Foaming agent composition for low temperature environment foam concrete and foam preparation method

Abstract

The application discloses a foaming agent composition for low-temperature environment foam concrete and a foam preparation method, and comprises 10-20 mass parts of a surfactant, 8-12 mass parts of calcium chloride, 2-3 mass parts of glycerol, 2-4 mass parts of temperature-adjusting capsules and 60-70 mass parts of water, wherein the temperature-adjusting capsules account for 2-4% of the total mass of the foaming agent composition. The application solves the problems of low foaming efficiency and poor foam stability of traditional foam concrete in a low-temperature environment.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, specifically to a foaming agent composition for low-temperature environment foamed concrete and a foam preparation method. Background Technology

[0002] Introducing air foam into concrete can reduce its density and improve its thermal insulation and sound insulation properties, making it widely used in roof structures, insulated walls, and other applications. Traditional methods for preparing foamed concrete face numerous challenges in low-temperature environments, primarily due to low foaming efficiency and poor foam stability at low temperatures. This is particularly evident in cold climates or winter construction, affecting the quality and application effectiveness of the foamed concrete. Currently, there is a lack of effective solutions on the market to address this issue.

[0003] Foam formation primarily depends on the mixing of a foaming agent and water, with the foaming agent typically containing surfactants. These surfactants reduce the surface tension of the water, allowing bubbles to form and remain stable in the water.

[0004] The effects of low temperature on foaming efficiency and foam stability are as follows:

[0005] (1) Increased surface tension: Low temperature leads to increased surface tension of water, which makes it more difficult for foaming agents to form stable foam in water.

[0006] (2) Increased viscosity: Low temperature will increase the viscosity of the mixture, which reduces the mobility and dispersion of bubbles, resulting in uneven foam.

[0007] (3) Reduced bubble stability: At low temperatures, the solubility of gas inside the bubble increases, which may cause the bubble to disappear quickly.

[0008] Due to these changes in physical and chemical mechanisms, traditional foaming agents are unable to effectively generate and maintain stable foam in low-temperature environments, which in turn affects the quality and performance of foamed concrete. Summary of the Invention

[0009] To overcome the shortcomings of existing technologies, a foaming agent composition and foam preparation method for foamed concrete in low-temperature environments are provided to solve the problems of low foaming efficiency and poor foam stability of traditional foamed concrete in low-temperature environments.

[0010] To achieve the above objective, a foaming agent composition for low-temperature environment foamed concrete is provided, comprising: 10-20 parts by weight of surfactant, 8-12 parts by weight of calcium chloride, 2-3 parts by weight of glycerol, 2-4 parts by weight of temperature-regulating capsule, and 60-70 parts by weight of water, wherein the temperature-regulating capsule accounts for 2-4% of the total mass of the foaming agent composition.

[0011] Furthermore, the surfactant is at least one of fatty alcohol polyoxyethylene ether, sodium alkylbenzene sulfonate, and lauryl alcohol polyether sulfate.

[0012] Furthermore, the temperature-regulating capsule includes a shell and a phase change material filled in the shell. When the temperature outside the shell rises to the melting point of the phase change material, the phase change material absorbs heat and changes from a solid to a liquid state to reduce the temperature outside the shell. After the temperature outside the shell decreases, the phase change material changes from a liquid to a solid state to release heat, thereby maintaining the temperature outside the shell.

[0013] Furthermore, the phase change material is paraffin wax, fatty acid, or a salt solution.

[0014] Furthermore, the shell is made of polyurethane, polyoxymethylene, or gelatin.

[0015] This invention provides a method for preparing foam using a foaming agent composition for low-temperature foamed concrete, comprising the following steps:

[0016] Weigh the surfactant, calcium chloride, glycerin, and temperature control agent and mix them thoroughly to obtain a dry mixture;

[0017] Add water to the dry material and stir at medium speed for two minutes to allow the calcium chloride to begin to dissolve and release heat. The stirring frequency is 80-100 rpm.

[0018] Adjust the medium-speed stirring to high-speed stirring, the frequency of the high-speed stirring is 120-150 rpm, and the high-speed stirring time is 8 minutes, until the foam is fully formed and evenly distributed;

[0019] The high-speed stirring is adjusted to gentle stirring, the frequency of gentle stirring is 40-60 rpm, and the time of gentle stirring is 5 minutes, in order to stabilize the foam structure. The temperature regulating capsule helps to regulate and maintain a suitable temperature to prevent the foam from breaking due to excessive temperature.

