High-volume fly ash excitation alkali water agent

Abstract

The invention discloses a large-dosage fly ash exciting alkaline water agent which comprises the following components: 10-30% of an alkaline exciting component, 40-60% of an efficient water reducing component, 5-15% of an active silicon-aluminum component, 0.5-2% of a retarding component and 0.1-0.5% of a foam stabilizer. The invention belongs to the technical field of concrete admixtures, and particularly provides a large-dosage fly ash exciting alkali water agent for solving the problems of low early strength, poor workability, insufficient durability and the like of large-dosage fly ash concrete.

Description

Technical Field

[0001] The present invention belongs to the technical field of concrete admixtures, specifically referring to a high-volume fly ash-activated alkali water reducer. Background Art

[0002] The activator and water reducer for high-volume fly ash concrete is a special concrete admixture. It can not only fully activate the activity of fly ash, but also significantly increase the content of fly ash in concrete or mortar, and has a high water-reducing effect. As an industrial solid waste, the resource utilization of fly ash is of great significance to environmental protection. In traditional concrete, the content of fly ash usually does not exceed 30% of the total amount of cementitious materials. Excessive content will lead to problems such as insufficient early strength and prolonged setting time. Ordinary water reducers are difficult to activate the potential activity of high-volume fly ash, and traditional alkali activators are prone to poor workability of concrete and the risk of alkali-aggregate reaction. A single activator cannot meet the requirements of both strength development and construction performance at the same time. Therefore, there is an urgent need for a new type of high-volume fly ash-activated alkali water reducer to solve the above problems. Summary of the Invention

[0003] To solve the above existing problems, the present invention provides a high-volume fly ash-activated alkali water reducer that solves the problems of low early strength, poor workability, and insufficient durability of high-volume fly ash concrete.

[0004] The technical solution adopted by the present invention is as follows: The high-volume fly ash-activated alkali water reducer of the present invention comprises the following components: 10-30% of alkaline activation component, 40-60% of high-efficiency water-reducing component, 5-15% of active silicon-aluminum component, 0.5-2% of setting retarder component, and 0.1-0.5% of foam stabilizer.

[0005] Further, the alkaline activation component includes modified sodium silicate and lithium carbonate, the high-efficiency water-reducing component includes polycarboxylate-based water reducer and amino sulfonate, the active silicon-aluminum includes nano-silica and metakaolin, and the setting retarder component includes sodium gluconate and trisodium citrate.

[0006] Preferably, the foam stabilizer adopts modified polyether silicone.

[0007] The preparation method of the high-volume fly ash-activated alkali water reducer includes the following steps:

[0008] (1) First, place portions of modified sodium silicate and lithium carbonate in a reaction kettle for premixing, and then heat to 60°C and react at this temperature for 120 min to obtain the alkaline activation component;

[0009] (2) Add portions of polycarboxylate-based water reducer, amino sulfonate, nano-silica, and metakaolin into the reaction kettle in sequence and ultrasonically disperse for 30 min;

[0010] (3) Finally, add sodium gluconate, trisodium citrate, and modified polyether siloxane into the reactor, and stir until homogeneous to prepare a high-volume fly ash-activated water reducer.

[0011] The beneficial effects achieved by the present invention with the above structure are as follows: For the high-volume fly ash-activated water reducer proposed in this solution, the alkaline activation component adopts pH slow-release technology to avoid the damage of the initial strong alkaline environment to the molecular structure of the water reducer. The water-reducing component and the activation component synergistically enhance the effect, and the active silicon-aluminum component provides nucleation sites to accelerate the secondary hydration reaction of fly ash. Detailed implementation manners

[0012] Now, the various exemplary implementation manners of the present invention will be described in detail. This detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics, and implementation manners of the present invention.

[0013] It should be understood that the terms used in the present invention are only for describing specific implementation manners and are not used to limit the present invention. Additionally, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded from the range.

[0014] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0015] Without departing from the scope or spirit of the present invention, various improvements and changes can be made to the specific implementation manners of the present invention specification, which are obvious to those skilled in the art. Other implementation manners obtained from the specification of the present invention are obvious to those skilled in the art. The specification and embodiments of this application are only exemplary.

[0016] Example 1

[0017] The high-volume fly ash-activated water reducer contains the following components: 20% of alkaline activation component, 50% of high-efficiency water-reducing component, 10% of active silicon-aluminum component, 1.25% of setting retarder component, and 0.3% of foam stabilizer.

[0018] The alkaline activation component includes 18 parts of modified sodium silicate and 2 parts of lithium carbonate. The high-performance water-reducing component includes 45 parts of polycarboxylate water-reducing agent and 5 parts of aminosulfonate. The active silica-aluminum includes 8 parts of nano-silica and 2 parts of metakaolin. The setting retardation component includes 1.2 parts of sodium gluconate and 0.05 part of trisodium citrate.

