirements. For details, please refer to Figure 10 as shown. While too little CaCl2 will cause the concrete to reduce water too slowly and solidify slowly, unable to solidify during foaming, not only prolonging the foaming and mixing time, but also due to too slow water reduction, resulting in too long reaction of the cementitious matrix, generating a huge amount of heat, making the test block full of bubbles and collapsing during the static curing process, unable to be completely shaped and failing to meet the specification requirements. For details, please refer to Figure 11 as shown.

[0082] The mass fraction of NaCl in the raw material components is 0.030 - 0.035 parts, which has a solidifying effect and can achieve faster plastic deformation. In this embodiment, the main function of NaCl is as an admixture, aiming to promote the catalytic reaction between CaCl2 and other additives, so as to rapidly solidify within a limited time. If there is too little NaCl, it cannot promote the full reaction with CaCl2, Стахемент-2000, diphenylmethane diisocyanate binder, which will lead to poor solidification performance of the test block, many holes, too large apparent density of the test block, and poor direct adhesion between fibers and aggregates. On the contrary, if there is too much NaCl, the catalysis is too rapid and the solidification is too fast, resulting in solidification before proceeding to the next mixing step, making it impossible to carry out the next experiment. At the same time, perhaps the catalysis of the cohesion between concrete and fibers will cause the fibers to quickly agglomerate, uneven mixing, too large fiber agglomeration, reducing the overall mechanical properties of the concrete partition wall, and at the same time will also cause dry shrinkage deformation of the plant fiber partition wall panel.

[0083] In summary, the combined use of an appropriate amount of CaCl2 and NaCl can comprehensively improve the influence of recycled aggregates (construction waste coarse aggregates and biological waste fine aggregates) on the performance of concrete and improve the workability of concrete.

[0084] Please refer to Figures 4 - 7 In this embodiment, the prepared lightweight concrete partition wall panel 100 is an assembled wall panel structure. The dimensions of the partition wall panel 100 are as follows: the width L is 0.8 - 0.95 m, the height H is 2.8 m - 3.2 m, and the thickness is 0.20 m - 0.22 m. One side in the width direction of the partition wall panel 100 is provided with a connecting part 110, the connecting part 110 extends along the height direction, and both ends extend to both ends in the height direction of the partition wall panel 100. The connecting hole 111 is arranged in the connecting part. Preferably, in this embodiment, there are multiple connecting holes 111, and the multiple connecting holes 111 are spaced along the height direction. When two adjacent partition wall panels 100 are connected, the connecting parts 110 of the two partition wall panels 100 are correspondingly fitted together, and bolts sequentially pass through the connecting holes 111 on the two connecting parts 110 to fixedly connect the left and right partition wall panels 100 into a whole. Further, in this embodiment, the thickness of the connecting part 110 is half of the thickness of the partition wall panel 100.

[0085] As Figure 6As shown in the figure, a number of transverse steel bars and longitudinal steel bars are arranged inside the lightweight partition board 100 of this embodiment (in this application, the steel bars are used as the frame structure in the prefabricated building. When the partition board is recycled, the main material of the partition board can be separated from the steel bars, and the main material of the partition board and the steel bar frame can be recycled and reused respectively). Specifically, in this embodiment, a single layer of steel bars is arranged inside the partition board 100, among which there are 10 transverse steel bars and 31 longitudinal steel bars, and they are tied by the plum blossom tying method. When making the wallboard, the steel bars are tied well and placed inside the mold, and there are cushion blocks between the steel bars and the mold. Cushion blocks with a thickness of 25 mm can be used to make a certain gap between the formwork and the steel bars. After pouring the concrete mixture prepared from the above raw materials into the mold, a protective layer with a certain thickness is formed outside the steel bars, which can effectively protect the steel bars and at the same time ensure that the fiber material can be more evenly integrated into the reinforced concrete.

[0086] Furthermore, on both sides of the partition board 100 in the height direction of this embodiment, there are respectively provided a matching tenon 120 and a groove 130. The tenon 120 and the groove 130 are matched. Adjacent two partition boards are positioned and connected with each other through the mutual engagement of the tenon 120 and the groove 130, and there are installation holes in the groove 130, and screw fixed connections are carried out in the installation holes. Among them, the tenon 120 and the groove 130 are respectively located at the central position in the thickness direction of the partition board 100 and extend along the height direction. The width of the tenon 120 is 4 cm to 8 cm smaller than the thickness of the partition board 100, and the depth of the groove 130 is 3 cm to 10 cm. Installation grooves are provided on both sides of the partition board 100 in the height direction, and screw holes are provided in the installation grooves for convenient fixed installation and use.

