Reinforced recycled concrete aggregate and preparation method thereof

Abstract

The invention relates to the field of recycled aggregate, in particular to reinforced recycled concrete aggregate and a preparation method thereof. The reinforced recycled concrete aggregate comprises the following raw materials: 90-110 parts of recycled concrete particles, 80-100 parts of a vinyl chloride-vinylidene chloride copolymer emulsion, 10-20 parts of diatomite and 10-20 parts of slag. The preparation method comprises the following steps: crushing the recycled concrete; mixing diatomite, slag and a vinyl chloride-vinylidene chloride copolymer emulsion to obtain a mixed solution; recycled concrete particles are put into the mixed solution, stirring is conducted for 20-30 min under the condition of 1500-1800 r / min, and then soaking is conducted for 4-6 h; and after soaking is finished, fishing out the solid part, and draining to obtain the reinforced recycled concrete aggregate. The performance of the recycled concrete aggregate can be effectively improved, the reinforced recycled concrete aggregate can replace natural coarse aggregate, and concrete is endowed with a good effect.

Description

Technical Field

[0001] The present invention relates to the field of recycled aggregates, and more specifically, to a reinforced recycled concrete aggregate and a preparation method thereof. Background Art

[0002] With the rapid advancement of urbanization, the amount of construction waste has risen sharply, becoming an environmental problem that needs to be solved urgently. These wastes not only occupy a large amount of precious land resources, pile up into mountains, and affect the urban landscape, but are also likely to cause serious pollution to the soil, water and air through infiltration and leaching, threatening the ecological balance and human health. At the same time, natural aggregate resources are becoming increasingly scarce due to over-exploitation, making it difficult to meet the growing construction needs.

[0003] In the face of this challenge, converting construction waste into valuable building materials has become an effective way to solve environmental problems and achieve resource conservation and recycling. However, as an important product in this conversion process, recycled concrete aggregates are often difficult to be widely used in more projects due to performance deficiencies, such as low strength, high water absorption, and poor durability. These problems not only limit the market potential of recycled concrete aggregates, but also hinder the process of resource utilization of construction waste. Therefore, there is still room for improvement. Summary of the invention

[0004] In order to improve the performance of recycled concrete aggregate, the present application provides a reinforced recycled concrete aggregate and a preparation method thereof.

[0005] In the first aspect, the present application provides a reinforced recycled concrete aggregate, using the following technical solution: A reinforced recycled concrete aggregate comprises the following raw materials in parts by mass: 90-110 parts of recycled concrete particles, 80-100 parts of chloromelic emulsion, 10-20 parts of diatomaceous earth and 10-20 parts of slag.

[0006] Preferably, the following raw materials are included in proportion by mass: 95-105 parts of recycled concrete particles, 85-90 parts of chloroform emulsion, 15-20 parts of diatomaceous earth, and 10-15 parts of slag.

[0007] By adopting the above technical solution, with the cooperation of chloroform emulsion, diatomaceous earth and slag, the rough structure inside the aggregate is effectively reduced, its water absorption rate is reduced, and its physical and mechanical properties are significantly improved.

[0008] Specifically, chloroform emulsion, as a high-performance emulsion material, has good permeability and adhesion. When chloroform emulsion is used together with diatomaceous earth and slag to soak the crushed recycled concrete particles, it can effectively carry these two materials deep into the internal structure of the recycled aggregate. As a porous material, diatomaceous earth has a microporous structure that can adsorb and fix the effective ingredients in chloroform emulsion, and its own chemical stability can also provide additional strength support for the recycled aggregate. Slag is a potentially active material that can form a denser microstructure inside the recycled aggregate when combined with chloroform emulsion. This dense structure not only reduces the roughness inside the recycled aggregate, but also improves its overall strength and durability. Chlorine form a protective film on the surface of recycled concrete particles, further improving the impermeability and corrosion resistance of the aggregate.

