Method for preparing concrete from solid waste aggregate sand
By treating industrial solid waste and urban garbage, solid waste aggregate sand is prepared to replace traditional sand and gravel aggregate aggregates, the problems of traditional sand and gravel aggregate resource depletion and environmental pollution are solved, and the effect of efficient use of waste is achieved, reducing production costs and improving concrete performance is achieved.
Patent Information
- Application Number
- CN202510039946.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-10
- Publication Date
- 2025-05-27
AI Technical Summary
In the prior art, the mining of traditional sand and gravel aggregate resources leads to depletion of natural resources and ecological environment problems, and poorly handled solid waste in construction, causing environmental pollution.
By processing industrial solid waste and urban garbage and other waste through crushing, screening, ball milling and other processes, solid waste aggregate sand with excellent performance is prepared, and used to replace traditional sand and gravel aggregates to prepare concrete with high strength and durability.
The resource utilization of waste has been achieved, environmental pollution and carbon emissions have been reduced, resource shortages have been alleviated, production costs have been reduced, and the mechanical properties and durability of concrete have been improved.
Smart Images
Figure SMS_1
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of concrete building materials, and particularly to a method for preparing concrete with solid waste aggregate sand. Background Art
[0002] Aggregate sand, as an indispensable component of concrete, plays a crucial role in the field of construction engineering. It is not only the key material for forming the concrete skeleton but also directly affects the strength, durability, and workability of concrete. However, with the rapid development of the global economy and the continuous advancement of urbanization, the exploitation of traditional sand and gravel aggregate resources has reached an unprecedented scale, which not only leads to the increasing depletion of natural resources but also causes serious ecological and environmental problems such as soil erosion and biodiversity reduction.
[0003] At the same time, construction solid waste mainly includes waste bricks, waste steel bars, waste wood, etc. generated from the demolition of old buildings, as well as muck, concrete blocks, etc. generated during the construction of new buildings. These wastes not only occupy a large amount of land resources but also cause environmental pollution. Therefore, how to properly handle these wastes has become an urgent task.
[0004] Facing this severe situation, the construction industry urgently needs to find sustainable and environmentally friendly sources of sand and gravel aggregates and methods for utilizing construction waste.
[0005] As an innovative solution, solid waste aggregate sand has emerged under this background. It uses industrial solid waste and urban garbage and other wastes, and through advanced preparation processes and technical means such as crushing, screening, ball milling, etc., converts them into aggregate sand with excellent performance. In this process, not only the resource utilization of waste is realized, but also environmental pollution and carbon emissions are significantly reduced, meeting the urgent requirements of global environmental protection, emission reduction, and sustainable development.
[0006] Compared with traditional sand and gravel aggregates, solid waste aggregate sand has many advantages. First of all, its preparation process can reduce the dependence on traditional sand and gravel resources, helping to alleviate the problem of resource shortage. Secondly, the waste generated during the preparation process of solid waste aggregate sand is less and easy to handle, reducing the risk of environmental pollution. In addition, the concrete prepared with solid waste aggregate sand performs well in terms of strength, durability, etc., and can meet the needs of various construction projects. More importantly, the preparation cost of solid waste aggregate sand is relatively low, which can reduce production costs, improve market competitiveness, and bring economic benefits to enterprises. Therefore, in-depth research on the technology and application of preparing concrete with solid waste aggregate sand not only helps to solve the resource and environmental problems faced by the construction industry but also promotes the green transformation and sustainable development of the construction industry. Summary of the Invention
[0007] The technical problem to be solved by the present invention is: in order to overcome the deficiencies existing in the prior art, a method for preparing concrete with solid waste aggregate sand is provided.
[0008] The technical solution adopted by the present invention is: a method for preparing concrete with solid waste aggregate sand, comprising the following steps:
[0009] A. Prepare solid waste aggregate sand. Mix the solid waste base materials and grind them in a ball mill for 30 minutes so that the median particle size D50 of the ground material is 7 microns. The weight component percentages in the waste base materials are as follows: 40 - 60 parts of mineral powder, 10 - 30 parts of slag, 10 - 20 parts of gypsum, 10 - 20 parts of carbide slag, 5 - 10 parts of boron mud, 0.02 - 0.04 parts of high-range water reducer, and 0.01 - 0.02 parts of catalyst.
[0010] B. Granulation. Put the solid waste aggregate sand in A into a container, add water accounting for 20% of the self-weight of the solid waste aggregate sand and stir evenly. Then put the evenly stirred aggregate sand into a granulator for granulation, and control the granulation process so that the particle size of the formed spherical embryo is less than 5.0 mm.