[0087] The partition board 100 of this embodiment adopts a prefabricated structure. The upper and lower partition boards 100 are positioned and installed through a mortise and tenon structure. The left and right partition boards 100 are mutually engaged through the installation part 110 and are tightly connected through bolt connection. The overall applicability is strong, which is convenient for on-site assembly and the construction is fast. After the above-mentioned prefabricated partition board 100 is installed, it is necessary to hang a net for the secondary structure, and then plaster a mortar protective layer with a thickness of 2 - 3 cm to form an integral partition board 100 structure; in addition, there are movable wire grooves at the splicing joints of the wallboards, so as to facilitate the owner to carry out line transformation and avoid damaging the wall by secondary grooving.

[0088] In the first aspect, a manufacturing method of a lightweight partition board made of recycled aggregate concrete is provided in the embodiments of this application, including the following steps:

[0089] S1: Dry mix cement with coarse aggregate, fine aggregate, pearl grains, and hydrophobic plant fibers to form a mixture;

[0090] When hydrophobic plant fibers are added to the raw materials, the fibers need to be pretreated before use. Taking reed fibers as an example, first roll and cut the reed stalks so that their dimensions meet the usage requirements. That is, the dimensions of the cut reed stalks are: the length is 20 mm to 30 mm, and the width is 1.0 mm to 1.5 mm. In this embodiment, a pulverizing machine can be used to strip and pulverize the reed fibers into fibrous shapes and remove the dust on the fiber surface. Then immerse the fibers in an alkali solution (5% NaOH), wash them with clean water and take them out for standby. After the reed fibers are treated with the alkali solution, they are dried and recorded as dry fibers. If they are not dried, they are recorded as wet fibers.

[0091] In practice, due to the relatively smooth surface and strong toughness of reeds, after treatment with an alkaline solution, the gelatinous layer on the surface of reed fibers can be removed, causing the relatively smooth surface of the reeds to peel off and become rough, making it easier to bond with cement during the later mixing process and enhancing the structural compactness of the wallboard.

[0092] In addition, the main components of reeds include fibers, lignin, and polysaccharides, etc. The sugars contained in them can dissolve in water, and the sugars dissolved from plant fibers greatly delay the hydration of C3S and hinder the formation of C-S-H. At this time, the amount of AFt generated is small and is not enough to cause the setting of the paste, so the setting is delayed. Therefore, the addition of reed fibers makes the setting delay of ordinary Portland cement more obvious, and the initial setting time reaches more than 22 h, which will seriously affect the forming, demolding, and handling processes of the blocks.

[0093] Removing the polysaccharides in the fibers through the alkali solution can, on the one hand, reduce the problem of slow cement setting after fiber addition. On the other hand, concrete is alkaline hydration heat, and the sugar bases of polysaccharides will react with the bases in the cement, consuming the bases in the cement and thus affecting the water-cement ratio. After being treated with the alkali solution and consuming the polysaccharides in the fibers, the influence of the fibers on the water-cement ratio can be effectively avoided, which is beneficial to improving the structural compactness of the wallboard. In Example 1, dry fibers are used, so it also includes air drying or drying treatment.

[0094] S2: After the binder and the first part of water are mixed, they are added to the mixture in the above step S1 to form a first mixture;

[0095] S3: CaCl2 and NaCl are mixed with the second part of water to form a mixed solution. At this time, the water temperature range is 38°C to 45°C. Then a plasticizer and a foaming agent are added to the mixed solution for foaming treatment. After the foaming is completed, a second mixture is formed;

[0096] S4: The second mixture after the foaming is completed in step S3 is dry-mixed with the first mixture in step S2 to obtain a concrete mixture;

[0097] S5: Add the above concrete mixture into a mold, and after curing, a lightweight partition board made of recycled aggregate concrete is obtained.

[0098] Specifically, in this embodiment, 750 g of cement is dry-mixed with 900 g of coarse aggregate, 600 g of fine aggregate, 200 g of pearl particles, and 100 g of long reed fibers with a length of 3 cm to form a mixture. At this time, the size of the reed fibers is: the length is 20 mm - 30 mm, and the width is 1.0 mm - 1.5 mm.

[0099] Then, after 13 g of diphenylmethane diisocyanate adhesive and 290 ml of water are mixed, they are added to the mixture to form a first mixture; then, 30 g of CaCl2 and 33 g of NaCl are mixed with 100 ml of water to form a mixed solution, and at this time, the water temperature is 40°C; then, 15 g of Стахемент-2000 superplasticizer and 400 g of anhydrous gypsum are added to the mixed solution for foaming treatment. After the foaming is completed, a second mixture is formed.

[0100] Finally, the second mixture after the foaming is completed is dry-mixed with the first mixture to obtain a concrete mixture, and the above concrete mixture is poured into a mold. After curing, a lightweight partition board made of recycled aggregate concrete is obtained. The above three groups of tests are repeated, and the average compressive strength of the partition board after 28 days of curing is 21.65 MPa, and the average flexural strength is 12 MPa, meeting the standard use requirements of the partition board. The preparation method of this embodiment is simple in operation, easy to control conditions, and easy to scale up production.

