Environment-friendly concrete water reducing agent and preparation method thereof

Abstract

The invention relates to the technical field of building materials, in particular to an environment-friendly concrete water reducing agent and a preparation method thereof. Comprising 30-50 parts of modified lignosulfonate, 20-40 parts of polycarboxylic acid mother liquor, 10-20 parts of industrial waste residue micro powder, 5-15 parts of a natural plant extract, 1-3 parts of an initiator, 0.5-2 parts of a chain transfer agent, 2-5 parts of nano silicon dioxide, 3-8 parts of a chitosan derivative, 1-4 parts of humic acid and 100-150 parts of water. According to the environment-friendly concrete water reducing agent and the preparation method thereof, industrial byproducts and natural renewable raw materials are taken as main components, so that resource utilization of wastes is realized, dependence on petrochemical raw materials is reduced, and the environment-friendly concrete water reducing agent meets the requirements of environmental protection and sustainable development, has an excellent water reducing effect, can improve the flowability and working performance of concrete, and is suitable for industrial production. Meanwhile, the compressive strength, the breaking strength and other mechanical properties of the concrete are improved, and the preparation method is simple and easy to implement, mild in reaction condition, low in production cost and suitable for large-scale industrial production.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, specifically to an environmentally friendly concrete water-reducing agent and its preparation method. Background Technology

[0002] Concrete water-reducing agents are indispensable additives in concrete. They can reduce the amount of mixing water while maintaining a relatively constant slump, thereby improving the strength and durability of concrete. Traditional concrete water-reducing agents mostly use petrochemical products as raw materials, which generate a large amount of pollutants during the production process, and the raw materials are non-renewable, which is inconsistent with the current green and environmentally friendly development concept.

[0003] With increasing environmental awareness and the advancement of sustainable development strategies, the development of environmentally friendly concrete water-reducing agents has become a research hotspot. Currently, although some research exists on environmentally friendly water-reducing agents, most suffer from problems such as poor water-reducing effects, limited improvement in concrete performance, or complex preparation processes and high costs. Therefore, developing a concrete water-reducing agent with good water-reducing effects, excellent environmental performance, and simple preparation is of significant practical importance. Summary of the Invention

[0004] The purpose of this invention is to provide an environmentally friendly concrete water-reducing agent and its preparation method to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an environmentally friendly concrete water-reducing agent, comprising the following raw materials by weight: 30-50 parts modified lignin sulfonate, 20-40 parts polycarboxylate mother liquor, 10-20 parts industrial waste residue powder, 5-15 parts natural plant extract, 1-3 parts initiator, 0.5-2 parts chain transfer agent, 2-5 parts nano silica, 3-8 parts chitosan derivative, 1-4 parts humic acid, and 100-150 parts water.

[0006] Preferably, the modified lignin sulfonate is obtained by hydroxylation modification of lignin sulfonate. Hydroxylation modification can increase the active groups of lignin sulfonate, improve its compatibility with other components and water-reducing properties. Lignosulfonate is derived from a byproduct of the pulp and paper industry, realizing the resource utilization of waste, reducing costs, and reducing environmental pollution.

[0007] Preferably, the industrial waste powder is one or more of fly ash powder, slag powder, or steel slag powder. The utilization of these industrial wastes not only solves the environmental problems caused by their stockpiling but also improves the strength and durability of concrete because the industrial waste powder has a certain pozzolanic activity and can react with cement hydration products to generate cementitious substances.

[0008] Preferably, the natural plant extract is one or more of saponin extract, tea saponin extract, or soapberry extract. These natural plant extracts have good surface activity, can reduce the surface tension of concrete mixes, improve water reduction effect, and are widely available, renewable, and environmentally friendly.

[0009] Preferably, the initiator is one or a mixture of ammonium persulfate, sodium persulfate, or hydrogen peroxide. Its function is to initiate the polymerization reaction.

[0010] Preferably, the chain transfer agent is one or more of mercaptoethanol, mercaptopropionic acid, or sodium bisulfite. This can adjust the molecular weight of the polymer and improve the performance of the water-reducing agent.