[0011] C. First place the solid waste aggregate sand in B in a curing box and cure it under the conditions of a temperature of 20°C and a humidity of 95% for 3 days, and then steam-cure it in an autoclave at a temperature of 180°C and a pressure of 1 Mpa for 1 day to form.
[0012] D. Prepare C30 concrete. Mix the solid waste aggregate sand in C with cement, stones, and water reducer. The weight component percentages are 7.5 parts of solid waste aggregate sand, 2.8 parts of cement, 10 parts of stones, and 0.04 parts of water reducer, and the water-cement ratio is 0.48.
[0013] Further, the mineral powder in the present invention is S95 grade granulated blast furnace slag powder, which meets the requirements of the activity index and fluidity ratio of S95 grade specified in GB / T 18046 - 2017 "Granulated Blast Furnace Slag Powder for Cement, Mortar and Concrete".
[0014] Further, the slag in the present invention is the slag produced by coal combustion.
[0015] Further, the gypsum in the present invention is at least one of industrial by-product desulfurized gypsum and phosphogypsum, which meets the requirements of GB / T 21371 - 2008 "Industrial By-Product Gypsum for Cement". The gypsum adjusts the pH value of the hydration system and promotes the hydration reaction;
[0016] Gypsum (mainly composed of calcium sulfate), as a sulfate activator, can react with the active components in slag and slag to generate products such as calcium sulfoaluminate hydrate.
[0017] The addition of gypsum can also adjust the pH value of the hydration system, which is beneficial to the progress of the hydration reaction. Under the synergistic action of calcium hydroxide and gypsum, while a large number of needle-like double salts crystals with a nanometer diameter are formed, a large number of nearly amorphous closely packed calcium silicate hydrate gels and zeolite-like phases are also formed, and the needle-like double salts crystals are tightly wrapped, making the entire gelling system have good density, strength, volume stability and the performance of resisting environmental erosion.
[0018] Furthermore, the carbide slag described in the present invention is the waste residue of a chemical plant, and its components include calcium hydroxide. As an alkaline activator, calcium hydroxide destroys the vitreous structure of slag and mineral powder, making it easier for water to penetrate into the interior, thereby accelerating the hydration reaction.
[0019] In an alkaline environment, the active components (such as silicates, aluminates, etc.) in slag and slag will undergo hydration reactions to generate gelling products such as calcium silicate hydrate and calcium aluminate hydrate.
[0020] Furthermore, the water reducer described in the present invention is a powder polycarboxylate water reducer.
[0021] Furthermore, the boron mud described in the present invention is a grayish-white or yellowish-white alkaline powdery solid produced in the production of boric acid and borax products, and its components include MgO and SiO 2 。
[0022] Furthermore, the catalyst described in the present invention is aluminate, specifically one of sodium aluminate or potassium aluminate.
[0023] The present invention has the following advantages compared with the prior art:
[0024] 1. After ball-milling the solid waste-based material, granulating it with a granulator, and obtaining the solid waste aggregate sand through standard curing and high-temperature steam curing, using the aggregate sand to replace ordinary sand to form concrete helps to alleviate the problem of resource shortage and can also avoid the environmental problems caused by the exploitation of traditional sand and gravel aggregates;
[0025] 2. The solid waste aggregate sand can use industrial solid wastes such as slag and slag as raw materials, has a wide range of raw material sources and significant environmental protection benefits;
[0026] 3. Utilizing the synergistic effect among the solid waste-based materials, the prepared solid waste aggregate sand has high cylinder compressive strength and low water absorption.
[0027] 4. By using the solid waste aggregate sand, the raw material cost of concrete is significantly reduced, and at the same time, the resource utilization efficiency is improved, bringing economic benefits;
[0028] 5. The solid waste aggregate concrete performs excellently in mechanical properties, can meet the safety and stability requirements of building structures, and has good durability, can resist environmental corrosion, and extend the service life of buildings. Detailed implementation mode
[0029] The following is a detailed description of the embodiments of the present invention. The embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operation processes are given. However, the protection scope of the present invention is not limited to the following embodiments.
