阅读说明：本技术 一种混凝土防冻剂及其制备方法 (Concrete antifreezing agent and preparation method thereof ) 是由 申全军 黄拓 穆明浩 杨耀辉 于 2021-08-16 设计创作，主要内容包括：本发明提供了一种混凝土防冻剂及其制备方法。本发明的防冻剂包括改性硫酸钙晶须35-50份,甲酸钙5-10份,改性硅藻土6-12份,尿素4-8份,木质素磺酸钠15-25份,固体醇胺8-15份,以上份数为重量份。通过以上各物质的组合、配比、协同配比,制备出了可以在-30℃工作的混凝土防冻剂,提高了混凝土的抗冻融性能,同时原料中不涉及有害离子,避免了对于混凝土的腐蚀,具有良好的耐久性。(The invention provides a concrete antifreezing agent and a preparation method thereof. The antifreezing agent comprises 35-50 parts of modified calcium sulfate whisker, 5-10 parts of calcium formate, 6-12 parts of modified diatomite, 4-8 parts of urea, 15-25 parts of sodium lignosulphonate and 8-15 parts of solid alcohol amine, wherein the parts are parts by weight. The concrete antifreezing agent capable of working at-30 ℃ is prepared by the combination, the proportion and the synergistic proportion of the substances, the freeze-thaw resistance of the concrete is improved, and meanwhile, harmful ions are not involved in the raw materials, so that the concrete is prevented from being corroded, and the concrete antifreezing agent has good durability.)

1. A concrete antifreeze, comprising: 35-50 parts of modified calcium sulfate whisker, 5-10 parts of calcium formate, 6-12 parts of modified diatomite, 4-8 parts of urea, 15-25 parts of sodium lignosulfonate and 8-15 parts of solid alcohol amine.

2. The concrete antifreezer according to claim 1, wherein the calcium sulfate whiskers are modified by sodium dodecyl benzene sulfonate, and the diatomite is modified by a silane coupling agent.

3. The concrete antifreezer according to claim 2, wherein the silane coupling agent is KH550 or KH 570.

4. The concrete antifreezer according to claim 1, wherein the preparation method of the modified calcium sulfate whiskers comprises the following steps: weighing calcium sulfate whiskers, adding the calcium sulfate whiskers into a modifier solution, stirring and reacting at 50-80 ℃ for 20-60min, then separating and drying to obtain the calcium sulfate whisker modifier, wherein the modifier is sodium dodecyl benzene sulfonate, and the mass ratio of the calcium sulfate whiskers to the sodium dodecyl benzene sulfonate is 1: 0.01-0.05; the stirring speed is 800-1200 r/min.

5. The concrete antifreezer as claimed in claim 1, wherein the modified diatomite is prepared by the following steps: weighing kieselguhr, adding the kieselguhr into a modifier solution, stirring and reacting at 90-130 ℃ for 30-90min, and then separating to obtain the modified kieselguhr-diatomite-modified kieselguhr composite material, wherein the modifier is KH550 or KH570, and the mass ratio of the kieselguhr to the modifier is 1: 0.01-0.1; the stirring speed is 800-1500 r/min.

6. A concrete antifreezer according to claim 4 or 5, which consists of: 45 parts of modified calcium sulfate whisker, 8 parts of calcium formate, 10 parts of modified diatomite, 6 parts of urea, 20 parts of sodium lignosulfonate and 11 parts of solid alcohol amine.

7. A concrete antifreezer according to claim 4 or 5, which consists of: 40 parts of modified calcium sulfate whisker, 10 parts of calcium formate, 7 parts of modified diatomite, 8 parts of urea, 25 parts of sodium lignosulfonate and 10 parts of solid alcohol amine.

8. The method for preparing the concrete antifreeze agent according to any one of claims 1 to 7, which comprises the steps of preparing modified calcium sulfate whiskers and modified diatomite, weighing the modified calcium sulfate whiskers, calcium formate, modified diatomite, urea, sodium lignosulfonate and solid alcohol amine according to a ratio, and uniformly mixing.

9. The preparation method of the concrete antifreeze according to claim 8, wherein the preparation method of the modified calcium sulfate whisker comprises the following steps: weighing calcium sulfate whiskers, adding the calcium sulfate whiskers into a modifier solution, stirring and reacting at 50-80 ℃ for 20-60min, then separating and drying to obtain the calcium sulfate whisker modifier, wherein the modifier is sodium dodecyl benzene sulfonate, and the mass ratio of the calcium sulfate whiskers to the sodium dodecyl benzene sulfonate is 1: 0.01-0.05; the stirring speed is 800-1200 r/min.

10. The method for preparing the concrete antifreezer according to claim 8, wherein the modified diatomite is prepared by the following steps: weighing kieselguhr, adding the kieselguhr into a modifier solution, stirring and reacting at 90-130 ℃ for 30-90min, and then separating to obtain the modified kieselguhr-diatomite-modified kieselguhr composite material, wherein the modifier is KH550 or KH570, and the mass ratio of the kieselguhr to the modifier is 1: 0.01-0.1; the stirring speed is 800-1500 r/min.

