阅读说明：本技术 一种钢渣替代水泥及提高钢渣替代水泥早期活性的方法 (Steel slag substituted cement and method for improving early activity of steel slag substituted cement ) 是由 李茂辉 陆有军 韩凤兰 邢质冰 罗富明 宋勇 于 2021-05-13 设计创作，主要内容包括：本发明公开了一种钢渣替代水泥及提高钢渣替代水泥早期活性的方法,涉及水泥替代技术领域。本发明的方法包括以下步骤：对钢渣进行粉磨,获得所述粒径分布的钢渣；将所述粒径分布的钢渣按照第一比例与水泥掺量得到第一混合物；向第一混合物中按第二比例添加碱,得到第二混合物。本发明方法发现化学激发在机械激发的基础上能够进一步激发钢渣的潜在胶凝活性,NaOH掺量为1.0％,芒硝掺量为3.0％,钢渣掺量为25％时,激发效果最佳,力学性能最优。(The invention discloses steel slag substituted cement and a method for improving early activity of the steel slag substituted cement, and relates to the technical field of cement substitution. The method of the invention comprises the following steps: grinding the steel slag to obtain the steel slag with the particle size distribution; mixing the steel slag with the particle size distribution with cement according to a first proportion to obtain a first mixture; and adding a base to the first mixture according to a second proportion to obtain a second mixture. The method disclosed by the invention finds that the chemical excitation can further excite the potential gelling activity of the steel slag on the basis of mechanical excitation, and the excitation effect is optimal and the mechanical property is optimal when the doping amount of NaOH is 1.0%, the doping amount of mirabilite is 3.0% and the doping amount of the steel slag is 25%.)

1. A steel slag substitute cement, comprising:

the steel slag accounts for 10 to 25 percent of the weight ratio;

alkali accounting for 0.5-2 wt% and cement in balance;

wherein the steel slag has the particle size distribution as follows: 3.71 μm<D₁₀<5.86μm，6.29μm<D₃₀<9.43μm，9.9μm<D₅₀<15.39μm，19.48μm<D₆₀<13.38μm，28.54μm<D₉₀<34.83μm。

2. The steel slag-substitute cement of claim 1, wherein said alkali is any one of: NaOH, KOH, Ca (OH)₂。

3. The steel slag-replacing cement of claim 1, wherein the steel slag-replacing cement further comprises a grinding aid in an amount of 0.1 to 0.2% by weight, and the grinding aid is triethanolamine.

4. The steel slag-substitute cement of claim 1, having a particle size distribution wherein: 4.08 μm<D₁₀<5.86μm，7.80μm<D₃₀<9.43μm，11.76μm<D₅₀<15.39μm，14.65μm<D₆₀<19.48μm，29.36μm<D₉₀<34.83μm。

5. A method for improving the early activity of steel slag-substituted cement, which is characterized by comprising the following steps:

grinding the steel slag to obtain the steel slag with the particle size distribution, wherein the particle size distribution is as follows: 3.71 μm<D₁₀<5.86μm，6.29μm<D₃₀<9.43μm，9.9μm<D₅₀<15.39μm，19.48μm<D₆₀<13.38μm，28.54μm<D₉₀<34.83μm；

Mixing the steel slag with the particle size distribution with cement according to a first proportion to obtain a first mixture;

adding a base to the first mixture in a second ratio to obtain a second mixture.

6. The steel slag-substitute cement according to claim 5, wherein said particle size distribution has a milling time of 10 to 40 mins.

7. The method of claim 5, wherein a grinding aid triethanolamine is added during the grinding process.

8. The method of claim 5, wherein the first proportion is 10% -25%.

9. The method of claim 5, wherein the base is NaOH and is added in a ratio of 0.5% to 2.0%.

10. The method of claim 5, wherein salt cake is further added to the first mixture at a third ratio of 2.0% to 3.5%.

Technical Field

The invention relates to the technical field of cement replacement, in particular to a method for improving early activity of steel slag-replaced cement.

Background

The steel slag is solid waste generated in the process of smelting steel, and the discharge amount accounts for 12 to 20 percent of the steel yield. With the continuous increase of steel yield in China, the accumulated steel slag stock reaches hundreds of millions of tons, and the large-scale stacking of the steel slag not only causes the waste of land resources, but also brings a series of environmental problems. At present, the utilization rate of steel slag in China is lower than 30%, and has a great gap with the utilization rate close to 100% in developed countries such as Germany. The comprehensive utilization of the steel slag resource can not only reduce the pollution to the environment, but also generate benefits for steel enterprises, so that the improvement of the utilization rate of the steel slag is a great problem in promoting the sustainable development of the enterprises and even the country. The steel slag has partial silicate components and potential gelling activity, but the steel slag has complex components and different sources, so that the effect of exciting the activity of the steel slag by adopting different excitation modes is greatly different.

