阅读说明：本技术 一种再生骨料混凝土用早强减水剂及其制备方法 (Early strength water reducing agent for recycled aggregate concrete and preparation method thereof ) 是由 庞永献 庞森林 易钢招 于 2020-03-03 设计创作，主要内容包括：本发明公开了一种再生骨料混凝土用早强减水剂及其制备方法,涉及建筑材料技术领域,再生骨料混凝土用早强减水剂,每100重量份早强减水剂包括以下重量份的组分：釜底料：水33-37.5份、聚醚大单体33-37.5份；A液：水3.1-3.4份、不饱和羧酸3.1-3.4份、甲基丙烯磺酸钠0.1-0.4份；B液：维生素C 0.04-0.07份、链转移剂0.14-0.17份、水10-13份；C液：水0.4-0.7份、引发剂0.13-0.16份；片碱0.3-0.6份、0.3-0.45份改性剂、余量为水。本发明的再生骨料混凝土用早强减水剂具有缩短凝结时间,增加早期强度,降低水灰比,增大混凝土的抗冻融效果的优点。(The invention discloses an early strength water reducing agent for recycled aggregate concrete and a preparation method thereof, and relates to the technical field of building materials, wherein each 100 parts by weight of the early strength water reducing agent for the recycled aggregate concrete comprises the following components in parts by weight: kettle bottom material: 33-37.5 parts of water and 33-37.5 parts of polyether macromonomer; solution A: 3.1-3.4 parts of water, 3.1-3.4 parts of unsaturated carboxylic acid and 0.1-0.4 part of sodium methallyl sulfonate; and B, liquid B: 0.04-0.07 part of vitamin C, 0.14-0.17 part of chain transfer agent and 10-13 parts of water; and C, liquid C: 0.4-0.7 part of water and 0.13-0.16 part of initiator; 0.3-0.6 part of caustic soda flakes, 0.3-0.45 part of modifier and the balance of water. The early strength water reducing agent for recycled aggregate concrete has the advantages of shortening the setting time, increasing the early strength, reducing the water-cement ratio and increasing the freeze-thaw resistance of concrete.)

1. The early strength water reducing agent for recycled aggregate concrete is characterized by comprising the following components in parts by weight per 100 parts by weight:

kettle bottom material: 33-37.5 parts of water and 33-37.5 parts of polyether macromonomer; solution A: 3.1-3.4 parts of water, 3.1-3.4 parts of unsaturated carboxylic acid and 0.1-0.4 part of sodium methallyl sulfonate; and B, liquid B: 0.04-0.07 part of vitamin C, 0.14-0.17 part of chain transfer agent and 10-13 parts of water; and C, liquid C: 0.4-0.7 part of water and 0.13-0.16 part of initiator; 0.3-0.6 part of caustic soda flakes, 0.3-0.45 part of modifier and the balance of water;

the modifier is prepared by mixing super absorbent resin, air entraining agent, antifreezing agent and nano diatomite according to the mass ratio of 1:0.2-0.4:0.6-0.8: 0.3-0.5.

2. The early strength water reducing agent for recycled aggregate concrete according to claim 1, wherein the super absorbent resin is prepared by the following method: mixing 5-10 parts of corn starch and 5-10 parts of acrylic acid in parts by weight, fully stirring, adding 10-15 parts of acrylamide, heating in a water bath to 75-80 ℃, adding 0.01-0.03 part of potassium persulfate and 0.001-0.003 part of N, N-methylene bisacrylamide, and stirring for 1-2 hours.

3. The early strength water reducing agent for recycled aggregate concrete according to claim 1, wherein the air entraining agent comprises the following components in parts by weight: 1.3-2.3 parts of sodium cocoanut alcohol sulfate, 1.3-1.7 parts of dodecyl dimethyl amine oxide, 2.5-3 parts of fatty amide propyl dimethyl betaine, 3-5 parts of aluminum powder and 1.8-2.4 parts of desulfurized gypsum.

4. The early strength water reducing agent for recycled aggregate concrete according to claim 3, characterized in that the air entraining agent is prepared by the following method: mixing fatty amide propyl dimethyl betaine and aluminum powder, adding desulfurized gypsum, mixing uniformly, drying at 80-90 deg.C for 4-8h, taking out, mixing uniformly with sodium cocoanut oil alcohol sulfate and dodecyl dimethyl amine oxide, and maintaining at constant temperature and constant pressure of 1-2MPa and 60-70 deg.C for 10-12 h.

5. The early strength water reducing agent for recycled aggregate concrete according to claim 1, wherein the antifreezing agent is prepared by mixing water glass, slag powder and metakaolin according to a mass ratio of 3.5-3.7:0.3-0.5: 1.