Technical Field

The invention relates to the field of concrete admixtures, in particular to a concrete antifreezing agent and a preparation method thereof.

Background

When the concrete does not reach the required strength, a certain amount of water is still arranged in the concrete, and after the ambient temperature reaches the freezing point of water, the water phase is promoted to be converted into ice, so that the water in the concrete is redistributed and an ice interlayer is formed, the cohesive force of the concrete aggregate and a cement stone interface is reduced, the volume expansion is caused, and the early freezing of the concrete is caused. In order to ensure the quality and the progress of concrete in low-temperature construction, an antifreezing agent needs to be added. The antifreezing agent can harden the concrete at negative temperature, and finally the concrete can reach the same quality as the concrete cured at normal temperature.

The common idea of the antifreeze design is to reduce the freezing point, the reduction degree of the liquid-phase freezing point of the concrete mixture material has a direct relation with the molar concentration of the antifreeze, and the freezing point reduction mode is adopted to ensure that the water in the concrete structure of the material at negative temperature is directly converted into liquid water, which is an action mechanism of applying the antifreeze in winter environmental construction. And the strength of the concrete is improved quickly at negative temperature, the long-term performance and the durability of the concrete are not influenced, and the concrete is harmless to human bodies.

At present, the concrete antifreezer in China mainly takes inorganic salt antifreezer as a main material and takes organic antifreezer as an auxiliary material, and a large amount of alkali metal ions, chloride ions and the like are doped when the doping amount of the antifreezer is high, so that hidden troubles are brought to the long-term performance and durability of concrete. In addition, the anti-freezing performance and the anti-freezing performance are two concepts, the anti-freezing performance relates to concrete construction, maintenance conditions are created in a negative temperature environment, concrete is prevented from being frozen, and hardening and strengthening are realized. The anti-freezing performance relates to the durability of concrete and the long-term resistance to freeze-thaw cycles. Areas needing to be prevented from freezing during construction usually have strong requirements on the freezing resistance of concrete, but the freezing resistance of the concrete cannot be improved by the current commercial freezing preventives.

Disclosure of Invention

The invention aims to overcome the defects of the prior art, avoid influencing the durability of concrete, and simultaneously improve the frost resistance, and provides a concrete antifreezing agent and a preparation method thereof.

A concrete antifreeze comprising: 35-50 parts of modified calcium sulfate whisker, 5-10 parts of calcium formate, 6-12 parts of modified diatomite, 4-8 parts of urea, 15-25 parts of sodium lignosulfonate and 8-15 parts of solid alcohol amine.

Wherein, the calcium sulfate whisker is modified by sodium dodecyl benzene sulfonate, the diatomite is modified by a silane coupling agent, and the silane coupling agent is preferably KH550 or KH 570.

The preparation method of the modified calcium sulfate whisker comprises the following steps: weighing calcium sulfate whisker, adding into modifier solution, stirring at 50-80 deg.C for reaction for 20-60min, separating, and oven drying. Wherein the modifier is sodium dodecyl benzene sulfonate, and the mass ratio of the calcium sulfate whisker to the sodium dodecyl benzene sulfonate is 1: 0.01-0.05; the stirring speed is 800-1200 r/min.

The preparation method of the modified diatomite comprises the following steps: weighing diatomite, adding the diatomite into the modifier solution, stirring and reacting at 90-130 ℃ for 30-90min, and then separating to obtain the diatomite-modified diatomite. Wherein the modifier is KH550 or KH570, and the mass ratio of the diatomite to the modifier is 1: 0.01-0.1; the stirring speed is 800-1500 r/min.

Preferably, the concrete antifreezer comprises the following components: 45 parts of modified calcium sulfate whisker, 8 parts of calcium formate, 10 parts of modified diatomite, 6 parts of urea, 20 parts of sodium lignosulfonate and 11 parts of solid alcohol amine.

Preferably, the concrete antifreezer comprises the following components: 40 parts of modified calcium sulfate whisker, 10 parts of calcium formate, 7 parts of modified diatomite, 8 parts of urea, 25 parts of sodium lignosulfonate and 10 parts of solid alcohol amine.

The preparation method of the concrete antifreezing agent comprises the following steps: preparing modified calcium sulfate whisker and modified diatomite, weighing the modified calcium sulfate whisker, calcium formate, the modified diatomite, urea, sodium lignin sulfonate and solid alcohol amine according to the proportion, and uniformly mixing.

