High-solid-waste anti-cracking mechanism sand concrete and preparation method thereof
Patent Information
- Application Number
- CN202610947443.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-06-29
- Publication Date
- 2026-09-18
AI Technical Summary
[0004]本发明的目的是提供一种高固废抗裂机制砂混凝土及其制备方法，以解决高固废掺量下混凝土收缩大、易开裂的技术难题
（1）本发明中多元固废复合粉占胶凝材料总量的60%-70%，大幅超过现有技术中固废掺量通常低于30%的水平。不仅显著降低了水泥用量和碳排放，还为钢渣、矿渣等工业固废的大宗利用提供了新途径。
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Figure CN122771682A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of building materials technology, and in particular to a high-solid-waste crack-resistant manufactured sand concrete and its preparation method. Background Technology
[0002] With the increasing depletion of natural sand resources and tightening environmental protection policies, manufactured sand has become the mainstream choice in the concrete industry as a substitute for natural sand. However, manufactured sand often suffers from problems such as sharp particle shape, poor gradation, and large fluctuations in stone powder content, resulting in high water demand, poor workability, and a tendency to shrinkage cracking when preparing concrete. At the same time, the large-scale stockpiling of industrial solid waste (such as steel slag, blast furnace slag, desulfurization gypsum, fly ash, etc.) has caused a serious environmental burden. How to efficiently utilize these solid wastes in building materials is a technical problem that urgently needs to be solved in this field.
[0003] While some attempts have been made to use solid waste in concrete preparation, such as using blast furnace slag and steel slag as admixtures, these methods generally suffer from limitations in the amount of solid waste added (usually not exceeding 30% of the cementitious materials), slow early strength development, and insufficient crack resistance. Particularly with high solid waste content, the shrinkage deformation of concrete intensifies, significantly increasing the risk of cracking, which limits the large-scale application of solid waste in structural concrete. Summary of the Invention
[0004] The purpose of this invention is to provide a high-solid-waste-content, crack-resistant manufactured sand concrete and its preparation method, so as to solve the technical problem of large shrinkage and easy cracking of concrete with high solid waste content.
[0005] To achieve the above objectives, the present invention provides a high solid waste crack-resistant manufactured sand concrete, which, by mass parts, comprises 350-450 parts of cementitious materials, 700-800 parts of manufactured sand, 1000-1100 parts of coarse aggregate, 25-40 parts of composite admixture, and 140-170 parts of mixing water. The cementing materials include silicate cement and multi-component solid waste composite powder, with a mass ratio of silicate cement to multi-component solid waste composite powder of 3-4:6-7. The multi-component solid waste composite powder is made by mixing steel slag, blast furnace slag, desulfurization gypsum and rice husk ash in a mass ratio of 5-7:2-3:0.5-1:1-2 and grinding them to a specific surface area ≥500m². 2 / kg was prepared; Composite admixtures include polycarboxylate superplasticizers, composite polyether-olamine shrinkage reducers, rheology modifiers, and formulated water.
[0006] Preferably, the mass ratio of polycarboxylate superplasticizer, composite polyether-olamine shrinkage reducer, rheology modifier and preparation water in the composite admixture is 30-40:15-25:5-10:25-50.
[0007] Furthermore, the preparation method of the composite polyether-alkanolamine shrinkage reducer includes the following steps: mixing polyoxyethylene polyoxypropylene pentaerythritol ether, triisopropanolamine, and ethylene glycol in a mass ratio of 4-6:1-2:2-3, and reacting at 40-60℃ for 30-60 min to obtain the composite polyether-alkanolamine shrinkage reducer.
[0008] Preferably, the rheology modifier includes warming sizing agent and modified starch ether, wherein the mass ratio of warming sizing agent to modified starch ether is 1-3:1.
[0009] Furthermore, the modified starch ether is hydroxypropyl distarch phosphate.
[0010] Preferably, the manufactured sand includes tunnel slag or tailings manufactured sand, with a fineness modulus of 2.6-3.0, a stone powder content of 5%-8%, and a methylene blue value ≤1.0.
[0011] Preferably, the steel slag is aged steel slag with a free calcium oxide content of ≤3% by mass; the blast furnace slag has a specific surface area of ≥400 m². 2 Granulated blast furnace slag with an activity index ≥95% / kg; desulfurized gypsum including hemihydrate desulfurized gypsum with a sulfur trioxide content ≥40%.
[0012] Preferably, the coarse aggregate is crushed stone with a continuous gradation of 5-25mm.
