CN113716884A

CN113716884A - Preparation method of wear-resistant cement suitable for roads and bridges

Info

Publication number: CN113716884A
Application number: CN202110983170.6A
Authority: CN
Inventors: 胡龙明; 郭文; 叶俊; 王林海
Original assignee: Yangxin Washi Cement Co Ltd
Current assignee: Yangxin Washi Cement Co Ltd
Priority date: 2021-08-25
Filing date: 2021-08-25
Publication date: 2021-11-30

Abstract

The invention discloses a preparation method of wear-resistant cement suitable for roads and bridges, which relates to the technical field of building materials, and comprises the following components in percentage by mass: 75-85% of silicate cement clinker, 0.02-0.05% of enhanced grinding aid, 5-15% of slag micropowder, 3-8% of steel slag powder, 3-6% of dihydrate gypsum and 0.3-1.0% of steel fiber. The invention aims to develop the cement suitable for roads and bridges, the research, development and preparation of the cement comprehensively utilizes solid wastes such as steel slag, not only meets the standard of railway concrete and is beneficial to improving the durability of the cement concrete, but also has the characteristics of small shrinkage rate, good wear resistance and the like, and effectively solves the problem of single function of the existing cement product.

Description

Preparation method of wear-resistant cement suitable for roads and bridges

Technical Field

The invention relates to the technical field of building materials, in particular to a preparation method of wear-resistant cement suitable for roads and bridges.

Background

Since the 21 st century, with the increase of the investment and the attention degree of the basic construction of China, the traffic construction develops rapidly, and the total mileage of roads and railways in China is increased continuously. The total mileage of the national highway in 2019 breaks through 500 kilometers, wherein the mileage of the rural highway reaches 420.05 kilometers, the construction of the highway is in a stable growth situation, and the total mileage in 2020 breaks through 15 kilometers. By the end of 2020, the national railway has a mileage of 14.63 kilometers, and a high-speed rail has a mileage of 3.79 kilometers. In the period of 2021-2025, countries will continue to perfect the road network construction, perfect the road network layout and implement and construct a batch of major engineering projects.

The cement concrete can not be used for road and railway construction, and the unique physical properties and the low maintenance cost of the cement concrete make the cement concrete irreplaceable in road and bridge construction. Compared with asphalt roads, cement concrete has the characteristics of high strength, difficult deformation, low maintenance cost, small air pollution and the like, so that lower-grade roads including rural roads are mainly made of cement concrete roads. However, cement concrete roads have some problems at present, most of which is poor wear resistance, the phenomena of sand generation and sand exposure caused by surface wear appear after a lot of concrete roads are driven for one or two years, the durability of the concrete is deteriorated due to surface damage, the anti-skid performance of the road surface is reduced, the driving safety is affected, and the service life and the range of the concrete road surface are severely limited.

The wear resistance of cement concrete pavement is an important index influencing the durability and safety of the pavement. At present, most of domestic and foreign research results on the wear resistance of cement concrete pavements focus on optimizing the mix proportion, adding mineral admixtures, improving the construction process and the like from the concrete perspective, the problem of poor wear resistance of the traditional cement concrete pavements is still not fundamentally solved, and the important point is that the cement performance does not meet the requirements. The surface of a cement concrete pavement is a cement mortar layer with a certain thickness, and the cement mortar layer is used as an important raw material of concrete, so that the wear resistance and the applicability of the cement often have decisive effects on the wear resistance of the concrete pavement and cannot be ignored.

Meanwhile, a large amount of steel slag produced by large-scale steel plants is difficult to be effectively treated, along with the strict control of water-soluble chromium content by cement, the steel slag cannot be used as an iron raw material for raw material proportioning because of high total chromium content (after the raw material is calcined at high temperature, trivalent chromium is oxidized into hexavalent chromium), a large amount of waste steel slag is piled up to cause waste of land resources and cause environmental pollution, and the steel slag needs to be effectively utilized.

The invention aims to develop the cement suitable for roads and bridges, the research, development and preparation of the cement comprehensively utilizes solid wastes such as steel slag, not only meets the standard of railway concrete and is beneficial to improving the durability of the cement concrete, but also has the characteristics of small shrinkage rate, good wear resistance and the like, and effectively solves the problem of single function of the existing cement product.

Disclosure of Invention

In order to overcome the defects of related products in the prior art, the invention provides a preparation method of wear-resistant cement suitable for roads and bridges.

The invention provides a preparation method of wear-resistant cement suitable for roads and bridges, which comprises the following components in percentage by mass: 75-85% of silicate cement clinker, 0.02-0.05% of enhanced grinding aid, 5-15% of slag micropowder, 3-8% of steel slag powder, 3-6% of dihydrate gypsum and 0.3-1.0% of steel fiber.