[0101] The reed fibers in this embodiment are dry fibers, and the fiber content is about 3% (2.9%).

[0102] Compressive and flexural tests are performed on the concrete partition board specimens prepared above, and the cracks generated during the axial compressive failure process of the specimens are observed. The direction of the cracks is roughly perpendicular to the load direction, the width of the cracks is uneven, the depth of the cracks is relatively shallow, and the number of cracks is small, as Figure 3 shown. It can be concluded that the reed fibers can limit the crack propagation of the concrete matrix, improve the crack resistance, disperse the directional stress of the concrete, increase the compressive strength, improve the toughness and impact resistance of the concrete, and enable the concrete to withstand large deformations and loads.

[0103] From Figure 3It can be seen that the length of reed fibers has a greater impact on the crack classification of specimens, while the dry-wet condition has a smaller impact. The reason lies in that long reed fibers have a better bridging effect, while the bridging effect of short reed fibers is poor. Dry-wet does not affect the tensile efficiency of reed fibers in concrete, but it affects the water-cement ratio. When the reed fiber concrete is continuously cyclically tensioned, the complete descending section of the stress-strain full curve exists, the loading time is long, the crack propagation is sufficient, and the slip and pull-out of short reed fibers generate more new splitting cracks, thus causing more microcracks and shear cracks; while the long reed fiber concrete can reach brittle failure, and when the stress reaches the tensile strength, the axial stress of the concrete drops vertically to 0, and the specimen is overall tensioned and damaged.

[0104] Example 2

[0105] In this example, the manufacturing method of the lightweight partition board of recycled aggregate concrete is the same as that in Example 1. The difference is that in this example, 750 g of cement is dry-mixed with 900 g of coarse aggregate, 600 g of fine aggregate, 200 g of pearl grains and 100 g of long reed fibers with a length of 3 cm to form a mixture.

[0106] The reed fibers in this example are wet fibers, with a fiber content of about 3% (2.9%). And before use, they are pretreated: the reed fibers are peeled and crushed into fibrous shape by a crushing machine, and the dust on the fiber surface is removed. Then the fibers are immersed in an alkali solution (5% NaOH), washed with clean water and taken out for standby.

[0107] Then 13 g of diphenylmethane diisocyanate binder and 290 ml of water are mixed and added to the mixture to form a first mixture; then 30 g of CaCl2 and 33 g of NaCl are mixed with 100 ml of water to form a mixed solution, and the water temperature at this time is 40 °C; then 15 g of Стахемент-2000 superplasticizer and 400 g of anhydrous gypsum are added to the mixed solution for foaming treatment. After the foaming is completed, a second mixture is formed.

[0108] Finally, the second mixture after foaming is dry-mixed with the first mixture to obtain a concrete mixture, and the above concrete mixture is poured into a mold. After curing, a lightweight partition board of recycled aggregate concrete is obtained. The above three groups of tests are repeated, and the average compressive strength of the partition board after 28 days of curing is 19.07 MPa, and the average flexural strength is 12.33 MPa, which also meets the standard use requirements of the partition board.

[0109] And at the reed fiber addition amount of 3%, the reed fibers can be well distributed in the concrete specimens, and there is no fiber agglomeration at all. The flexural and compressive strengths of the reed concrete were obtained from the test results, and the apparent mechanism of the concrete specimens after failure was analyzed. The test results show that the addition of reed fibers enhances the mechanical properties of the concrete. The compressive strength of the concrete increases by about 1.13 MPa compared with the control concrete, and the flexural strength increases by about 2.32 MPa. The specimens with dry or wet reed fibers added can improve the flexural strength of the concrete. The flexural strength of the dry reed fibers is slightly higher than the compressive strength of the wet reed fibers. After adding fibers, their flexural strengths are slightly higher than those of ordinary concrete, and the overall compressive strength increases by about 12.1%-18.3%.

[0110] Example 3

[0111] In this example, the manufacturing method of the lightweight partition board made of recycled aggregate concrete is the same as that in Example 1. The difference is that in this example, 750 g of cement, 900 g of coarse aggregate, 600 g of fine aggregate, 200 g of pearl particles and 150 g of long reed fibers with a length of 3 cm are dry mixed together to form a mixture.

[0112] The reed fibers in this example are dry fibers, and the fiber content is about 4.3%. And before use, they are pretreated first: the reed fibers are peeled and crushed into fibrous by a crushing machine, and the dust on the fiber surface is removed. Then the fibers are immersed in an alkali solution (5% NaOH), taken out after washing with clean water, and dried for standby.

