阅读说明：本技术 用于超大体积混凝土的外加剂 (Additive for ultra-large volume concrete ) 是由 文军 田成 闫俊阳 涂潇竹 于 2021-11-25 设计创作，主要内容包括：本发明属于混凝土领域,具体涉及一种用于超大体积混凝土的外加剂。本发明,按质量分数计算,引入减水型聚羧酸减水剂原液2％～5％用于减少混凝土用水量；缓凝型聚羧酸缓凝剂原液10％～15％用于延长混凝土凝结时间；碳水型能量释放调节剂3％～5％用于减小混凝土坍落度损失；碱金属型-生物供能分子多羟基羧酸钠1％～2％用于提高混凝土强度；氨基醇衍生物0.01％～0.02％用于防止混凝土内部钢筋锈蚀。各个材料组分形成的整体能够有效延长超大体积混凝土的凝结时间,降低超大混凝土单位时间水化热量。(The invention belongs to the field of concrete, and particularly relates to an additive for ultra-large-volume concrete. According to the invention, 2-5% of a water-reducing polycarboxylic acid water reducer stock solution is introduced for reducing the water consumption of concrete according to the mass fraction; 10-15% of the original solution of the delayed coagulation type polycarboxylic acid delayed coagulation agent is used for prolonging the setting time of concrete; 3% -5% of the carbon water type energy release regulator is used for reducing the slump loss of concrete; 1-2% of alkali metal type-biological energy supply molecule polyhydroxy sodium carboxylate is used for improving the strength of concrete; 0.01 to 0.02 percent of amino alcohol derivative is used for preventing the steel bars in the concrete from being corroded. The whole formed by the material components can effectively prolong the setting time of the oversized concrete and reduce the hydration heat of the oversized concrete in unit time.)

1. The admixture for the ultra-large volume concrete is characterized by comprising the following raw materials in percentage by mass: 2-5% of water-reducing polycarboxylic acid water reducer stock solution, 10-15% of retarding polycarboxylic acid retarder stock solution, 3-5% of carbohydrate energy release regulator, 1-2% of alkali metal type-biological energy supply molecule sodium polyhydroxycarboxylate, 0.01-0.02% of amino alcohol derivative and the balance of water.

2. The admixture for ultra-large volume concrete according to claim 1, further comprising 0.2 to 0.5% by mass of linear carboxylic acid-derived polymeric water molecular complexes.

3. The admixture for ultra-large volume concrete according to claim 1 or 2, further comprising sodium thiosulfate in an amount of 0.5% to 1.0% by mass.

4. The admixture for ultra-large volume concrete according to claim 3, further comprising 0.1-0.2% of polyvinyl alcohol, 0.01-0.03% of organic polymer gas-liquid interface compensation material and 0.05-0.1% of nano gas phase homogenizing agent by mass fraction.

5. The admixture for ultra-large volume concrete according to claim 1, comprising the following raw materials in mass fraction: 2% of water-reducing polycarboxylic acid water reducer stock solution, 10% of retarding polycarboxylic acid retarder stock solution, 4.5% of carbohydrate energy release regulator, 1.5% of alkali metal-biological energizing molecule polyhydroxy sodium carboxylate, 0.02% of amino alcohol derivative, 0.3% of linear carboxylic acid derivative polymeric water molecule complex, 0.8% of sodium thiosulfate, 0.2% of polyvinyl alcohol, 0.01% of organic polymer gas-liquid interface compensation material, 0.05% of nano gas phase homogenizing agent and the balance of water.

Technical Field

The invention belongs to the field of concrete, and particularly relates to an additive for ultra-large-volume concrete.

Background

Concrete is one of the most widely used and large-consumption building materials in engineering construction. The material has the advantages of wide material source, large adjustable performance range, strong plasticity, simple and variable construction process, higher strength and durability and the like. The definition of bulk concrete generally means that the smallest dimension of concrete structure entity is greater than or equal to 1m, while the definition of ultra-bulk concrete generally means that the concrete structure entity has a volume of 10000m³The above concrete.

