A self-leveling mortar based on recycled solid waste materials and its preparation method
By utilizing the synergistic effect of modified rice husk ash powder and additives, a self-leveling mortar based on recycled solid waste materials was prepared, solving the problems of high energy consumption, large resource consumption, and high cost of traditional self-leveling mortar. This achieved efficient and environmentally friendly utilization of solid waste, improved the fluidity and early strength of the mortar, and reduced production costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- GUANGDONG KAIENDE ENVIRONMENTAL PROTECTION BUILDING MATERIALS CO LTD
- Filing Date
- 2025-10-13
- Publication Date
- 2026-05-26
AI Technical Summary
Traditional self-leveling mortar production is energy-intensive and generates a large amount of carbon emissions. It also uses natural river sand, which increases the consumption of natural resources and environmental pressure. In addition, the addition of solid waste leads to poor mortar fluidity, difficulty in controlling setting time, and a decrease in early strength, resulting in high costs and making it difficult to achieve large-scale application.
By using recycled solid waste materials such as granulated blast furnace slag powder, fly ash microspheres, waste glass sand, and waste stone powder, and through the synergistic effect of modified rice husk ash powder and additives, a self-leveling mortar based on recycled solid waste materials is prepared. The additive powder replaces the traditional alkaline solution to achieve dry-powdered polymer reaction. Combined with waste modifiers such as papermaking black liquor and molasses, it provides excellent water reduction and water retention effects, and controls setting time and early strength.
It achieves excellent flowability and early strength of self-leveling mortar, improves the overall performance of solid waste-based building materials, reduces production costs, reduces carbon emissions and natural resource consumption in the cement industry, and has both economic and environmental benefits.
Abstract
Description
Technical Background
[0001] This invention relates to the field of building materials technology, specifically to a self-leveling mortar based on recycled solid waste materials and its preparation method. Background Technology
[0002] Self-leveling mortar, as a high-performance floor leveling material, is widely used in modern building flooring projects. Traditional self-leveling mortar mainly relies on silicate cement as a binder, which has high energy consumption and large carbon emissions in its production process. In addition, it uses a large amount of natural river sand, which exacerbates the consumption of natural resources and environmental pressure. At present, some studies have tried to use slag, fly ash and other materials to replace part of the cement, or use waste glass, construction waste and other materials to replace natural aggregates.
[0003] However, existing technologies face many technical bottlenecks: First, the addition of ordinary solid waste often leads to problems such as poor mortar fluidity, difficulty in controlling setting time, and decreased strength, especially early strength. Second, in order to achieve performance requirements, it is usually necessary to rely on high amounts of cement and expensive chemical additives, resulting in high costs and difficulty in achieving large-scale application. Based on this, the present invention proposes a self-leveling mortar based on recycled solid waste materials and its preparation method. Summary of the Invention
[0004] The purpose of this invention is to provide a self-leveling mortar based on recycled solid waste materials and its preparation method. The self-leveling mortar prepared by this invention not only has excellent fluidity and early strength, but also excellent stability and durability, effectively improving the comprehensive performance of solid waste-based building materials.
[0005] To achieve the above objectives, the present invention provides the following technical solution:
[0006] In a first aspect, the present invention provides a self-leveling mortar based on recycled solid waste materials, comprising the following raw materials in parts by weight: 100 parts additives, 120-150 parts aggregates, 0.3-0.8 parts auxiliary agents, 0.05-0.15 parts cellulose ethers, 0.1-0.3 parts defoamer, and 25-35 parts water;
[0007] The additive is composed of the following components: 50-70 parts of granulated blast furnace slag powder, 20-30 parts of fly ash microspheres, and 10-20 parts of additive powder.
[0008] The aggregate is a mixture of 40-100 mesh waste glass sand and 80-150 mesh waste stone powder in a mass ratio of 1:(1-1.5).
[0009] Furthermore, the additive powder is prepared by the following method:
[0010] S1: The modified rice husk ash powder and solid sodium hydroxide are mixed at a mass ratio of 1:(0.8-1.2) to obtain the first mixed powder;
[0011] S2: Industrial grade sodium metasilicate nonahydrate is heated at 150-200℃ to dehydrate until the moisture content is less than 5%, and then pulverized to obtain the second powder.
