阅读说明：本技术 一种可抑制花岗岩骨料碱硅酸反应活性的改性复合掺合料 (Modified composite admixture capable of inhibiting reaction activity of alkali silicate of granite aggregate ) 是由 赵凯 熊训飞 刘骁凡 吴航 安宁 鲁凯 胡泽书 骆行 王琰耀 陈磊 冯郑承 王 于 2020-05-19 设计创作，主要内容包括：本发明属于混凝土改性技术领域,具体涉及一种可抑制花岗岩骨料碱硅酸反应活性的改性复合掺合料,按照重量份数计算,包括如下组分：花岗岩骨料60~70份,燃煤炉渣粉20~30份,粉煤灰10~20份,硅灰20~30份。本发明利用粉煤灰与燃煤炉渣粉和硅灰产生的协同作用,在少量掺和粉煤灰的情况下达到抑制花岗岩骨料碱硅酸反应活性的目的,具有产业价值。(The invention belongs to the technical field of concrete modification, and particularly relates to a modified composite admixture capable of inhibiting the reaction activity of granite aggregate alkali silicate, which comprises the following components in parts by weight: 60-70 parts of granite aggregate, 20-30 parts of coal-fired furnace slag powder, 10-20 parts of fly ash and 20-30 parts of silica fume. The invention utilizes the synergistic effect of the fly ash, the coal-fired slag powder and the silica fume to achieve the purpose of inhibiting the alkali silicate reaction activity of granite aggregate under the condition of being mixed with a small amount of fly ash, and has industrial value.)

1. A modified composite admixture capable of inhibiting the alkali silicate reaction activity of granite aggregate is characterized by comprising the following components in parts by weight: 60-70 parts of granite aggregate, 20-30 parts of coal-fired furnace slag powder, 10-20 parts of fly ash and 20-30 parts of silica fume.

2. The modified composite admixture capable of inhibiting the alkali silicate reaction activity of granite aggregate according to claim 1, wherein the modified composite admixture further comprises 10-20 parts by weight of limestone powder.

3. The modified composite admixture capable of inhibiting the alkali silicate reaction activity of granite aggregate according to claim 1 or 2, wherein the particle size of the coal-fired slag powder is 5-40 nm.

4. The modified composite admixture capable of inhibiting alkali silicate reaction activity of granite aggregate according to claim 3, wherein the particle size of the fly ash is 2-10 μm.

5. The modified composite admixture capable of inhibiting the alkali silicate reaction activity of granite aggregate according to claim 4, wherein the particle size of the silica fume is 0.1-0.3 μm.

6. The modified composite admixture capable of inhibiting the alkali silicate reaction activity of granite aggregate according to claim 4 or 5, wherein the coal-fired slag powder is modified by ferrocene and polyethylene wax.

7. The modified composite admixture capable of inhibiting the alkali silicate reaction activity of granite aggregate as claimed in claim 6, wherein said silica fume is silica/wollastonite composite particles.

8. The modified composite admixture capable of inhibiting the alkali silicate reaction activity of granite aggregate of claim 7, wherein the preparation method of the silica/wollastonite composite particles is an inorganic coating precipitation method.

9. The modified composite admixture capable of inhibiting alkali silicate reaction activity of granite aggregate according to claim 1, wherein the modified composite admixture further comprises 5-20 parts by weight of vermiculite powder.

10. The modified composite admixture capable of inhibiting the alkali silicate reaction activity of granite aggregate according to claims 1 to 9, wherein the modification method of the coal-fired slag powder is as follows:

s1, drying and crushing treatment: putting the coal-fired slag powder into a drying chamber with the temperature of 90-100 ℃ for drying treatment, and then taking out for crushing treatment;

s2, putting the coal-fired furnace slag powder obtained in the step S1 into a hydrochloric acid solution for soaking for 8-10 hours, and filtering and drying to obtain acidified coal-fired furnace slag powder;

s3, adding the acidified coal-fired furnace slag powder into a ferrocene aqueous solution at normal temperature, stirring for 30-40 min, and filtering to obtain ferrocene-modified coal-fired furnace slag powder;

and S4, adding the ferrocene modified coal-fired furnace slag powder obtained in the step S3 into a polyethylene wax aqueous solution, heating to 70-80 ℃, continuously stirring for 20-30 min, filtering and drying to obtain the ferrocene and polyethylene wax modified coal-fired furnace slag powder.

