CN-117550829-B - Additive for rockfill concrete engineering and preparation method thereof

CN117550829BCN 117550829 BCN117550829 BCN 117550829BCN-117550829-B

Abstract

The application relates to an additive for a rockfill concrete project, which at least comprises the following components, by mass, 1.6% -3.5% of a starch dextrin retarder, 5.2% -21.3% of an exciting agent, 0.25% -0.90% of a polycarboxylate thixotropic agent and 75.2% -90.5% of a water reducer, wherein the additive is used for changing the working performance and the hardening performance of the concrete with high self-compaction performance. The admixture of the application is added into the concrete with high self-compaction performance used in the rockfill concrete engineering, which not only can improve the fluidity, thixotropic property, longer initial setting time and other working performances of the concrete with high self-compaction performance, but also has good volume stability, good impermeability and frost resistance, lower cement consumption and other hardening performances, and has remarkable economic benefit.

Inventors

LI FENGLIANG
WANG TENGFEI
QIAO ZHICHAO
BI ZHONGMING
WU YU
WU YUANPENG
JI GUANGFU
YANG YU

Assignees

北京华石纳固科技有限公司

Dates

Publication Date: 20260505
Application Date: 20231024

Claims (7)

1. The additive for the rockfill concrete engineering is characterized by at least comprising the following components of a starch dextrin retarder, an exciting agent, a polycarboxylate thixotropic agent and a water reducing agent, wherein the additive is used for changing the working performance and the hardening performance of high self-compaction concrete, and the mass percentages of the components are as follows: 1.6 to 3.5 percent of starch dextrin retarder; 5.2% -21.3% of exciting agent; 0.25 to 0.90 percent of polycarboxylate thixotropic agent; 75.2% -90.5% of water reducer; the starch dextrin retarder comprises white dextrin and yellow dextrin, wherein the mass ratio of the white dextrin to the yellow dextrin is 1:1, and the starch dextrin retarder is used for reducing the hydration temperature peak value of the high self-compaction concrete; the excitant comprises an alkanolamine excitant and a soluble sulfate excitant, when the excitant comprises diethanolamine, triisopropanolamine and sodium sulfate, the mass ratio of the diethanolamine to the isopropanolamine to the sodium sulfate is 1:2:10, and the excitant is used for improving the hydration efficiency of a cementing material and reducing the cement consumption.
2. The admixture for rockfill concrete works according to claim 1, further comprising an emulsion type water absorbing agent in an amount of 1 to 2% by mass.
3. The admixture for rockfill concrete engineering according to claim 1, wherein the alkanolamine excitant comprises any one or a combination of more than one of diethanolamine, triethanolamine and triisopropanolamine, and the soluble sulfate excitant comprises any one or a combination of more than one of sodium sulfate, potassium sulfate and ferric sulfate.
4. The admixture for rockfill concrete engineering according to claim 1, wherein the polycarboxylate thixotropic agent comprises any one or a combination of more than one of an ammonia polycarboxylate, sodium polyacrylate and a polycarboxylate sulfonate, and is used for adjusting the thixotropic property of the high self-compaction property concrete.
5. The admixture for rockfill concrete works according to claim 1, wherein the water reducing agent comprises any one or a combination of more than one of a high water reducing agent, a slump retaining water reducing agent and a slow releasing water reducing agent, which is used for improving the fluidity of concrete.
6. The admixture for rockfill concrete works according to claim 2, wherein the emulsion-type water absorbing agent comprises a super absorbent resin emulsion for reducing the risk of cracking due to a difference between inside and outside humidity, and improving the strength of concrete under actual curing conditions in the works.
7. A method for preparing the admixture for rockfill concrete works according to any one of claims 1 to 6, comprising the steps of: Taking the components of the additive for the rock-fill concrete engineering as raw materials, and weighing the raw materials according to the mass percentage of each component; and (3) putting the weighed raw materials into a container of a stirring device, and stirring for 20-60 minutes to obtain the additive for the rockfill concrete engineering.