[0012] S3: Mix the first mixed powder and the second powder at a mass ratio of 1:(0.5-1), calcine at 250-350℃ for 1-2 hours to obtain coarse material, cool the coarse material to room temperature, and grind it to a specific surface area ≥500m². 2 / kg, to obtain additive powder.
[0013] Further, the modified rice husk ash powder is prepared by the following method: after rinsing the rice husks with clean water, soaking them in dilute hydrochloric acid for 2-4 hours, washing the soaked rice husks until neutral, drying them, calcining the dried rice husks at 600-700℃ in an oxygen-deficient environment for 2-3 hours to obtain rice husk ash, mixing the rice husk ash with the first modifier at a mass ratio of 100:(3-8), adding deionized water and stirring to obtain a slurry, stirring the slurry at 60-80℃ for 2-4 hours, filtering, drying the filtered material to obtain dry material, and pulverizing and grinding the dry material to obtain modified rice husk ash powder.
[0014] Furthermore, the first modifier is prepared by the following method:
[0015] Step 1: Centrifuge the black liquor of papermaking at 8000-12000 rpm for 20-30 minutes to obtain the supernatant. Add concentrated sulfuric acid dropwise to the supernatant until the pH of the solution is 3-4, then stop adding the sulfuric acid. Filter to obtain the precipitate.
[0016] Step 2: Wash the precipitate until neutral to obtain crude lignin. Mix the crude lignin with molasses at a mass ratio of 1:(0.2-0.5) to obtain a second mixture. Add deionized water and stir to dissolve to obtain a first mixture.
[0017] Step 3: Introduce ozone into the first mixture and irradiate it with ultraviolet light at the same time. React for 1-2 hours to obtain the first modifier.
[0018] Further, the additive is prepared by the following method: the second modifier is mixed with deionized water at a mass ratio of 1:(8-12), stirred and dissolved to obtain a second mixture, ammonium persulfate is added to the second mixture, and the mixture is reacted at 60-70℃ for 3-5 hours to obtain an intermediate product, and the intermediate product is spray-dried to obtain the additive, wherein the mass of ammonium persulfate is 5-15% of the mass of the second modifier.
[0019] Further, the second modifier is prepared by the following method: rosin is pulverized and heated to 120-140℃, maleic anhydride is added under stirring, and the reaction is carried out at 120-140℃ for 2-3 hours to obtain maleic rosin. Maleic rosin and sodium lignosulfonate are mixed at a mass ratio of 1:(2-4) to obtain a third mixture. Ethanol is added and stirred to dissolve to obtain a third mixture. The third mixture is refluxed at 70-80℃ for 4-6 hours. After the reaction is completed, ethanol is recovered by vacuum distillation. The remaining product of distillation is dried and pulverized to obtain the second modifier.
[0020] Furthermore, the mass of the maleic anhydride is 10-20% of the mass of the rosin, the mass fraction of the ethanol is greater than 95%, and the mass of the ethanol is 3-5 times the total mass of the third mixture.
[0021] Furthermore, the concentrated sulfuric acid in step 1 has a mass fraction of 90-98%, the amount of deionized water added in step 2 is 5-10 times the total mass of the second mixture, and the ozone flow rate in step 3 is 0.5-1.0 L / min.
[0022] Furthermore, the mass fraction of the dilute hydrochloric acid is 5-10%, and the amount of dilute hydrochloric acid used must completely submerge the rice husks. The amount of deionized water added is 2-3 times the mass of the rice husk ash.
[0023] Secondly, the present invention also provides a method for preparing self-leveling mortar based on recycled solid waste materials, which is obtained by the following method:
[0024] Step 1: First, put the additives, aggregates, cellulose ethers and defoamers into the mixer and dry mix them for 3-5 minutes at a speed of 300-500 rpm to obtain the premix.
[0025] Step 2: Add the additives to the premix and continue dry mixing at 300-500 rpm for 2-3 minutes to obtain the dry mix.