[0020] The foam is transferred to a concrete mixer for use in preparing foamed concrete at low temperatures.

[0021] The beneficial effect of the present invention is that the foaming agent composition of the present invention for low-temperature environment foamed concrete significantly improves the stability and uniformity of the foam prepared in the low-temperature environment, which helps to improve the overall quality of concrete.

[0022] The foaming agent composition of this invention for low-temperature environment foamed concrete is harmless to the durability of concrete structures. Calcium chloride (CaCl2) contains calcium ions (Ca... 2+ ) and chloride ions (Cl –Calcium ions are one of the products of cement hydration, and their increased content does not harm the strength or durability of concrete. Although chloride ions cause corrosion of steel bars in reinforced concrete structures, there is no steel bar embedded in foamed concrete, so there is no problem with chloride ion corrosion.

[0023] The foaming agent composition for low-temperature foamed concrete of the present invention uses calcium chloride as a self-heating source, which promotes the early strength development of concrete. Chloride ions enter the interior of concrete through diffusion and penetration, react with cement hydration products to generate hydrated chloroaluminate (C3A·3CaCl2·10H2O) salt, which densifies the pores inside the concrete.

[0024] The foaming agent composition for low-temperature foamed concrete of the present invention uses calcium chloride as a self-heating source, which promotes the early-stage freeze-thaw resistance of the concrete structure. Calcium chloride combines with water molecules in the concrete to form hydrates, lowering the ice crystal formation temperature in the concrete, thereby improving the freeze-thaw resistance of the concrete. Attached Figure Description

[0025] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0026] Figure 1 This is a schematic diagram of the structure of foamed concrete for use in low-temperature environments, according to an embodiment of the present invention. Detailed Implementation

[0027] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0028] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0029] The present invention provides a foaming agent composition for foamed concrete in low-temperature environments, comprising: 10-20 parts by weight of a surfactant, 8-12 parts by weight of calcium chloride (CaCl2), 2-3 parts by weight of glycerol, 2-4 parts by weight of a temperature-regulating capsule, and 60-70 parts by weight of water.

[0030] The temperature-regulating capsules account for 2-4% of the total mass of the foaming agent composition.

[0031] In a preferred embodiment, the surfactant is at least one of fatty alcohol polyoxyethylene ether, sodium alkylbenzene sulfonate, and lauryl alcohol polyether sulfate.

[0032] In a preferred embodiment, the temperature-regulating capsule includes a capsule shell and a phase change material filled in the capsule shell. When the temperature of the phase change material outside the capsule shell rises to the melting point of the phase change material, the phase change material absorbs heat and changes from a solid state to a liquid state to reduce the temperature outside the capsule shell. After the temperature outside the capsule shell decreases, the phase change material changes from a liquid state to a solid state to release heat, thereby maintaining the temperature outside the capsule shell.

[0033] In this embodiment, the phase change material is paraffin wax, fatty acid, and salt water solution.

[0034] In this embodiment, the shell is made of polyurethane, polyoxymethylene, or gelatin.

[0035] The temperature-regulating capsule used in the foaming agent composition for low-temperature foamed concrete of the present invention ensures that the temperature does not become too high during the foaming process and remains within the optimal foaming temperature range. It accounts for 2-4% of the total mass of the foaming agent.

[0036] The foaming agent composition for low-temperature environment foamed concrete of the present invention uses calcium chloride (CaCl2) as a self-heating source.

[0037] A self-heating source is a substance that is soluble in water and releases heat upon dissolution. In calcium chloride (CaCl2), substances that produce iron ions (Fe2+) upon dissolution should not be used. 3+ ), ferrous ions (Fe) 2+ ), aluminum ions (Al) 3+ (The chemical substances, because these ions affect the hydration process of concrete.)

[0038] Thermoregulating capsules, as temperature control agents, consist of a core material and a shell. The core material is a phase change agent or phase change substance. The core material can absorb or release heat near its phase change point (such as melting or freezing point).

[0039] The phase change material or phase change substance is paraffin, fatty acid, or salt solution.

[0040] The shell is a sturdy outer shell that encloses the phase change material or phase change substance to prevent leakage.