In certain embodiments of the invention, the portland cement clinker comprises the following components in percentage by mass: 78.0-88.0% of calcium raw material, 5.0-13.0% of silicon-aluminum raw material, 5.0-10.0% of iron raw material and 0.3% of raw material auxiliary agent; respectively grinding and drying the calcareous raw material, the alumino-silico raw material and the irony raw material to obtain raw material fine powder with the average particle size of 25-30 mu m and the sieve residue of 80 mu m of 10-16%, uniformly mixing the raw material fine powder, adding appropriate amount of water, stirring to prepare raw material balls with the diameter of 6-12 mm, drying the raw material balls, firing at the high temperature of 1350-;

the portland cement clinker comprises: alkali equivalent is less than or equal to 0.6%, free calcium oxide is less than or equal to 0.8%, C3A content is less than or equal to 7.0%, C4AF content is more than or equal to 12.0%, MgO content is less than or equal to 3.5%, 3-day compressive strength is more than or equal to 30.0MPa, and 28-day compressive strength is more than or equal to 58.0 MPa.

In some embodiments of the present invention, the first and second electrodes are,the calcareous raw material comprises limestone and mineral separation powder or high-calcium waste residue with the balance of 0-20%, wherein the CaO content in the mineral separation powder or the high-calcium waste residue is more than or equal to 45%, the CaO content in the calcareous raw material is more than or equal to 48%, the MgO content is less than or equal to 2.0%, and R₂The content of 0 is less than or equal to 0.2 percent.

In certain embodiments of the invention, the alumino-silica feedstock is at least one of shale, sandstone, and the alumino-silica feedstock has R therein₂The content of 0 is less than or equal to 1.5 percent.

In certain embodiments of the present invention, the ferrous raw material is at least two of steel slag, iron tailings, and copper slag, and R in the ferrous raw material is₂0 content is less than or equal to 0.3 percent.

In some embodiments of the present invention, the raw meal assistant is a high molecular raw meal catalyst, including an organic acid salt.

In certain embodiments of the invention, the enhanced grinding aid is a liquid grinding aid that is an alkanolamine.

In certain embodiments of the invention, the specific surface area of the slag micro powder is 380-420m2/kg, and the activity reaches above S95 level.

In certain embodiments of the invention, the specific surface area of the steel slag powder is 400-600m 2/kg.

In certain embodiments of the invention, the dihydrate gypsum is at least one of desulfurized gypsum, modified phosphogypsum.

Compared with the prior art, the invention has the following advantages:

1. the invention provides a wear-resistant cement suitable for roads and bridges, which properly improves the iron phase content in clinker components and reduces the contents of tricalcium silicate and tricalcium aluminate by screening raw materials and optimizing a batching scheme, so that the wear resistance of the clinker is greatly improved, and simultaneously, the addition of a raw material auxiliary agent is beneficial to improving the easy burning property, reducing the decomposition temperature of carbonate in raw materials, improving the strength of the clinker and reducing the free calcium oxide of the clinker.

2. According to the invention, a proper amount of steel fiber is added into cement, which is beneficial to improving the wear resistance of the cement, and the steel slag powder with a certain proportion is added, so that the precious performances of low hydration heat, high impermeability, high wear resistance and high carbonization resistance which are not possessed by the conventional cement are brought by utilizing the low activity and high magnesium oxide content of the active components in the steel slag.

3. The wear-resistant cement provided by the invention has the advantages of low alkali content, small dry shrinkage, good wear resistance, moderate early strength and high later strength, can also meet various index requirements of cement designed for durability in railway concrete standards, has low water demand and good adaptability with concrete admixtures, can be widely used for high-performance concrete, is suitable for projects such as roads, bridges, airports and the like, and can also be used for heavy-spot projects such as railways, high-rise buildings and the like.

Detailed Description

In order to make the technical solutions of the present invention better understood by those skilled in the art, the technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. This invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, but rather should be construed as broadly as the present disclosure is set forth in order to provide a more thorough understanding thereof. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.

Example 1

The invention provides a preparation method of wear-resistant cement suitable for roads and bridges, which comprises the following steps:

selecting 84.0 percent of calcium raw material, 10.5 percent of aluminum-silicon raw material and 6.5 percent of iron raw material according to the mass percentage, and 0.3 percent of raw material additive; respectively grinding and drying the calcareous raw material, the alumino-silico raw material and the irony raw material to obtain raw material fine powder with the average grain diameter of 28 microns and the screen residue of 80 microns of 14 percent, uniformly mixing the raw material fine powder, adding appropriate amount of water, stirring to prepare raw material balls with the diameter of 12mm, drying the raw material balls, firing at 1450 ℃, keeping the temperature for 1.5 hours at the firing temperature, and immediately quenching to normal temperature by using strong cold air after the high-temperature calcination is finished to obtain the required portland cement clinker. The portland cement clinker comprises: alkali equivalent is less than or equal to 0.6%, free calcium oxide is less than or equal to 0.8%, C3A content is less than or equal to 7.0%, C4AF content is more than or equal to 12.0%, MgO content is less than or equal to 3.5%, 3-day compressive strength is more than or equal to 30.0MPa, and 28-day compressive strength is more than or equal to 58.0 MPa.