[0026] Step 3: Place the dry mix in a planetary mixer and mix at 200-300 rpm for 1 minute, then mix at 800-1000 rpm for 3-5 minutes to obtain self-leveling mortar.
[0027] Compared with the prior art, the beneficial effects of the present invention are:
[0028] 1. This invention uses additive powder to replace traditional alkaline solutions. The additive powder achieves the dry powdering of the geopolymer reaction during the preparation process, which solves the industry problems of strong corrosiveness of alkali-activated mortar, difficulty in storage and transportation, and complex on-site preparation process, making it compatible with existing dry powder mortar production lines.
[0029] 2. The core additive of this invention uses waste materials such as papermaking black liquor, molasses, and rosin as raw materials. Through ozone-ultraviolet synergistic modification and esterification reaction, a highly efficient additive with high compatibility with geopolymer system is synthesized, which provides excellent water reduction and water retention effects, gives mortar an ultra-long construction window and high early strength, and overcomes the common performance defects of solid waste-based materials.
[0030] 3. This invention achieves efficient synergistic and high-value utilization of various solid wastes. Slag, fly ash, waste glass, waste stone powder, rice husk ash, papermaking black liquor, and molasses are all derived from solid wastes. The product contains a very high amount of solid waste, which not only significantly reduces production costs but also significantly reduces carbon emissions from the cement industry and the consumption of natural resources, thus achieving both excellent economic and environmental benefits. Detailed Implementation
[0031] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0032] Example 1:
[0033] Aggregate preparation: 40-mesh waste glass sand and 80-mesh waste stone powder are mixed at a mass ratio of 1:1 to obtain aggregate.
[0034] Preparation of the first modifier:
[0035] Step 1: Centrifuge the black liquor of papermaking at 8000 rpm for 20 minutes to obtain the supernatant. Add concentrated sulfuric acid dropwise to the supernatant until the pH of the solution reaches 3, then stop adding the sulfuric acid. Filter to obtain the precipitate, in which the mass fraction of concentrated sulfuric acid is 90%.
[0036] Step 2: Wash the precipitate until neutral to obtain crude lignin. Mix the crude lignin with molasses at a mass ratio of 1:0.2 to obtain a second mixture. Add deionized water and stir to dissolve to obtain a first mixture. The amount of deionized water added is 5 times the total mass of the second mixture.
[0037] Step 3: Introduce ozone at a flow rate of 0.5 L / min into the first mixture and irradiate it with ultraviolet light at the same time. React for 1 hour to obtain the first modifier.
[0038] Preparation of modified rice husk ash powder: After rinsing the rice husks with clean water, soak them in 5% dilute hydrochloric acid for 2 hours. Wash the soaked rice husks until neutral, dry them, and calcine them at 600℃ in an oxygen-deficient environment for 2 hours to obtain rice husk ash. Mix the rice husk ash with the first modifier at a mass ratio of 100:3, add deionized water and stir to obtain a slurry. Stir the slurry at 60℃ for 2 hours, filter it, and dry it to obtain a dry material. Crush and grind the dry material to obtain modified rice husk ash powder. The amount of dilute hydrochloric acid should completely submerge the rice husks, and the amount of deionized water added should be twice the mass of the rice husk ash.
[0039] Preparation of the added powder:
[0040] S1: The modified rice husk ash powder and solid sodium hydroxide are mixed at a mass ratio of 1:0.8 to obtain the first mixed powder;
[0041] S2: Industrial grade sodium metasilicate nonahydrate is heated at 150°C to dehydrate until the moisture content is less than 5%, and then pulverized to obtain the second powder.
[0042] S3: Mix the first mixed powder and the second powder at a mass ratio of 1:0.5, calcine at 250℃ for 1 hour to obtain coarse material, cool the coarse material to room temperature, and grind it to a specific surface area ≥500m². 2 / kg, to obtain additive powder.