[0013] This invention also provides a method for preparing high-solid-waste crack-resistant manufactured sand concrete, comprising the following steps: S1. Dissolve the warm wheel adhesive and modified starch ether in the preparation water, add the polycarboxylate superplasticizer and the composite polyether-alcohol amine shrinkage reducer, stir, and obtain the composite additive; S2. Mix the manufactured sand and coarse aggregate, add silicate cement and multi-component solid waste composite powder and dry mix to obtain a mixture; S3. Add composite admixture and mixing water to the mixture, wet mix, and obtain high solid waste crack-resistant manufactured sand concrete.
[0014] Preferably, the temperature of the water prepared in S1 is 30-40℃, the dry mixing time in S2 is 20-40s, and the wet mixing time in S3 is 120-150s.
[0015] In this invention, the polycarboxylate superplasticizer can be any polycarboxylate-based high-efficiency superplasticizer commonly used in the art, without any specific limitation.
[0016] Therefore, the present invention employs the above-mentioned high-solid-waste crack-resistant manufactured sand concrete and its preparation method, which has the following beneficial effects: (1) In this invention, the multi-component solid waste composite powder accounts for 60%-70% of the total cementitious material, which is significantly higher than the level of less than 30% in the prior art. It not only significantly reduces cement consumption and carbon emissions, but also provides a new way for the large-scale utilization of industrial solid wastes such as steel slag and ore slag.
[0017] (2) This invention suppresses cracking through a multi-synergistic mechanism of "rigid skeleton, flexible filling, and chemical shrinkage reduction". Coarse aggregate forms a macroscopic skeleton in concrete, providing compressive strength and dimensional stability; coarse particles in manufactured sand fill the voids in coarse aggregate, forming a secondary skeleton with continuous gradation, and the two together constitute a rigid support system. Under the constraint of this rigid skeleton, the micro-expansion characteristics of steel slag can compensate for the later shrinkage of concrete; ultrafine slag and rice husk ash fill the micro-voids between the rigid skeleton, densifying the slurry structure; rice husk ash can also be used as an internal curing material to reduce autogenous shrinkage; the shrinkage reduction agent in the composite admixture can reduce capillary tension, and the combination of warm wheel adhesive and modified starch ether improves the rheology and water retention of the slurry, reducing plastic shrinkage.
[0018] (3) The present invention controls the stone powder content within a reasonable range of 5%-8%, and utilizes the rheology-modifying components in the composite additive to activate and make the stone powder compatible, transforming the stone powder from a disadvantageous factor into a favorable factor for micro-aggregate filling. Compared with the existing method of removing stone powder by washing with water, the present invention is more environmentally friendly and economical.
[0019] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description
[0020] Figure 1 These are mechanical property diagrams of the high solid waste crack-resistant manufactured sand concrete and its preparation method according to Examples 1-3 and Comparative Examples 1-2 of the present invention. Detailed Implementation
[0021] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.
[0022] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.
[0023] In this invention, unless otherwise specified, the test materials and instruments are all conventional test materials in the field and can be purchased through commercial channels.
[0024] Example 1 A high-solid-waste crack-resistant manufactured sand concrete, by mass parts, comprises 400 parts of cementitious materials, 700 parts of manufactured sand, 1100 parts of coarse aggregate, 32 parts of composite admixture, and 170 parts of mixing water. The cementitious materials include 120 parts of silicate cement and 280 parts of multi-component solid waste composite powder. The multi-component solid waste composite powder is made by mixing steel slag, blast furnace slag, desulfurized gypsum and rice husk ash in a mass ratio of 5:3:0.8:1.2 and grinding them to a specific surface area of 500 m². 2 / kg was obtained; the steel slag was aged steel slag with a free calcium oxide content ≤3%; the slag had a specific surface area of 450m². 2 Granulated blast furnace slag with an activity index of 98% per kg; desulfurized gypsum is hemihydrate desulfurized gypsum with a sulfur trioxide content of 42% by mass; The composite admixture includes 9.6 parts of polycarboxylate superplasticizer, 8 parts of composite polyether-alkanolamine shrinkage reducer, 1.6 parts of rheology modifier, and 12.8 parts of water. The preparation method of the composite polyether-alkanolamine shrinkage reducer includes the following steps: polyoxyethylene polyoxypropylene pentaerythritol ether, triisopropanolamine, and ethylene glycol are mixed in a mass ratio of 6:1:2.5 and reacted at 50°C for 45 min to obtain the composite polyether-alkanolamine shrinkage reducer; the rheology modifier includes 1.2 parts of acetone and 0.4 parts of hydroxypropyl distarch phosphate. The manufactured sand is tunnel slag manufactured sand, with a fineness modulus of 2.6, stone powder content of 8%, and methylene blue value of 0.8; The coarse aggregate is crushed stone with a continuous gradation of 5-25mm.