[0113] Then 13 g of diphenylmethane diisocyanate binder and 290 ml of water are mixed and added to the mixture to form a first mixture; then 30 g of CaCl2 and 33 g of NaCl are mixed with 100 ml of water to form a mixed solution, and the water temperature at this time is 40°C; then 15 g of Стахемент-2000 superplasticizer and 400 g of anhydrous gypsum are added to the mixed solution for foaming treatment. After the foaming is completed, a second mixture is formed.

[0114] Finally, the second mixture after foaming is dry mixed with the first mixture to obtain a concrete mixture, and the above concrete mixture is poured into a mold. After curing, a lightweight partition board made of recycled aggregate concrete is obtained. The above three groups of tests are repeated, and the average compressive strength of the partition board after 28 days of curing is 15.02 MPa, and the average flexural strength is 10.66 MPa, which also meets the standard use requirements of the partition board.

[0115] Example 4

[0116] In this embodiment, the manufacturing method of the recycled aggregate concrete lightweight partition board is the same as that of Embodiment 1. The difference is that in this embodiment, 750 g of cement is dry-mixed with 900 g of coarse aggregate, 600 g of fine aggregate, 200 g of pearl particles, and 130 g of long reed fibers with a length of 3 cm to form a mixture.

[0117] The reed fibers in this embodiment are dry fibers with a fiber content of 3.7%. And before use, they are pretreated as follows: using a crushing machine to strip and crush the reed fibers into fibrous shape, removing the dust on the fiber surface, then immersing the fibers in an alkali solution (5% NaOH), taking them out after washing with clean water, and drying for standby.

[0118] Then, 13 g of diphenylmethane diisocyanate binder and 290 ml of water are mixed and added to the mixture to form a first mixture; then, 30 g of CaCl2 and 33 g of NaCl are mixed with 100 ml of water to form a mixed solution, and the water temperature is 40 °C at this time; then, 15 g of Стахемент-2000 superplasticizer and 400 g of anhydrous gypsum are added to the mixed solution for foaming treatment. After the foaming is completed, a second mixture is formed.

[0119] Finally, the second mixture after the foaming is completed is dry-mixed with the first mixture to obtain a concrete mixture, and the above concrete mixture is poured into a mold. After curing, a recycled aggregate concrete lightweight partition board is obtained. The above three groups of tests are repeated, and the average compressive strength of the partition board after 28 days of curing is 15.47 MPa, and the average flexural strength is 10.33 MPa, which also meets the standard use requirements of the partition board.

[0120] Embodiment 5

[0121] In this embodiment, the manufacturing method of the recycled aggregate concrete lightweight partition board is the same as that of Embodiment 1. The difference is that in this embodiment, 750 g of cement is dry-mixed with 900 g of coarse aggregate, 600 g of fine aggregate, 200 g of pearl particles, and 80 g of long reed fibers with a length of 3 cm to form a mixture.

[0122] The reed fibers in this embodiment are dry fibers with a fiber content of 2.3%. And before use, they are pretreated as follows: using a crushing machine to strip and crush the reed fibers into fibrous shape, removing the dust on the fiber surface, then immersing the fibers in an alkali solution (5% NaOH), taking them out after washing with clean water, and drying for standby.

[0123] Then, 13 g of diphenylmethane diisocyanate binder and 290 ml of water were mixed and added to the mixture to form a first mixture; then, 30 g of CaCl2 and 33 g of NaCl were mixed with 100 ml of water to form a mixed solution, and the water temperature was 40 °C at this time; then, 15 g of Стахемент - 2000 superplasticizer and 400 g of anhydrous gypsum were added to the mixed solution for foaming treatment. After the foaming was completed, a second mixture was formed.

[0124] Finally, the second mixture after the foaming was completed was dry - mixed with the first mixture to obtain a concrete mixture, and the above - mentioned concrete mixture was poured into a mold. After curing, a lightweight partition board made of recycled aggregate concrete was obtained. The above - mentioned steps were repeated for three groups of tests. The average compressive strength of the partition board after 28 - day curing was 18.8 MPa, and the average flexural strength was 10.92 MPa, which also met the standard usage requirements of the partition board.

[0125] Example 6

[0126] In this example, the manufacturing method of the lightweight partition board made of recycled aggregate concrete was the same as that in Example 1. The difference was that in this example, 750 g of cement was dry - mixed with 900 g of coarse aggregate, 600 g of fine aggregate, 200 g of pearl grains, and 180 g of long reed fibers with a length of 3 cm to form a mixture.

[0127] The reed fibers in this example were dry fibers, with a fiber content of 5.1%. And before use, they were pretreated: the reed fibers were peeled and crushed into fibrous shape by a crushing machine, and the dust on the fiber surface was removed. Then the fibers were immersed in an alkaline solution (5% NaOH), washed with clean water, taken out, and dried for standby.