[0043] Preparation of the second modifier: Rosin was pulverized and heated to 120°C. Maleic anhydride was added under stirring, and the mixture was reacted at 120°C for 2 hours to obtain maleic rosin. Maleic rosin and sodium lignosulfonate were mixed at a mass ratio of 1:2 to obtain a third mixture. Ethanol was added and stirred to dissolve the mixture to obtain a third mixture. The third mixture was refluxed at 70°C for 4 hours. After the reaction was completed, ethanol was recovered by vacuum distillation. The remaining product from distillation was dried and pulverized to obtain the second modifier. The mass of maleic anhydride was 10% of the mass of rosin, the mass fraction of ethanol was greater than 95%, and the mass of ethanol was 3 times the total mass of the third mixture.
[0044] Preparation of the additive: The second modifier and deionized water are mixed at a mass ratio of 1:8 and stirred to dissolve, resulting in a second mixture. Ammonium persulfate is added to the second mixture and reacted at 60°C for 3 hours to obtain an intermediate product. The intermediate product is then spray-dried to obtain the additive, wherein the mass of ammonium persulfate is 5% of the mass of the second modifier.
[0045] Raw material preparation: 100 parts additives, 120 parts aggregates, 0.3 parts auxiliary agents, 0.05 parts cellulose ethers, 0.1 parts defoamer, and 25 parts water; wherein, the additives are composed of the following components: 50 parts granulated blast furnace slag powder, 20 parts fly ash microspheres, and 10 parts additive powder.
[0046] Preparation of self-leveling mortar based on recycled solid waste materials:
[0047] Step 1: First, put the additives, aggregates, cellulose ethers and defoamers into the mixer and dry mix them at 300 rpm for 3 minutes to obtain the premix.
[0048] Step 2: Add the additives to the premix and continue dry mixing at 300 rpm for 2 minutes to obtain the dry mix.
[0049] Step 3: Place the dry mix in a planetary mixer and mix at 200 rpm for 1 minute, then mix at 800 rpm for 3 minutes to obtain self-leveling mortar.
[0050] Example 2:
[0051] Aggregate preparation: 60-mesh waste glass sand and 100-mesh waste stone powder are mixed at a mass ratio of 1:1.25 to obtain aggregate.
[0052] Preparation of the first modifier:
[0053] Step 1: Centrifuge the black liquor of papermaking at 10,000 rpm for 25 minutes to obtain the supernatant. Add concentrated sulfuric acid dropwise to the supernatant until the pH of the solution reaches 3.5, then stop adding the sulfuric acid. Filter to obtain the precipitate, in which the mass fraction of concentrated sulfuric acid is 95%.
[0054] Step 2: Wash the precipitate until neutral to obtain crude lignin. Mix the crude lignin with molasses at a mass ratio of 1:0.3 to obtain a second mixture. Add deionized water and stir to dissolve to obtain a first mixture. The amount of deionized water added is 7 times the total mass of the second mixture.
[0055] Step 3: Introduce ozone at a flow rate of 0.75 L / min into the first mixture and irradiate it with ultraviolet light at the same time. React for 1.5 h to obtain the first modifier.
[0056] Preparation of modified rice husk ash powder: After rinsing the rice husks with clean water, soak them in 8% dilute hydrochloric acid for 3 hours. Wash the soaked rice husks until neutral, dry them, and calcine them at 650℃ in an oxygen-deficient environment for 2.5 hours to obtain rice husk ash. Mix the rice husk ash with the first modifier at a mass ratio of 100:5, add deionized water and stir to obtain a slurry. Stir the slurry at 70℃ for 3 hours, filter it, and dry it to obtain a dry material. Crush and grind the dry material to obtain modified rice husk ash powder. The amount of dilute hydrochloric acid should completely submerge the rice husks, and the amount of deionized water added should be 2.5 times the mass of the rice husk ash.
[0057] Preparation of the added powder:
[0058] S1: Modified rice husk ash powder and solid sodium hydroxide are mixed at a mass ratio of 1:1 to obtain the first mixed powder;
[0059] S2: Industrial grade sodium metasilicate nonahydrate is heated at 175°C to dehydrate until the moisture content is less than 5%, and then pulverized to obtain the second powder.