[0009] The surface of the recycled aggregate after special treatment is smoother, which reduces the friction resistance between aggregates and makes the concrete mixture easier to compact during pouring and vibration. In addition, the bonding properties of the chloro-meta-emulsion and the filling effects of diatomaceous earth and slag enhance the interfacial bonding between aggregates and cement paste, thereby improving the compressive strength, tensile strength and flexural strength of concrete. The enhancement of these mechanical properties makes concrete components safer and more reliable when bearing loads.

[0010] After the treatment, the recycled aggregate forms a more compact microstructure, reducing the number and size of pores and cracks. This allows the concrete to be more fully hydrated during the hardening process, forming a more compact and uniform hardened body. This optimization of the microstructure not only improves the strength and durability of the concrete, but also enables the concrete to distribute the load more evenly when subjected to stress, reducing the risk of stress concentration and damage.

[0011] Preferably, the diatomaceous earth is 200-300 mesh, and the slag is 500-600 mesh.

[0012] By adopting the above technical solution, the specifications of diatomaceous earth and slag are further limited. At this particle size, diatomaceous earth can penetrate the recycled aggregate more deeply, effectively adsorb and fix the components of the chloro-melamine emulsion, and provide stronger chemical stability support. The fine slag particles are more active and cooperate more fully with the chloro-melamine emulsion to form a denser microstructure, significantly reducing the roughness and water absorption of the aggregate. This particle size combination not only enhances the physical and mechanical properties of the recycled aggregate, but also enhances the subsequent improvement of the density and interfacial adhesion of the concrete mixture, thereby significantly improving the compressive, tensile and flexural strength of the concrete, ensuring the safety, reliability and durability of the concrete components.

[0013] In a second aspect, the present application provides a method for preparing reinforced recycled concrete aggregate, using the following technical solution: A method for preparing reinforced recycled concrete aggregate comprises the following steps: Step 1: crushing the recycled concrete to obtain recycled concrete particles; Step 2: mixing diatomaceous earth, slag and chloroform emulsion at 1000-1200 r / min to obtain a mixed solution; Step 3: Add the recycled concrete particles into the mixed solution, stir at 1500-1800r / min for 20-30min, and then soak for 4-6h; Step 4: After soaking, remove the solid part and drain it to obtain reinforced recycled concrete aggregate.

[0014] By adopting the above technical solution, specific conditions are provided for the immersion of diatomite, slag, chlorinated emulsion and recycled concrete particles, which promotes the mixed liquid to penetrate into the recycled aggregate, effectively fill the pores and enhance the bonding force between the surface and the interior of the aggregate. Not only does it significantly improve the strength and durability of the recycled aggregate, but it also ensures good uniformity and density when preparing the concrete mixture in the subsequent preparation, thereby effectively improving the quality and service life of the overall concrete structure.

[0015] Preferably, in step 1, the concrete is crushed into recycled concrete particles of 5-25 mm.

[0016] By adopting the above technical solution, the particle size of recycled concrete particles is further limited, and they serve as coarse aggregate in concrete preparation, effectively solving the problem of tight resources of natural aggregates.

[0017] Preferably, during the soaking in step 3, stirring is performed for 10-15 minutes every 30-40 minutes.

[0018] Preferably, the recycled concrete particles are soaked in water for 1-2 hours, then dried, and then mixed with the mixed liquid.

[0019] By adopting the above technical solution, some impurities on the surface of particles, such as dust and free ions, can be significantly removed. These impurities may interfere with or slow down the subsequent chemical reactions. Through pretreatment, not only the surface of particles is purified, but also the effective contact and reaction between active materials such as chloroform emulsion, diatomaceous earth and slag and recycled aggregates are promoted, thereby enhancing the internal bonding force of aggregates and improving overall strength and durability. Not only that, it can also help optimize the penetration effect of the mixed liquid, ensure that the active ingredients can be more deeply and evenly distributed in the recycled aggregate, and further improve the performance of recycled concrete aggregates.