Technical Field

The invention belongs to concrete modification technology, and particularly relates to a modified composite admixture capable of inhibiting the reaction activity of granite aggregate alkali silicate.

Background

The durability of concrete is largely affected by alkali aggregate reaction, and non-reactive aggregate does not cause alkali aggregate reaction, while if it is reactive aggregate or some of the aggregate therein is reactive, it is highly likely to cause alkali aggregate reaction or some of the aggregate therein is reactive, and thus the concrete is unevenly cracked or expanded. Therefore, measures are needed to inhibit the alkali-aggregate reaction, the alkali-aggregate reaction comprises an alkali silicic acid reaction and an alkali carbonate reaction, and the inhibition of the alkali-aggregate reaction is often carried out by blending fly ash in the industry at present. However, the resources of the traditional admixture in many areas such as Yunnan and the like are very scarce in China at present, and the use of a large amount of outsourced fly ash and other materials can undoubtedly generate high transportation cost, so how to effectively inhibit the alkali-silicic acid reaction activity of the aggregate by taking local ground materials as main admixture components and reduce the use of outsourced fly ash admixtures is an important problem to be solved urgently in local engineering construction.

In view of the above-mentioned drawbacks of the existing admixtures for inhibiting the alkali-silicate reactivity of granite aggregate, the present inventors have made active research and innovation based on the practical experience and professional knowledge of many years of design and manufacture of such products and by using the theory, in order to create a modified composite admixture for inhibiting the alkali-silicate reactivity of granite aggregate, so as to reduce the usage amount of fly ash and make it more practical. After continuous research and design and repeated trial production and improvement, the invention with practical value is finally created.

Disclosure of Invention

The invention aims to provide a modified composite admixture capable of inhibiting the alkali silicate reaction activity of granite aggregate, which achieves the purpose of inhibiting the alkali silicate reaction activity of the granite aggregate under the condition of blending a small amount of fly ash by utilizing the synergistic effect of the fly ash, coal-fired slag powder and silica fume, and has industrial value.

The technical purpose of the invention is realized by the following technical scheme:

the invention provides a modified composite admixture capable of inhibiting the alkali silicate reaction activity of granite aggregate, which comprises the following components in parts by weight: 60-70 parts of granite aggregate, 20-30 parts of coal-fired furnace slag powder, 10-20 parts of fly ash and 20-30 parts of silica fume. The fly ash can be mixed with the coal-fired furnace slag powder and the silica fume to generate effects of induction activation, surface microcrystallization, interface coupling and the like in the cement hydration process, so that the complementary advantages of various mineral blending materials can be fully exerted, the performance defect of a single variety is overcome, and the performance of the blending material is more excellent.

Generates good synergistic effect, thereby inhibiting the alkali silicate reaction activity of granite aggregate when a small amount of fly ash is mixed.

Furthermore, the modified composite admixture also contains 10-20 parts of limestone powder according to parts by weight.

Furthermore, the particle size of the coal-fired slag powder is 5-40 nm.

Furthermore, the particle size of the fly ash is 2-10 mu m.

Furthermore, the particle size of the silica fume is 0.1-0.3 μm.

Furthermore, the coal-fired furnace slag powder is modified by ferrocene and polyethylene wax. After the ferrocene and the polyethylene wax are used for modifying the coal-fired furnace slag powder, spherical particles of the coal-fired furnace slag powder coated by the polyethylene wax can be obtained, the size is uniform, the comparative area is increased, the synergistic effect between the particles and the coal ash can be improved, meanwhile, the rigidity of the composite admixture can be improved, and after the admixture is blended into concrete, a spatial net structure can be formed through the action of the polyethylene wax, so that the cracking of the concrete can be effectively prevented; the existence of the ferrocene can enable the coal-fired furnace slag powder to be inserted into the ferrocene layer to form a sandwich structure, on one hand, the specific surface area of the coal-fired furnace slag is improved, and on the other hand, the ferrocene can also inhibit the alkali silicate reaction.