The invention has the following beneficial effects: the calcium sulfate whisker is a micron-grade material, can improve the framework strength of the calcium sulfate whisker by being doped into concrete, can combine with the calcium sulfate whisker by cement hydration products, enhances the strength of a space framework, avoids generating cracks, can continuously fill pores and micropores generated in the production process, and further improves the strength, durability and frost resistance. The invention adopts the sodium dodecyl benzene sulfonate to modify the calcium sulfate, improves the activity of the calcium sulfate whisker and further improves the performance of the concrete. The diatomite is modified by the silane coupling agent, so that the dispersibility of the diatomite in concrete is improved, the pores are filled, and the strength is improved. The sodium lignosulfonate has the effects of early strength, water reduction and air entraining, the calcium formate has the effect of early strength, the urea can reduce the freezing point, the solid alcohol amine is convenient to use relative to liquid alcohol amines such as triethanolamine and the like, simultaneously hydration products are more reasonably distributed, the slurry structure is more perfect, and the strength is ensured. The concrete antifreezing agent capable of working at-30 ℃ is prepared by the combination, the proportion and the synergistic proportion of the substances, the freeze-thaw resistance of the concrete is improved, and meanwhile, harmful ions are not involved in the raw materials, so that the concrete is prevented from being corroded, and the concrete antifreezing agent has good durability.

Detailed Description

The following description of the preferred embodiments of the present invention is provided for the purpose of illustration and description, and is in no way intended to limit the invention.

Example 1:

a concrete antifreeze comprising: 45 parts of modified calcium sulfate whisker, 8 parts of calcium formate, 10 parts of modified diatomite, 6 parts of urea, 20 parts of sodium lignosulfonate and 11 parts of solid alcohol amine.

The preparation method of the modified calcium sulfate whisker comprises the following steps: weighing calcium sulfate whisker, adding into modifier solution, stirring at 80 deg.C for reaction for 30min, separating, and oven drying. Wherein the modifier is sodium dodecyl benzene sulfonate, and the mass ratio of the calcium sulfate whisker to the sodium dodecyl benzene sulfonate is 1: 0.01; the stirring speed was 1000 r/min.

The preparation method of the modified diatomite comprises the following steps: weighing diatomite, adding the diatomite into the modifier solution, stirring and reacting for 60min at 120 ℃, and then separating to obtain the product. Wherein the modifier is KH570, and the mass ratio of the diatomite to the modifier is 1: 0.05; the stirring speed is 1500 r/min.

The preparation method of the concrete antifreezing agent comprises the following steps: preparing modified calcium sulfate whisker and modified diatomite, weighing the modified calcium sulfate whisker, calcium formate, the modified diatomite, urea, sodium lignin sulfonate and solid alcohol amine according to the proportion, and uniformly mixing.

Example 2

A concrete antifreeze comprising: the concrete antifreezing agent comprises the following components: 40 parts of modified calcium sulfate whisker, 10 parts of calcium formate, 7 parts of modified diatomite, 8 parts of urea, 25 parts of sodium lignosulfonate and 10 parts of solid alcohol amine.

The preparation method of the modified calcium sulfate whisker comprises the following steps: weighing calcium sulfate whisker, adding into modifier solution, stirring at 70 deg.C for reaction for 30min, separating, and oven drying. Wherein the modifier is sodium dodecyl benzene sulfonate, and the mass ratio of the calcium sulfate whisker to the sodium dodecyl benzene sulfonate is 1: 0.03; the stirring speed was 1000 r/min.

The preparation method of the modified diatomite comprises the following steps: weighing diatomite, adding the diatomite into the modifier solution, stirring and reacting for 60min at 120 ℃, and then separating to obtain the product. Wherein the modifier is KH570, and the mass ratio of the diatomite to the modifier is 1: 0.05; the stirring speed is 1500 r/min.

The preparation method of the concrete antifreezing agent comprises the following steps: preparing modified calcium sulfate whisker and modified diatomite, weighing the modified calcium sulfate whisker, calcium formate, the modified diatomite, urea, sodium lignin sulfonate and solid alcohol amine according to the proportion, and uniformly mixing.

Comparative example 1

The calcium sulfate whiskers were not modified, and the rest was the same as in example 1.

Comparative example 2

The diatomaceous earth was not modified, and the procedure was as in example 1.

Comparative example 3

30 parts of modified calcium sulfate whisker, 10 parts of calcium formate, 15 parts of modified diatomite, 8 parts of urea, 25 parts of sodium lignosulfonate and 12 parts of solid alcohol amine, and the rest is the same as that of the embodiment 1.

Comparative example 4

The modified calcium sulfate whiskers were not added, and the rest was the same as in example 1.

Comparative example 5

The procedure of example 1 was repeated except that modified diatomaceous earth was not added.

And (3) testing the freezing resistance: the antifreeze of the examples and comparative examples was used in concrete at-30 ℃ to observe the occurrence of icing.

Freeze-thaw strength loss ratio test 50 times tests were performed according to GB/T50082-2009 and the strength loss ratio was calculated. The compressive strength and the compressive strength ratio are tested according to GB/T50081, and the negative temperature is-10 ℃.

From the results, the invention realizes the frost resistance and the antifreezing performance of the concrete by modifying the calcium sulfate whisker and the diatomite and adopting the specific raw material proportion.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.