[0020] In a third aspect, the present application provides an application of reinforced recycled concrete aggregate in concrete.

[0021] Recycled aggregate is made from waste concrete, which reduces the generation of construction waste and is beneficial to environmental protection and resource conservation. In addition, the production cost of recycled aggregate is relatively low, and replacing natural aggregate can reduce construction costs and improve economic benefits. The reinforced recycled concrete aggregate provided by this application is close to or even reaches the standard of natural aggregate in performance, can meet various engineering needs, and has a stable output, which can effectively make up for the current situation of insufficient natural aggregate.

[0022] In summary, this application has the following beneficial effects: 1. The physical and mechanical properties of reinforced recycled concrete aggregates treated with chloro-partial emulsion, diatomaceous earth and slag have been significantly improved. The permeability and adhesion of chloro-partial emulsion allow these materials to penetrate into the internal structure of the recycled aggregate and tightly bond with the aggregate, reducing the rough structure inside the aggregate and reducing water absorption. The microporous structure and chemical stability of diatomaceous earth provide additional strength support for the recycled aggregate, while the potential activity of slag works together with chloro-partial emulsion to form a denser microstructure. This structural optimization effectively enhances the overall strength and durability of the aggregate.

[0023] 2. The surface of reinforced recycled concrete aggregate after special treatment is smoother, reducing the friction resistance between aggregates. This feature makes the concrete mixture easier to compact during pouring and vibration, improving the uniformity and density of concrete. At the same time, the adhesion of chloro-partial emulsion and the filling effect of diatomaceous earth and slag enhance the interfacial adhesion between aggregate and cement paste. This not only improves the mechanical properties of concrete, but also makes the concrete smoother during the construction process such as mixing, pouring and vibration, reducing the construction difficulty and time cost. The optimized concrete mixture can also better adapt to various construction environments and conditions, improving construction efficiency and quality.

[0024] 3. Strengthened recycled concrete aggregates are made from waste concrete, which not only reduces the generation of construction waste, but also is beneficial to environmental protection and resource conservation. At the same time, the production cost of strengthened recycled concrete aggregates is relatively low, and replacing natural aggregates can reduce construction costs and improve economic benefits. Strengthened recycled concrete aggregates that have been specially treated are close to or even reach the standards of natural aggregates in performance and can meet various engineering needs. It not only solves the problem of shortage of natural aggregate resources, but also promotes the process of resource utilization of construction waste. DETAILED DESCRIPTION

[0025] The present application is further described in detail below with reference to the embodiments.

[0026] The raw materials used in the following examples and comparative examples are all commercially available products. Example

[0027] Example 1 A reinforced recycled concrete aggregate comprises the following raw materials: 95 kg of recycled concrete particles, 85 kg of chloromemulsion, 15 kg of diatomaceous earth and 12 kg of slag.

[0028] Chloroform emulsion was commercially available from Wuhan Jiyesheng Chemical Co., Ltd.

[0029] Diatomaceous earth was commercially available from Kaiyao Mineral Products Processing Plant in Lingshou County; the specification was 250 mesh.

[0030] The slag was commercially available from Lingshou County Yiran Mineral Products Processing Plant; the specification was 550 mesh.

[0031] Recycled concrete particles are made from crushed concrete recycled from the market.

[0032] This embodiment also provides a method for preparing reinforced recycled concrete aggregate, comprising the following steps: Step 1: Remove large impurities from the recycled concrete and crush it to 5-25 mm to obtain recycled concrete particles.

[0033] Step 2: Wash the recycled concrete particles with clean water and soak them in water for 1.5 hours.

[0034] After the soaking treatment, use 80℃ hot air drying for 4 hours.

[0035] Step 3: Mix and stir the diatomaceous earth, slag and chloroform emulsion at 1100 r / min for 10 min to obtain a mixed solution for standby use.

[0036] Step 4: Add the recycled concrete particles from step 2 into the mixed solution, and then stir at 1600 r / min for 25 min.