[0060] S3: Mix the first mixed powder and the second powder at a mass ratio of 1:0.75, calcine at 300℃ for 1.5 hours to obtain coarse material, cool the coarse material to room temperature, and grind it to a specific surface area ≥500m². 2 / kg, to obtain additive powder.
[0061] Preparation of the second modifier: Rosin was pulverized and heated to 130°C. Maleic anhydride was added under stirring, and the mixture was reacted at 130°C for 2.5 h to obtain maleic rosin. Maleic rosin and sodium lignosulfonate were mixed at a mass ratio of 1:3 to obtain a third mixture. Ethanol was added and stirred to dissolve the mixture to obtain a third mixture solution. The third mixture solution was refluxed at 75°C for 5 h. After the reaction was completed, ethanol was recovered by vacuum distillation. The remaining product of distillation was dried and pulverized to obtain the second modifier. The mass of maleic anhydride was 15% of the mass of rosin, the mass fraction of ethanol was greater than 95%, and the mass of ethanol was 4 times the total mass of the third mixture.
[0062] Preparation of the additive: The second modifier and deionized water were mixed at a mass ratio of 1:10 and stirred to dissolve, resulting in a second mixture. Ammonium persulfate was added to the second mixture and reacted at 65°C for 4 hours to obtain an intermediate product. The intermediate product was spray-dried to obtain the additive, wherein the mass of ammonium persulfate was 10% of the mass of the second modifier.
[0063] Raw material preparation: 100 parts additives, 130 parts aggregates, 0.5 parts auxiliary agents, 0.10 parts cellulose ethers, 0.2 parts defoamer, and 30 parts water; wherein, the additives are composed of the following components: 60 parts granulated blast furnace slag powder, 25 parts fly ash microspheres, and 15 parts additive powder.
[0064] Preparation of self-leveling mortar based on recycled solid waste materials:
[0065] Step 1: First, put the additives, aggregates, cellulose ethers and defoamers into the mixer and dry mix them at 400 rpm for 4 minutes to obtain the premix.
[0066] Step 2: Add the additives to the premix and continue dry mixing at 400 rpm for 3 minutes to obtain the dry mix;
[0067] Step 3: Place the dry mix in a planetary mixer and mix at 250 rpm for 1 minute, then mix at 900 rpm for 4 minutes to obtain self-leveling mortar.
[0068] Example 3:
[0069] Aggregate preparation: 100-mesh waste glass sand and 150-mesh waste stone powder are mixed at a mass ratio of 1:1.5 to obtain aggregate.
[0070] Preparation of the first modifier:
[0071] Step 1: Centrifuge the black liquor of papermaking at 12000 rpm for 30 minutes to obtain the supernatant. Add concentrated sulfuric acid dropwise to the supernatant until the pH of the solution is 4, then stop adding the sulfuric acid. Filter to obtain the precipitate, in which the mass fraction of concentrated sulfuric acid is 98%.
[0072] Step 2: Wash the precipitate until neutral to obtain crude lignin. Mix the crude lignin with molasses at a mass ratio of 1:0.5 to obtain a second mixture. Add deionized water and stir to dissolve to obtain a first mixture. The amount of deionized water added is 10 times the total mass of the second mixture.
[0073] Step 3: Introduce ozone at a flow rate of 1.0 L / min into the first mixture and irradiate it with ultraviolet light at the same time. React for 2 hours to obtain the first modifier.
[0074] Preparation of modified rice husk ash powder: After rinsing the rice husks with clean water, soak them in 10% dilute hydrochloric acid for 4 hours. Wash the soaked rice husks until neutral, dry them, and calcine them at 700℃ in an oxygen-deficient environment for 3 hours to obtain rice husk ash. Mix the rice husk ash with the first modifier at a mass ratio of 100:8, add deionized water and stir to obtain a slurry. Stir the slurry at 80℃ for 4 hours, filter it, and dry it to obtain a dry material. Crush and grind the dry material to obtain modified rice husk ash powder. The amount of dilute hydrochloric acid should completely submerge the rice husks, and the amount of deionized water added should be 3 times the mass of the rice husk ash.