[0041] The shell is made of polymers, such as polyurethane, polyoxymethylene, or gelatin, which have good chemical stability, mechanical strength, and thermal stability.

[0042] The working principle of the temperature-regulating capsule is as follows:

[0043] During the endothermic (melting) process, when the ambient temperature rises to the melting point of the phase change substance, the substance absorbs heat and changes from a solid to a liquid state. The heat absorbed in this process can effectively slow down the temperature rise of the system.

[0044] During exothermic (solidification) processes, when the ambient temperature drops to a certain level, the phase change substance releases heat and transforms from a liquid to a solid state. The heat released during this process helps maintain the system's temperature.

[0045] The present invention provides a foaming agent composition for foamed concrete in low-temperature environments, in which glycerol is used as a foam stabilizer.

[0046] The foaming agent composition for low-temperature environment foamed concrete of the present invention uses water as the solvent of the foaming agent.

[0047] This invention provides a method for preparing foam using a foaming agent composition for low-temperature foamed concrete, comprising the following steps:

[0048] Weigh the surfactant, calcium chloride, glycerin, and temperature control agent and mix them thoroughly to obtain a dry mixture;

[0049] Add water to the dry materials and stir at medium speed for two minutes to allow the calcium chloride to begin to dissolve and release heat. The stirring frequency should be 80-100 rpm.

[0050] Adjust the medium speed to high speed, with a mixing frequency of 120-150 rpm and a mixing time of 8 minutes, until the foam is fully formed and evenly distributed.

[0051] Adjust the high-speed stirring to gentle stirring, with a stirring frequency of 40-60 rpm and a stirring time of 5 minutes, to stabilize the foam structure. The temperature-regulating capsule helps to adjust and maintain a suitable temperature to prevent the foam from breaking due to excessive temperature.

[0052] The foam is transferred to a concrete mixer for use in preparing foamed concrete at low temperatures.

[0053] Specifically, the foam preparation method of the present invention using a foaming agent composition for low-temperature environment foamed concrete includes:

[0054] (1) Preparation of dry ingredients (takes about 5 minutes):

[0055] Accurately weigh the surfactant, calcium chloride, glycerin, and temperature control agent using an electronic scale. Pour these solid ingredients into a mixing container and mix for 5 minutes at low speed (60-80 rpm) using a high-speed stirrer to ensure that the ingredients are evenly mixed.

[0056] (2) Add water to activate calcium chloride (takes about 2 minutes):

[0057] Slowly add the pre-weighed water to the mixed dry ingredients. After adding the water, continue mixing at medium speed (80-100 rpm) using a high-speed mixer for 2 minutes. During this process, calcium chloride begins to dissolve and releases heat.

[0058] (3) Foaming process (approximately 10 minutes):

[0059] As the solution temperature gradually increases, the surfactant begins to produce foam. Adjust the stirrer speed to high (120–150 rpm) and continue stirring for approximately 8 minutes, until the foam is fully formed and evenly distributed. Throughout the foaming process, observe the stability and consistency of the foam to ensure it meets the required quality standards.

[0060] (4) Stabilization treatment of foam (approximately 5 minutes):

[0061] Once foam has formed, reduce the stirring speed and continue gently stirring (40–60 rpm) for about 5 minutes to stabilize the foam structure. During this stage, the temperature-regulating capsule helps to regulate and maintain a suitable temperature, preventing the foam from bursting due to excessive heat.

[0062] (5) Completion and Transfer:

[0063] After the foaming process is complete, the foam is transferred from the mixing container to a concrete mixer to prepare foamed concrete.

[0064] The entire foaming process takes approximately 22 minutes from start to finish. This process allows for the effective production of high-quality foam at low temperatures, which can then be used in the subsequent preparation of foamed concrete.

[0065] To further illustrate the performance of the foaming agent composition for low-temperature environment foamed concrete of the present invention, the following examples and comparative examples are provided for comparison and illustration. The specific components and amounts of the foaming agent compositions in the examples and comparative examples are shown in Table 1 below.

[0066]

[0067] See Figure 1 , Figure 1 The foaming effects of comparative examples and embodiments are given. The foaming effect was determined according to GB / T 7462-1994 "Determination of foaming power of surfactants - Modified Ross-Miles method". The test principle is as follows: the foam volume is measured after 500 mL of surfactant solution is flowed from a height of 450 mm onto the surface of the same liquid.