[0037] Soak for 5 hours, stirring for 10 minutes every 30 minutes, and the stirring speed is 1600r / min.

[0038] Step 5: After soaking, remove the solid part and drain it naturally to obtain reinforced recycled concrete aggregate.

[0039] Example 2 A reinforced recycled concrete aggregate, which is different from Example 1 in that it includes the following raw materials: 105 kg of recycled concrete particles, 90 kg of chloromemulsion, 18 kg of diatomaceous earth, and 15 kg of slag.

[0040] Example 3 A reinforced recycled concrete aggregate, which is different from Example 1 in that it includes the following raw materials: 90 kg of recycled concrete particles, 80 kg of chloromemulsion, 10 kg of diatomaceous earth, and 10 kg of slag.

[0041] The specification of diatomaceous earth is 200 mesh.

[0042] The slag specification is 500 mesh.

[0043] A method for preparing reinforced recycled concrete aggregate, which is different from Example 1 in that some parameters are different, specifically comprises the following steps: Step 1: Remove large impurities from the recycled concrete and crush it to 5-25 mm to obtain recycled concrete particles.

[0044] Step 2: Wash the recycled concrete particles with clean water and soak them in water for 1 hour.

[0045] After the soaking treatment, use 80℃ hot air drying for 4 hours.

[0046] Step 3: Mix and stir the diatomaceous earth, slag and chloroform emulsion at 1000 r / min for 15 min to obtain a mixed solution for standby use.

[0047] Step 4: Add the recycled concrete particles from step 2 into the mixed solution, and then stir at 1500r / min for 30min.

[0048] Soak for 4 hours, stirring for 15 minutes every 40 minutes, and the stirring speed is 1500r / min.

[0049] Step 5: After soaking, remove the solid part and drain it naturally to obtain reinforced recycled concrete aggregate.

[0050] Example 4 A reinforced recycled concrete aggregate, which is different from Example 1 in that it includes the following raw materials: 110 kg of recycled concrete particles, 100 kg of chloroform emulsion, 20 kg of diatomaceous earth, and 20 kg of slag.

[0051] The specification of diatomaceous earth is 300 mesh.

[0052] The slag specification is 600 mesh.

[0053] A method for preparing reinforced recycled concrete aggregate, which is different from Example 1 in that some parameters are different, specifically comprises the following steps: Step 1: Remove large impurities from the recycled concrete and crush it to 5-25 mm to obtain recycled concrete particles.

[0054] Step 2: Wash the recycled concrete particles with clean water and soak them in water for 2 hours.

[0055] After the soaking treatment, use 80℃ hot air drying for 4 hours.

[0056] Step 3: Mix and stir the diatomaceous earth, slag and chloroform emulsion at 1200 r / min for 8 min to obtain a mixed solution for standby use.

[0057] Step 4: Add the recycled concrete particles from step 2 into the mixed solution, and then stir at 1800 r / min for 20 min.

[0058] Soak for 6 hours, stirring for 10 minutes every 30 minutes, and the stirring speed is 1800r / min.

[0059] Step 5: After soaking, remove the solid part and drain it naturally to obtain reinforced recycled concrete aggregate.

[0060] Comparative Example Comparative Example 1 A reinforced recycled concrete aggregate, which is different from Example 1 in that the chloroform emulsion is replaced by styrene acrylic emulsion.

[0061] Styrene acrylic emulsion was commercially available from Zhengzhou Wandao New Material Technology Co., Ltd.

[0062] Comparative Example 2 A reinforced recycled concrete aggregate is different from Example 1 in that diatomaceous earth is replaced by fly ash.

[0063] Comparative Example 3 A reinforced recycled concrete aggregate, which is different from Example 1 in that slag is replaced by limestone powder.

[0064] Comparative Example 4 A method for preparing reinforced recycled concrete aggregate, which is different from Example 1 in that the stirring speed in step 4 is 1000 r / min.

