High-impermeability concrete and preparation method therefor
By using a polycarboxylate superplasticizer, organosilicon waterproofing agent, and a modified sepiolite and lignocellulose nanofiber anti-permeability composition in concrete, the problem of insufficient anti-permeability of concrete in humid environments is solved, achieving high-efficiency anti-permeability performance and stable structural performance.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- BEIHUA UNIV
- Filing Date
- 2024-12-27
- Publication Date
- 2026-07-02
AI Technical Summary
Existing concrete has insufficient impermeability in humid or corrosive environments, leading to structural stability and safety issues. Furthermore, traditional waterproofing measures are costly or have inconsistent effectiveness.
The polycarboxylate superplasticizer, organosilicon waterproofing agent, and anti-permeability composition (composed of modified sepiolite and modified lignocellulose nanofibers) are used in combination to improve the pore structure and surface properties of concrete, forming a stable spatial network structure to enhance its impermeability.
It significantly improves the impermeability of concrete, extends the service life of buildings, and has a simple and cost-effective preparation method.
Smart Images
Figure PCTCN2024143013-FTAPPB-I100001
Abstract
Description
A type of impermeable concrete and its preparation method Technical Field
[0001] This invention relates to the field of concrete technology, and in particular to a type of concrete with strong impermeability and its preparation method. Background Technology
[0002] Concrete, as a widely used building material, is favored for its excellent mechanical properties, durability, and economy. However, concrete often faces permeability problems in practical applications, especially when exposed to humid environments or corrosive media for extended periods, where permeability can severely impact its performance and lifespan. Therefore, developing concrete with superior impermeability has become an important research direction.
[0003] The impermeability of concrete refers to its ability to resist the penetration of liquids or gases, which is crucial for ensuring the safety of buildings and extending their service life. In humid environments, if the impermeability of concrete is poor, moisture can easily enter the concrete through capillary pores, leading to problems such as steel corrosion and concrete expansion and cracking, thereby affecting the overall stability and safety of the structure. Especially in environments with severe chemical corrosion, improving the impermeability of concrete is an effective means of preventing the intrusion of harmful substances and protecting the internal structure from damage.
[0004] Although various methods and technologies exist for improving the impermeability of concrete, these solutions often suffer from drawbacks such as high cost, complex construction, or inconsistent results. For example, while adding waterproofing agents can improve the impermeability of concrete to some extent, improper selection of the agent or poor dosage control can negatively impact other properties of the concrete, such as workability and mechanical properties. Furthermore, some traditional waterproofing measures, such as surface coatings, while effectively preventing moisture intrusion in the short term, are prone to aging and peeling under long-term exposure to harsh environmental conditions, losing their protective function.
[0005] With the rapid development of infrastructure construction, higher requirements have been placed on the impermeability of concrete. Especially in some special projects, such as undersea tunnels and dams, concrete must not only withstand long-term water pressure but also resist chemical corrosion. Therefore, it is particularly urgent to develop a new type of concrete with excellent impermeability, simple construction, and reasonable cost, as well as its preparation method. Summary of the Invention
[0006] The purpose of this invention is to provide a concrete with strong impermeability and its preparation method, so as to solve the problems existing in the prior art.
[0007] To achieve the above objectives, the present invention provides the following solution:
[0008] One of the technical solutions of the present invention is: a concrete with strong impermeability, the raw materials of which include: cement, fine aggregate, coarse aggregate, polycarboxylate superplasticizer, organosilicon waterproofing agent, impermeable composition and water;
[0009] The mass ratio of cement, fine aggregate, coarse aggregate, and water is 1.0:1.5-2.0:2.5-3.0:0.35-0.45;
[0010] The dosage of the polycarboxylate superplasticizer is 0.5-1.0% of the cement mass;
[0011] The amount of the organosilicon waterproofing agent used is 1.5-2.5% of the cement mass;
[0012] The amount of the anti-seepage composition is 5-8% of the cement mass;
[0013] The impermeable composition is made by mixing modified sepiolite and modified lignocellulose nanofibers in a mass ratio of 2-3:1-2.
[0014] Silicone waterproofing agents, with their excellent hydrophobicity and permeability, can penetrate into the tiny pores of concrete, forming a thin film that seals these pores and reduces water penetration. Furthermore, silicone waterproofing agents can improve the hydrophilicity of the concrete surface, making water droplets slide off more easily and less likely to remain, further reducing the risk of water intrusion.