[0025] The above-mentioned method for preparing high-solid-waste crack-resistant manufactured sand concrete includes the following steps: S1. Dissolve the warm wheel rubber and modified starch ether in water at 30°C, add polycarboxylate superplasticizer and composite polyether-alcohol amine shrinkage reducer, stir, and obtain composite additive; S2. Mix the manufactured sand and coarse aggregate, add silicate cement and multi-component solid waste composite powder, and dry mix for 30 seconds to obtain a mixture. S3. Add composite admixture and mixing water to the mixture, wet mix for 120s to obtain high solid waste crack-resistant manufactured sand concrete.
[0026] Example 2 A high-solid-waste crack-resistant manufactured sand concrete, by mass parts, comprises 450 parts of cementitious materials, 800 parts of manufactured sand, 1000 parts of coarse aggregate, 25 parts of composite admixture, and 140 parts of mixing water. The cementitious materials include 150 parts of silicate cement and 300 parts of multi-component solid waste composite powder; the multi-component solid waste composite powder is made by mixing steel slag, blast furnace slag, desulfurized gypsum and rice husk ash in a mass ratio of 7:2:1:1 and grinding them to a specific surface area of 520 m². 2 / kg was obtained; the steel slag was aged steel slag with a free calcium oxide content ≤3%; the slag had a specific surface area of 450m². 2 Granulated blast furnace slag with an activity index of 98% per kg; desulfurized gypsum is hemihydrate desulfurized gypsum with a sulfur trioxide content of 42% by mass; The composite admixture includes 10 parts of polycarboxylate superplasticizer, 3.75 parts of composite polyether-alkanolamine shrinkage reducer, 2.5 parts of rheology modifier, and 8.75 parts of water. The preparation method of the composite polyether-alkanolamine shrinkage reducer includes the following steps: polyoxyethylene polyoxypropylene pentaerythritol ether, triisopropanolamine, and ethylene glycol are mixed in a mass ratio of 4:2:3 and reacted at 50°C for 45 min to obtain the composite polyether-alkanolamine shrinkage reducer; the rheology modifier includes 1.25 parts of warm sizing agent and 1.25 parts of hydroxypropyl distarch phosphate. The manufactured sand is tailings manufactured sand with a fineness modulus of 3.0, a stone powder content of 5%, and a methylene blue value of 0.8. The coarse aggregate is crushed stone with a continuous gradation of 5-25mm.
[0027] The preparation method of the above-mentioned high solid waste crack-resistant manufactured sand concrete is the same as that in Example 1, except that the temperature of the water in S1 is 40°C and the wet mixing time in S3 is 150s.
[0028] Example 3 A high-solid-waste crack-resistant manufactured sand concrete, by mass parts, comprises 350 parts of cementitious materials, 750 parts of manufactured sand, 1050 parts of coarse aggregate, 40 parts of composite admixture, and 155 parts of mixing water. The cementitious materials include 105 parts silicate cement and 245 parts multi-component solid waste composite powder; the multi-component solid waste composite powder is made by mixing steel slag, blast furnace slag, desulfurized gypsum and rice husk ash in a mass ratio of 6:2.5:0.5:2 and grinding them to a specific surface area of 500 m². 2 / kg was obtained; the steel slag was aged steel slag with a free calcium oxide content ≤3%; the slag had a specific surface area of 450m². 2 Granulated blast furnace slag with an activity index of 98% per kg; desulfurized gypsum is hemihydrate desulfurized gypsum with a sulfur trioxide content of 42% by mass; The composite admixture includes 14 parts of polycarboxylate superplasticizer, 8 parts of composite polyether-alkanolamine shrinkage reducer, 2.8 parts of rheology modifier, and 15.2 parts of water. The preparation method of the composite polyether-alkanolamine shrinkage reducer includes the following steps: polyoxyethylene polyoxypropylene pentaerythritol ether, triisopropanolamine, and ethylene glycol are mixed in a mass ratio of 5:1.5:2 and reacted at 50°C for 45 min to obtain the composite polyether-alkanolamine shrinkage reducer; the rheology modifier includes 1.87 parts of warm wheel rubber and 0.93 parts of hydroxypropyl distarch phosphate. The manufactured sand is tailings manufactured sand with a fineness modulus of 2.8, a stone powder content of 6.5%, and a methylene blue value of 0.8. The coarse aggregate is crushed stone with a continuous gradation of 5-25mm.