[0065] Comparative Example 5 A reinforced recycled concrete aggregate, which is different from Example 1 in that chloro-meta-emulsion, diatomaceous earth and slag are omitted.

[0066] A method for preparing reinforced recycled concrete aggregate comprises the following steps: Step 1: Remove large impurities from the recycled concrete and crush it to 5-25 mm to obtain recycled concrete particles.

[0067] Step 2: Wash the recycled concrete particles with clean water and soak them in water for 1.5 hours.

[0068] After the soaking treatment, the aggregate was dried with hot air at 80°C for 4 hours to obtain the reinforced recycled concrete aggregate.

[0069] Application Examples Application Example 1 A concrete comprises the following raw materials: 335 kg P.II 42.5R cement, 640 kg river sand, 1070 kg reinforced recycled concrete aggregate of Example 1, 145 kg water, 90 kg fly ash (grade II), 80 kg mineral powder (S95), and FST-6 admixture.

[0070] The above raw materials are mixed until uniform to obtain concrete.

[0071] Application Example 2 A concrete, which is different from Application Example 1 in that the reinforced recycled concrete aggregate adopts that of Example 2.

[0072] Application Example 3 A concrete, which is different from Application Example 1 in that the reinforced recycled concrete aggregate adopts that of Example 3.

[0073] Application Example 4 A concrete, which is different from Application Example 1 in that the reinforced recycled concrete aggregate adopts that of Example 4.

[0074] Application Example 5 A concrete, which is different from Application Example 1 in that the reinforced recycled concrete aggregate adopts that of Comparative Example 1.

[0075] Application Example 6 A concrete, which is different from Application Example 1 in that the reinforced recycled concrete aggregate adopts that of Comparative Example 2.

[0076] Application Example 7 A concrete, which is different from Application Example 1 in that the reinforced recycled concrete aggregate adopts that of Comparative Example 3.

[0077] Application Example 8 A concrete, which is different from Application Example 1 in that the reinforced recycled concrete aggregate adopts that of Comparative Example 4.

[0078] Application Example 9 A concrete, which is different from Application Example 1 in that the reinforced recycled concrete aggregate adopts the one of Comparative Example 5.

[0079] Application Example 10 A concrete, which is different from Application Example 1 in that commercially available crushed stone with a size of 5-25 mm is used to replace the reinforced recycled concrete aggregate.

[0080] The crushed stone was purchased from Shunxing Stone Quarry and the type was granite.

[0081] Performance testing 1. Water absorption rate: Referring to JGJ52-2006 "Standard for Quality and Inspection Methods of Sand and Stone for Ordinary Concrete", the water absorption rate of the reinforced recycled concrete aggregates of Examples 1-4 and Comparative Examples 1-5 was tested, and the water absorption rate was recorded in Table 1.

[0082] Table 1 Comparative Example 5 is based on Example 1, omitting the chlorine-based emulsion, diatomaceous earth, and slag, and its effect is similar to that of recycled aggregates on the market. According to the test data in Table 1, the water absorption rate of Comparative Example 5 is 6.9%, and the water absorption rate of Example 1 is 3.2%. The water absorption rate of Example 1 is significantly lower than that of Comparative Example 5.

[0083] Comparative Examples 1-3 are based on Example 1, and any of the chlorine-based emulsion, diatomaceous earth, and slag is replaced by other principles. Comparative Example 4 is based on Example 1, and the stirring conditions of the chlorine-based emulsion, diatomaceous earth, slag and recycled concrete particles are changed. According to the test data in Table 1, the water absorption rates of Comparative Examples 1-4 are all higher than that of Example 1.

[0084] This shows that the performance of the reinforced recycled concrete aggregate obtained by treating the recycled concrete particles with chloroform emulsion, diatomaceous earth and slag is indeed improved, the water absorption rate is effectively reduced, and the subsequent impact on concrete preparation is weakened.