With the development of super high-rise building technology, super-long, super-wide, super-thick and high reinforcement ratio super-large-volume foundation slab concrete projects are increasing day by day, and the requirements of super-large-volume concrete on internal cracks and deformation control are very strict. Among them, prolonging the setting time of the concrete with super large volume and reducing the hydration heat per unit time are one of the control points. When the setting time of the ultra-large volume concrete is short, the hydration heat of the ultra-large volume concrete in unit time is high, at the moment, the heat inside the ultra-large volume concrete is not dissipated quickly without surface heat, so that the temperature difference between the inside and the outside is too large, and the generated temperature stress can crack the ultra-large volume concrete, so that the structure safety and the normal use are influenced. The existing admixture of the ultra-large volume concrete is usually solved by using a water reducing agent and a retarder, but the obtained ultra-large volume concrete has poor effects of shortening the setting time and reducing the hydration heat of the concrete per unit time.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the admixture for the ultra-large volume concrete can prolong the setting time of the ultra-large volume concrete and reduce the hydration heat of the ultra-large volume concrete in unit time.

In order to solve the technical problems, the invention adopts the following technical scheme: the admixture for the ultra-large volume concrete comprises the following raw materials in percentage by mass: 2-5% of water-reducing polycarboxylic acid water reducer stock solution, 10-15% of retarding polycarboxylic acid retarder stock solution, 3-5% of carbohydrate energy release regulator, 1-2% of alkali metal type-biological energy supply molecule sodium polyhydroxycarboxylate, 0.01-0.02% of amino alcohol derivative and the balance of water.

Further, the water molecule complex derived from linear carboxylic acid is 0.2-0.5% by mass.

Further, the sodium thiosulfate also comprises 0.5 to 1.0 percent by mass.

Further, the material also comprises 0.1 to 0.2 percent of polyvinyl alcohol, 0.01 to 0.03 percent of organic polymer gas-liquid interface compensation material and 0.05 to 0.1 percent of nano gas-phase substance homogenizing agent according to the mass fraction.

Further, the composite material comprises the following raw materials in percentage by mass: 2% of water-reducing polycarboxylic acid water reducer stock solution, 10% of retarding polycarboxylic acid retarder stock solution, 4.5% of carbohydrate energy release regulator, 1.5% of alkali metal-biological energizing molecule polyhydroxy sodium carboxylate, 0.02% of amino alcohol derivative, 0.3% of linear carboxylic acid derivative polymeric water molecule complex, 0.8% of sodium thiosulfate, 0.2% of polyvinyl alcohol, 0.01% of organic polymer gas-liquid interface compensation material, 0.05% of nano gas phase homogenizing agent and the balance of water.

According to the invention, 2-5% of a water-reducing polycarboxylic acid water reducer stock solution is introduced for reducing the water consumption of concrete according to the mass fraction; 10-15% of the original solution of the delayed coagulation type polycarboxylic acid delayed coagulation agent is used for prolonging the setting time of concrete; 3% -5% of the carbon water type energy release regulator is used for reducing the slump loss of concrete; 1-2% of alkali metal type-biological energy supply molecule polyhydroxy sodium carboxylate is used for improving the strength of concrete; 0.01 to 0.02 percent of amino alcohol derivative is used for preventing the steel bars in the concrete from being corroded. The whole formed by the material components can prolong the setting time of the oversized concrete and reduce the hydration heat of the oversized concrete in unit time.

Detailed Description

The admixture for the ultra-large volume concrete comprises the following raw materials in percentage by mass: 2-5% of water-reducing polycarboxylic acid water reducer stock solution, 10-15% of retarding polycarboxylic acid retarder stock solution, 3-5% of carbohydrate energy release regulator, 1-2% of alkali metal type-biological energy supply molecule sodium polyhydroxycarboxylate, 0.01-0.02% of amino alcohol derivative and the balance of water.

In order to enhance the plasticity of the concrete with super large volume and ensure the water retention, the admixture also comprises 0.2 to 0.5 percent of linear carboxylic acid derived polymeric water molecular complex.