[0019] A preparation method of a high-volume fly ash-activated alkali water-reducing agent, which comprises the following steps:

[0020] (1) First, place 18 parts of modified sodium silicate and lithium carbonate in a reaction kettle for premixing, and then heat to 60 °C and react at this temperature for 120 min to obtain the alkaline activation component;

[0021] (2) Add 45 parts of polycarboxylate water-reducing agent, 5 parts of aminosulfonate, 8 parts of nano-silica and 2 parts of metakaolin to the reaction kettle in sequence, and perform ultrasonic dispersion for 30 min;

[0022] (3) Finally, add sodium gluconate, trisodium citrate and modified polyether siloxane to the reaction kettle, and stir until uniform to prepare a high-volume fly ash-activated alkali water-reducing agent.

[0023] A usage method of a high-volume fly ash-activated alkali water-reducing agent, which comprises the following steps:

[0024] During the concrete production process, on the premise that the coarse and fine aggregates and their proportions change little, reduce the amount of cement used, increase the amount of fly ash used, and incorporate this activated water-reducing agent into the fly ash at 3.0% - 3.5% of the mass of the cementitious material. Under the condition that other processes remain unchanged, a high-volume fly ash concrete with increased slump of the mixture, improved pumping performance, and compressive strength at 7 days and 28 days being similar to that of ordinary concrete, and the compressive strength at 60 days reaching 89.73% - 121.58% of that of ordinary concrete is produced.

[0025] Example 2

[0026] A high-volume fly ash-activated alkali water-reducing agent contains the following components: 10% of alkaline activation component, 40% of high-performance water-reducing component, 5% of active silica-aluminum component, 0.5% of setting retardation component, and 0.1% of foam stabilizer.

[0027] The alkaline activation component includes 9 parts of modified sodium silicate and 1 part of lithium carbonate. The high-performance water-reducing component includes 36 parts of polycarboxylate water-reducing agent and 4 parts of aminosulfonate. The active silica-aluminum includes 4 parts of nano-silica and 1 part of metakaolin. The setting retardation component includes 0.48 part of sodium gluconate and 0.02 part of trisodium citrate.

[0028] The preparation method and usage method of the high-volume fly ash-activated alkali water-reducing agent are the same as those in Example 1.

[0029] Example 3

[0030] High-volume fly ash-activated alkali water reducer, comprising the following components: 30% of alkaline activation component, 60% of high-efficiency water-reducing component, 15% of active silicon-aluminum component, 2% of setting retarder component, and 0.5% of foam stabilizer.

[0031] The alkaline activation component includes 27 parts of modified sodium silicate and 3 parts of lithium carbonate. The high-efficiency water-reducing component includes 54 parts of polycarboxylate water reducer and 6 parts of amino sulfonate. The active silicon-aluminum includes 12 parts of nano-silica and 3 parts of metakaolin. The setting retarder component includes 1.92 parts of sodium gluconate and 0.08 parts of trisodium citrate.

[0032] The preparation method and usage method of the high-volume fly ash-activated alkali water reducer are the same as those in Example 1.

[0033] The embodiments described above are the preferred embodiments of the present invention, rather than all embodiments. The detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

Claims

1. High-volume fly ash-activated water reducer, characterized in that, It contains the following components: 10-30% of alkaline activation component, 40-60% of high-efficiency water-reducing component, 5-15% of active silica-alumina component, 0.5-2% of setting retarder component, and 0.1-0.5% of foam stabilizer.

2. The high-volume fly ash-activated water reducer according to claim 1, characterized in that: The alkaline activation component includes modified sodium silicate and lithium carbonate; the high-efficiency water-reducing component includes polycarboxylate superplasticizer and amino sulfonate; the active silica-alumina includes nano-silica and metakaolin; the setting retarder component includes sodium gluconate and trisodium citrate.

3. The high-volume fly ash-activated water reducer according to claim 2, characterized in that: The foam stabilizer uses modified polyether polysiloxane.

4. The preparation method of the high-volume fly ash-activated water reducer according to claim 3, characterized in that, It includes the following steps: (1) First, put [X] parts of modified sodium silicate and [X] parts of lithium carbonate into a reaction kettle for premixing, then heat to 60°C and react at this temperature for 120 minutes to obtain the alkaline activation component; (2) Add [X] parts of polycarboxylate superplasticizer, [X] parts of amino sulfonate, nano-silica and metakaolin into the reaction kettle in sequence, and disperse ultrasonically for 30 minutes; (3) Finally, add sodium gluconate, trisodium citrate and modified polyether polysiloxane into the reaction kettle, and stir until uniform to prepare a high-volume fly ash-activated alkali water reducer.