[0075] Preparation of the added powder:
[0076] S1: The modified rice husk ash powder and solid sodium hydroxide are mixed at a mass ratio of 1:1.2 to obtain the first mixed powder;
[0077] S2: Industrial grade sodium metasilicate nonahydrate is heated at 200℃ to dehydrate until the moisture content is less than 5%, and then pulverized to obtain the second powder.
[0078] S3: Mix the first mixed powder and the second powder at a mass ratio of 1:1, calcine at 350℃ for 2 hours to obtain coarse material, cool the coarse material to room temperature, and grind it to a specific surface area ≥500m². 2 / kg, to obtain additive powder.
[0079] Preparation of the second modifier: Rosin was pulverized and heated to 140°C. Maleic anhydride was added under stirring, and the mixture was reacted at 140°C for 3 hours to obtain maleic rosin. Maleic rosin and sodium lignosulfonate were mixed at a mass ratio of 1:4 to obtain a third mixture. Ethanol was added and stirred to dissolve the mixture to obtain a third mixture. The third mixture was refluxed at 80°C for 6 hours. After the reaction was completed, ethanol was recovered by vacuum distillation. The remaining product from distillation was dried and pulverized to obtain the second modifier. The mass of maleic anhydride was 20% of the mass of rosin, the mass fraction of ethanol was greater than 95%, and the mass of ethanol was 5 times the total mass of the third mixture.
[0080] Preparation of the additive: The second modifier and deionized water were mixed at a mass ratio of 1:12 and stirred to dissolve, resulting in a second mixture. Ammonium persulfate was added to the second mixture and reacted at 70°C for 5 hours to obtain an intermediate product. The intermediate product was spray-dried to obtain the additive, wherein the mass of ammonium persulfate was 15% of the mass of the second modifier.
[0081] Raw material preparation: 100 parts additives, 150 parts aggregates, 0.8 parts auxiliary agents, 0.15 parts cellulose ethers, 0.3 parts defoamer, and 35 parts water; wherein, the additives are composed of the following components: 70 parts granulated blast furnace slag powder, 30 parts fly ash microspheres, and 20 parts additive powder.
[0082] Preparation of self-leveling mortar based on recycled solid waste materials:
[0083] Step 1: First, put the additives, aggregates, cellulose ethers and defoamers into the mixer and dry mix for 5 minutes at a speed of 500 rpm to obtain the premix.
[0084] Step 2: Add the additives to the premix and continue dry mixing at 500 rpm for 3 minutes to obtain the dry mix.
[0085] Step 3: Place the dry mix in a planetary mixer and mix at 300 rpm for 1 minute, then mix at 1000 rpm for 5 minutes to obtain self-leveling mortar.
[0086] Comparative Example 1: The difference between this comparative example and Example 1 is that the addition of the first modifier is omitted, and in the preparation of modified rice husk ash powder, an equal mass of deionized water is used instead of the first modifier.
[0087] Comparative Example 2: The difference between this comparative example and Example 1 is that the addition of the second modifier is omitted, and an equal mass of ordinary sodium lignosulfonate is used instead of the second modifier when preparing the auxiliary agent.
[0088] Comparative Example 3: The difference between this comparative example and Example 1 is that the addition of the self-made additive powder is omitted, and an equal amount of traditional alkaline activator is added together with water in the form of an aqueous solution in step three of mortar preparation.
[0089] Comparative Example 4: The difference between this comparative example and Example 1 is that ordinary quartz sand aggregate is used.
[0090] Performance testing: Performance tests were conducted on the self-leveling mortars based on recycled solid waste materials from Examples 1, 2, 3, Comparative Examples 1, 2, 3, and 4. The test data are recorded in the table below:
[0091] sample Initial flowability (mm) Flowability (mm) at 20 min 1-day compressive strength (MPa) 28-day compressive strength (MPa) Initial setting time (min) Example 1 145 139 16.5 49.5 265 Example 2 146 140 17.1 50.1 280 Example 3 144 139 17.5 51.5 250 Comparative Example 1 125 105 10.2 35.6 195 Comparative Example 2 130 112 12.8 42.3 175 Comparative Example 3 142 120 15.0 47.8 90 Comparative Example 4 135 131 15.5 46.5 270
[0092] Test methods: Flowability refers to GB / T 29756-2013, testing initial flowability and 20-minute flowability, in mm; compressive strength refers to GB / T 17671-2021, testing 1-day and 28-day compressive strength, in MPa; setting time refers to GB / T 1346-2024, testing initial setting time, in min.