[0029] The preparation method of the above-mentioned high solid waste crack-resistant manufactured sand concrete is the same as that in Example 1, except that the temperature of the water in S1 is 35°C and the wet mixing time in S3 is 135s.
[0030] Comparative Example 1 This comparative example is the same as the high solid waste crack-resistant manufactured sand concrete in Example 1, except that rice husk ash is not added to the multi-element solid waste composite powder, and steel slag, blast furnace slag and desulfurized gypsum are mixed in a mass ratio of 6:2.5:0.8, while the other components and their amounts remain unchanged.
[0031] The preparation method of the above-mentioned high solid waste crack-resistant manufactured sand concrete is the same as that in Example 1.
[0032] Comparative Example 2 This comparative example is the same as the high solid waste crack-resistant manufactured sand concrete of Example 1, except that no rheology modifier is added to the composite admixture, the mass ratio of polycarboxylate superplasticizer, composite polyether-olamine shrinkage reducer and water is 35:20:45, and the other components and their dosages remain unchanged.
[0033] The preparation method of the above-mentioned high solid waste crack-resistant manufactured sand concrete is the same as that in Example 1, except that: in S1, warm wheel glue and modified starch ether are not added, and polycarboxylate superplasticizer, composite polyether-alcohol amine shrinkage reducer are mixed with the prepared water and stirred evenly to obtain composite admixture.
[0034] According to the requirements of GB / T 50081-2019 "Standard for Test Methods of Physical and Mechanical Properties of Concrete", the mechanical properties of high solid waste crack-resistant manufactured sand concrete in Examples 1-3 and Comparative Examples 1-2 were tested, and the results are as follows: Figure 1 As shown.
[0035] from Figure 1 As can be seen, the 28-day compressive strength of the high-solid-waste crack-resistant manufactured sand concrete in Examples 1-3 is ≥50MPa, reaching the C50 concrete strength grade and meeting the requirements for structural concrete. In Comparative Example 1, the multi-element solid waste composite powder did not contain rice husk ash, and the 28-day strength of the high-solid-waste crack-resistant manufactured sand concrete was about 11% lower than that in Example 1, indicating that the pozzolanic activity and micro-aggregate filling effect of rice husk ash are crucial to the strength of concrete. In Comparative Example 2, the rheology modifier was removed from the composite admixture, and the 28-day strength of the high-solid-waste crack-resistant manufactured sand concrete was about 8.7% lower than that in Example 1. The lack of rheology modifier led to poor workability of the concrete mixture, severe bleeding, uneven aggregate distribution during specimen molding, and excessively high water-cement ratio in some areas, forming weak areas. This shows that the cementitious material ratio and composite admixture system of the present invention successfully achieved a high efficiency improvement in the compressive strength of concrete under the premise of high solid waste content.
[0036] According to the requirements of GB / T 50082-2024 "Standard for Test Methods of Long-Term Performance and Durability of Concrete", the volume stability and crack resistance of high solid waste crack-resistant manufactured sand concrete in Examples 1-3 and Comparative Examples 1-2 were tested, and the results are shown in Table 1.
[0037] Table 1. Volume stability and crack resistance of high solid waste-grade crack-resistant manufactured sand concrete
[0038] As can be seen from Table 1, the 56-day drying shrinkage values of the high solid waste crack-resistant manufactured sand concrete in Examples 1-3 are 270-310×10⁻⁶. -6 Between these, and ordinary manufactured sand concrete (typically 450-550×10). -6 The crack resistance was reduced by more than 30%, and the early crack resistance grade reached LI (no visible cracks) in all samples, demonstrating excellent crack resistance and volume stability. In Comparative Example 1, the multi-component solid waste composite powder without rice husk ash produced high-solid-waste crack-resistant manufactured sand concrete with a drying shrinkage value of 420×10⁻⁶. -6 The presence of moderate cracking indicates a lack of internal curing and micro-expansion compensation effects from rice husk ash, resulting in significantly increased shrinkage. In Comparative Example 2, the removal of the rheology modifier from the composite admixture resulted in a drying shrinkage value of 480 × 10⁻⁶ for the high-solid-waste crack-resistant manufactured sand concrete. -6 Furthermore, severe cracking occurred, and the lack of rheology modifiers led to poor water retention and cohesiveness of the paste, exacerbated bleeding and plastic shrinkage, and the synergistic crack-resistant effect with the composite polyether-olamine shrinkage reducer failed, ultimately resulting in a significant reduction in the crack resistance of the concrete.
