阅读说明：本技术 一种钢渣透水混凝土及其制备工艺 (Steel slag pervious concrete and preparation process thereof ) 是由 颜凡 金强 杨刚 王文君 郜钢 刘国威 于 2020-12-01 设计创作，主要内容包括：本发明涉及新型建筑材料技术领域,特别是涉及一种钢渣透水混凝土及其制备工艺,本发明第一方面提供一种用于钢渣透水混凝土的胶凝材料,所述胶凝材料至少包括以下重量份的组分：硅酸盐水泥：1-1.5,矿粉：1-1.5,硬石膏磨细粉：0.04-0.06。本发明第二方面提供一种钢渣透水混凝土,所述钢渣透水混凝土由第一方面所述胶凝材料、基底料、水和聚羧酸减水剂,混合搅拌获得,所述胶凝材料、所述基底料、所述水和所述聚羧酸减水剂的重量比为3-4.6：20：0.9-1.84：0.045-0.0675,所述基底料包括以下重量份的组分：再生骨料：5-7,钢渣：27-28,钢渣集料：4-5,细砂：3-5。本发明制备的钢渣透水混凝土抗压强度高,成本低。(The invention relates to the technical field of novel building materials, in particular to steel slag pervious concrete and a preparation process thereof, and the invention provides a cementing material for the steel slag pervious concrete in a first aspect, wherein the cementing material at least comprises the following components in parts by weight: portland cement: 1-1.5, mineral powder: 1-1.5, grinding anhydrite into fine powder: 0.04-0.06. The second aspect of the invention provides steel slag pervious concrete, which is prepared by mixing and stirring the cementing material, the base material, water and the polycarboxylate superplasticizer according to the first aspect, wherein the weight ratio of the cementing material to the base material to the water to the polycarboxylate superplasticizer is 3-4.6: 20: 0.9-1.84: 0.045-0.0675, wherein the base material comprises the following components in parts by weight: recycled aggregate: 5-7, steel slag: 27-28, steel slag aggregate: 4-5, fine sand: 3-5. The steel slag permeable concrete prepared by the invention has high compressive strength and low cost.)

1. The cementing material for the steel slag pervious concrete is characterized by at least comprising the following components in parts by weight:

portland cement: 1-1.5;

mineral powder: 1-1.5;

grinding anhydrite into fine powder: 0.04-0.06.

2. The cementing material for the steel slag pervious concrete as claimed in claim 1, wherein: the density of the mineral powder is not less than 2.8g/cm³Specific surface area of not less than 350m²The activity index of the catalyst per kg and 28d is not less than 95 percent.

3. The cementing material for the steel slag pervious concrete as claimed in claim 1, wherein: the anhydrite grind powder includes anhydrous calcium sulfate.

4. The steel slag permeable concrete is characterized in that: the steel slag pervious concrete is prepared by mixing and stirring the cementing material, the base material, water and a polycarboxylate superplasticizer according to any one of claims 1 to 3, wherein the weight ratio of the cementing material to the base material to the water to the polycarboxylate superplasticizer is 3-4.6: 20: 0.9-1.84: 0.045-0.0675, wherein the base material at least comprises the following components in parts by weight:

recycled aggregate: 5-7;

steel slag: 27-28;

steel slag aggregate: 4-5;

fine sand: 3-5.

5. The steel slag pervious concrete of claim 4, which is characterized in that: the content of free calcium in the steel slag is less than 5 percent, and the particle size range is 5-15 mm.

6. The steel slag pervious concrete of claim 4, which is characterized in that: the grain size range of the steel slag aggregate is 0.8-3 mm.

7. The steel slag pervious concrete of claim 4, which is characterized in that: the particle size range of the recycled aggregate is 5-10 mm.

8. The steel slag pervious concrete of claim 4, which is characterized in that: the particle size range of the fine sand is 0.5-1 mm.

9. The method for preparing the steel slag pervious concrete of any one of claims 4 to 8, which is characterized by comprising the following steps of:

1) uniformly dividing the cementing material into two parts according to the proportion, and mixing one part of the cementing material with the substrate material to obtain primary steel slag concrete;

2) and (3) mixing and stirring the other part of the cementing material, the primary steel slag concrete, the water reducer and water in the step 1) to obtain the steel slag permeable concrete.

10. The method of claim 9, wherein: in step 1), the steel slag in the substrate material is pre-wetted in advance.

Technical Field

The invention relates to the technical field of novel building materials, in particular to steel slag pervious concrete and a preparation process thereof.

Background

At present, comprehensive utilization of solid wastes is emphasized at home and abroad. The metallurgical slag and the construction waste are used as a large amount of solid waste, and the resource utilization of the metallurgical slag and the construction waste is paid attention by people all the time. The proportion of blast furnace slag in the iron and steel waste residue is the highest, 0.4-1.0 ton of blast furnace slag can be generated every 1 ton of pig iron, 3.0-8.0 hundred million tons of blast furnace slag are estimated to be generated every year, and the research of replacing part of cement with the blast furnace slag as concrete admixture has great potential value. In addition, with the continuous promotion of urbanization, a large amount of construction wastes are generated, the annual output of the construction wastes in China is about 35 hundred million tons, but the comprehensive utilization rate is less than 5 percent, the construction wastes are usually treated in a centralized stacking or landfill mode, precious land resources are occupied, and the surrounding environment is polluted. The harmless, quantitative reduction and resource comprehensive utilization of a large amount of solid wastes such as metallurgical slag, building garbage and the like are promoted.