[0128] Then, 13 g of diphenylmethane diisocyanate binder and 290 ml of water were mixed and added to the mixture to form a first mixture; then, 30 g of CaCl2 and 33 g of NaCl were mixed with 100 ml of water to form a mixed solution, and the water temperature was 40 °C at this time; then, 15 g of Стахемент - 2000 superplasticizer and 400 g of anhydrous gypsum were added to the mixed solution for foaming treatment. After the foaming was completed, a second mixture was formed.

[0129] Finally, the second mixture after the foaming was completed was dry - mixed with the first mixture to obtain a concrete mixture, and the above - mentioned concrete mixture was poured into a mold. After curing, a lightweight partition board made of recycled aggregate concrete was obtained. The above - mentioned steps were repeated for three groups of tests. The average compressive strength of the partition board after 28 - day curing was 14.44 MPa, and the average flexural strength was 10.33 MPa, which also met the standard usage requirements of the partition board.

[0130] Example 7

[0131] In this embodiment, the manufacturing method of the recycled aggregate concrete lightweight partition board is the same as that in Embodiment 1. The difference is that in this embodiment, 750 g of cement is dry-mixed with 900 g of coarse aggregate, 600 g of fine aggregate, 200 g of pearl particles and 200 g of long reed fibers with a length of 3 cm to form a mixture.

[0132] The reed fibers in this embodiment are dry fibers with a fiber content of 5.7%. And before use, they are pretreated as follows: using a crushing machine to strip and crush the reed fibers into fibrous shape, removing the dust on the fiber surface, then immersing the fibers in an alkali solution (5% NaOH), taking them out after washing with clean water and drying for standby.

[0133] Then, 13 g of diphenylmethane diisocyanate adhesive and 290 ml of water are mixed and added to the mixture to form a first mixture; then, 30 g of CaCl2 and 33 g of NaCl are mixed with 100 ml of water to form a mixed solution, and at this time the water temperature is 40°C; then, 15 g of Стахемент-2000 superplasticizer and 400 g of anhydrous gypsum are added to the mixed solution for foaming treatment. After the foaming is completed, a second mixture is formed.

[0134] Finally, the second mixture after the foaming is completed is dry-mixed with the first mixture to obtain a concrete mixture, and the above concrete mixture is poured into a mold. After curing, a recycled aggregate concrete lightweight partition board is obtained. The above process is repeated for three groups of tests. The average compressive strength of the partition board after 28 days of curing is 15.39 MPa, and the average flexural strength is 9.08 MPa, which no longer meets the standard use requirements of the partition board. It can be seen that when the fiber content exceeds a certain range, the flexural strength of the partition board will be affected.

[0135] Comparative Example 1

[0136] In this comparative example, the manufacturing method of the recycled aggregate concrete lightweight partition board is the same as that in Embodiment 1. The difference is that in this comparative example, 750 g of cement is dry-mixed with 900 g of coarse aggregate, 600 g of fine aggregate, 200 g of pearl particles and 50 g of long reed fibers with a length of 3 cm to form a mixture.

[0137] The reed fibers in this comparative example are short and dry fibers with a fiber content of about 1.5%. And before use, they are pretreated as follows: using a crushing machine to strip and crush the reed fibers into fibrous shape, removing the dust on the fiber surface, then immersing the fibers in an alkali solution (5% NaOH), taking them out after washing with clean water and drying for standby.

[0138] Then, 13 g of diphenylmethane diisocyanate adhesive and 290 ml of water were mixed and added to the mixture to form a first mixture. Then, 30 g of CaCl2 and 33 g of NaCl were mixed with 100 ml of water to form a mixed solution, and the water temperature was 40 °C at this time. Then, 15 g of Стахемент-2000 superplasticizer and 400 g of anhydrous gypsum were added to the mixed solution for foaming treatment. After the foaming was completed, a second mixture was formed.

[0139] Finally, the second mixture after foaming was dry-mixed with the first mixture to obtain a concrete mixture, and the above concrete mixture was poured into a mold. After curing, a lightweight partition board made of recycled aggregate concrete was obtained. The above three groups of tests were repeated, and the average compressive strength of the partition board after 28 days of curing was 16.24 MPa, and the average flexural strength was 8.68 MPa, which also met the standard use requirements of the partition board.

[0140] In this comparative example, due to the too small amount of fiber added, an effective three-dimensional reinforcement network could not be formed, resulting in a decrease in flexural strength, an increased risk of brittle fracture, difficulty in fully exerting the mechanical interlocking effect with the cement matrix, weakening of the fiber-matrix interfacial bonding strength, inability to improve the cohesiveness of the mixture, easy occurrence of aggregate segregation and bleeding phenomena, and the specimens were not lightweight enough, and more agricultural waste reed fibers could not be consumed, failing to meet the requirements of sustainable development of the building environment.