[0068] Continue reading Figure 1Similarly, at low temperatures (5°C), the foam volume and retention capacity obtained using the foaming agent composition for low-temperature foamed concrete of the present invention (Examples 1-3) are significantly improved compared to conventional techniques (Comparative Example 1). The foam volume and retention capacity obtained using the foaming agent composition for low-temperature foamed concrete of the present invention at a water temperature of 5°C are comparable to those obtained using conventional techniques at a water temperature of 20°C.

[0069] The foaming agent composition of this invention for foamed concrete in low-temperature environments solves the construction problems of traditional foamed concrete in cold environments. The stability and uniformity of the foam are significantly improved, which helps to improve the overall quality of the concrete.

[0070] The foaming agent composition of this invention for low-temperature environment foamed concrete is harmless to the durability of concrete structures. Calcium chloride (CaCl2) contains calcium ions (Ca... 2+ ) and chloride ions (Cl – Calcium ions are one of the products of cement hydration, and their increased content does not harm the strength or durability of concrete. Although chloride ions cause corrosion of steel bars in reinforced concrete structures, there is no steel bar embedded in foamed concrete, so there is no problem with chloride ion corrosion.

[0071] The foaming agent composition for low-temperature foamed concrete of the present invention uses calcium chloride as a self-heating source, which promotes the early strength development of concrete. Chloride ions enter the interior of concrete through diffusion and penetration, react with cement hydration products to generate hydrated chloroaluminate (C3A·3CaCl2·10H2O) salt, which densifies the pores inside the concrete.

[0072] The foaming agent composition for low-temperature foamed concrete of the present invention uses calcium chloride as a self-heating source, which promotes the early-stage freeze-thaw resistance of the concrete structure. Calcium chloride combines with water molecules in the concrete to form hydrates, lowering the ice crystal formation temperature in the concrete, thereby improving the freeze-thaw resistance of the concrete.

[0073] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A foaming agent composition for low-temperature environment foamed concrete, characterized in that, include: The foaming agent composition comprises 10-20 parts by weight of surfactant, 8-12 parts by weight of calcium chloride, 2-3 parts by weight of glycerin, 2-4 parts by weight of temperature-regulating capsules, and 60-70 parts by weight of water, wherein the temperature-regulating capsules account for 2-4% of the total mass of the foaming agent composition, and the temperature-regulating capsules assist in regulating and maintaining a suitable temperature to prevent the foam from bursting due to excessive temperature. The surfactant is at least one of fatty alcohol polyoxyethylene ether, sodium alkylbenzene sulfonate, and lauryl alcohol polyether sulfate; The temperature-regulating capsule includes a shell and a phase change material filled in the shell. When the temperature outside the shell rises to the melting point of the phase change material, the phase change material absorbs heat and changes from a solid to a liquid state to reduce the temperature outside the shell. After the temperature outside the shell decreases, the phase change material changes from a liquid to a solid state to release heat, thereby maintaining the temperature outside the shell.

2. The foaming agent composition for low-temperature environment foamed concrete according to claim 1, characterized in that, The phase change material is paraffin wax and fatty acid.

3. The foaming agent composition for low-temperature environment foamed concrete according to claim 1, characterized in that, The shell is made of polyurethane, polyoxymethylene, or gelatin.

4. A method for preparing foam using the foaming agent composition for low-temperature environment foamed concrete as described in any one of claims 1 to 3, characterized in that, Includes the following steps: Weigh the surfactant, calcium chloride, glycerin, and temperature-regulating capsules and mix them thoroughly to obtain the dry material; Add water to the dry material and stir at medium speed for two minutes to allow the calcium chloride to begin to dissolve and release heat. The stirring frequency is 80-100 rpm. Adjust the medium-speed stirring to high-speed stirring, the frequency of the high-speed stirring is 120~150 rpm, and the high-speed stirring time is 8 minutes, until the foam is fully formed and evenly distributed; The high-speed stirring is adjusted to gentle stirring, the frequency of gentle stirring is 40~60 rpm, and the time of gentle stirring is 5 minutes, in order to stabilize the foam structure. The temperature regulating capsule helps to regulate and maintain a suitable temperature to prevent the foam from breaking due to excessive temperature. The foam is transferred to a concrete mixer for use in preparing foamed concrete at low temperatures.

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