Wufang et al studied the influence of steel slag incorporation on the early strength and rheological properties of the paste, and the results show that the steel slag incorporation increases the yield stress and slurry viscosity of the sample. At present, more researches are carried out for improving the comprehensive utilization of steel slag materials, but most researches are carried out by focusing on one or two excitation modes, and the effects of the multiple excitation modes on the activity excitation of the steel slag are less researched, so that the activity excitation effect of the steel slag is poor, and the steel slag doping amount cannot be effectively improved.

Disclosure of Invention

In view of the above defects in the prior art, the technical problem to be solved by the present invention is to provide a thought, that is, a plurality of ways such as mechanical excitation, alkaline excitation, salt excitation and the like are adopted to systematically investigate the excitation effect of different excitation ways on the early-stage gelling activity of the steel slag material, so as to maximally improve the potential gelling activity of the steel slag, increase the mixing amount of the steel slag in the cement, so as to improve the comprehensive utilization rate of the steel slag, and lay a foundation for the resource utilization of industrial solid wastes.

In order to achieve the above object, the present invention provides a steel slag-improved cement, comprising:

the steel slag accounts for 10 to 25 percent of the weight ratio;

alkali accounting for 0.5-2 wt% and cement in balance;

wherein the steel slag has the particle size distribution as follows: 3.71 μm<D₁₀<5.86μm，6.29μm<D₃₀<9.43μm，9.9μm<D₅₀<15.39μm，19.48μm<D₆₀<13.38μm，28.54μm<D₉₀<34.83μm。

The invention also provides a method for improving the early activity of the steel slag substituted cement, which is characterized by comprising the following steps:

grinding the steel slag to obtain the steel slag with the particle size distribution, wherein the particle size distribution is as follows: 3.71 μm<D₁₀<5.86μm，6.29μm<D₃₀<9.43μm，9.9μm<D₅₀<15.39μm，19.48μm<D₆₀<13.38μm，28.54μm<D₉₀<34.83μm；；

Mixing the steel slag with the particle size distribution with cement according to a first proportion to obtain a first mixture;

adding a base to the first mixture according to a second proportion to obtain a second mixture;

compared with the prior art, the method has the technical advantages that:

(1) according to the method, through a mechanical grinding experiment, the gradual left shift of the grain size distribution curve of the steel slag is known, and D is obtained after grinding for 40mins₅₀Decrease by 72.9%, D₉₀The reduction is 85.4 percent, the change range of coarse particles in the steel slag is larger than that of fine particles, and the fine particles are more difficult to be further ground;

(2) the method of the invention finds out through experiments that the mechanical excitation has obvious improvement effect on the early gelation activity of the steel slag, the milled powder is 10mins, the 3d compressive strength can reach 19.29MPa, and the 7d compressive strength can reach 23.32 MPa. The comprehensive excitation effect and the economic cost are achieved, and when the milled powder is 20mins, the doping amount of the early strength agent is 2.0 percent, and the doping amount of the steel slag is 20 percent, the cost performance is optimal;

(3) according to the method, the potential gelling activity of the steel slag can be further stimulated on the basis of mechanical stimulation by chemical stimulation through tests, when the doping amount of NaOH is 1.0%, the doping amount of mirabilite is 3.0%, and the doping amount of the steel slag is 25%, the stimulation effect is optimal, and the mechanical property is optimal;

(4) the method of the invention passesIt was proved that the steel slag mainly replaces calcite (CaCO) as the cement hydration product₃) Portlandite (Ca (OH)₂) And dicalcium silicate (Ca)₂SiO₄) With the increase of the maintenance age, the hydration products are thicker and are interwoven with each other to form a fiber net structure, so that the mechanical property is further enhanced.

The conception, the specific structure and the technical effects of the present invention will be further described with reference to the accompanying drawings to fully understand the objects, the features and the effects of the present invention.