[0141] Comparative Example 2

[0142] In this comparative example, the manufacturing method of the lightweight partition board made of recycled aggregate concrete was the same as that in Example 1. The difference was that in this comparative example, 750 g of cement was dry-mixed with 900 g of coarse aggregate, 600 g of fine aggregate, 200 g of perlite beads, and 100 g of reed fibers with a length of 1.0 cm to form a mixture.

[0143] The reed fibers in this comparative example were short and wet fibers, and the fiber content was about 3% (2.9%). And before use, they were pretreated: the reed fibers were peeled and crushed into fibrous shapes by a crushing machine, and the dust on the fiber surface was removed. Then the fibers were immersed in an alkali solution (5% NaOH), taken out after washing with clean water, and reserved.

[0144] Then, 13 g of diphenylmethane diisocyanate adhesive and 290 ml of water were mixed and added to the mixture to form a first mixture. Then, 30 g of CaCl2 and 33 g of NaCl were mixed with 100 ml of water to form a mixed solution, and the water temperature was 40 °C at this time. Then, 15 g of Стахемент-2000 superplasticizer and 400 g of anhydrous gypsum were added to the mixed solution for foaming treatment. After the foaming was completed, a second mixture was formed.

[0145] Finally, the second mixture that has completed foaming is dry-mixed with the first mixture to obtain a concrete mixture, and the above concrete mixture is poured into a mold. After curing, a lightweight partition board made of recycled aggregate concrete is obtained. The above three groups of tests are repeated, and the average compressive strength of the partition board after 28 days of curing is 15.57 MPa, and the average flexural strength is 8.03 MPa, which also meets the standard usage requirements of the partition board.

[0146] In this comparative example, due to the too short length of the reed fibers, it is difficult to form an effective three-dimensional support network in the concrete, resulting in a decrease in the flexural and tensile strength of the material.

[0147] Comparative Example 3

[0148] In this comparative example, 750 g of cement is dry-mixed with 900 g of coarse aggregate, 600 g of fine aggregate, 200 g of pearl grains, and 100 g of long reed fibers with a length of 3 cm to form a mixture.

[0149] The reed fibers in this comparative example are wet fibers, and the fiber content is about 3% (2.9%). And before use, pretreatment is carried out: the reed fibers are peeled and crushed into fibrous shape by a crushing machine, and the dust on the fiber surface is removed. Then the fibers are immersed in an alkali solution (5% NaOH), taken out after washing with clean water, and reserved.

[0150] Then, after mixing 13 g of binder and 290 ml of water, it is added to the mixture to form a first mixture; then, after mixing 45 g of CaCl2 and 33 g of NaCl with 100 ml of water, a mixed solution is formed, and the water temperature at this time is 40 °C; then, 15 g of Стахемент-2000 superplasticizer and 400 g of anhydrous gypsum are added to the mixed solution and then foaming treatment is carried out to form a second mixture.

[0151] Finally, the second mixture is dry-mixed with the first mixture to obtain a concrete mixture, and the above concrete mixture is poured into a mold. After curing, test blocks of lightweight partition boards made of recycled aggregate concrete are obtained. For details, please refer to Figure 10 As shown, in this comparative example, due to the excessive amount of CaCl2 used, there are many bubbles on the surface of the test blocks, which are not beautiful, and the mechanical properties are poor, not meeting the specification requirements.

[0152] Comparative Example 4

[0153] In this comparative example, 750 g of cement is dry-mixed with 900 g of coarse aggregate, 600 g of fine aggregate, 200 g of pearl grains, and 100 g of long reed fibers with a length of 3 cm to form a mixture.

[0154] The reed fiber in this comparative example is wet fiber, with a fiber content of about 3% (2.9%). Before use, it is pretreated as follows: The reed fiber is peeled and crushed into fibrous form by a crushing machine, and the dust on the fiber surface is removed. Then the fiber is immersed in an alkali solution (5% NaOH), taken out after washing with clean water, and reserved for use.

[0155] Then, 13 g of binder and 290 ml of water are mixed and added to the mixture to form a first mixture. Then, 15 g of CaCl2 and 33 g of NaCl are mixed with 100 ml of water to form a mixed solution, and the water temperature at this time is 40 °C. Then, 15 g of Стахемент - 2000 superplasticizer and 400 g of anhydrous gypsum are added to the mixed solution for foaming treatment to form a second mixture.

[0156] Finally, the second mixture and the first mixture are dry - mixed to obtain a concrete mixture, and the above - mentioned concrete mixture is poured into a mold. After curing, a test block of recycled aggregate concrete lightweight partition board is obtained. For details, please refer to Figure 11 As shown, in this comparative example, due to the too - small dosage of CaCl2, the interior of the test block is full of air bubbles, collapses during the static curing process, cannot be shaped completely, and does not meet the specification requirements.