Description

Additive for rockfill concrete engineering and preparation method thereof Technical Field The application relates to the field of building materials, in particular to an additive for a rock-fill concrete project and a preparation method thereof. Background The rock-fill concrete technology is a novel large-volume concrete technology and is generally used for dam engineering in water conservancy and hydropower engineering construction. Mainly comprises rock-fill material and high self-compaction concrete. Because dam body concrete has characteristics such as single pouring volume is big, pouring time is long, the storehouse face size is big and the gap size scope that the rock-fill body formed is big (from centimeter level to millimeter level), in the aspect of working property, the high self-compaction performance concrete that needs possess mobility big, mobility hold time long, suitable thixotropy and longer initial setting time advantage to this guarantees that high self-compaction performance concrete fills the gap between the rock-fill body completely, forms closely knit, even rock-fill concrete, and avoids producing the cold joint. In terms of hardening properties of high self-compaction performance concrete, the design strength class of the concrete is low, typically C 90 or C 90, because of the low level of dam stress and large structural size, but the concrete is required to have good volume stability. Moreover, since the dam concrete is in contact with water for a long time, the high self-compaction concrete is required to have good impermeability and frost resistance so as to ensure the service life of the dam. Therefore, the concrete is usually doped with a proper amount of additive, so that the performance of the concrete can be improved, and the concrete has obvious economic and social benefits. However, the high self-compaction concrete prepared by the existing additive is difficult to simultaneously consider the working performance and the hardening performance, so that the engineering quality is low, and the requirements of the high self-compaction concrete on the working performance and the hardening performance cannot be met. Disclosure of Invention Aiming at the technical problems in the prior art, the application provides an additive for a rock-fill concrete project, which is used for changing the working performance and hardening performance of high self-compaction concrete, and at least comprises the following components in percentage by mass: the additive for the rockfill concrete engineering further comprises an emulsion water absorbent, wherein the mass percentage of the emulsion water absorbent is 1-2%. The additive for the rock-fill concrete engineering comprises any one or more of white dextrin and yellow dextrin, and the starch dextrin retarder is used for reducing the hydration temperature peak value of the high self-compaction concrete. When the starch dextrin retarder comprises white dextrin and yellow dextrin, the mass ratio of the white dextrin to the yellow dextrin is 1:1. The additive for the rockfill concrete engineering comprises an alkanolamine excitant and a soluble sulfate excitant, wherein the alkanolamine excitant comprises any one or more of diethanolamine, triethanolamine and triisopropanolamine, the soluble sulfate excitant comprises any one or more of sodium sulfate, potassium sulfate and ferric sulfate, and the excitant is used for improving the hydration efficiency of a cementing material and reducing the cement consumption. When the excitant comprises diethanolamine, triisopropanolamine and sodium sulfate, the mass ratio of the diethanolamine, the isopropanolamine and the sodium sulfate is 1:2:10. The additive for the rockfill concrete engineering comprises any one or more of polycarboxylate ammonia salt, sodium polyacrylate and polycarboxylate sulfonate, and the polycarboxylate thixotropic agent is used for adjusting the thixotropic property of the high self-compaction concrete. The additive for the rockfill concrete engineering comprises any one or more of a high water-reducing water reducer, a slump retaining water reducer and a slow release water reducer, wherein the water reducer is used for improving the flowability of concrete. The additive for the rockfill concrete engineering, which is described above, is characterized in that the emulsion water absorbing agent comprises super absorbent resin emulsion, and the emulsion water absorbing agent is used for reducing the internal and external humidity difference, reducing the cracking risk and improving the concrete strength under the actual curing condition in the engineering. According to another aspect of the present application, there is provided a method for preparing the admixture for a rockfill concrete engineering as described above, comprising the steps of: The additive for the rock-fill concrete engineering is prepared by taking the components of the additive for the rock-fill concrete engineer