Anti-cracking and high-strength concrete antifreezing agent and preparation method thereof

Abstract

The present application relates to a kind of anti-cracking and high-strength concrete antifreeze and its preparation method, it includes organic alcohol antifreeze component, plant-based water-retaining component, carboxylic acid-based early strength component, alkali-free and chloride-free water-reducing component, inorganic mineral filling component;The plant-based water-retaining component is modified guar gum.The present application is introduced by modified guar gum, not only does not hinder bubble escape due to increase slurry viscosity, but instead effectively inhibits the combination and growth of bubble due to viscosity increase, thereby reducing air content, and improving compressive strength.In addition, modified guar gum can form a "water-locking network" inside the concrete, which can lock water, prevent its migration and freezing, thereby preventing frost damage and microcracks caused by ice crystal expansion.At the same time, the "water-locking network" can fix free water inside the paste, prevent water absorption by aggregate or evaporation on the surface, thereby slowing down the decrease in fluidity caused by the decrease in free water.

Description

Technical Field

[0001] This invention relates to a concrete antifreeze agent, and more particularly to a crack-resistant and high-strength concrete antifreeze agent and its preparation method. Background Technology

[0002] Currently, to address the challenges of concrete construction at sub-zero temperatures, existing technologies commonly employ antifreeze agents containing chlorides, nitrites, or highly alkaline components. However, these antifreeze agents can cause steel corrosion, environmental pollution, and alkali-aggregate reactions, leading to their increasingly limited use. Consequently, chloride-free and alkali-free antifreeze agents have emerged on the market, but these often use a single alcohol as the antifreeze component. While single alcohol-based antifreeze agents can lower the freezing point, they cannot effectively control moisture migration within the concrete, resulting in micro-cracks at low temperatures. Furthermore, a single component cannot simultaneously achieve water retention, early strength, and water reduction properties, often requiring the formulation of multiple admixtures, which increases costs and reduces compatibility.

[0003] Therefore, there is an urgent need to develop a concrete antifreeze agent that integrates antifreeze, water retention, early strength, and water reduction, and can utilize natural plant-based materials to improve the microstructure. Summary of the Invention

[0004] The present invention aims to solve the problems of single function, insufficient crack resistance and poor slump retention of existing chlorine-free and alkali-free antifreeze agents.

[0005] This invention provides a concrete antifreeze agent, which includes an organic alcohol antifreeze component, a plant-based water-retaining component, a carboxylic acid-based early strength component, an alkali-free and chlorine-free water-reducing component, and an inorganic mineral filler component; the plant-based water-retaining component is modified guar gum.

[0006] Furthermore, the modified guar gum is hydroxypropyl guar gum.

[0007] Furthermore, the organic alcohol antifreeze component is glycerol and ethylene glycol monobutyl ether; the mass ratio of glycerol to ethylene glycol monobutyl ether is 5-8:1.

[0008] Furthermore, the carboxylic acid early strength component is calcium formate and calcium citrate; the mass ratio of calcium formate to calcium citrate is 3-5:1.

[0009] Furthermore, the alkali-free and chlorine-free water-reducing component is a polycarboxylate water-reducing agent.

[0010] Furthermore, the inorganic mineral filler component is talc powder and silica fume; the mass ratio of talc powder to silica fume is 2-5:1.

[0011] Furthermore, the concrete antifreeze agent, by weight, comprises the following components: Organic alcohol antifreeze component 25-35 parts 3-6 parts of plant-based water-retaining components 12-18 parts of carboxylic acid group early strength component 8-12 parts of alkali-free and chlorine-free water-reducing components 20-28 parts of inorganic mineral filler Solvent 40-55 parts.

[0012] Furthermore, the solvent is water.

[0013] Another objective of this invention is to provide a method for preparing the above-mentioned concrete antifreeze agent, the method comprising the following steps: heating a solvent to 40-50°C according to a predetermined weight percentage, adding a plant-based water-retaining component and an inorganic mineral filler component, mixing to obtain a slurry; cooling the slurry to below 30°C, adding an organic alcohol antifreeze component and a carboxylic acid early-strength component, mixing, and then adding an alkali-free and chlorine-free water-reducing component, mixing to obtain the concrete antifreeze agent.