[0015] The modified lignocellulose nanofibers in the anti-seepage composition can fill the gaps between the cementitious materials and aggregates in concrete, effectively bridging them. Furthermore, the high strength of lignocellulose itself enhances the strength of hydration products, and its water-absorbing and swelling properties allow it to better fill concrete gaps, significantly improving the concrete's anti-seepage properties. The nano-silica within the modified sepiolite in the anti-seepage composition can form CSH gel with the calcium hydroxide generated during cement hydration, resulting in a tighter bond between the cementitious materials and aggregates. As the degree of cement hydration deepens, the formed gel becomes more stable, creating a spatial network structure that increases the concrete's density and further improves its anti-seepage properties. Simultaneously, the fibrous structure of sepiolite can fill the tiny pores in the concrete, thereby increasing its density and reducing the possibility of water penetration. The synergistic effect of the components in the organosilicon waterproofing and anti-seepage composition effectively improves the anti-seepage performance of concrete.
[0016] Furthermore, the fine aggregate is river sand.
[0017] Furthermore, the fineness modulus of the river sand is 2.8-3.0.
[0018] Furthermore, the coarse aggregate is crushed stone.
[0019] Furthermore, the particle size of the crushed stone is 5-25 mm.
[0020] Furthermore, the preparation method of the modified sepiolite includes: acidifying and pretreating sepiolite to obtain pretreated sepiolite; mixing and grinding the pretreated sepiolite with nano-silica to obtain mixed powder; calcining the mixed powder to obtain calcined product; immersing the calcined product in carboxymethyl cellulose solution for 40-60 minutes and drying it to obtain the modified sepiolite.
[0021] Furthermore, the acidification pretreatment of sepiolite includes soaking sepiolite in hydrochloric acid solution for 30-40 minutes.
[0022] Furthermore, the mass ratio of the pretreated sepiolite to nano-silica is 1.0:0.5-0.8; the calcination temperature is 550-600℃, and the time is 15-25 min.
[0023] Furthermore, the concentration of the hydrochloric acid is 4-6 mol / L; the mass concentration of the carboxymethyl cellulose solution is 50-60%.
[0024] Furthermore, the preparation method of the modified lignocellulose nanofibers includes: mixing lignocellulose nanofibers, acrylamide, sodium p-styrene sulfonate and water, then adding an initiator and a crosslinking agent, stirring and reacting for 0.5-2 hours to obtain the modified lignocellulose nanofibers.
[0025] Furthermore, the initiator is ammonium persulfate; the crosslinking agent is N,N'-methylenebisacrylamide.
[0026] Further, the mass ratio of the lignocellulose nanofibers, acrylamide, sodium p-styrene sulfonate, and water is 10-15:1-2:1-2:100-120; the amount of the initiator added is 0.8-1.0% of the mass of the acrylamide; and the amount of the crosslinking agent added is 0.8-1.0% of the mass of the acrylamide.
[0027] The second technical solution of the present invention: The preparation method of the above-mentioned concrete with strong impermeability includes the following steps: first, fine aggregate and coarse aggregate are mixed evenly, then cement is added and mixed evenly to obtain dry mix; water and polycarboxylate water-reducing agent are mixed evenly and then added to the dry mix, mixed evenly, and then organosilicon waterproofing agent and impermeable composition are added and mixed evenly to obtain the concrete with strong impermeability.
[0028] The present invention discloses the following technical effects:
[0029] This invention, through the rational selection of raw materials and mix design, combined with the application of highly efficient admixtures (polycarboxylate superplasticizer and organosilicon waterproofing agent) and anti-seepage composition, successfully prepared a concrete with strong impermeability and stable performance. This concrete not only effectively resists the penetration of moisture and harmful substances, extending the service life of buildings, but its preparation method is also simple, easy to implement, and has broad application prospects. Detailed Implementation
[0030] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.
[0031] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.
[0032] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.
[0033] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be readily apparent to those skilled in the art. This specification and embodiments are merely exemplary.
[0034] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.
[0035] All steps in the following examples and comparative examples where the operating temperature is not specified were performed at room temperature (20-30°C).
[0036] All raw materials used in the following examples and comparative examples are commercially available products. The fineness modulus of the river sand is 2.8-3.0, the particle size of the crushed stone is 5-25mm, the cement is ordinary Portland cement (PO 42.5), the polycarboxylate superplasticizer is PCE 40%, and the silicone waterproofing agent is silicone No. 3 waterproofing agent.