[0039] Therefore, the present invention adopts the above-mentioned high solid waste crack-resistant manufactured sand concrete and its preparation method. Through rigid skeleton constraint, multi-element solid waste function synergy, and combined with a new type of composite admixture, it effectively solves the technical problems of poor workability, large shrinkage and easy cracking of concrete with high solid waste content, and realizes the organic unity of efficient utilization of solid waste resources and improvement of concrete performance.
[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.
Claims
1. A high-solid-waste-resistant, crack-resistant manufactured sand concrete, characterized in that: By weight, it includes 350-450 parts of cementitious materials, 700-800 parts of manufactured sand, 1000-1100 parts of coarse aggregate, 25-40 parts of composite admixture, and 140-170 parts of mixing water. The cementing materials include silicate cement and multi-component solid waste composite powder, with a mass ratio of silicate cement to multi-component solid waste composite powder of 3-4:6-7. The multi-component solid waste composite powder is made by mixing steel slag, blast furnace slag, desulfurization gypsum and rice husk ash in a mass ratio of 5-7:2-3:0.5-1:1-2 and grinding them to a specific surface area ≥500m². 2 / kg was prepared; Composite admixtures include polycarboxylate superplasticizers, composite polyether-olamine shrinkage reducers, rheology modifiers, and formulated water.
2. The high-solid-waste crack-resistant manufactured sand concrete according to claim 1, characterized in that: The mass ratio of polycarboxylate superplasticizer, composite polyether-olamine shrinkage reducer, rheology modifier and water in the composite admixture is 30-40:15-25:5-10:25-50.
3. The high solid waste crack-resistant manufactured sand concrete according to claim 2, characterized in that: The preparation method of the composite polyether-alkanolamine shrinkage reducer includes the following steps: polyoxyethylene polyoxypropylene pentaerythritol ether, triisopropanolamine, and ethylene glycol are mixed in a mass ratio of 4-6:1-2:2-3 and reacted at 40-60℃ for 30-60 min to obtain the composite polyether-alkanolamine shrinkage reducer.
4. The high-solid-waste crack-resistant manufactured sand concrete according to claim 1, characterized in that: The rheology modifiers include warming sizing agent and modified starch ether, with a mass ratio of warming sizing agent to modified starch ether of 1-3:
1.
5. The high-solid-waste crack-resistant manufactured sand concrete according to claim 4, characterized in that: The modified starch ether is hydroxypropyl distarch phosphate.
6. The high solid waste crack-resistant manufactured sand concrete according to claim 1, characterized in that: Manufactured sand includes tunnel slag or tailings manufactured sand, with a fineness modulus of 2.6-3.0, a stone powder content of 5%-8%, and a methylene blue value ≤1.
0.
7. The high solid waste crack-resistant manufactured sand concrete according to claim 1, characterized in that: The steel slag is aged steel slag with a free calcium oxide content of ≤3% by mass; Slag has a specific surface area ≥ 400 m² 2 Granulated blast furnace slag with an activity index ≥95% per kg; The desulfurized gypsum is selected from hemihydrate desulfurized gypsum, with a sulfur trioxide content of ≥40%.
8. The high solid waste crack-resistant manufactured sand concrete according to claim 1, characterized in that: The coarse aggregate is crushed stone with a continuous gradation of 5-25mm.
9. A method for preparing high-solid-waste crack-resistant manufactured sand concrete as described in any one of claims 1-8, characterized in that: Includes the following steps: S1. Dissolve the warm wheel adhesive and modified starch ether in the preparation water, add the polycarboxylate superplasticizer and the composite polyether-alcohol amine shrinkage reducer, stir, and obtain the composite additive; S2. Mix the manufactured sand and coarse aggregate, add silicate cement and multi-component solid waste composite powder, and dry mix to obtain a mixture; S3. Add mixing water and composite admixture obtained in S1 to the mixture obtained in S2, and wet mix to obtain high solid waste crack-resistant manufactured sand concrete.
10. The method for preparing high-solid-waste crack-resistant manufactured sand concrete according to claim 9, characterized in that, The water temperature in S1 is 30-40℃, the dry mixing time in S2 is 20-40s, and the wet mixing time in S3 is 120-150s.