[0030] Embodiment 1:
[0031] A method for preparing concrete with solid waste aggregate sand according to the present invention includes the following steps:
[0032] A. Prepare solid waste aggregate sand. Mix the solid waste base materials and grind them in a ball mill for 30 minutes so that the median particle size D50 of the ground material is 7 microns; the weight component percentages in the waste base materials are: 40 parts of mineral powder, 20 parts of slag, 10 parts of gypsum, 20 parts of carbide slag, 10 parts of boron mud, 0.02 parts of high-range water reducer, and 0.01 parts of catalyst;
[0033] B. Granulation. Put the solid waste aggregate sand in A into a container, add 20% of the self-weight of the solid waste aggregate sand of water and stir evenly. Then put the evenly stirred aggregate sand into a granulator for granulation, and control the granulation process so that the particle size of the formed spherical embryo is less than 5.0 mm;
[0034] C. First place the solid waste aggregate sand in B in a curing box and cure it under standard conditions at a temperature of 20°C and a humidity of 95% for 3 days, and then steam-cure it in an autoclave at a temperature of 180°C and a pressure of 1 Mpa for 1 day and then form it;
[0035] D. Prepare C30 concrete. Mix the solid waste aggregate sand in C with cement, stones, and water reducer; the weight component percentages are 7.5 parts of solid waste aggregate sand, 2.8 parts of cement, 10 parts of stones, and 0.04 parts of water reducer, and the water-cement ratio is 0.48.
[0036] Among them, the mineral powder is S95 grade granulated blast furnace slag powder, which meets the requirements of the activity index and fluidity ratio of S95 grade specified in GB / T 18046-2017 "Granulated Blast Furnace Slag Powder for Cement, Mortar and Concrete".
[0037] The slag is the slag produced by coal combustion. The gypsum is at least one of industrial by-product desulfurized gypsum and phosphogypsum, which meets the requirements of GB / T 21371-2008 "Industrial By-Product Gypsum for Cement". The gypsum adjusts the pH value of the hydration system and promotes the hydration reaction;
[0038] Gypsum (mainly composed of calcium sulfate), as a sulfate activator, can react with the active components in slag and slag to generate products such as calcium sulfoaluminate hydrate.
[0039] The addition of gypsum can also adjust the pH value of the hydration system, which is beneficial to the progress of the hydration reaction. Under the synergistic action of calcium hydroxide and gypsum, while a large number of needle-like double salts crystals with nanometer diameter are formed, a large number of hydrated calcium silicate gels and zeolite-like phases that are nearly amorphous and closely packed are also formed, and the needle-like double salts crystals are tightly wrapped, making the entire gelling system have good density, strength, volume stability and resistance to environmental erosion.
[0040] The carbide slag is the waste residue of a chemical plant, and its components include calcium hydroxide. As an alkaline activator, calcium hydroxide destroys the vitreous structure of the slag and mineral powder, making it easier for water to penetrate into the interior, thus accelerating the hydration reaction.
[0041] In an alkaline environment, the active components (such as silicates, aluminates, etc.) in the slag and slag will undergo hydration reactions to generate gelling products such as hydrated calcium silicate and hydrated calcium aluminate.
[0042] The water reducing agent is a powder polycarboxylate water reducing agent.
[0043] The boron mud is a grayish-white or yellowish-white alkaline powdery solid produced in the production of boric acid and borax products, and its components include MgO and SiO 2 。
[0044] The catalyst is aluminate, specifically one of sodium aluminate or potassium aluminate.
[0045] Example 2:
[0046] Set the weight percentage of the waste base materials in the prepared solid waste aggregate sand to 60 parts of mineral powder, 10 parts of slag, 10 parts of gypsum, 10 parts of carbide slag, 10 parts of boron mud, 0.04 parts of high-efficiency water reducing agent, and 0.01 parts of catalyst. The remaining steps are the same as in Example 1.
[0047] Example 3:
[0048] Set the weight percentage of the waste base materials in the prepared solid waste aggregate sand to 50 parts of mineral powder, 10 parts of slag, 15 parts of gypsum, 20 parts of carbide slag, 5 parts of boron mud, 0.02 parts of high-efficiency water reducing agent, and 0.02 parts of catalyst. The remaining steps are the same as in Example 1.
[0049] Example 4:
[0050] Set the weight percentage of the waste base materials in the prepared solid waste aggregate sand to 40 parts of mineral powder, 20 parts of slag, 15 parts of gypsum, 15 parts of carbide slag, 10 parts of boron mud, 0.02 parts of high-efficiency water reducing agent, and 0.02 parts of catalyst. The remaining steps are the same as in Example 1.
[0051] Comparative Example 1:
[0052] Set the weight percentage of waste base materials in the prepared solid waste aggregate sand as 60 parts of mineral powder, 20 parts of slag, 10 parts of gypsum, 10 parts of boron mud, 0.04 part of high-range water reducer, and 0.02 part of catalyst. The remaining steps are the same as those in Example 1.