[0011] Preferably, the nano-silica has a particle size of 10-50 nm; it possesses extremely high surface activity and a filling effect, capable of filling the tiny pores inside concrete, improving the density of concrete, and reacting with cement hydration products to generate more cementitious substances, enhancing the strength and durability of concrete. The chitosan derivative is carboxymethyl chitosan or hydroxypropyl chitosan; chitosan is derived from the shells of crustaceans such as shrimp and crab, and is a natural, renewable polymer compound. Modified chitosan derivatives have good water solubility and dispersibility, improving the dispersion effect of water-reducing agents in concrete. Simultaneously, the active groups in its molecules can adsorb onto the surface of cement particles, further enhancing the water-reducing effect. The humic acid is weathered coal humic acid or lignite humic acid. Humic acid is a natural organic polymer with abundant functional groups, capable of complexing with calcium ions in cement, slowing down the hydration rate of cement, improving the workability of concrete, and simultaneously enhancing the impermeability and corrosion resistance of concrete.

[0012] A method for preparing an environmentally friendly concrete water-reducing agent includes the following steps:

[0013] S1: Weigh each raw material according to the specified weight proportions, and perform stepwise activation treatment on the industrial waste residue powder. First, calcine it in a muffle furnace at 500-600℃ for 1-2 hours. After cooling, soak it in a 5%-8% sulfuric acid solution for 30-60 minutes. Filter, wash until neutral, and dry for later use. Calcination can remove organic impurities and some water of crystallization from the industrial waste residue powder, improving its activity. Soaking in sulfuric acid solution can dissolve some inert components in the waste residue, increasing its specific surface area and active sites, thereby enhancing its reactivity with other components and its effect in concrete.

[0014] S2: Add the modified lignin sulfonate and water to the reaction vessel, stir until homogeneous, heat to 50-70℃, turn on the microwave-assisted device, and set the microwave power to 300-500W. Microwave-assisted reaction can utilize the thermal and non-thermal effects of microwaves to accelerate the movement of molecules, promote collisions and reactions between reactants, increase the reaction rate and degree, shorten the reaction time, and at the same time make the reaction more uniform and improve the performance stability of the product.

[0015] S3: Add the initiator to the reactor, stir for 10-20 minutes, then slowly add the polycarboxylate mother liquor, and react at 50-70℃ for 1-2 hours;

[0016] S4: Then add the industrial waste residue powder treated by S1, natural plant extracts, chain transfer agent, nano silica, chitosan derivatives and humic acid, heat to 70-90℃, keep in microwave-assisted state, and react for 2-3 hours.

[0017] S5: After the reaction is complete, turn off the microwave device and cool it to room temperature to obtain an environmentally friendly concrete water-reducing agent.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] 1. This environmentally friendly concrete water-reducing agent and its preparation method incorporate three innovative raw materials—nano-silica, chitosan derivatives, and humic acid—in addition to the original raw materials. Nano-silica improves the density and strength of concrete; chitosan derivatives enhance the dispersion effect and water-reducing performance of the water-reducing agent; and humic acid improves the workability and durability of concrete. The synergistic effect of these three raw materials significantly enhances the overall performance of the water-reducing agent.

[0020] 2. The environmentally friendly concrete water-reducing agent and its preparation method adopt stepwise activation treatment of industrial waste residue powder and microwave-assisted reaction. Stepwise activation treatment improves the activity and reactivity of industrial waste residue powder; microwave-assisted reaction accelerates the reaction rate, improves reaction efficiency and product performance stability, and reduces energy consumption.

[0021] 3. This environmentally friendly concrete water-reducing agent and its preparation method utilize industrial by-products, natural renewable raw materials, and innovative functional raw materials as main components, achieving resource utilization of waste, reducing dependence on petrochemical raw materials, meeting the requirements of environmental protection and sustainable development, exhibiting excellent water-reducing effects, improving the fluidity and workability of concrete, and simultaneously enhancing the compressive strength, flexural strength, and other mechanical properties of concrete. Furthermore, the preparation method is simple and easy to implement, with mild reaction conditions, low energy consumption, and low production costs, making it suitable for large-scale industrial production. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a flowchart of the preparation method of the environmentally friendly concrete water-reducing agent of the present invention. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Please see Figure 1 The present invention provides a technical solution: an environmentally friendly concrete water-reducing agent, comprising the following raw materials by weight: 30-50 parts of modified lignin sulfonate, 20-40 parts of polycarboxylate mother liquor, 10-20 parts of industrial waste residue powder, 5-15 parts of natural plant extract, 1-3 parts of initiator, 0.5-2 parts of chain transfer agent, 2-5 parts of nano silica, 3-8 parts of chitosan derivative, 1-4 parts of humic acid, and 100-150 parts of water.