[0157] Comparative Example 5

[0158] The difference between this comparative example and Example 1 is that instead of using Стахемент - 2000 superplasticizer, ordinary plasticizer phthalate is used, and the component selection and production and construction processes are the same as those in Example 1.

[0159] Through experimental verification, it is found that when reed fiber is added to the main material components, using ordinary plasticizer phthalate results in poor shrinkage of the made test blocks. Therefore, Стахемент - 2000 superplasticizer is considered as the preferred plasticizer.

[0160] Comparative Example 6

[0161] The difference between this comparative example and Example 1 is that the plant fiber is not pretreated as above (using a crushing machine to peel and crush the reed fiber into fibrous form, removing the dust on the fiber surface, immersing the fiber in an alkali solution, and washing with clean water) before use, but is simply cut and used directly. The materials and production and construction processes are the same as those in Example 1.

[0162] Through experimental verification, it is found that due to the relatively smooth surface, strong toughness, and high polysaccharide content of the reed, the adhesion with cement is poor, and the compactness of the wallboard structure is insufficient.

[0163] The pretreatment of the alkaline solution is crucial for the solution of the present invention. Through the alkaline solution, the present invention can dissolve the gum substances such as lignin and hemicellulose remaining on the surface of reed fibers, expose a purer cellulose structure, enhance the chemical affinity between the fibers and the cement matrix, and the alkaline solution has a micro-etching effect on the fiber surface, forming more groove structures and enhancing the mechanical biting force between the fibers and the matrix. The bonding strength between the fibers treated with the alkaline solution and the cement paste; the pretreatment reduces the charge repulsion effect on the fiber surface, making the reed fibers more easily and evenly dispersed during dry mixing, avoiding local strength defects caused by agglomeration, and the pretreated fibers are more suitable for the subsequent foaming process, avoiding the interference of the surface residues of untreated fibers on the foaming agent and ensuring the uniformity and stability of the foaming structure; this process and the pretreatment of recycled aggregates act together to form a systematic optimization plan from raw materials to finished products.

[0164] Comparative Example 7

[0165] In this comparative example, 750 g of cement, 900 g of coarse aggregate, 600 g of fine aggregate, 200 g of pearl particles and 100 g of long reed fibers with a length of 3 cm were dry mixed together to form a mixture.

[0166] The reed fibers in this comparative example are wet fibers, with a fiber content of about 3% (2.9%), and pretreatment is carried out before use: the reed fibers are peeled and crushed into fibrous shape by a crushing machine, and the dust on the fiber surface is removed, and then the fibers are immersed in an alkaline solution (5% NaOH), washed with clean water and taken out for standby.

[0167] Then, 13 g of diphenylmethane diisocyanate binder and 290 ml of water were mixed and added to the mixture to form a first mixture; then, 30 g of CaCl2 and 33 g of NaCl were mixed with 100 ml of water to form a mixed solution, and the water temperature was 70 °C at this time; then, 15 g of Стахемент-2000 superplasticizer and 400 g of anhydrous gypsum were added to the mixed solution for foaming treatment, and after foaming was completed, a second mixture was formed.

[0168] Finally, the second mixture after foaming was dry mixed with the first mixture to obtain a concrete mixture, and the above concrete mixture was poured into a mold and cured to obtain a lightweight partition board made of recycled aggregate concrete.

[0169] It was found through experimental verification that due to the too high mixing temperature, the properties of plant fibers would change, such as turning yellow, generating bubbles, and becoming less tough, and the obtained partition board was dense and its mechanical properties and so on were poor.

[0170] Comparative Example 8

[0171] In this comparative example, 750 g of cement was dry-mixed with 900 g of coarse aggregate, 600 g of fine aggregate, 200 g of pearl particles, and 100 g of long reed fibers with a length of 3 cm to form a mixture.

[0172] The reed fibers in this comparative example were wet fibers, with a fiber content of approximately 3% (2.9%). Before use, they were pretreated as follows: The reed fibers were peeled and crushed into fibrous form using a crushing machine, and the dust on the fiber surface was removed. Then, the fibers were immersed in an alkali solution (5% NaOH), washed with clean water, and taken out for standby.

[0173] Then, 13 g of diphenylmethane diisocyanate binder and 290 ml of water were mixed and added to the mixture to form a first mixture. Then, 30 g of CaCl2 and 33 g of NaCl were mixed with 100 ml of water to form a mixed solution, and the water temperature at this time was 15°C. Then, 15 g of Стахемент-2000 superplasticizer and 400 g of anhydrous gypsum were added to the mixed solution for foaming treatment. After the foaming was completed, a second mixture was formed.