6. The early strength water reducing agent for recycled aggregate concrete according to claim 1, wherein the polyether macromonomer is one or a combination of prenyl polyoxyethylene ether, methyl propanol polyoxyethylene ether and methyl alkenyl polyoxyethylene ether.

7. The early strength water reducing agent for recycled aggregate concrete according to claim 1, wherein the unsaturated carboxylic acid is one or a combination of acrylic acid, methacrylic acid and fumaric acid.

8. The early strength water reducing agent for recycled aggregate concrete according to claim 1, wherein the chain transfer agent is one or a combination of mercaptopropionic acid, thioglycolic acid, mercaptoethanol and n-dodecyl mercaptan.

9. The early strength water reducing agent for recycled aggregate concrete according to claim 1, wherein the initiator is one or a combination of more of concentrated sulfuric acid, hydrogen peroxide, sodium persulfate and sodium bisulfite.

10. The preparation method of the early strength water reducing agent for recycled aggregate concrete according to any one of claims 1 to 9, characterized by comprising the following steps: mixing water and a polyether macromonomer, stirring and dissolving to form a kettle bottom material, adding a solution C prepared by mixing water and an initiator into the kettle bottom material, mixing and stirring, adding a solution A prepared by mixing water, unsaturated carboxylic acid and sodium methallyl sulfonate and a solution B prepared by mixing vitamin C, a chain transfer agent and water, controlling the adding time of the solution A to be 2.5-3h and the adding time of the solution B to be 3-3.5h, stirring for 1-1.5h after the solution A and the solution B are added, adding caustic soda flakes and a modifier, supplementing water to 100 parts by weight, and uniformly stirring to obtain a finished product.

Technical Field

The invention relates to the technical field of water reducing agents for buildings, in particular to an early strength water reducing agent for recycled aggregate concrete and a preparation method thereof.

Background

The building industry is a large household generating garbage and is an important industry capable of applying garbage waste to regenerate resources, so that the comprehensive utilization of the building garbage not only can solve the environmental problems caused by the building garbage, but also is an effective way for solving the resources and protecting the ecological environment.

The recycled aggregate is the aggregate generated by crushing, cleaning and grading the waste concrete blocks, and the concrete using the recycled aggregate to partially or completely replace the natural aggregate is called recycled aggregate concrete. .

Disclosure of Invention

Aiming at the defects in the prior art, the first object of the invention is to provide an early strength water reducing agent for recycled aggregate concrete, which has the advantages of shortening the setting time of concrete, increasing the early strength, reducing the water-cement ratio and increasing the freeze-thaw resistance effect of concrete.

The second purpose of the invention is to provide a preparation method of the early strength water reducing agent for recycled aggregate concrete, which has the advantages of simple preparation method and easy operation.

In order to achieve the first object, the invention provides the following technical scheme: an early strength water reducing agent for recycled aggregate concrete, wherein each 100 parts by weight of the early strength water reducing agent comprises the following components in parts by weight:

kettle bottom material: 33-37.5 parts of water and 33-37.5 parts of polyether macromonomer; solution A: 3.1-3.4 parts of water, 3.1-3.4 parts of unsaturated carboxylic acid and 0.1-0.4 part of sodium methallyl sulfonate; and B, liquid B: 0.04-0.07 part of vitamin C, 0.14-0.17 part of chain transfer agent and 10-13 parts of water; and C, liquid C: 0.4-0.7 part of water and 0.13-0.16 part of initiator; 0.3-0.6 part of caustic soda flakes, 0.3-0.45 part of modifier and the balance of water; the modifier is prepared by mixing super absorbent resin, air entraining agent, antifreezing agent and nano diatomite according to the mass ratio of 1:0.2-0.4:0.6-0.8: 0.3-0.5. By adopting the technical scheme, the polyether macromonomer, the initiator, the chain transfer agent and the like are used for polymerization reaction, the modifier is matched to prepare the early strength water reducing agent, the super absorbent resin has good water absorption and high water retention rate, the roughness of the surface of the recycled aggregate can be improved, the water consumption is reduced, the drying shrinkage is inhibited, the compressive strength is improved, the cohesiveness of concrete slurry can be obviously improved by the air entraining agent, the consistency is increased, and the initial density is reduced, so that the gas generating pressure in the slurry is reduced, the growth of bubbles is facilitated, the nano diatomite is added, the effect of further modifying the early strength water reducing agent is achieved, the effect of inducing the hydration reaction of the concrete and improving the microstructure of a hydration product is achieved, the compressive strength and the compactness of the concrete are improved, the shrinkage rate is reduced, the production period is shortened, and the crystal nucleus effect is achieved, on the basis of the original network structure of the concrete, and a new network structure taking the nano diatomite as a node is established, and the two network structures are combined with each other to form a stable three-dimensional network, so that the performance of the concrete is greatly improved, meanwhile, the concrete has a self-repairing function, the defects of cracks and the like are greatly reduced, the service life is prolonged, and the safety is improved.