80% of the cement clinker, 10% of slag micropowder, 4% of dihydrate gypsum and 6% of steel slag powder are selected, and 0.03% of grinding aid and 0.5% of steel fiber are added in the preparation process. The wear-resistant cement suitable for roads and bridges is prepared according to the mass percentage. The slag micro powder and the steel slag powder are independently pre-ground, the cement clinker and the industrial gypsum are mixed by adding a grinding aid, the mixture is ground to a specified fineness by a ball mill, and the mixture is uniformly mixed to obtain the wear-resistant cement suitable for roads and bridges, wherein the specific surface area of the cement is 320m2/kg, the sulfur trioxide is 2.10%, and the loss on ignition is 1.15%.

Wherein, the dihydrate gypsum is desulfurized gypsum: the content of SO3 is more than or equal to 40 percent, the content of crystal water is more than or equal to 18 percent, the content of insoluble substances is less than or equal to 7 percent, and the content of calcium sulfate dihydrate is more than or equal to 87 percent. The enhanced grinding aid is an alcamine liquid grinding aid, and the increasing ratio of 3d strength to 28 d strength reaches more than 10%.

Example 2

Selecting 78.0 percent, 13 percent and 9 percent of calcium raw material, aluminum-silicon raw material and iron raw material according to the mass percentage, and mixing the raw material additive by 0.3 percent; respectively grinding and drying the calcareous raw material, the alumino-silico raw material and the irony raw material to obtain raw material fine powder with the average particle size of 15 mu m and the sieved residue of 80 mu m of 16 percent, uniformly mixing the raw material fine powder, adding appropriate amount of water, stirring to prepare raw material balls with the diameter of 10mm, drying the raw material balls, firing at the high temperature of 1450 ℃, keeping the temperature for 1 hour at the firing temperature, and immediately quenching to the normal temperature by using strong cold air after the high-temperature calcination is finished to obtain the required portland cement clinker. The portland cement clinker comprises: alkali equivalent is less than or equal to 0.6%, free calcium oxide is less than or equal to 0.8%, C3A content is less than or equal to 7.0%, C4AF content is more than or equal to 12.0%, MgO content is less than or equal to 3.5%, 3-day compressive strength is more than or equal to 30.0MPa, and 28-day compressive strength is more than or equal to 58.0 MPa.

The cement clinker is 85 percent, the slag micropowder is 8 percent, the dihydrate gypsum is 3 percent, the steel slag powder is 4 percent, and the grinding aid is 0.03 percent and the steel fiber is 0.5 percent in the preparation process. The wear-resistant cement suitable for roads and bridges is prepared according to the mass percentage. The slag micro powder and the steel slag powder are independently pre-ground, the cement clinker and the industrial gypsum are mixed by adding a grinding aid, the mixture is ground to a specified fineness by a ball mill, and the mixture is uniformly mixed to obtain the wear-resistant cement suitable for roads and bridges, wherein the specific surface area of the cement is 320m2/kg, the sulfur trioxide is 2.10%, and the loss on ignition is 1.15%.

Example 3

Selecting a calcareous raw material, an aluminum-silicon raw material and an iron raw material which are respectively 79%, 13% and 8% in percentage by mass, wherein the mixing amount of the raw material auxiliary agent is 0.3%; respectively grinding and drying the calcareous raw material, the alumino-silico raw material and the irony raw material to obtain raw material fine powder with the average grain size of 25 mu m and the screen residue of 80 mu m of 14 percent, uniformly mixing the raw material fine powder, adding appropriate amount of water, stirring to prepare raw material balls with the diameter of 10mm, drying the raw material balls, firing at the high temperature of 1450 ℃, keeping the temperature of the raw material balls at the firing temperature for 0.5 hour, and immediately quenching to the normal temperature by using strong cold air after the high-temperature calcination is finished to obtain the required portland cement clinker. The portland cement clinker comprises: alkali equivalent is less than or equal to 0.6%, free calcium oxide is less than or equal to 0.8%, C3A content is less than or equal to 7.0%, C4AF content is more than or equal to 12.0%, MgO content is less than or equal to 3.5%, 3-day compressive strength is more than or equal to 30.0MPa, and 28-day compressive strength is more than or equal to 58.0 MPa.