[0053] Comparative Example 2:
[0054] Prepare concrete with ordinary sand.
[0055] The properties of the solid waste aggregate sand and concrete prepared by the present invention are shown in the following table:
[0056]
[0057] It can be seen from Comparative Example 1 and Example 2 that adding carbide slag can improve the cylindrical compressive strength of the aggregate sand. The main component of carbide slag is calcium hydroxide, and under the synergistic action with gypsum, the effect of activating slag and mineral powder is better, and the strength of the prepared concrete is higher. It can be seen from Comparative Example 2 that the concrete prepared with aggregate sand has better fluidity, which is beneficial to construction, and its compressive performance is higher than that of the concrete prepared with ordinary sand. During the preparation of concrete, the rolling effect is utilized to increase the fluidity of the concrete.
[0058] Preparing concrete with solid waste aggregate sand effectively converts solid wastes such as waste building materials and construction waste into valuable aggregate resources, which not only reduces the environmental pollution caused by these wastes, but also reduces the dependence on natural resources and the exploitation cost.
[0059] By using solid waste aggregate sand, the raw material cost of concrete is significantly reduced, while the resource utilization efficiency is improved, bringing economic benefits. In addition, solid waste aggregate concrete shows excellent mechanical properties, can meet the safety and stability requirements of building structures, and has good durability, can resist environmental corrosion, and extend the service life of buildings. These advantages are closely related to the invention purpose and significantly improve the disadvantages of the prior art, making solid waste aggregate sand have a wide application prospect in concrete engineering.
Claims
1. A method for preparing concrete using solid waste aggregate sand, characterized in that: The following steps are involved: A. preparing solid waste aggregate sand, mixing solid waste-based materials and grinding them in a ball mill for 30 minutes, so that the median particle size D50 of the ground material is 7 microns; wherein the weight percentages of the waste-based materials are: 40-60 parts of mineral powder, 10-30 parts of slag, 10-20 parts of gypsum, 10-20 parts of calcium carbide slag, 5-10 parts of boric mud, 0.02-0.04 parts of high-efficiency water reducing agent, and 0.01-0.02 parts of catalyst; B. Granulation, putting the solid waste aggregate sand in A into a container, adding 20% of water by weight to stir evenly, then putting the evenly stirred aggregate sand into a granulator for granulation, and controlling the granulation process so that the particle size of the spherical embryo after granulation is less than 5.0 mm; C. The solid waste aggregate sand in B is first placed in a curing box at a temperature of 20°C and a humidity of 95% for 3 days, and then steamed in an autoclave at a temperature of 180°C and a pressure of 1Mpa for 1 day before molding; D. To prepare C30 concrete, the solid waste aggregate sand in C is mixed with cement, gravel and water reducing agent; the weight percentage of the components is 7.5 parts of solid waste aggregate sand, 2.8 parts of cement, 10 parts of gravel and 0.04 parts of water reducing agent, wherein the water-cement ratio is 0.
48.
2. The method for preparing concrete from solid waste aggregate sand according to claim 1, characterized in that: The mineral powder is S95 grade granulated blast furnace slag powder.
3. The method for preparing concrete from solid waste aggregate sand as claimed in claim 1, characterized in that: The slag is produced by burning coal.
4. The method for preparing concrete from solid waste aggregate sand as claimed in claim 1, characterized in that: The gypsum is at least one of industrial by-product desulfurized gypsum and phosphogypsum. The gypsum adjusts the pH value of the hydration system and promotes the hydration reaction.
5. The method for preparing concrete from solid waste aggregate sand as claimed in claim 1, characterized in that: The carbide slag is waste residue from chemical plants, and its components include calcium hydroxide. Calcium hydroxide acts as an alkaline activator to destroy the glass structure of slag and mineral powder, making it easier for water to penetrate into the interior, thereby accelerating the hydration reaction.
6. The method for preparing concrete from solid waste aggregate sand as claimed in claim 1, characterized in that: The water reducing agent is a powdered polycarboxylic acid water reducing agent.
7. The method for preparing concrete from solid waste aggregate sand as claimed in claim 1, characterized in that: The borax mud is a gray or yellowish white alkaline powder solid produced by the production of boric acid and borax products. Its components include MgO and SiO 2 .
8. The method for preparing concrete from solid waste aggregate sand as claimed in claim 1, characterized in that: The catalyst is an aluminate, specifically one of sodium aluminate or potassium aluminate.