[0026] Example 1

[0027] An environmentally friendly concrete water-reducing agent, by weight, comprises the following raw materials: 30 parts modified lignin sulfonate, 20 parts polycarboxylate mother liquor, 10 parts fly ash powder, 5 parts soap extract, 1 part ammonium persulfate, 0.5 parts mercaptoethanol, 2 parts nano silica, 3 parts carboxymethyl chitosan, 1 part weathered coal humic acid, and 100 parts water.

[0028] Its preparation method is as follows:

[0029] S1: Weigh each raw material according to the above weight proportions, and perform stepwise activation treatment on the fly ash powder. First, calcine it in a muffle furnace at 500℃ for 1 hour. After cooling, add a 5% sulfuric acid solution and soak for 30 minutes. Filter, wash until neutral, and dry for later use.

[0030] S2: Add modified lignin sulfonate and water to the reaction vessel, stir evenly, heat to 50°C, turn on the microwave auxiliary device, and set the microwave power to 300W;

[0031] S3: Add ammonium persulfate to the reactor, stir for 10 minutes, then slowly add polycarboxylate mother liquor, and react at 50°C for 1 hour;

[0032] S4: Then add the fly ash powder treated by S1, soap extract, mercaptoethanol, nano silica, carboxymethyl chitosan and weathered coal humic acid, heat to 70°C, maintain microwave-assisted state, and react for 2 hours.

[0033] S5: After the reaction is complete, turn off the microwave device and cool it to room temperature to obtain an environmentally friendly concrete water-reducing agent.

[0034] Example 2

[0035] An environmentally friendly concrete water-reducing agent, by weight, comprises the following raw materials: 40 parts modified lignin sulfonate, 30 parts polycarboxylate mother liquor, 15 parts slag powder, 10 parts tea saponin extract, 2 parts sodium persulfate, 1 part mercaptopropionic acid, 3.5 parts nano silica, 5.5 parts hydroxypropyl chitosan, 2.5 parts lignite humic acid, and 120 parts water.

[0036] Its preparation method is as follows:

[0037] S1: Weigh each raw material according to the above weight proportions, and perform stepwise activation treatment on the slag powder. First, calcine it in a muffle furnace at 550℃ for 1.5 hours. After cooling, add a 6.5% sulfuric acid solution and soak for 45 minutes. Filter, wash until neutral, and dry for later use.

[0038] S2: Add modified lignin sulfonate and water to the reaction vessel, stir evenly, heat to 60℃, turn on the microwave auxiliary device, and set the microwave power to 400W;

[0039] S3: Add sodium persulfate to the reactor, stir for 15 minutes, then slowly add polycarboxylate mother liquor, and react at 60°C for 1.5 hours;

[0040] S4: Then add the slag powder treated by S1, tea saponin extract, mercaptopropionic acid, nano silica, hydroxypropyl chitosan and lignite humic acid, heat to 80℃, maintain microwave-assisted state, and react for 2.5 hours.

[0041] S5: After the reaction is complete, turn off the microwave device and cool it to room temperature to obtain an environmentally friendly concrete water-reducing agent.

[0042] Example 3

[0043] An environmentally friendly concrete water-reducing agent, by weight, comprises the following raw materials: 50 parts modified lignin sulfonate, 40 parts polycarboxylate mother liquor, 20 parts steel slag powder, 15 parts Sapindus mukorossi extract, 3 parts hydrogen peroxide, 2 parts sodium bisulfite, 5 parts nano silica, 8 parts carboxymethyl chitosan, 4 parts lignite humic acid, and 150 parts water.

[0044] Its preparation method is as follows:

[0045] S1: Weigh each raw material according to the above weight proportions, and perform stepwise activation treatment on the steel slag powder. First, calcine it in a muffle furnace at 600℃ for 2 hours. After cooling, add an 8% sulfuric acid solution and soak for 60 minutes. Filter, wash until neutral, and dry for later use.