Drawings

FIG. 1(a) is an XRD spectrum of a steel slag component;

FIG. 1(b) is a graph showing the distribution of the particle size of steel slag;

FIG. 2 is a curve showing the variation of the particle size of steel slag with grinding time;

FIG. 3(a) is a curve showing the change of 3d compressive strength of steel slag substituted cement along with grinding time;

FIG. 3(b) is a curve showing the change of the compressive strength of steel slag-substituted cement 7d with grinding time;

FIG. 4(a) is a curve showing the 3d compressive strength of steel slag-substituted cement varying with the amount of the early strength agent;

FIG. 4(b) is a curve showing the change of the compressive strength of the steel slag-substituted cement at 7d according to the amount of the early strength agent;

FIG. 5(a) is a curve showing the change of 3d compressive strength of steel slag-substituted cement with the amount of sodium hydroxide added;

FIG. 5(b) is a curve showing the change of the compressive strength of the steel slag-substituted cement 7d with the amount of sodium hydroxide added;

FIG. 6(a) is a curve showing the change of 3d compressive strength of steel slag-substituted cement with the amount of mirabilite added;

FIG. 6(b) is a curve showing the variation of compressive strength of steel slag-substituted cement 7d with the amount of mirabilite added;

FIG. 7(a) is an XRD (X-ray diffraction) diagram of a steel slag-substituted cement hydrate curing time of 3 d;

FIG. 7(b) is an XRD pattern of curing time of steel slag-substituted cement hydrate product of 7 d;

FIG. 8(a) is an SEM image of a steel slag-substituted cement hydrate product 3 d;

FIG. 8(b) is an SEM image of a steel slag-substituted cement hydrate product 7 d.

Detailed Description

The technical contents of the preferred embodiments of the present invention will be more clearly and easily understood by referring to the drawings attached to the specification. The present invention may be embodied in many different forms of embodiments and the scope of the invention is not limited to the embodiments set forth herein.

The invention adopts a plurality of modes such as mechanical excitation, alkaline excitation, salt excitation and the like to systematically investigate the excitation effect of different excitation modes on the early-stage gelling activity of the steel slag material, thereby improving the potential gelling activity of the steel slag to the maximum extent, improving the mixing amount of the steel slag in the cement, improving the comprehensive utilization rate of the steel slag and laying a foundation for the resource utilization of industrial solid wastes.

The invention provides steel slag substituted cement, which comprises the following components:

the steel slag accounts for 10 to 25 percent of the weight ratio;

alkali accounting for 0.5-2 wt% and cement in balance;

wherein the steel slag has the particle size distribution as follows: 3.71 μm<D₁₀<5.86μm，6.29μm<D₃₀<9.43μm，9.9μm<D₅₀<15.39μm，19.48μm<D₆₀<13.38μm，28.54μm<D₉₀<34.83μm。

Further, the base may be any one of: NaOH, KOH, Ca (OH)₂。

Furthermore, the steel slag substitute cement also comprises a grinding aid, wherein the grinding aid accounts for 0.1-0.2% of the weight of the steel slag substitute cement, and the grinding aid is triethanolamine.

Further, in the particle size distribution: 4.08 μm<D₁₀<5.86μm，7.80μm<D₃₀<9.43μm，11.76μm<D₅₀<15.39μm，14.65μm<D₆₀<19.48μm，29.36μm<D₉₀<34.83μm。

The invention provides a method for improving early activity of steel slag substituted cement, which is characterized by comprising the following steps:

grinding the steel slag to obtain the steel slag with the particle size distribution, wherein the particle size distribution is：3.71μm<D₁₀<5.86μm，6.29μm<D₃₀<9.43μm，9.9μm<D₅₀<15.39μm，19.48μm<D₆₀<13.38μm，28.54μm<D₉₀<34.83μm；

Mixing the steel slag with the particle size distribution with cement according to a first proportion to obtain a first mixture;

adding a base to the first mixture in a second ratio to obtain a second mixture.

Further, the grinding time of the particle size distribution is 10-40 mins.

Further, a grinding aid triethanolamine is added in the grinding process.

Further, the first proportion is 10% -25%.

Further, the base is any one of: NaOH KOH, Ca (OH)₂The adding proportion is 0.5-2.0%.

Furthermore, mirabilite can be added into the first mixture according to a third proportion, wherein the addition proportion is 2.0% -3.5%.

Compared with the prior art, the method has the advantages that,

on one hand, the method of the invention learns that the grain size distribution curve of the steel slag gradually moves left through a mechanical grinding experiment, and D is obtained after grinding for 40mins₅₀Decrease by 72.9%, D₉₀The reduction is 85.4 percent, the change range of coarse particles in the steel slag is larger than that of fine particles, and the fine particles are more difficult to be further ground;

on the other hand, the method of the invention learns that the mechanical excitation has obvious improvement effect on the early gelation activity of the steel slag through experiments, the milling time is 10mins, the 3d compressive strength can reach 19.29MPa, and the 7d compressive strength can reach 23.32 MPa. The comprehensive excitation effect and the economic cost are achieved, and when the milled powder is 20mins, the doping amount of the early strength agent is 2.0 percent, and the doping amount of the steel slag is 20 percent, the cost performance is optimal;

secondly, the method disclosed by the invention can further stimulate the potential gelling activity of the steel slag on the basis of mechanical stimulation by chemical stimulation through tests, and when the doping amount of NaOH is 1.0%, the doping amount of mirabilite is 3.0%, and the doping amount of the steel slag is 25%, the stimulation effect is optimal, and the mechanical property is optimal;

finally, the method of the invention has been tested to show that the steel slag substitutes for the cement hydration products, mainly calcite (CaCO)₃) Portlandite (Ca (OH)₂) And dicalcium silicate (Ca)₂SiO₄) With the increase of the maintenance age, the hydration products are thicker and are interwoven with each other to form a fiber net structure, so that the mechanical property is further enhanced.

The following description will explain embodiments of the present invention by referring to specific examples.

Test raw materials:

the steel slag in the material used in the test is solid waste produced by enterprises, wherein the steel slag is converter steel slag (D) of Ningxia steel mill₅₀＝36.85μm，D₉₀195.6 μm) and the steel slag material was subjected to chemical principal component analysis, as shown in table 1, fig. 1(a) is a steel slag component XRD spectrum, and fig. 1(b) is a steel slag particle size distribution diagram; the calculation shows that the alkalinity coefficient of the steel slag is 2.22, the alkalinity coefficient is more than 1, the steel slag is alkaline steel slag, sodium hydroxide (analytically pure, Shanghai Vocko Biotechnology Co., Ltd.), sodium sulfate, triethanolamine and absolute ethyl alcohol are all analytically pure grade reagents produced by the national drug group chemical reagent Co., Ltd, and the cement is 425 grade cement produced by Ningxia Saima Cement Co., Ltd.

TABLE 1 chemical principal Components and contents (mass fraction) of raw materials

The test method comprises the following steps:

based on the research idea of steel slag early-stage gelling activity excitation, selecting mechanical excitation and chemical excitation modes to carry out steel slag activity excitation, carrying out tests according to cement mortar strength test standards, testing the size of a test piece to be 40m multiplied by 40mm multiplied by 160mm, placing the test piece into a standard curing box (the temperature is 20 ℃, and the humidity is 95%) after pouring and forming, curing the test piece to the age of 3d and 7d, testing the uniaxial compressive strength of a sample, selecting a sample with better strength to carry out XRD and SEM tests, and analyzing the strength increase mechanism.

Test results and discussion:

1) influence of mechanical excitation on the particle size of the steel slag:

the steel slag powder obtained from a certain steel mill in Ningxia is subjected to a grinding test by a ball mill, the grinding time is controlled to be 10min, 20min, 30min and 40min, a certain amount of triethanolamine is required to be added as a grinding aid in the grinding process considering that the steel slag is not easy to grind, the particle size distribution of the steel slag is measured by a laser particle sizer after grinding, and the result is shown in table 2 and fig. 2.

TABLE 2 particle size parameter of steel slag after grinding

Fig. 2 is a curve showing the variation of the steel slag particle size with grinding time, and it can be known from the table that the steel slag particle size gradually decreases and the distribution curve gradually shifts to the left as the grinding time increases. Wherein the grinding time is 40mins compared with 10mins, D₁₀Decrease by 36.7%, D₅₀Decrease by 35.1%, D₉₀Reduced by 18.1 percent compared with the original steel slag D₅₀Decrease by 72.9%, D₉₀The reduction of 85.4 percent indicates that coarse particles in the steel slag are sharply reduced through proper mechanical grinding, and the variation amplitude of the fine particles is smaller than that of the coarse particles, which indicates that the fine particles are more difficult to be further ground after grinding to a certain degree.

2) Influence of mechanical excitation on early gelling activity of steel slag

The steel slag after being ground at different time is subjected to a strength test by replacing cement with different mixing amounts, and the grinding time, the steel slag mixing amount and the self-made early strength agent are subjected to a three-factor four-level orthogonal test (table 3), and the results are shown in the following figures 3 and 4:

TABLE 3 orthogonal experimental design table for substituting cement with steel slag

FIG. 3 is a curve showing the variation of the compressive strength of the steel slag-substituted cement with grinding time, wherein FIG. 3(a) is a curve showing the variation of the compressive strength of the steel slag-substituted cement 3d with grinding time; FIG. 3(b) is a curve showing the change of the compressive strength of steel slag-substituted cement 7d with grinding time; as can be known from FIG. 3, under the conditions of different steel slag mixing amounts, the 3d and 7d age compressive strength shows a gradually increasing change trend along with the increase of the milling time, the strength increase is mainly concentrated in the period from 10min to 20min, and particularly the 3d strength is more obvious. Through mechanical milling, the particle size distribution curve of steel slag gradually moves to the left, large particles gradually decrease, small particles gradually increase, and the compressive strength gradually increases along with milling time. The small particles have larger specific surface area when hydration reaction occurs in the system, and can participate in the hydration reaction more and continuously fill the gaps in the system to promote the further occurrence of the hydration reaction, so that the strength is continuously improved, and the mechanical grinding powder can effectively improve the early-stage gelling activity of the steel slag. And (3) integrating the change rule of the strength in the 3d and 7d age periods and the starting point of improving the utilization rate of the steel slag, wherein the optimal milling time is 20min, and the mixing amount of the steel slag is 20%.

FIG. 4 is a curve showing the variation of the 3d compressive strength of the steel slag-substituted cement with the doping amount of the early strength agent, wherein FIG. 4(a) is a curve showing the variation of the 3d compressive strength of the steel slag-substituted cement with the doping amount of the early strength agent; FIG. 4(b) is a curve showing the change of the compressive strength of the steel slag-substituted cement at 7d according to the amount of the early strength agent; as can be known from FIG. 4, under the conditions of different steel slag doping proportions, the 3d and 7d age compressive strengths have larger fluctuation range along with the change of the early strength admixture, when the steel slag doping proportion is 10%, the strength shows a gradually increasing change trend along with the early strength admixture, the steel slag doping proportion is 15%, the strength shows a change trend of firstly decreasing and then increasing along with the early strength admixture, the steel slag doping proportions are 20% and 25%, and the strength basically shows a change trend of firstly increasing and then decreasing along with the early strength admixture. The steel slag doping amount and the early strength admixture doping amount have the optimal proportion, when the steel slag doping amount is within a certain range, the excitation effect of the early strength admixture is better along with the increase of the doping amount, when the steel slag doping amount is beyond the certain range, the excitation effect of the early strength admixture is not obvious, the comprehensive 3d and 7d age strength is that the steel slag doping amount is 20%, and the early strength admixture doping amount is 2.0%.

(2) Influence of chemical excitation on early gelling activity of steel slag

On the basis of mechanical excitation, a chemical excitation test is carried out by utilizing sodium hydroxide and mirabilite, theoretically, the alkali can be sodium hydroxide, potassium hydroxide or calcium hydroxide, and the sodium hydroxide is adopted in the chemical excitation part. The results are shown in fig. 5 and 6 by using steel slag, sodium hydroxide and mirabilite as orthogonal factors; FIG. 5 is a curve showing the variation of the compressive strength of steel slag-substituted cement with the amount of sodium hydroxide added, wherein FIG. 5(a) is a curve showing the variation of the compressive strength of steel slag-substituted cement 3d with the amount of sodium hydroxide added; FIG. 5(b) is a curve showing the change of the compressive strength of the steel slag-substituted cement 7d with the amount of sodium hydroxide added; as can be seen from FIG. 5, at a steel slag content of 10%, the compressive strengths of 3d and 7d gradually decreased with increasing NaOH content; in the steel slag doping proportion of 15%, 20% and 25%, the 3d and 7d compressive strengths show the change trend of increasing and then decreasing along with the doping amount of NaOH, which shows that the NaOH has obvious excitation effect on the early gelation activity of the steel slag when the steel slag doping amount is large, and the optimal NaOH doping amount and the optimal steel slag doping amount are respectively 1.0% and 25% by synthesizing the change conditions of the 3d and 7d compressive strengths.