[0014] The beneficial effects of this invention are as follows: 1. This invention, by introducing modified guar gum, not only avoids hindering bubble escape due to increased paste viscosity, but also effectively inhibits bubble coalescence and growth due to increased viscosity, thereby reducing air content and improving compressive strength. Furthermore, modified guar gum can form a "water-locking network" within the concrete. In sub-zero temperatures, this network locks in moisture, preventing its migration and freezing, thus preventing frost heave damage and micro-cracks caused by ice crystal expansion. Simultaneously, this network fixes free water within the paste, preventing water absorption by aggregates or evaporation to the surface, thereby mitigating the decrease in fluidity caused by reduced free water.

[0015] 2. The concrete antifreeze agent of this invention does not contain formaldehyde, ammonia, or heavy metal ions. It is chlorine-free, alkali-free, non-toxic, does not corrode steel bars, and does not pollute soil or water sources.

[0016] 3. The concrete antifreeze agent of this invention has multiple functions such as antifreeze, water retention, early strength and water reduction, and does not require the addition of other admixtures. Detailed Implementation

[0017] The following non-limiting embodiments are intended to enable those skilled in the art to more fully understand the invention, but do not limit the invention in any way.

[0018] The hydroxypropyl guar gum described below was purchased from Guangdong Yuanxin Chemical Reagent Co., Ltd.

[0019] The following polycarboxylate superplasticizer was purchased from Shandong Zhongwei High-Tech Materials Co., Ltd.

[0020] Example 1 Slurry premixing: By weight, heat 50 parts of water to 45°C, add 5 parts of hydroxypropyl guar gum, 18 parts of talc and 6 parts of silica fume, and stir and disperse at 1000 r / min for 15 min to obtain slurry; Cooling and compounding: Cool the slurry naturally to room temperature, add 24 parts glycerol, 4 parts ethylene glycol monobutyl ether, 12 parts calcium formate and 3 parts calcium citrate, stir for 20 minutes, then add 10 parts polycarboxylate superplasticizer and stir for 10 minutes to obtain concrete antifreeze agent.

[0021] Example 2 Slurry premixing: By weight, heat 45 parts of water to 45°C, add 5 parts of hydroxypropyl guar gum, 20 parts of talc and 5 parts of silica fume, and stir and disperse at 1000 r / min for 15 min to obtain slurry; Cooling and compounding: Allow the slurry to cool naturally to room temperature, add 28 parts glycerol, 4 parts ethylene glycol monobutyl ether, 12 parts calcium formate and 4 parts calcium citrate, stir for 20 minutes, then add 12 parts polycarboxylate superplasticizer and stir for 10 minutes to obtain concrete antifreeze agent.

[0022] Comparative Example 1 The difference from Example 1 is that unmodified guar gum is used instead of modified guar gum, that is, guar gum is used instead of hydroxypropyl guar gum.

[0023] Comparative Example 2 The difference from Example 1 is that no modified guar gum is added, that is, no hydroxypropyl guar gum is added.

[0024] Comparative Example 3 The difference from Example 1 is that no inorganic mineral filler components are added, that is, no talc and silica fume are added.

[0025] Concrete was prepared according to the mix proportions of 461 kg of cement, 512 kg of sand, 1252 kg of gravel, 175 kg of water, and 18 kg of concrete antifreeze prepared in Examples 1-2 and Comparative Examples 1-3 per cubic meter of concrete. The concrete was then cured at -10℃ for 7 days and the following performance tests were conducted. The results are shown in Table 1.

[0026] Air content and time loss: determined according to GB / T 50080-2016 "Standard for Test Methods of Performance of Ordinary Concrete Mixtures".

[0027] Compressive strength: determined according to GB / T 50081-2019 "Standard for Test Methods of Physical and Mechanical Properties of Concrete".