[0046] S2: Add modified lignin sulfonate and water to the reaction vessel, stir evenly, heat to 70°C, turn on the microwave auxiliary device, and set the microwave power to 500W;

[0047] S3: Add hydrogen peroxide to the reactor, stir for 20 minutes, then slowly add polycarboxylic acid mother liquor, and react at 70°C for 2 hours;

[0048] S4: Then add the steel slag powder treated by S1, Sapindus mukorossi extract, sodium bisulfite, nano silica, carboxymethyl chitosan and lignite humic acid, heat to 90℃, maintain microwave-assisted state, and react for 3 hours.

[0049] S5: After the reaction is complete, turn off the microwave device and cool it to room temperature to obtain an environmentally friendly concrete water-reducing agent.

[0050] The performance of the environmentally friendly concrete water-reducing agents prepared in Examples 1-3 above was tested, and the results are shown in the table below:

[0051]

[0052] As can be seen from the data in the table, Example 3 is the best embodiment of the present invention, and the environmentally friendly concrete water-reducing agent prepared by the present invention has a better water-reducing effect and a stronger effect, which can meet the higher requirements of concrete engineering.

[0053] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0054] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An environmentally friendly concrete water-reducing agent, characterized in that, By weight, it includes the following raw materials: 30-50 parts modified lignin sulfonate, 20-40 parts polycarboxylate mother liquor, 10-20 parts industrial waste residue powder, 5-15 parts natural plant extract, 1-3 parts initiator, 0.5-2 parts chain transfer agent, 2-5 parts nano silica, 3-8 parts chitosan derivative, 1-4 parts humic acid, and 100-150 parts water.

2. The environmentally friendly concrete water-reducing agent and its preparation method according to claim 1, characterized in that: The modified lignin sulfonate is obtained by hydroxylation modification of lignin sulfonate.

3. The environmentally friendly concrete water-reducing agent according to claim 1, characterized in that: The industrial waste residue powder is one or more of fly ash powder, slag powder, or steel slag powder.

4. The environmentally friendly concrete water-reducing agent according to claim 1, characterized in that: The natural plant extract is one or more of the following: soapberry extract, tea saponin extract, or soapberry extract.

5. The environmentally friendly concrete water-reducing agent according to claim 1, characterized in that: The initiator is one or a mixture of ammonium persulfate, sodium persulfate, or hydrogen peroxide.

6. The environmentally friendly concrete water-reducing agent according to claim 1, characterized in that: The chain transfer agent is one or more of mercaptoethanol, mercaptopropionic acid, or sodium bisulfite.

7. The environmentally friendly concrete water-reducing agent according to claim 1, characterized in that: The nano-silica has a particle size of 10-50 nm; the chitosan derivative is carboxymethyl chitosan or hydroxypropyl chitosan; and the humic acid is weathered coal humic acid or lignite humic acid.

8. A method for preparing an environmentally friendly concrete water-reducing agent according to any one of claims 1-7, characterized in that, Includes the following steps: S1: Weigh each raw material according to the weight percentage, and perform stepwise activation treatment on the industrial waste residue powder. First, place it in a muffle furnace at 500-600℃ for calcination for 1-2 hours. After cooling, add a sulfuric acid solution with a mass fraction of 5%-8% and soak for 30-60 minutes. Filter, wash until neutral, and dry for later use. S2: Add the modified lignin sulfonate and water to the reaction vessel, stir evenly, heat to 50-70℃, turn on the microwave auxiliary device, and set the microwave power to 300-500W; S3: Add the initiator to the reactor, stir for 10-20 minutes, then slowly add the polycarboxylate mother liquor, and react at 50-70℃ for 1-2 hours; S4: Then add the industrial waste residue powder treated in step S1, natural plant extracts, chain transfer agent, nano silica, chitosan derivatives and humic acid, heat to 70-90℃, keep in microwave-assisted state, and react for 2-3 hours. S5: After the reaction is complete, turn off the microwave device and cool it to room temperature to obtain an environmentally friendly concrete water-reducing agent.

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