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CN-120698726-B - Early-strength composite foam concrete foaming agent and preparation method thereof

CN120698726BCN 120698726 BCN120698726 BCN 120698726BCN-120698726-B

Abstract

The invention discloses an early-strength composite foam concrete foaming agent and a preparation method thereof, and belongs to the technical field of concrete foaming agents. The concrete foaming agent consists of 20-40 parts of composite foaming agent, 10-15 parts of early strength agent, 5-10 parts of activating agent, 0.5-1 part of organic coagulant, 1-3 parts of dispersing agent and 70-90 parts of deionized water. The modified plant protein prepared by taking peanut shells (agricultural waste) and peanut meal (byproducts) as raw materials is compounded with other raw materials to prepare the composite foaming agent, so that the dependence on surfactant type foaming agents is reduced, the foaming multiple is high, the stability is good, and the 1-day and 28-day strength of the foam concrete is obviously improved.

Inventors

  • WANG HONGWEI
  • WANG YONG
  • GUO JIANHU
  • REN CHUANQING
  • WANG RIZHENG

Assignees

  • 临沂天元混凝土工程有限公司

Dates

Publication Date
20260508
Application Date
20250711

Claims (9)

  1. 1. The early-strength composite foam concrete foaming agent is characterized by comprising, by weight, 20-40 parts of a composite foaming agent, 10-15 parts of an early-strength agent, 5-10 parts of an activating agent, 0.5-1 part of an organic coagulant, 1-3 parts of a dispersing agent and 70-90 parts of deionized water, wherein the early-strength agent is formed by mixing modified nano alumina and modified superfine silica fume according to a mass ratio of 3:1, the composite foaming agent is formed by sodium dodecyl sulfate, modified plant protein and guar gum according to a mass ratio of 1 (2-3) (0.1-0.3), and the activating agent is formed by metakaolin and nano silica according to a mass ratio of 5:1; The modified vegetable protein is prepared by the following method: (1) Drying peanut shells, crushing, and sieving with a 60-mesh sieve to obtain peanut shell powder; (2) Mixing peanut shell powder and ethanol according to a feed liquid ratio of 1:20 g/mL, performing ultrasonic treatment for 20-40min, stirring for 2-4h at 50-70 ℃, removing solvent by rotary evaporation after the completion of the ultrasonic treatment, and drying the obtained product to obtain a peanut shell extract; (3) Drying peanut meal, pulverizing to 80 meshes, soaking in sodium bicarbonate solution according to solid-to-liquid ratio, magnetically stirring at 50deg.C for 30-40min, and filtering to obtain wet meal; (4) Adding wet meal, water, peanut shell extract and ferric chloride into a reaction kettle in proportion, magnetically stirring and reacting at 40 ℃, introducing air and aerating for 3-3.5h, adjusting the pH value of the mixed solution to 7.0 after the reaction is finished, and freeze-drying to obtain the modified plant protein.
  2. 2. The early-strength type composite foam concrete foaming agent according to claim 1, wherein the concentration of ethanol in the step (2) is 60-65%.
  3. 3. The early-strength composite foam concrete foaming agent according to claim 1, wherein the solid-to-liquid ratio in the step (3) is 1 g/10 ml, and the mass fraction of sodium bicarbonate solution is 0.1%.
  4. 4. The early-strength composite foam concrete foaming agent according to claim 1, wherein the mass ratio of the wet meal to the water in the step (4) is 1:5, the peanut shell extract is used in an amount of 0.05-0.1% of the mass of the wet meal, and the ferric chloride is used in an amount of 0.2-0.3% of the mass of the wet meal.
  5. 5. The early-strength composite foam concrete foaming agent according to claim 1, wherein the modified nano alumina and the modified superfine silica fume are all obtained by modification treatment with a silane coupling agent KH 550.
  6. 6. The early-strength composite foam concrete foaming agent according to claim 1, wherein the specific surface area of the superfine silica fume is more than or equal to 15 m2/g, the particle size of nano alumina is 80-100nm, and the particle size of nano silica is 10-20nm.
  7. 7. The early-strength composite foam concrete foaming agent according to claim 1, wherein the organic coagulant is one of triethanolamine, sodium aminoacetate and disodium edetate.
  8. 8. The early-strength composite foam concrete foaming agent according to claim 1, wherein the dispersant is a polycarboxylic acid type dispersant.
  9. 9. A method for preparing the early-strength composite foam concrete foaming agent according to any one of claims 1 to 8, which comprises the following steps: Step 1, preparing modified vegetable protein, and uniformly mixing the modified vegetable protein with sodium dodecyl sulfate and guar gum according to a proportion to obtain a compound foaming agent; Step 2, respectively taking nano alumina and superfine silica fume, dispersing in absolute ethyl alcohol according to a solid-to-liquid ratio of 1:20, adding 3wt% of silane coupling agent KH550, refluxing and stirring at 70 ℃ for 2 hours, centrifugally washing, drying at 80 ℃ to obtain modified nano alumina and modified superfine silica fume, and mixing the modified nano alumina and the modified superfine silica fume according to a mass ratio to obtain an early strength agent for later use; step 3, heating deionized water to 40 ℃, adding a dispersing agent and an organic coagulant in proportion, magnetically stirring and uniformly mixing to obtain a mixture; And 4, adding an activating agent into the mixture, stirring at 600rpm for 10min, adding an early strength agent at 1200rpm for high-speed dispersion for 20min, finally adding a composite foaming agent at 800rpm for stirring for 15-20min, transferring into a high-pressure homogenizer for 3 times of circulating homogenization under 35MPa pressure, and standing for 24h to obtain the early-strength composite foam concrete foaming agent.