Further, the super absorbent resin is prepared by the following method: mixing 5-10 parts of corn starch and 5-10 parts of acrylic acid in parts by weight, fully stirring, adding 10-15 parts of acrylamide, heating in a water bath to 75-80 ℃, adding 0.01-0.03 part of potassium persulfate and 0.001-0.003 part of N, N-methylene bisacrylamide, and stirring for 1-2 hours.

By adopting the technical scheme, the corn starch is directly combined with the acrylic acid monomer without gelatinization, the polymerization process is simple, the polymerization speed is high, the water absorption of the super absorbent resin is good, the water retention is strong, the compressive strength of concrete can be improved, the surface smoothness and the internal water content of the concrete are kept constant, the continuous proceeding of cement hydration is ensured, the early drying shrinkage is inhibited, the water precipitation on the surface of the concrete is reduced, the permeability of hardened concrete is reduced, the water-absorbing super absorbent resin can block pores and capillary pipelines in the concrete, the concrete is more compact, and the impermeability and the freezing resistance of the concrete are improved.

Further, the air entraining agent comprises the following components in parts by weight: 1.3-2.3 parts of sodium cocoanut alcohol sulfate, 1.3-1.7 parts of dodecyl dimethyl amine oxide, 2.5-3 parts of fatty amide propyl dimethyl betaine, 3-5 parts of aluminum powder and 1.8-2.4 parts of desulfurized gypsum.

By adopting the technical scheme, the fatty acyl propyl dimethyl betaine is an amphoteric surfactant and can increase the compatibility among raw materials, the dodecyl dimethyl amine oxide is a polar nonionic surfactant and can show strong ionicity or non-ionicity, and the dodecyl dimethyl amine oxide has excellent performances of increasing bubbles, stabilizing bubbles, dispersing, resisting static electricity and the like, and some aluminum powder particles are wrapped in the bubbles, so that the gas-forming environment of the aluminum powder particles is improved.

Further, the preparation method of the air entraining agent comprises the following steps: mixing fatty amide propyl dimethyl betaine and aluminum powder, adding desulfurized gypsum, mixing uniformly, drying at 80-90 deg.C for 4-8h, taking out, mixing uniformly with sodium cocoanut oil alcohol sulfate and dodecyl dimethyl amine oxide, and maintaining at constant temperature and constant pressure of 1-2MPa and 60-70 deg.C for 10-12 h.

By adopting the technical scheme, the aluminum powder and the fatty acyl are mixed according to the propyl dimethyl betaine, the added desulfurized gypsum is diluted, and the diluted desulfurized gypsum is dried and then mixed with the sodium cocoanut oil alcohol sulfate and the dodecyl dimethyl amine oxide, and is maintained at constant pressure and constant temperature, so that the prepared air entraining agent has a good air entraining effect, and the compressive strength of concrete can be increased.

Furthermore, the antifreezing agent is prepared by mixing water glass, slag powder and metakaolin according to the mass ratio of 3.5-3.7:0.3-0.5: 1.

By adopting the technical scheme, the main components of the slag and the metakaolin are silicon dioxide and aluminum oxide, the silicon dioxide and the aluminum oxide react with water glass, Si-O bonds and Al-O bonds are broken and bonded again to form a compact three-dimensional network structure, the soluble silicon can increase the bonding of particles in the polymer, so that the cementing material is more compact, the interface bonding is stronger, the anti-permeability capability is strong, and the freeze-thaw resistance effect is enhanced.

Further, the polyether macromonomer is one or a combination of more of prenyl polyoxyethylene ether, methyl propanol polyoxyethylene ether and methyl alkenyl polyoxyethylene ether.

Further, the unsaturated carboxylic acid is one or a combination of acrylic acid, methacrylic acid and fumaric acid.

Further, the chain transfer agent is one or a combination of several of mercaptopropionic acid, thioglycolic acid, mercaptoethanol and n-dodecyl mercaptan.

Further, the initiator is one or a combination of more of concentrated sulfuric acid, hydrogen peroxide, sodium persulfate and sodium bisulfite.