[0085] 2. Compressive performance: According to GB / T50081-2019 "Standard for Test Methods for Physical and Mechanical Properties of Concrete", the concrete of Cases 1-10 was tested for 28d compressive performance, and the compressive strength was recorded in Table 2.

[0086] 3. Durability: According to GB / T50082-2009 "Standard for Test Methods for Long-term Performance and Durability of Ordinary Concrete", the concrete of Cases 1-10 was tested for its resistance to chloride ion penetration using the RCM method, and the chloride ion diffusion coefficient results were recorded in Table 2.

[0087] Table 2 Group Compressive strength(MPa) <![CDATA[Chloride ion diffusion coefficient (×10-12m 2 / s)]]> Application Example 1 72.2 1.3 Application Example 2 72.8 1.1 Application Example 3 71.6 1.5 Application Example 4 71.9 1.5 Application Example 5 65.8 2.8 Application Example 6 66.5 2.6 Application Example 7 67.3 2.5 Application Example 8 68.5 2.3 Application Example 9 62.0 3.5 Application Example 10 72.0 1.2 Application Example 10 is based on Application Example 1, using commercially available 5-25 mm crushed stone to replace the reinforced recycled concrete aggregate, that is, simulating the concrete of conventional natural aggregate on the market. According to the test data in Table 2, the compressive strength and chloride ion diffusion coefficient data of Application Example 1 and Application Example 10 are similar, indicating that the effects of Application Example 1 and Application Example 10 are equivalent. In other words, the reinforced recycled concrete aggregate provided in this application can replace natural aggregate.

[0088] Application Examples 5-9 correspond to the reinforced recycled concrete aggregates of Application Examples 1-5 respectively. According to the test data in Table 2, there is a big gap between Application Examples 5-9 and Application Example 1, and the general situation is similar to the performance gap of the aggregates in Table 1. This shows that the specific reinforced recycled concrete aggregate provided by this application can play a good role. If the formula is changed at will, the synergy cannot be exerted and the performance is low.

[0089] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A reinforced recycled concrete aggregate, characterized in that: The raw materials include the following in proportion by weight: 90-110 parts of recycled concrete particles, 80-100 parts of chloroform emulsion, 10-20 parts of diatomaceous earth, and 10-20 parts of slag.

2. The reinforced recycled concrete aggregate according to claim 1, characterized in that: The raw materials include the following in proportion by weight: 95-105 parts of recycled concrete particles, 85-90 parts of chloroform emulsion, 15-20 parts of diatomaceous earth, and 10-15 parts of slag.

3. The reinforced recycled concrete aggregate according to claim 1, characterized in that: The diatomaceous earth has a mesh size of 200-300, and the slag has a mesh size of 500-600.

4. A method for preparing the reinforced recycled concrete aggregate according to any one of claims 1 to 3, characterized in that: The following steps are involved: Step 1: crushing the recycled concrete to obtain recycled concrete particles; Step 2: mixing diatomaceous earth, slag and chloroform emulsion at 1000-1200 r / min to obtain a mixed solution; Step 3: Add the recycled concrete particles into the mixed solution, stir at 1500-1800r / min for 20-30min, and then soak for 4-6h; Step 4: After soaking, remove the solid part and drain it to obtain reinforced recycled concrete aggregate.

5. The method for preparing reinforced recycled concrete aggregate according to claim 4, characterized in that: In the step 1, the concrete is crushed into recycled concrete particles of 5-25 mm.

6. The method for preparing reinforced recycled concrete aggregate according to claim 4, characterized in that: During the soaking in step 3, stir for 10-15 minutes every 30-40 minutes.

7. The method for preparing reinforced recycled concrete aggregate according to claim 4, characterized in that: The recycled concrete particles are soaked in water for 1-2 hours, then dried, and then mixed with the mixed liquid.

8. Use of the reinforced recycled concrete aggregate obtained by the preparation method of the reinforced recycled concrete aggregate according to any one of claims 1 to 3 or any one of claims 4 to 7 in concrete.

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