[0037] The modified sepiolite used in the following examples and comparative examples was prepared as follows: sepiolite was soaked in a 5 mol / L hydrochloric acid solution for 30 min (the solid-liquid ratio of sepiolite to hydrochloric acid solution was 1 g: 8 mL), filtered, and dried to obtain pretreated sepiolite; the pretreated sepiolite was mixed with nano-silica at a mass ratio of 1.0:0.8 and ground for 10 min to obtain a mixed powder; the mixed powder was calcined at 550 °C for 20 min to obtain a calcined product; the calcined product was soaked in a 50% carboxymethyl cellulose solution for 40 min (the solid-liquid ratio of sepiolite to hydrochloric acid solution was 1 g: 6 mL), filtered, and dried to obtain modified sepiolite.
[0038] The modified lignocellulose nanofibers used in the following examples and comparative examples were prepared as follows: lignocellulose nanofibers, acrylamide, sodium p-styrene sulfonate and water were mixed in a mass ratio of 10:1:1:100, then ammonium persulfate (1% of the mass of acrylamide) and N,N'-methylenebisacrylamide (1% of the mass of acrylamide) were added, the mixture was stirred and reacted for 1 hour, and after the reaction was completed, it was dried to obtain modified lignocellulose nanofibers.
[0039] Example 1
[0040] A type of concrete with strong impermeability, the raw material composition is: cement, fine aggregate (river sand), coarse aggregate (crushed stone), polycarboxylate superplasticizer, organosilicon waterproofing agent, impermeable composition and water;
[0041] The mass ratio of cement, fine aggregate, coarse aggregate, and water is 1.0:1.5:2.5:0.35.
[0042] The dosage of polycarboxylate superplasticizer is 0.5% of the cement mass;
[0043] The dosage of organosilicon waterproofing agent is 1.5% of the cement mass;
[0044] The amount of the anti-seepage composition is 5% of the cement mass;
[0045] The impermeable composition is made by uniformly mixing modified sepiolite and modified lignocellulose nanofibers at a mass ratio of 2:1.
[0046] The preparation method is as follows:
[0047] First, mix the fine aggregate and coarse aggregate evenly, then add cement and mix evenly to obtain dry mix; then mix water and polycarboxylate superplasticizer evenly and add them to the dry mix (add while stirring), mix evenly, then add organosilicon waterproofing agent and anti-seepage composition and mix evenly to obtain concrete with strong impermeability.
[0048] Example 2
[0049] A type of concrete with strong impermeability, the raw material composition is: cement, fine aggregate (river sand), coarse aggregate (crushed stone), polycarboxylate superplasticizer, organosilicon waterproofing agent, impermeable composition and water;
[0050] The mass ratio of cement, fine aggregate, coarse aggregate, and water is 1.0:1.8:2.8:0.4.
[0051] The dosage of polycarboxylate superplasticizer is 0.8% of the cement mass;
[0052] The dosage of organosilicon waterproofing agent is 2.0% of the cement mass;
[0053] The amount of the impermeable composition is 6% of the cement mass;
[0054] The impermeable composition is made by uniformly mixing modified sepiolite and modified lignocellulose nanofibers at a mass ratio of 2.5:1.5.
[0055] The preparation method is as follows:
[0056] First, mix the fine aggregate and coarse aggregate evenly, then add cement and mix evenly to obtain dry mix; then mix water and polycarboxylate superplasticizer evenly and add them to the dry mix (add while stirring), mix evenly, then add organosilicon waterproofing agent and anti-seepage composition and mix evenly to obtain concrete with strong impermeability.
[0057] Example 3
[0058] A type of concrete with strong impermeability, the raw material composition is: cement, fine aggregate (river sand), coarse aggregate (crushed stone), polycarboxylate superplasticizer, organosilicon waterproofing agent, impermeable composition and water;
[0059] The mass ratio of cement, fine aggregate, coarse aggregate, and water is 1.0:2.0:3.0:0.45.
[0060] The dosage of polycarboxylate superplasticizer is 1.0% of the cement mass;
[0061] The dosage of organosilicon waterproofing agent is 2.5% of the cement mass;
[0062] The amount of the impermeable composition is 8% of the cement mass;
[0063] The impermeable composition is made by uniformly mixing modified sepiolite and modified lignocellulose nanofibers in a mass ratio of 3:2.
[0064] The preparation method is as follows:
[0065] First, mix the fine aggregate and coarse aggregate evenly, then add cement and mix evenly to obtain dry mix; then mix water and polycarboxylate superplasticizer evenly and add them to the dry mix (add while stirring), mix evenly, then add organosilicon waterproofing agent and anti-seepage composition and mix evenly to obtain concrete with strong impermeability.
[0066] Comparative Example 1
[0067] Same as Example 1, except that the impermeable composition used is a uniform mixture of sepiolite and modified lignocellulose nanofibers in a mass ratio of 2:1.