[0093] The data obtained from the performance test table show that the self-leveling mortars prepared in Examples 1, 2, and 3 are significantly better than those in Comparative Examples 1, 2, 3, and 4 in terms of fluidity retention, early strength, and setting time control. This indicates that the additive powder and the auxiliary agent used in this invention have a key synergistic effect. As a slow-release alkali activator, the additive powder's special high-temperature calcination structure ensures that the geopolymerization reaction can start and continue smoothly, providing a stable foundation for the strength development of the mortar. The auxiliary agent, through the rich functional groups in its molecular structure, forms a steric hindrance layer on the surface of solid waste particles, ensuring the excellent fluidity and long-term stability of the slurry. On the other hand, it precisely controls the rate of the geopolymerization reaction, avoiding uncontrolled setting or structural defects caused by excessive reaction.
[0094] Comparative Example 1, lacking the first modifier, exhibited unsatisfactory slurry stability and strength development, demonstrating the crucial role of the first modifier in optimizing the surface activity of rice husk ash and ensuring the uniform action of the activator. Comparative Example 2, lacking the second modifier, showed significantly shortened setting time and lower strength, indicating the irreplaceable role of the second modifier in regulating reaction kinetics and enhancing interfacial adhesion. Comparative Example 3, despite using traditional alkaline solution activation and exhibiting high initial fluidity, suffered from extremely poor workability and excessively rapid setting, highlighting the significant advantage of the dry powder design of the added powder in ensuring a favorable construction window. Comparative Example 4, using ordinary aggregate, showed slightly lower later-stage strength, confirming the contribution of the potential micro-aggregate filling effect and weak pozzolanic activity of solid waste materials such as waste glass powder to the long-term compactness of the system.
[0095] By comparing and analyzing the relevant data in the table, it can be seen that the additives and auxiliaries of this invention, through the combination of dry powder geopolymer activation technology and bio-based functional additives, successfully solve the industry problems of poor workability, low early strength, and poor construction adaptability of traditional solid waste-based materials. Simultaneously, the multi-level synergistic effect formed between the self-made additives and solid waste particles enables the product to achieve comprehensive performance comparable to or even better than traditional products while maintaining extremely high solid waste content. This demonstrates that the technical solution provided by this invention not only achieves high-value utilization of solid waste but also exhibits excellent engineering application potential and has broad market prospects.
Claims
1. A self-leveling mortar based on recycled solid waste materials, characterized in that, It includes the following raw materials by weight: 100 parts additives, 120-150 parts aggregates, 0.3-0.8 parts auxiliary agents, 0.05-0.15 parts cellulose ethers, 0.1-0.3 parts defoamer, and 25-35 parts water; The additive consists of the following components: 50-70 parts of granulated blast furnace slag powder, 20-30 parts of fly ash microspheres, and 10-20 parts of additive powder. The additive powder is prepared by the following method: S1: The modified rice husk ash powder and solid sodium hydroxide are mixed at a mass ratio of 1:(0.8-1.2) to obtain the first mixed powder; S2: Industrial grade sodium metasilicate nonahydrate is heated at 150-200℃ to dehydrate until the moisture content is less than 5%, and then pulverized to obtain the second powder. S3: the first mixed powder is mixed with the second powder in a mass ratio of 1:(0.5-1), calcined at 250-350℃ for 1-2h to obtain a coarse material, which is cooled to room temperature and ground to a specific surface area ≥500m 2 / kg to prepare the additive powder; Modified rice husk ash powder is prepared by the following method: After rinsing rice husks with clean