Further, the modification method of the coal-fired slag powder comprises the following specific steps:

s1, drying and crushing treatment: putting the coal-fired slag powder into a drying chamber with the temperature of 90-100 ℃ for drying treatment, and then taking out for crushing treatment;

s2, putting the coal-fired furnace slag powder obtained in the step S1 into a hydrochloric acid solution for soaking for 8-10 hours, and filtering and drying to obtain acidified coal-fired furnace slag powder;

s3, adding the acidified coal-fired furnace slag powder into a ferrocene aqueous solution at normal temperature, stirring for 30-40 min, and filtering to obtain ferrocene-modified coal-fired furnace slag powder;

and S4, adding the ferrocene modified coal-fired furnace slag powder obtained in the step S3 into a polyethylene wax aqueous solution, heating to 70-80 ℃, continuously stirring for 20-30 min, filtering and drying to obtain the ferrocene and polyethylene wax modified coal-fired furnace slag powder.

As a preferable scheme of the technical scheme, the mass fraction of the ferrocene aqueous solution is 0.1-0.3%. If the mass fraction of the ferrocene in the water solution is too large, the synergistic effect between the fly ash and the coal-fired slag powder can be damaged due to the large amount of the ferrocene, and if the mass fraction of the ferrocene is too small, the effect of improving the specific surface area of the coal-fired slag powder after the coal-fired slag powder is inserted between ferrocene layers cannot be achieved.

In a preferable embodiment of the above technical solution, the polyethylene wax has a mass fraction of 10-12% in an aqueous solution, and 0.4-0.6% of EDTA is contained therein as an auxiliary dispersant.

Further, the silica fume is silicon dioxide/wollastonite composite particles. The silicon dioxide/wollastonite composite particles are adopted to further improve the synergistic effect between the silica fume and the fly ash, the silicon dioxide/wollastonite composite particles have stronger rigidity, and generate certain bonding force with the ferrocene and polyethylene wax modified coal-fired slag powder, and after the composite admixture is doped into concrete, the rigidity and the anti-cracking performance of the concrete are effectively improved.

Furthermore, the preparation method of the silicon dioxide/wollastonite composite particle is an inorganic coating precipitation method.

As a preferable scheme of the above technical scheme, it specifically is: the ratio of silica to wollastonite was 3: 7, composite rotation speed of 1200r/min, reaction time of 40min, ball-material ratio of 5: 1, the dosage of the dispersant is 6 percent.

Furthermore, the modified composite admixture also comprises 5-20 parts by weight of vermiculite powder. The vermiculite powder has a strong adsorption effect on water, the fly ash and the silica fume can be dispersed on the surface of the vermiculite powder after the vermiculite powder is added into the composite admixture, and the synergistic effect between the fly ash and the silica fume can be improved due to the existence of water.

In conclusion, the invention has the following beneficial effects:

the invention designs a modified composite admixture, which fully exerts the synergistic coupling effect of the composite admixture, can solve the problem of insufficient performance of a single variety of admixture, simultaneously remarkably improves the cost performance of an admixture system, and can effectively inhibit the alkali-silicic acid reaction activity of granite aggregate.

Drawings

FIG. 1 shows the results of the tests on the alkali-silicic acid reaction activity of the composite admixtures of examples 1 to 4.

Detailed Description

To further illustrate the technical means and effects of the present invention for achieving the predetermined objects, the present invention provides a modified composite admixture capable of inhibiting the alkali silicate reaction activity of granite aggregate, the specific embodiments, features and effects thereof are described in detail below.

Wherein: the particle size of the coal-fired slag powder is 5-40 nm; the particle size of the fly ash is 2-10 mu m; the particle size of the silica fume is 0.1-0.3 μm.