[0028] Table 1 1. As shown in Table 1, comparing Example 1 and Comparative Example 1, compared to Comparative Example 1, Example 1 exhibits a 33% reduction in air content, a 45% increase in compressive strength, a 71% reduction in heat loss, and an improvement in surface quality from slight sanding and minor cracking to smoothness and crack-free surfaces. These results indicate that although guar gum has a higher viscosity than hydroxypropyl guar gum, in the concrete antifreeze system of this invention (including organic alcohol antifreeze components, plant-based water-retaining components, carboxylic acid-based early-strength components, alkali-free and chlorine-free water-reducing components, and inorganic mineral filler components), hydroxypropyl guar gum possesses superior stability, low-temperature resistance, and anti-segregation properties.

[0029] 2. As shown in Table 1, comparing Example 1 and Comparative Example 2, compared to Comparative Example 2, Example 1 exhibits a 46% reduction in air content, a 73% increase in compressive strength, an 80% reduction in time loss, and an improvement in surface quality from slight sanding and cracking to smoothness and crack-free surfaces. These results indicate that hydroxypropyl guar gum can reduce air content and increase compressive strength, while also preventing microcracks caused by ice crystal expansion and mitigating the decrease in fluidity due to reduced free water.

[0030] 3. As shown in Table 1, comparing Example 1 with Comparative Example 3, the air content of Example 1 decreased by 27%, the compressive strength increased by 71%, and the surface quality improved from sandy and slightly cracked to smooth and crack-free. These results indicate that talc and silica fume can fill the capillary pores between cement particles, aggregates, and hydration products, thereby improving compressive strength and surface quality; simultaneously, their physical filling effect also helps to reduce air content and prolong slump retention time.

Claims

1. A concrete antifreeze agent, characterized in that: The concrete antifreeze agent includes organic alcohol antifreeze components, plant-based water-retaining components, carboxylic acid-based early strength components, alkali-free and chlorine-free water-reducing components, and inorganic mineral filler components. The plant-based water-retaining component is modified guar gum.

2. The concrete antifreeze agent according to claim 1, characterized in that: The modified guar gum is hydroxypropyl guar gum.

3. The concrete antifreeze agent according to claim 1, characterized in that: The organic alcohol antifreeze component is glycerol and ethylene glycol monobutyl ether; The mass ratio of glycerol to ethylene glycol monobutyl ether is 5-8:

1.

4. The concrete antifreeze agent according to claim 1, characterized in that: The carboxylic acid early strength component is calcium formate and calcium citrate; The mass ratio of calcium formate to calcium citrate is 3-5:

1.

5. The concrete antifreeze agent according to claim 1, characterized in that: The alkali-free and chlorine-free water-reducing component is a polycarboxylate water-reducing agent.

6. The concrete antifreeze agent according to claim 1, characterized in that: The inorganic mineral filler component is talc powder and silica fume; The mass ratio of talc powder to silica fume is 2-5:

1.

7. The concrete antifreeze agent according to claim 1, characterized in that: The concrete antifreeze agent, by weight, comprises the following components: Organic alcohol antifreeze component 25-35 parts 3-6 parts of plant-based water-retaining components 12-18 parts of carboxylic acid group early strength component 8-12 parts of alkali-free and chlorine-free water-reducing components 20-28 parts of inorganic mineral filler Solvent 40-55 parts.

8. The concrete antifreeze agent according to claim 1, characterized in that: The solvent is water.

9. The method for preparing the concrete antifreeze agent according to claim 1, 2, 3, 4, 5, 6, 7 or 8, characterized in that: The preparation method includes the following steps: According to the predetermined weight proportions, the solvent is heated to 40-50℃, and plant-based water-retaining components and inorganic mineral filler components are added and mixed to obtain a slurry; Cool the slurry to below 30°C, add organic alcohol antifreeze components and carboxylic acid early strength components, mix them, then add alkali-free and chlorine-free water-reducing components, mix them again, and obtain concrete antifreeze agent.

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