[0174] Finally, the second mixture after the foaming was completed was dry-mixed with the first mixture to obtain a concrete mixture, and the above concrete mixture was poured into a mold. After curing, a lightweight partition board made of recycled aggregate concrete was obtained.

[0175] Through experimental verification, it was found that due to the too low mixing temperature, the fluidity of the mixed materials decreased, the mixing uniformity was poor, and after hardening, the internal porosity was high and the internal residual stress was concentrated.

[0176] In the embodiments of the present invention, the mechanical properties of the prepared test blocks were measured and weighed: After being completely dried for the standard curing days (28 days), the weighing values of the standard concrete test blocks were 0.90 - 1.0 kg. The test blocks prepared in the embodiments of the present invention with the same size as the standard concrete test blocks had a measured mass of 0.30 - 0.45 kg after measurement, and all could meet the relevant requirements of the mechanical properties. The lighter test blocks, such as those prepared in Example 10, could reach 0.34 kg.

[0177] The comparison of the weighing between the present invention and the standard concrete test blocks is as Figure 12 shown. The weighing values of the standard concrete test blocks were 0.93 kg and 0.94 kg respectively.

[0178] It can be understood that the same or similar parts in the above embodiments can be referred to each other. For the content not detailed in some embodiments, reference can be made to the same or similar content in other embodiments.

[0179] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application.

Claims

1. A lightweight partition board made of recycled aggregate concrete, characterized in that Comprising the following components in parts by mass: Wherein the coarse aggregate is recycled concrete stone powder, which is sourced from construction waste; the fine aggregate is obtained by crushing treated biological shell waste.

2. The lightweight partition board made of recycled aggregate concrete according to claim 1, characterized in that: The hydrophobic plant fiber is any one of reed fiber, coconut shell fiber, and sisal fiber.

3. A lightweight partition board made of recycled aggregate concrete according to claim 1, characterized in that: The length of the reed fiber is 20 mm to 30 mm, and the width is 1.0 mm to 1.5 mm.

4. A lightweight partition board made of recycled aggregate concrete according to claim 1, characterized in that: The content of the hydrophobic plant fiber is 3%.

5. A lightweight partition board made of recycled aggregate concrete according to any one of claims 1-4, characterized in that: The foaming agent is anhydrous gypsum; and / or, the plasticizer uses Стахемент-2000 superplasticizer; and / or, the binder uses diphenylmethane diisocyanate binder.

6. The lightweight partition board made of recycled aggregate concrete according to claim 1, characterized in that: The partition board (100) is an assembled wallboard structure. A connecting part (110) is provided on one side in the width direction of the partition board (100), and a connecting hole (111) is provided in the connecting part (110); and / or, the dimensions of the partition board (100) are: width is 0.8 m to 0.95 m, height is 2.8 m to 3.2 m, thickness is 0.20 m to 0.22 m; the thickness of the mortar protective layer is 2 - 3 cm; and / or, a number of transverse steel bars and longitudinal steel bars are arranged inside the partition board (100).

7. The lightweight partition board of recycled aggregate concrete according to claim 6, wherein: On both sides in the height direction of the partition board (100), a mating tenon (120) and groove (130) are respectively provided, and the tenon (120) and the groove (130) are matched; and / or, the tenon (120) and the groove (130) are respectively located at the center position in the thickness direction of the partition board and extend along the width direction; and / or, the width of the tenon (120) is 4 cm to 8 cm smaller than the thickness of the partition board, and the depth of the groove (130) is 3 cm to 10 cm.

8. The manufacturing method of a lightweight partition board made of recycled aggregate concrete according to any one of claims 1-7, characterized in that, Including the following steps: S1: Dry mix cement with the coarse aggregate, fine aggregate, pearl grains, and hydrophobic plant fiber to form a mixture. S2: After mixing the binder and the first part of water, add them to the mixture in step S1 to form a first mixture. S3: Mix CaCl2 and NaCl with the second part of water to form a mixed solution. At this time, the water temperature range is 38°C to 45°C. Then, add a plasticizer and a foaming agent to the mixed solution for foaming treatment. After foaming is completed, a second mixture is formed. S4: Dry mix the second mixture after foaming in step S3 with the first mixture in step S2 to obtain a concrete mixture. S5: Add the above concrete mixture into a mold, and after curing, a lightweight partition board made of recycled aggregate concrete is obtained.

9. The manufacturing method of a lightweight partition board made of recycled aggregate concrete according to claim 8, characterized in that: In step S1, the hydrophobic plant fiber is subjected to rolling and cutting treatment to make its size meet the usage requirements. Then, the dust on the surface of the hydrophobic plant fiber is removed, and the fiber is immersed in an alkali solution and taken out for standby after a certain period of time.

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