Description

Early-strength composite foam concrete foaming agent and preparation method thereof Technical Field The invention belongs to the technical field of concrete foaming agents, and particularly relates to an early-strength composite foam concrete foaming agent and a preparation method thereof. Background The foam concrete is prepared by adding foam prepared by a foaming agent into cement paste or cement mortar in a physical and mechanical foaming mode, uniformly stirring, pouring into various specifications, and curing to form the light concrete with a large number of closed air holes, and has the characteristics of light weight, good heat preservation and heat insulation performance, good sound insulation and fire resistance, good shock resistance, environmental protection and the like, and is widely used at present. The foaming agent is one of key components of the foam concrete and plays a decisive role in the performance of the foam concrete. The foaming agent is mainly divided into a chemical foaming agent and a physical foaming agent according to a foaming principle. The physical foaming agent is a foaming agent which is produced by foaming a foaming agent solution by introducing air into the solution through a mechanical mode such as high-speed stirring and compressed air. Compared with chemical foaming agents, the process of preparing foam concrete by using the physical foaming agents is to prepare foam in advance, then mix and stir the foam concrete with materials such as concrete slurry, lightweight aggregate, additives and the like, and finally pour a mold for curing to prepare a foam concrete sample. The physical foaming agent is characterized in that the prepared foam has long service life, the diameter of the foam is generally less than 1mm, the foam size is more consistent, and in addition, the foam is not easy to crack in concrete slurry to form air holes or communicating holes. The physical foaming agent has the advantages of low cost, simple preparation process and the like, and is dominant in the related research field. The physical foaming agents commonly used at present are mainly divided into rosin resin foaming agents, surfactant foaming agents, protein foaming agents and composite foaming agents. However, in practical applications, there are still many limitations to the various physical blowing agents available. The rosin resin foaming agent has wide sources of raw materials and low cost, but has relatively insufficient foaming times and foam stability, is difficult to meet the engineering requirements on higher foam performance, has strong foaming capacity, has high foam uniformity and stability influenced by environmental factors, has obvious performance fluctuation under different temperature and humidity conditions, has good foam stability, has relatively difficult raw material acquisition, has higher cost and is easy to be corroded by microorganisms to cause performance reduction, and the composite foaming agent combines the advantages of various foaming agents to a certain extent, but has still to be improved in terms of early strength performance. Early strength of foam concrete is critical to construction progress and engineering quality. In many practical projects, such as rush-repair construction projects, winter construction projects, etc., foam concrete is required to reach a certain strength in a short time in order to perform subsequent processes or bear a certain load. However, the early strength of the foam concrete prepared by the existing physical foaming agent is slow to develop, and the requirements of the special projects are difficult to meet, so that the construction period is prolonged, the cost is increased, and the safety and the durability of the engineering structure are even affected. Therefore, the preparation of the early-strength composite foam concrete foaming agent for improving the early strength of foam concrete and simultaneously achieving good foaming performance and stability becomes a key problem to be solved urgently in the technical field of the current foam concrete. Disclosure of Invention The invention aims to provide an early-strength composite foam concrete foaming agent which has high foaming multiple and good foam stability and can obviously improve the early strength of foam concrete. In order to achieve the technical purpose, the invention adopts the following technical scheme: The early strength type composite foam concrete foaming agent is prepared from the following raw materials, by weight, 20-40 parts of a composite foaming agent, 10-15 parts of an early strength agent, 5-10 parts of an activating agent, 0.5-1 part of an organic coagulant, 1-3 parts of a dispersing agent and 70-90 parts of deionized water, wherein the early strength agent is formed by mixing modified nano alumina and modified superfine silica fume according to a mass ratio of 3:1, the composite foaming agent is formed by sodium dodecyl sulfate, modified plant prote