75 percent of the cement clinker, 11 percent of slag micropowder, 6 percent of dihydrate gypsum and 8 percent of steel slag powder are selected, and 0.03 percent of grinding aid and 0.5 percent of steel fiber are added in the preparation process. The wear-resistant cement suitable for roads and bridges is prepared according to the mass percentage. The slag micro powder and the steel slag powder are independently pre-ground, the cement clinker and the industrial gypsum are mixed by adding a grinding aid, the mixture is ground to a specified fineness by a ball mill, and the mixture is uniformly mixed to obtain the wear-resistant cement suitable for roads and bridges, wherein the specific surface area of the cement is 320m2/kg, the sulfur trioxide is 2.10%, and the loss on ignition is 1.15%.

Testing the performance of the cement: measuring the setting time of the cement according to the GB/T1346-2011 standard; the 3-day and 28-day strengths were tested according to GB/T17671-1999 standard.

The main properties of the wear resistant cement of the present invention are shown in the following table:

measurement items	The result of the detection
		Initial setting time of cement min	198
Cement final setting time min	254
		Water requirement for standard consistency (%)	24.8
Specific surface area m2/kg	320
		Alkali equivalent (%)	0.48
Compressive strength MPa in 3 days	28.5
		28 days compressive strength MPa	58.2
C3A in Clinker (%)	5.12
		C4AF in Clinker (%)	12.95
Free calcium oxide in clinker (%)	0.65
		Shrinkage on drying in 28 days (%)	0.06
Abrasion resistance (kg/m2)	1.8

Those not described in detail in this specification are within the skill of the art. Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described in the foregoing detailed description, or equivalent changes may be made in some of the features of the embodiments. All equivalents that can be substituted by the contents of the specification of the present invention and applied directly or indirectly to other related technical fields are within the scope of the present invention.

Claims

1. The preparation method of the wear-resistant cement suitable for roads and bridges is characterized by comprising the following components in percentage by mass: 75-85% of silicate cement clinker, 0.02-0.05% of enhanced grinding aid, 5-15% of slag micropowder, 3-8% of steel slag powder, 3-6% of dihydrate gypsum and 0.3-1.0% of steel fiber.

2. The method for preparing the wear-resistant cement suitable for roads and bridges as claimed in claim 1, wherein the portland cement clinker comprises the following components in percentage by mass: 78.0-88.0% of calcium raw material, 5.0-13.0% of silicon-aluminum raw material, 5.0-10.0% of iron raw material and 0.3% of raw material auxiliary agent; respectively grinding and drying the calcareous raw material, the alumino-silico raw material and the irony raw material to obtain raw material fine powder with the average particle size of 25-30 mu m and the sieve residue of 80 mu m of 10-16%, uniformly mixing the raw material fine powder, adding appropriate amount of water, stirring to prepare raw material balls with the diameter of 6-12 mm, drying the raw material balls, firing at the high temperature of 1350-;

3. The preparation method of the wear-resistant cement suitable for roads and bridges as claimed in claim 2, wherein the preparation method comprises the following steps: the calcareous raw material comprises limestone and mineral separation powder or high-calcium waste residue with the balance of 0-20%, wherein the CaO content in the mineral separation powder or the high-calcium waste residue is more than or equal to 45%, the CaO content in the calcareous raw material is more than or equal to 48%, the MgO content is less than or equal to 2.0%, and R₂The content of 0 is less than or equal to 0.2 percent.

4. The preparation method of the wear-resistant cement suitable for roads and bridges as claimed in claim 2, wherein the preparation method comprises the following steps: the silicoaluminophosphate raw material is at least one of shale and sandstone, and R in the silicoaluminophosphate raw material₂The content of 0 is less than or equal to 1.5 percent.

5. The preparation method of the wear-resistant cement suitable for roads and bridges as claimed in claim 2, wherein the preparation method comprises the following steps: the iron raw material is at least two of steel slag, iron tailings and copper slag, and R in the iron raw material₂0 content is less than or equal to 0.3 percent.

6. The preparation method of the wear-resistant cement suitable for roads and bridges according to claim 1, wherein the preparation method comprises the following steps: the raw material assistant is a macromolecular raw material catalyst and comprises organic acid salt.

7. The preparation method of the wear-resistant cement suitable for roads and bridges according to claim 1, wherein the preparation method comprises the following steps: the enhanced grinding aid is an alcamine liquid grinding aid.

8. The preparation method of the wear-resistant cement suitable for roads and bridges according to claim 1, wherein the preparation method comprises the following steps: the specific surface area of the slag micro powder is 380-420m2/kg, and the activity reaches more than S95 level.

9. The preparation method of the wear-resistant cement suitable for roads and bridges according to claim 1, wherein the preparation method comprises the following steps: the specific surface area of the steel slag powder is 400-600m 2/kg.

10. The preparation method of the wear-resistant cement suitable for roads and bridges according to claim 1, wherein the preparation method comprises the following steps: the dihydrate gypsum is at least one of desulfurized gypsum and modified phosphogypsum.