CN114524633B

CN114524633B - Fly ash activity excitant and preparation method thereof

Info

Publication number: CN114524633B
Application number: CN202210378531.9A
Authority: CN
Inventors: 王仁元; 范爱国; 刘文亮; 解嵩; 陈墨喜; 刘佳斌
Original assignee: Dezhou Runde Concrete Co ltd
Current assignee: Dezhou Runde Concrete Co ltd
Priority date: 2022-04-12
Filing date: 2022-04-12
Publication date: 2022-08-09
Anticipated expiration: 2042-04-12
Also published as: CN114524633A

Abstract

The invention discloses an activity excitant of fly ash and a preparation method thereof. In order to solve the problem that the early strength of a fly ash-cement system in the prior art is not high, and the influence on the performance reduction of the cement doped with fly ash is easily caused by excessive use of the traditional alkali activator and sulfate activator, the fly ash activity activator comprises the following components in percentage by weight: 5-20% of alcohol amine, 5-10% of sodium dodecyl sulfate, 5-10% of fatty alcohol-polyoxyethylene ether sodium sulfate, 10-15% of acetamide, 15-30% of sodium tripolyphosphate and the balance of water. The fire extinguishing activity activator can effectively excite the activity of the fly ash in the cement, improve the performance of the fly ash-doped cement, ensure that the fly ash has higher doping amount in the cement, and has remarkable economic benefit.

Description

Fly ash activity excitant and preparation method thereof

Technical Field

The invention relates to an activity excitant of fly ash and a preparation method thereof.

Background

With the popularization of coal gasification technology, the utilization rate of coal is continuously improved, but a large amount of solid waste is still generated. Recycling of the coal slag produced after coal combustion is a common concern. The residual fly ash after coal combustion is used as an additive in cement, sintered bricks and the like in building construction, so that waste is changed into valuable, and a common waste utilization mode is formed. However, studies have shown that a large amount of fly ash substituted for cement results in a significant reduction in the early strength of the cement, which is extremely detrimental to projects with early strength requirements, and greatly limits the large-scale application of fly ash in concrete.

Currently, the main activators used in the market include alkali activators and sulfate activators. Although the alkali activator can excite the early activity of the fly ash to a certain degree, the excitation effect of a small amount of the alkali activator is not obvious enough, and the excessive alkali content is easily caused by a large amount of the alkali activator, so that the performance of concrete is influenced. The sulfate excitant is similar to the alkali excitant, and excessive addition of the sulfate excitant can easily cause the sulfur content in cement to exceed the standard, so that the corrosion of reinforcing steel bars in reinforced concrete is caused, and the application of the fly ash in building materials is influenced. In addition, the unreasonable proportion of the excitant in the prior art can also cause the excitation effect of the fly ash to be poor, and influence the mechanical properties of cement, sintered bricks and reinforced concrete.

Disclosure of Invention

In order to solve the technical problems in the prior art, the invention provides a fly ash activity excitant and a preparation method thereof, which improve the structural performance of the fly ash when the fly ash is used as an additive of materials such as cement.

The invention is realized by the following technical scheme:

the fly ash activity excitant comprises the following components in percentage by weight: 5-20% of alcohol amine, 5-10% of sodium dodecyl sulfate, 5-10% of fatty alcohol-polyoxyethylene ether sodium sulfate, 10-15% of acetamide, 15-30% of sodium tripolyphosphate and the balance of water.

Further, the alcohol amine is one or more of diethanolamine and triisopropanolamine.

Further, the alcohol amine comprises the following components: 5-10% of diethanolamine and 5-10% of triisopropanolamine.

Further, the exciting agent comprises the following components in percentage by weight: 5% of diethanolamine, 10% of triisopropanolamine, 8% of sodium dodecyl sulfate, 8% of fatty alcohol-polyoxyethylene ether sodium sulfate, 12% of acetamide, 25% of sodium tripolyphosphate and the balance of water.

A preparation method of a fly ash activity excitant specifically comprises the following steps:

(1) adding sodium tripolyphosphate and alcohol amine into water of 40-50 deg.C according to the weight ratio of exciting agent, stirring at constant temperature for 10 min;

(2) adjusting the water temperature to 50-55 ℃, sequentially adding sodium dodecyl benzene sulfonate, fatty alcohol-polyoxyethylene ether sodium sulfate and acetamide into the water, and uniformly stirring to obtain the reagent of the fly ash activity excitant.