water, soak them in dilute hydrochloric acid for 2-4 hours. Wash the soaked rice husks until neutral, dry them, and calcine the dried rice husks at 600-700℃ in an oxygen-deficient environment for 2-3 hours to obtain rice husk ash. Mix the rice husk ash with the first modifier at a mass ratio of 100:(3-8), add deionized water and stir to obtain a slurry. Stir the slurry at 60-80℃ for 2-4 hours, filter it, and dry it to obtain dry material. Crush and grind the dry material to obtain modified rice husk ash powder. The first modifier is prepared by the following method: Step 1: Centrifuge the wastewater generated by the alkaline pulping process at 8000-12000 rpm for 20-30 minutes to obtain the supernatant. Add concentrated sulfuric acid dropwise to the supernatant until the pH of the solution is 3-4, then stop adding the sulfuric acid. Filter the solution to obtain the precipitate. Step 2: Wash the precipitate until neutral to obtain crude lignin. Mix the crude lignin with molasses at a mass ratio of 1:(0.2-0.5) to obtain a second mixture. Add deionized water and stir to dissolve to obtain a first mixture. Step 3: Introduce ozone into the first mixture and irradiate it with ultraviolet light at the same time. React for 1-2 hours to obtain the first modifier. The aggregate is a mixture of 40-100 mesh waste glass sand and 80-150 mesh waste stone powder in a mass ratio of 1:(1-1.5). The additive is prepared by the following method: the second modifier is mixed with deionized water at a mass ratio of 1:(8-12), stirred and dissolved to obtain a second mixture, ammonium persulfate is added to the second mixture, and the mixture is reacted at 60-70℃ for 3-5 hours to obtain an intermediate product. The intermediate product is then spray-dried to obtain the additive, wherein the mass of ammonium persulfate is 5-15% of the mass of the second modifier. The second modifier is prepared by the following method: rosin is pulverized and heated to 120-140℃, maleic anhydride is added under stirring, and the reaction is carried out at 120-140℃ for 2-3 hours to obtain maleic rosin. Maleic rosin and sodium lignosulfonate are mixed at a mass ratio of 1:(2-4) to obtain a third mixture. Ethanol is added and stirred to dissolve to obtain a third mixture. The third mixture is refluxed at 70-80℃ for 4-6 hours. After the reaction is completed, ethanol is recovered by vacuum distillation. The remaining product of distillation is dried and pulverized to obtain the second modifier.
2. The self-leveling mortar based on recycled solid waste materials according to claim 1, characterized in that, The mass of maleic anhydride is 10-20% of the mass of rosin, the mass fraction of ethanol is greater than 95%, and the mass of ethanol is 3-5 times the total mass of the third mixture.
3. The self-leveling mortar based on recycled solid waste materials according to claim 1, characterized in that, The concentrated sulfuric acid in step 1 has a mass fraction of 90-98%, the amount of deionized water added in step 2 is 5-10 times the total mass of the second mixture, and the ozone flow rate in step 3 is 0.5-1.0 L / min.
4. The self-leveling mortar based on recycled solid waste materials according to claim 1, characterized in that, In the preparation of the modified rice husk ash powder, the mass fraction of the dilute hydrochloric acid is 5-10%, and the amount of dilute hydrochloric acid used must completely submerge the rice husk. The amount of deionized water added is 2-3 times the mass of the rice husk ash.
5. The self-leveling mortar based on recycled solid waste materials according to any one of claims 1-4, characterized in that, It is prepared by the following method: Step 1: First, put the additives, aggregates, cellulose ethers and defoamers into the mixer and dry mix them for 3-5 minutes at a speed of 300-500 rpm to obtain the premix. Step 2: Add the additives to the premix and continue dry mixing at 300-500 rpm for 2-3 minutes to obtain the dry mix. Step 3: Place the dry mix in a planetary mixer and mix at 200-300 rpm for 1 minute, then mix at 800-1000 rpm for 3-5 minutes to obtain self-leveling mortar.
Citation Information
Patent Citations
Concrete composition
JP2005126271A
Hydraulic binder compositions comprising steel making slag, a co-binder and an alkali mineral salt
US20250313511A1