In order to improve the early strength of the concrete with the ultra-large volume, the admixture also comprises 0.5 to 1.0 percent of sodium thiosulfate in percentage by mass. At the moment, the concrete with the ultra-large volume has a certain early strength effect, the consumption of the rubber material of the concrete with unit volume can be reduced, and the hydration heat is reduced.

In order to ensure that the concrete with the ultra-large volume has excellent workability and cohesiveness, the materials of the components in the concrete with the ultra-large volume are combined more tightly, the self-contraction of the concrete is inhibited, and the cracks of the concrete are reduced, the admixture further comprises 0.1-0.2 percent of polyvinyl alcohol, 0.01-0.03 percent of organic polymer gas-liquid interface compensation material and 0.05-0.1 percent of nano gas phase homogenizing agent according to the mass fraction.

0.1 to 0.2 percent of polyvinyl alcohol increases the cohesiveness of the concrete with the super-large volume; the organic polymer gas-liquid interface compensation material accounts for 0.01-0.03 percent and has the functions of eliminating bubbles in the concrete with the ultra-large volume and improving the compactness; 0.05-0.1% of nano gas-phase homogenizing agent, and has the functions of air entraining and improving the workability of the ultra-large volume concrete.

Preferably, the admixture for the ultra-large volume concrete comprises the following raw materials in percentage by mass: 2% of water-reducing polycarboxylic acid water reducer stock solution, 10% of retarding polycarboxylic acid retarder stock solution, 4.5% of carbohydrate energy release regulator, 1.5% of alkali metal-biological energizing molecule polyhydroxy sodium carboxylate, 0.02% of amino alcohol derivative, 0.3% of linear carboxylic acid derivative polymeric water molecule complex, 0.8% of sodium thiosulfate, 0.2% of polyvinyl alcohol, 0.01% of organic polymer gas-liquid interface compensation material, 0.05% of nano gas phase homogenizing agent and the balance of water.

The present invention is further illustrated by the following examples, which are not intended to limit the scope of the invention.

The main tower bearing platform of the Changjiang river bridge of the Yangtze river high-speed project of Jiangnan provides some technical requirements for the concrete with the super-large volume: controlling hydration heat and reducing the cracking risk of concrete.

The admixture for the ultra-large volume concrete comprises the following raw materials in percentage by mass: 2% of water-reducing polycarboxylic acid water reducer stock solution, 10% of retarding polycarboxylic acid retarder stock solution, 4.5% of carbohydrate energy release regulator, 1.5% of alkali metal-biological energizing molecule polyhydroxy sodium carboxylate, 0.02% of amino alcohol derivative, 0.3% of linear carboxylic acid derivative polymeric water molecule complex, 0.8% of sodium thiosulfate, 0.2% of polyvinyl alcohol, 0.01% of organic polymer gas-liquid interface compensation material, 0.05% of nano gas phase homogenizing agent and the balance of water.

After the additive is adopted, the technical effects are as follows:

1. the setting time of the concrete is effectively prolonged, and the hydration heat of the concrete in unit time is reduced;

ultra-large volume concrete	Initial setting time	Final setting time
			With the admixture of the present invention	21h	30h
Using general additives	5.5h	13h

TABLE 1 set time for very large volume concrete

2. The produced concrete with the super-large volume has excellent workability and cohesiveness, can enable the materials of all components of the concrete to be combined more tightly, inhibit the self-contraction of the concrete and reduce the cracks of the concrete;

ultra-large volume concrete	Slump constant	Degree of expansion
			With the admixture of the present invention	220mm	620mm
Using general additives	210mm	560mm

TABLE 2 workability, cohesion for very voluminous concrete

3. The produced concrete with super large volume has certain early strength effect, can reduce the consumption of the glue material of the concrete with unit volume and reduce the hydration heat;

concrete and its production method	3d strength	7d strength	28d strength
				By using composite additives	25.5MPa	35.4MPa	46.1MPa
Using general additives	23.6MPa	31.0MPa	43.7MPa

TABLE 3 early strength Effect on very Large volume concrete

In the process of the large-volume bearing platform poured by the engineering, the temperature inside and outside the ultra-large-volume concrete is in a control range, and after forming and demolding, the surface of the concrete is flat and smooth, and has no crack and no deformation.