Compared with the prior art, the invention has the beneficial effects that: 1. the fly ash active agent can effectively stimulate the activity of fly ash as an auxiliary material in a building material, increases the early strength of a fly ash-cement system, and has remarkable economic and social benefits. 2. The fly ash activity excitant provided by the invention can improve the mixing amount of fly ash in cement, improves the utilization rate of fly ash cement, and has obvious economic benefit.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It is to be noted that the features in the following embodiments and examples may be combined with each other without conflict.

The invention will now be further described with reference to the following examples, but the invention is not limited thereby within the scope of the examples.

Table 1 shows different component ratios of the fly ash activity excitant in each example.

TABLE 1

Preparing the fly ash activity excitant from the raw materials of the above embodiments according to the following steps:

Cement blending is carried out according to the proportion of portland cement clinker, dihydrate gypsum, fly ash and exciting agent =39:5:55:1, the flexural strength and the compressive strength of the fly ash cement obtained by blending are respectively tested for 7d and 28d, the performances of the fly ash cement with different components and proportions of the exciting agent are researched, and the performances of the cement obtained by the test are shown in table 2.

TABLE 2

As can be seen from tables 1 and 2, the fly ash activity excitant of the invention can effectively excite the activity of fly ash in cement, so that various strength indexes of the cement doped with fly ash in large quantity can meet the standard strength requirements of fly ash portland cement. Acetamide, sodium dodecyl sulfate, sodium fatty alcohol-polyoxyethylene ether sulfate and the like have the synergistic effect of promoting in the excitation of the activity of the fly ash.

In addition, when precast concrete, it is usually necessary to add a water reducing agent in addition to the fly ash activator.

In the test, commercially available P.O42.5 cement, class II fly ash, medium sand with fineness modulus of 2.5 and crushed stone with particle size of 5-31.5 mm are selected. The mixing amount of the exciting agent is 2.5 percent, and a proper amount of water reducing agent is added at the same time. The raw material mixing ratio is as follows: (kg/m 3)

Experimental number	Cement	Fly ash	Sand	Crushing stone	Water (W)	Exciting agent	Naphthalene series water reducing agent	Aliphatic series water reducing agent	Polycarboxylic acid water reducing agent
										1	200	170	735	1090	175	2.5%	2.5%	-	-
2	200	170	735	1090	175	2.5%	-	2.5%	-
										3	200	170	735	1090	175	2.5%	-	-	2.5%

Carrying out compression strength test on the standard cubic concrete blocks of the three experimental examples;

	28d compressive Strength (MPa)
		Experimental example 1	37.2
Experimental example 2	42.5
		Experimental example 3

The fly ash excitant has better compatibility with the polycarboxylate water reducer in the production of premixed concrete, and can obtain concrete with higher strength under the same fly ash consumption when being compounded with the polycarboxylate water reducer.

The above description is only a preferred embodiment of the present invention, and therefore should not be taken as limiting the scope of the invention, which is defined by the appended claims.

Claims

1. The fly ash activity excitant is characterized by comprising the following components in percentage by weight: 5-20% of alcohol amine, 5-10% of sodium dodecyl sulfate, 5-10% of fatty alcohol-polyoxyethylene ether sodium sulfate, 10-15% of acetamide, 15-30% of sodium tripolyphosphate and the balance of water.

2. The fly ash activity stimulant as claimed in claim 1, wherein the alcohol amine is one or more of diethanolamine and triisopropanolamine.

3. The fly ash activity excitant according to claim 2, wherein the alcohol amine comprises, in weight percent: 5-10% of diethanolamine and 5-10% of triisopropanolamine.

4. A fly ash activity stimulant as claimed in any one of claims 1 to 3, wherein the stimulant comprises the following components by weight percentage: 5% of diethanolamine, 10% of triisopropanolamine, 8% of sodium dodecyl sulfate, 8% of fatty alcohol-polyoxyethylene ether sodium sulfate, 12% of acetamide, 25% of sodium tripolyphosphate and the balance of water.

5. A method for preparing a fly ash activity stimulant as claimed in any one of claims 1 to 3, wherein the method comprises the following steps: