CN112341092A - Concrete doped with high-silicon tailing powder and preparation method thereof - Google Patents

Abstract

A concrete doped with high-silicon tailing powder and a preparation method thereof belong to the technical field of building materials, and the concrete comprises cement, high-silicon tailing powder, broken stone, natural sand and water, and the concrete comprises the following components in parts by weight: 439 parts of cement and high-silicon tailing powder, 1134 parts of broken stone, 611 parts of sand and 215 parts of water, wherein the high-silicon tailing powder accounts for 10-30% of the cement. The strength of the concrete, particularly the later strength, is improved, the energy is saved, the consumption is reduced, the environmental pollution is reduced, and the green high-performance concrete is formed. The replacement amount of the tailings is 10-30%, and the proportion gives consideration to both the performance of the concrete and the production cost.

Description

Concrete doped with high-silicon tailing powder and preparation method thereof

Technical Field

The invention belongs to the technical field of building materials, and particularly relates to high-silicon tailing powder doped concrete and a preparation method thereof.

Background

The tailing powder doped concrete is adopted in many important projects so far, particularly shows unique superiority in building projects, and generates obvious benefits in the aspects of safe engineering service life, economic rationality, adaptability to environmental conditions and the like, so that the tailing powder doped concrete is accepted by experts of various countries and is considered as a development direction of concrete technology in the future. The tailings are used as building materials, the utilization mode of the tailings has large utilization amount, the difficult problems of treatment and utilization of industrial waste residues can be realized, and the supply amount of concrete mineral admixture in most regions in China can be increased. One of the modes of utilizing the tailings as the building materials is to apply the tailings as the admixture to concrete, so that the utilization not only solves the problem of tailing stockpiling, but also provides replaceable resources for the building materials, and simultaneously reduces the problems of environmental pollution caused by the tailings and the like. Therefore, the comprehensive utilization of tailing resources is indispensable for research.

At present, the following problems exist in most of the ore powder-doped concrete: 1. the mixing amount of slag powder in concrete is small, and the utilization rate of tailing powder is low; 2. the unactivated tailings are inert substances, generally have low activity, and need to be activated first for being used as an admixture in a building material.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides the concrete doped with the high-silicon tailing powder and the preparation method thereof.

In order to achieve the purpose, the invention adopts the main technical scheme that:

the concrete doped with the high-silicon tailing powder comprises cement, the high-silicon tailing powder, broken stone, natural sand and water, and is prepared from the following components in parts by weight: 439 parts of cement and high-silicon tailing powder, 1134 parts of broken stone, 611 parts of sand and 215 parts of water, wherein the high-silicon tailing powder accounts for 10-30% of the cement.

Further, the high-silicon tailing powder is mineral powder with the silicon dioxide content higher than 50% after mechanical force activation, and the particle size is refined to the diameter D50<8 mu m.

Further, the cement is 42.5-grade ordinary portland cement, and the maximum particle size of the broken stone is 20 cm.

The preparation method of the concrete doped with the high-silicon tailing powder comprises the following steps:

s1, preparing a raw material for the high-silicon tailing powder-doped concrete according to the method disclosed by the claims 1 to 3, adding broken stones and sand, stirring for 30S, then adding the high-silicon tailing powder and cement, stirring for 30S, adding water, stirring for 30S, and finally discharging;

and S2, putting the material discharged in the step S1 into a vibrating table for vibrating.

Further, the stirring time is 90s in total, and the stirring speed is 45-48 r/min.

The technical principle of the method is as follows: the cement is used as a basic raw material for manufacturing the concrete, and the concrete made of cement cemented macadam has higher strength after hardening and can resist the erosion of fresh water or salt water; the high-silicon tailing powder is a high-quality concrete admixture, so that the use amount of cement can be effectively reduced, and the cost is reduced; the high-silicon tailing powder is doped in the concrete, so that a large amount of cement is saved, the workability of concrete mixture is improved, the pumpability of the concrete is enhanced, creep of the concrete is reduced, hydration heat and thermal expansion are reduced, the anti-permeability capability of the concrete is improved, and the modification property of the concrete is increased.

The invention has the beneficial effects that:

the concrete doped with the high-silicon tailing powder provided by the invention adopts the high-silicon tailing powder to replace cement, so that the use of the cement can be reduced, the production cost can be saved and the income can be increased; the compactness of the concrete is improved, so that the slump of the concrete is small, and the gaps in the concrete are reduced; the working performance of the concrete is improved by improving the compactness, the concrete is convenient to transport, the concrete is not easy to segregate in the transportation process, the concrete is not easy to layer and stick to a tank, the friction coefficient of the concrete can be reduced by adding the iron tailing powder, the resistance of the pump truck is reduced in the pumping process, the service lives of the pump truck and a pump pipe are prolonged, the pouring time is shortened, the labor intensity of workers is reduced, and the working efficiency is improved.

According to the invention, by adding the high-silicon tailing powder, the concrete has lower hydration heat in the early hardening stage and smaller shrinkage deformation in the later hardening stage, the water-gel ratio and the void ratio are reduced, and the stability of the concrete is improved.

The concrete is green, waste tailings can be utilized, resources are saved, the environment is protected, and effective utilization of resources is promoted.

The concrete doped with the high-silicon tailing powder further enhances the compressive strength of the concrete, further reduces the friction coefficient of the concrete and enhances the pumpability. The strength of the concrete, particularly the later strength, is improved, the energy is saved, the consumption is reduced, the environmental pollution is reduced, and the green high-performance concrete is formed. The replacement amount of the tailings is 10-30%, and the proportion gives consideration to both the performance of the concrete and the production cost.

Detailed Description

For a better understanding of the present invention, reference will now be made in detail to the present invention by way of specific embodiments thereof.

The concrete doped with the high-silicon tailing powder comprises cement, the high-silicon tailing powder, broken stone, natural sand and water, and is prepared from the following components in parts by weight: 439 parts of cement and high-silicon tailing powder, 1134 parts of broken stone, 611 parts of sand and 215 parts of water, wherein the high-silicon tailing powder accounts for 10-30% of the cement.

The high-silicon tailing powder is mineral powder with the silicon dioxide content higher than 50% after mechanical activation, and the particle size is thinned to the diameter D50<8 mu m.

The cement is 42.5-grade ordinary portland cement, and the maximum particle size of the broken stone is 20 cm.

The preparation method of the concrete doped with the high-silicon tailing powder is characterized by comprising the following steps of:

s1, preparing raw materials according to the concrete doped with the high-silicon tailing powder, adding broken stone and sand, stirring for 30S, then adding the high-silicon tailing powder and cement, stirring for 30S, adding water, stirring for 30S, and finally discharging;

and S2, putting the material discharged in the step S1 into a vibrating table for vibrating.

The stirring time is 90s in total, and the stirring speed is 45-48 r/min.

Example 1

A preparation method of high-silicon tailing powder doped concrete comprises the following steps:

1. stirring: and (2) stirring by adopting a forced stirrer, adding 1134 parts of crushed stone and 611 parts of sand, stirring for 30s, then adding 439 parts of high-silicon tailing powder and cement in total, wherein 395 parts of cement is added, stirring for 30s, adding 215 parts of water, stirring for 30s, and finally discharging. Wherein the maximum particle size of the crushed stone is 20 cm.

2. Vibrating: putting into a vibrating table for vibrating.

3. And (5) maintenance: the mixture was maintained in a standard curing room at 20 ℃ and 90% humidity for 28 d.

Example 2

A preparation method of high-silicon tailing powder doped concrete comprises the following steps:

1. stirring: and (2) stirring by adopting a forced stirrer, adding 1134 parts of crushed stone and 611 parts of sand, stirring for 30s, then adding 439 parts of high-silicon tailing powder and cement in total, wherein the cement is 351 parts, stirring for 30s, adding 215 parts of water, stirring for 30s, and finally discharging. Wherein the particle size of the crushed stone is 20 cm.

2. Vibrating: putting into a vibrating table for vibrating.

3. And (5) maintenance: the mixture was maintained in a standard curing room at 20 ℃ and 90% humidity for 28 d.

Example 3

A preparation method of high-silicon tailing powder doped concrete comprises the following steps:

1. stirring: and (2) stirring by adopting a forced stirrer, adding 1134 parts of crushed stone and 611 parts of sand, stirring for 30s, then adding 439 parts of high-silicon tailing powder and cement in total, wherein the cement is 307 parts, stirring for 30s, adding 215 parts of water, stirring for 30s, and finally discharging. Wherein the particle size of the crushed stone is 20 cm.

2. Vibrating: putting into a vibrating table for vibrating.

3. And (5) maintenance: the mixture was maintained in a standard curing room at 20 ℃ and 90% humidity for 28 d.

Comparative example

1. Stirring: and (2) stirring by adopting a forced stirrer, adding 1134 parts of crushed stone and 611 parts of sand, stirring for 30s, adding 439 parts of cement, stirring for 30s, adding 215 parts of water, stirring for 30s, and finally discharging, wherein the particle size of the crushed stone is 20 cm.

2. Vibrating: putting into a vibrating table for vibrating.

3. And (5) maintenance: the mixture was maintained in a standard curing room at 20 ℃ and 90% humidity for 28 d.

The mixing ratios of the concrete used in examples 1 to 3 and comparative examples are shown in Table 1:

TABLE 1 concrete ratio

	Water (W)	Cement	High silicon tailing powder	Crushing stone	Sand
						Comparative examples	215	439	0	1134	611
Example 1	215	395	44	1134	611
						Example 2	215	351	88	1134	611
Example 3	215	307	132	1134	611

The concrete prepared in the above examples and comparative examples was tested and the results are shown in table 2:

TABLE 2 concrete indexes

	Slump (mm)	Slump after one hour (mm)	28d concrete Strength (MPa)
				Example 1	82	91	45.15
Example 2	80	89	41.31
				Example 3	76	87	39.80
Comparative examples	84	95	45.35

Slump determination method: pouring concrete into a horn-shaped slump bucket with an upper opening of 100mm, a lower opening of 200mm and a height of 300mm for three times, uniformly impacting 25 times along the wall of the bucket from outside to inside by using a tamping hammer after each filling, tamping and leveling. Then the barrel is pulled up, the concrete generates the slump phenomenon due to the dead weight, and the height of the highest point of the slump concrete is subtracted from the barrel height (300mm), namely the slump.

The slump for one hour is measured after concrete is put into a slump bucket, then the bucket is pulled up and stands for 1 hour.

The 28d concrete strength measurement method comprises the following steps: concrete samples (100 × 100) were produced, cured for 28d, and then subjected to a compression test using a press machine to measure strength data.

The design slump is 75-90mm, the slump is the best within the range, which indicates that the slump of the concrete after adding the iron ore powder also meets the requirement, and indicates that the workability of the concrete also meets the requirement.

Concrete strength for 28 days: the strength of the concrete with the strength of C30 is designed to meet 34.93mpa, and all test pieces can be seen to meet the requirements.

After the tailings partially replace cement, the compressive strength of the concrete is reduced along with the increase of the replacement amount. As the amount of the tailings replacing the cement is increased, the amount of the cement clinker is relatively reduced, and the cement hydration products are reduced, which is one of the reasons for the reduction of the compressive strength of the concrete(ii) a The reduction of cement hydration products also means that Ca (OH) of secondary hydration reactions with tailings occur₂The reduction in the amount is a further important reason why the compressive strength of concrete tends to decrease with increasing amount of tailings instead of cement.

In the embodiment, when the content of the high-silicon iron tailing powder reaches 30%, the strength requirement of the C30 concrete can be met, and the same strength grade as that of the standard concrete is achieved. Thus, the tailings are utilized to solve the problem of tailing stockpiling, provide substitutable resources for building materials, and reduce the problems of environmental pollution caused by the tailings and the like.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in other forms, and any person skilled in the art can change or modify the technical content disclosed above into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification of the above embodiments according to the technical essence of the present invention are within the protection scope of the technical solution of the present invention.

Claims (5)

1. The concrete doped with the high-silicon tailing powder is characterized by comprising cement, the high-silicon tailing powder, broken stone, sand and water, and the concrete is prepared from the following components in parts by weight: 439 parts of cement and high-silicon tailing powder, 1134 parts of broken stone, 611 parts of sand and 215 parts of water, wherein the high-silicon tailing powder accounts for 10-30% of the cement.

2. The high-silicon tailing powder-doped concrete according to claim 1, wherein the high-silicon tailing powder is mineral powder with the silicon dioxide content higher than 50% after mechanical force activation, and the particle size is refined to the diameter D50<8 μm.

3. The high-silicon tailing powder-doped concrete as claimed in claim 1, wherein the cement is 42.5-grade ordinary portland cement, and the maximum particle size of the crushed stone is 20 cm.

4. The method for preparing the high-silicon tailing powder-doped concrete according to any one of claims 1 to 3, which is characterized by comprising the following steps of:

s1, preparing a raw material for the high-silicon tailing powder-doped concrete according to the method disclosed by the claims 1 to 3, adding broken stones and sand, stirring for 30S, then adding the high-silicon tailing powder and cement, stirring for 30S, adding water, stirring for 30S, and finally discharging;

and S2, putting the material discharged in the step S1 into a vibrating table for vibrating.

5. The method for preparing the high-silicon tailing powder-doped concrete according to claim 4, wherein the method comprises the following steps: the stirring time is 90s in total, and the stirring speed is 45-48 r/min.