FIG. 6 is a curve showing the variation of the compressive strength of steel slag-substituted cement with the amount of mirabilite added; wherein, FIG. 6(a) is the curve of the 3d compressive strength of the steel slag-substituted cement varying with the amount of mirabilite; FIG. 6(b) is a curve showing the change of 3d compressive strength of steel slag-substituted cement with the amount of mirabilite added; from fig. 6, it can be known that, under the condition that the steel slag content is 10%, the compressive strengths of 3d and 7d gradually decrease with the increase of the mirabilite content, and the decrease range is very obvious within the range of 2.0% to 2.5%; under the condition of the proportion of 15 percent, 20 percent and 25 percent of steel slag doping amount, the compressive strength shows a change trend of increasing first and then decreasing along with the increase of the mirabilite doping amount, which indicates that the mirabilite is in a certain range in the steel slag doping amount, and the excitation effect is stronger along with the increase of the steel slag doping amount. The reason is that when the mixing amount of the steel slag is low, the system is mainly hydrated by cement, and the mixing of the mirabilite reduces the hydration process of the cement, so the strength is reduced; when the steel slag is doped in a large amount, the hydration proportion of the steel slag is increased in the hydration process, and the early gelling activity of the steel slag can be effectively excited by doping mirabilite, so that the strength is gradually increased. The optimal mirabilite mixing amount and the optimal steel slag mixing amount are respectively 3.0 percent and 25 percent under the condition of comprehensive strength change.

(3) X-ray diffraction analysis of the steel slag-substituted cement:

after the test piece is subjected to standard curing for 3d and 7d, a proper amount of sample is prepared, dried and ground to powder, and XRD test is carried out, and the test result is shown in a phase diffraction diagram of 25% steel slag doping in figure 7, wherein the curing time in figure 7(a) is 3d, and the curing time in figure 7(b) is 7 d. As can be seen from the figure, partial hydration has begun in 3 d-aged slurries, with the hydration products being predominantly calcite (CaCO)₃) And portlandite (Ca (OH)₂) With the increase of the curing time, the calcium oxide and the silicon oxide in the steel slag gradually react, the diffraction peak of the portlandite is strengthened, the content of the portlandite in the system is continuously increased, and the dicalcium silicate (Ca) is generated₂SiO₄) And C-S-H gel, so that the mechanical property of the system is promoted to be further improved.

(4) And (3) analyzing the microscopic morphology of the steel slag-substituted cement:

obtaining a structure diagram of the steel slag-substituted cement hydration product through a Scanning Electron Microscope (SEM), as shown in an SEM image of the steel slag-substituted cement hydration product in FIG. 8, wherein FIG. 8(a) is an SEM image of a steel slag-substituted cement hydration product 3 d; FIG. 8(b) is an SEM image of a steel slag-substituted cement hydrate product 7 d. As can be seen from the figure, at 3d, the hydration reaction in the system is started, and the hydration products which can be observed are hexagonal plate-shaped Ca (OH)₂Crystalline and amorphous C-S-H gel, and pin-shaped hydration products ettringite are generated on the other surface, but the amount and the types of the hydration products are less, so that the test piece is obviously loose in structure and large in gap. When the paste is maintained for 7d, the structure of the paste is gradually compacted, the gaps are obviously reduced, the true rod-shaped ettringite becomes bigger and is interwoven with each other to form an obvious fiber net structure, which shows that the active ingredients in the system are further mixed with Ca (OH)₂Hydration reaction occurs to promote the system to become more compact, and the mechanical property of the test block on a macroscopic scale is further enhanced.

Conclusion

(1) Through mechanical grinding experiment, the particle size distribution curve of the steel slag gradually shifts to the left, and the powderAfter grinding for 40min, D₅₀Decrease by 72.9%, D₉₀The reduction is 85.4 percent, the change range of coarse particles in the steel slag is larger than that of fine particles, and the fine particles are more difficult to be ground.

(2) The early gelling activity of the steel slag is obviously improved by mechanical excitation, the steel slag is ground for 10min, the 3d compressive strength can reach 19.29MPa, and the 7d compressive strength can reach 23.32 MPa. Comprehensive excitation effect and economic cost, and the cost performance is optimal when the powder is ground for 20min, the mixing amount of the early strength agent is 2.0 percent, and the mixing amount of the steel slag is 20 percent.

(3) The chemical excitation can further excite the potential gelling activity of the steel slag on the basis of mechanical excitation, and when the doping amount of NaOH is 1.0%, the doping amount of mirabilite is 3.0%, and the doping amount of the steel slag is 25%, the excitation effect is optimal, and the mechanical property is optimal.

(4) The steel slag substitutes cement hydration product mainly calcite (CaCO)₃) Portlandite (Ca (OH)₂) And dicalcium silicate (Ca)₂SiO₄) With the increase of the maintenance age, the hydration products are thicker and are interwoven with each other to form a fiber net structure, so that the mechanical property is further enhanced.

The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.