[0068] Comparative Example 2
[0069] Same as Example 1, except that the impermeable composition used is made by uniformly mixing modified sepiolite and lignocellulose nanofibers in a mass ratio of 2:1.
[0070] Comparative Example 3
[0071] Same as Example 1, except that the use of silicone waterproofing agent is omitted.
[0072] Test case
[0073] Concrete specimens prepared according to Examples 1-3 and Comparative Examples 1-3 were poured into specimens according to JGJ55-2011 "Specification for Mix Proportion Design of Ordinary Concrete". The specimens were demolded 24 hours later and cured for 28 days under standard curing conditions. The chloride ion penetration resistance of the specimens was tested according to the electrical flux method in GB / T 50082-2019 "Standard for Test Methods of Long-Term Performance and Durability of Ordinary Concrete", and the water penetration resistance was tested according to the water penetration height method. The results are shown in Table 1.
[0074] Table 1
[0075] As shown in Table 1, the concrete prepared in Examples 1-3 of this invention has excellent impermeability. The impermeability of Comparative Examples 1-2, which replaced the modified sepiolite or modified lignocellulose nanofibers in the impermeable composition, and Comparative Example 3, which omitted the organosilicon waterproofing agent, all decreased. This indicates that each component in the impermeable composition and the organosilicon waterproofing agent play an important role in improving the impermeability of the concrete. The synergistic effect of the above components achieved the best improvement effect.
[0076] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.
Claims
1. A concrete having high impermeability, characterized by, The raw materials include: cement, fine aggregate, coarse aggregate, polycarboxylate superplasticizer, silicone waterproofing agent, anti-seepage composition, and water; The mass ratio of cement, fine aggregate, coarse aggregate, and water is 1.0:1.5-2.0:2.5-3.0:0.35-0.45; The dosage of the polycarboxylate superplasticizer is 0.5-1.0% of the cement mass; The amount of the organosilicon waterproofing agent used is 1.5-2.5% of the cement mass; The amount of the anti-seepage composition is 5-8% of the cement mass; The impermeable composition is made by mixing modified sepiolite and modified lignocellulose nanofibers in a mass ratio of 2-3:1-2.
2. The high impermeability concrete according to claim 1, wherein The fine aggregate is river sand.
3. The high impermeability concrete according to claim 1, wherein The coarse aggregate is crushed stone.
4. The high impermeability concrete as claimed in claim 1, wherein, The method for preparing the modified sepiolite includes: acidifying and pretreating sepiolite to obtain pretreated sepiolite; mixing and grinding the pretreated sepiolite with nano-silica to obtain a mixed powder; calcining the mixed powder to obtain a calcined product; immersing the calcined product in a carboxymethyl cellulose solution for 40-60 minutes and drying it to obtain the modified sepiolite.
5. The high impermeability concrete as claimed in claim 4, wherein, The acidification pretreatment of sepiolite includes soaking sepiolite in hydrochloric acid solution for 30-40 minutes.
6. The high impermeability concrete as claimed in claim 4, wherein, The mass ratio of pretreated sepiolite to nano-silica is 1.0:0.5-0.8; the calcination temperature is 550-600℃ and the time is 15-25 min.
7. The high impermeability concrete as claimed in claim 1, wherein, The method for preparing the modified lignocellulose nanofibers includes: mixing lignocellulose nanofibers, acrylamide, sodium p-styrene sulfonate and water, then adding an initiator and a crosslinking agent, stirring and reacting for 0.5-2 hours to obtain the modified lignocellulose nanofibers.
8. The high impermeability concrete as claimed in claim 7, wherein, The initiator is ammonium persulfate; the crosslinking agent is N,N'-methylenebisacrylamide.
9. The high impermeability concrete as claimed in claim 7, wherein, The mass ratio of the lignocellulose nanofibers, acrylamide, sodium p-styrene sulfonate, and water is 10-15:1-2:1-2:100-120; the amount of the initiator added is 0.8-1.0% of the mass of the acrylamide; and the amount of the crosslinking agent added is 0.8-1.0% of the mass of the acrylamide.
10. The method of producing a high impermeability concrete according to any one of claims 1 to 9, wherein Includes the following steps: First, mix the fine aggregate and coarse aggregate evenly, then add cement and mix evenly to obtain a dry mix; After water and polycarboxylate superplasticizer are mixed evenly, they are added to the dry mix and mixed evenly. Then, organosilicon waterproofing agent and anti-seepage composition are added and mixed evenly to obtain the concrete with strong anti-seepage properties.