In order to achieve the second object, the invention provides the following technical scheme: a preparation method of an early strength water reducing agent for recycled aggregate concrete comprises the following steps: mixing water and a polyether macromonomer, stirring and dissolving to form a kettle bottom material, adding a solution C prepared by mixing water and an initiator into the kettle bottom material, mixing and stirring, adding a solution A prepared by mixing water, unsaturated carboxylic acid and sodium methallyl sulfonate and a solution B prepared by mixing vitamin C, a chain transfer agent and water, controlling the adding time of the solution A to be 2.5-3h and the adding time of the solution B to be 3-3.5h, stirring for 1-1.5h after the solution A and the solution B are added, adding caustic soda flakes and a modifier, supplementing water to 100 parts by weight, and uniformly stirring to obtain a finished product.

In conclusion, the invention has the following beneficial effects:

firstly, the water reducing agent is prepared through polymerization, the modifier prepared from the super absorbent resin, the air entraining agent, the antifreezing agent and the nano diatomite is added, the workability of the cement-based composite material is improved under the condition of increasing the water reducing effect of the water reducing agent, the micro pore channels of the concrete are blocked through the super absorbent resin, the hydration is accelerated, the setting time of the concrete is shortened, the early mechanical property is improved, the compactness is increased, and the impermeability and the antifreezing property can be enhanced and the durability is improved through the matching of the super absorbent resin, the air entraining agent and the antifreezing agent.

Secondly, the air entraining agent is prepared from the raw materials such as aluminum powder, desulfurized gypsum and fatty acyl according to propyl dimethyl betaine, the cohesiveness of the concrete is increased, the internal gas forming pressure of the concrete is reduced, the aluminum powder can be wrapped in bubbles, the bubble environment is improved, the compactness of the concrete is increased, the early strength is improved, and the frost resistance of the concrete is improved.

Thirdly, the slag powder, the metakaolin and the water glass are mixed to prepare the antifreezing agent, and a three-dimensional network structure can be formed in the concrete, so that the cohesiveness in the concrete is increased, the compactness is improved, and the impermeability and the freezing resistance are increased.

Detailed Description

The present invention will be described in further detail with reference to examples.

Super absorbent resin preparation examples 1 to 3

Preparation example 1: mixing 5kg of corn starch with 5kg of acrylic acid, stirring thoroughly, adding 10kg of acrylamide, heating in a water bath to 75 ℃, adding 0.01kg of potassium persulfate and 0.001kg of N, N-methylene-bisacrylamide, and stirring for 1 h.

Preparation example 2: mixing 8kg of corn starch with 8kg of acrylic acid, fully stirring, adding 13kg of acrylamide, heating in a water bath to 78 ℃, adding 0.02kg of potassium persulfate and 0.002kg of N, N-methylene-bisacrylamide, and stirring for 1.5 h.

Preparation example 3: mixing 10kg of corn starch with 10kg of acrylic acid, fully stirring, adding 15kg of acrylamide, heating in a water bath to 80 ℃, adding 0.03kg of potassium persulfate and 0.0013kg of N, N-methylene-bisacrylamide, and stirring for 2 hours.

Preparation examples 4 to 6 of air-entraining agent

Preparation example 4: mixing 2.5kg of fatty amide propyl dimethyl betaine and 3kg of aluminum powder, adding 1.8kg of desulfurized gypsum, uniformly mixing, drying at the temperature of 80 ℃ for 8 hours, taking out, uniformly mixing with 1.3kg of sodium cocoanut alcohol sulfate and 1.3kg of dodecyl dimethyl amine oxide, and maintaining at constant temperature and constant pressure at the temperature of 1MPa and 70 ℃ for 10 hours.

Preparation example 5: mixing 2.8kg of fatty acid amide propyl dimethyl betaine and 4kg of aluminum powder, adding 2.1kg of desulfurized gypsum, uniformly mixing, drying at 85 ℃ for 6h, taking out, uniformly mixing with 1.8kg of sodium cocoanut alcohol sulfate and 1.5kg of dodecyl dimethyl amine oxide, and maintaining at constant temperature and constant pressure at 1.5MPa and 65 ℃ for 11 h.

Preparation example 6: mixing 3kg of fatty amide propyl dimethyl betaine and 5kg of aluminum powder, adding 2.4kg of desulfurized gypsum, uniformly mixing, drying at the temperature of 90 ℃ for 4 hours, taking out, uniformly mixing with 2.3kg of sodium cocoanut alcohol sulfate and 1.7kg of lauryl dimethyl amine oxide, and maintaining at constant temperature and constant pressure at the temperature of 2MPa and 60 ℃ for 12 hours.