The invention takes the large-doping-amount mineral powder admixture as a technical route, and replaces single cement with proper amount of high-grade cement and a small amount of alkali activator as a steel slag-based permeable concrete cementing material to prepare the dry and hard steel slag permeable concrete, thereby prolonging the initial setting time, improving the constructability, preparing products meeting the requirements, reducing the production cost of the products, improving the market competitiveness of the products, selling and utilizing more steel slag resources and construction waste renewable resources, turning waste into wealth, and conforming to the national circular economy utilization policy.

Disclosure of Invention

In view of the above-mentioned disadvantages of the prior art, the present invention is to provide a steel slag pervious concrete and a preparation process thereof, which are used for solving the problems in the prior art.

In order to achieve the above and other related objects, a first aspect of the present invention provides a cementitious material for water-permeable concrete made of steel slag, the cementitious material at least comprising the following components in parts by weight:

portland cement: 1-1.5;

mineral powder: 1-1.5;

grinding anhydrite into fine powder: 0.04-0.06.

The second aspect of the invention provides steel slag pervious concrete, which is prepared by mixing and stirring the cementing material, the base material, water and the polycarboxylate superplasticizer according to the first aspect, wherein the weight ratio of the cementing material to the base material to the water to the polycarboxylate superplasticizer is 3-4.6: 20: 0.9-1.84: 0.045-0.0675.

The base material comprises the following components in parts by weight:

recycled aggregate: 5-7;

steel slag: 27-28;

steel slag aggregate: 4-5;

fine sand: 3-5.

In a third aspect of the present invention, there is provided a method for preparing the steel slag pervious concrete of the second aspect, the method comprising the steps of:

1) uniformly dividing the cementing material into two parts according to the proportion, and mixing one part of the cementing material with the substrate material to obtain primary steel slag concrete;

2) and (3) mixing and stirring the other part of the cementing material, the primary steel slag concrete, the water reducer and water in the step 1) to obtain the steel slag permeable concrete.

As described above, the present invention has the following advantageous effects:

(1) the mineral powder mainly contains glass phase and crystal phase, the glass phase is composed of silicon-poor phase and silicon-rich phase, and in the alkaline environment promoted by additive and steel slag, the slag powder is dissociated to form SiO4]^4-Ionic energy and Ca²⁺Ion formationThe mineral powder can replace part of cement clinker to be used as a cementing material in concrete, and has the volcanic ash effect, so that the hydration heat of the concrete can be obviously reduced, and the compressive strength of the concrete can be increased.

(2) The steel slag concrete is doped with a proper amount of recycled aggregate and a small amount of fine sand, so that the mutual rolling resistance between the steel slag aggregates with multi-edge angles and roughness on the surface in the stirring process is relieved by the recycled aggregate with smaller apparent density and the fine sand particles with nearly spherical shape, and the working performance of the concrete is effectively improved.

(3) The mineral powder is used for replacing part of cement clinker to be used as a cementing material, the cost can be saved by 15-25 yuan/square meter, the steel slag aggregate and the building reclaimed material are used as the aggregate to prepare the concrete, the solid waste can be absorbed, the aggregate cost of the product is reduced, the mining of natural sandstone is reduced, and the environment is protected, so that the obvious environmental protection and economic benefits are expected.

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.

The invention provides a cementing material for steel slag pervious concrete, which at least comprises the following components in parts by weight:

portland cement: 1-1.5;

mineral powder: 1-1.5;

grinding anhydrite into fine powder: 0.04-0.06.

The mineral powder is doped in the invention, can replace part of cement clinker to be used as a cementing material for concrete, and in addition, the mineral powder has the action of volcanic ash, can obviously reduce the hydration heat of the concrete and increase the compressive strength of the concrete, and can save the cost by 15-25 yuan/square meter by replacing part of the cement clinker to be used as the cementing material.

In one embodiment, the portland cement is model number ppi 52.5.

The portland cement is commercially available portland cement, and specifically can be purchased from taicang conch cement limited.

In one embodiment, the ore fines have a density of not less than 2.8g/cm³Specific surface area of not less than 350m²The activity index of the catalyst per kg and 28d is not less than 95 percent.

Preferably, the grade of the mineral powder is S95, the grades of the mineral powder commonly available on the market are three grades of S75, S95 and S105, and the strength of the mineral powder with the grade of S95 is close to that of cement in 28d and has cost advantage compared with the mineral powder with the grade of S105.

In this example, the ore powder is a conventional ore powder available on the market, and is specifically available from baotian new building materials co.

In one embodiment, the anhydrite fines include anhydrous calcium sulfate.

In this example, the anhydrite grind powder is commercially available conventional anhydrite grind powder, and is specifically available from Nanjing Teheng building materials science and technology Co.

The second aspect of the invention provides steel slag pervious concrete, which is prepared by mixing and stirring the cementing material, the base material, water and the polycarboxylate superplasticizer according to the first aspect, wherein the weight ratio of the cementing material to the base material to the water to the polycarboxylate superplasticizer is 3-4.6: 20: 0.9-1.84: 0.045-0.0675.

The base material at least comprises the following components in parts by weight:

recycled aggregate: 5-7;

steel slag: 27-28;

steel slag aggregate: 4-5;

fine sand: 3-5.

In the present invention, in the alkaline environment promoted by the anhydrite fine powder and the steel slag, the mineral powder in the cementing material is dissociated to form [ SiO4 ]]^4-Ionic energy and Ca²⁺The ions form calcium silicate hydrate gel, the hydration heat of the concrete can be obviously reduced, the compressive strength of the concrete is increased, and the mixed recycled aggregate and fine sand can effectively improve the working performance of the concrete.

In this embodiment, the polycarboxylate water reducer is a conventional polycarboxylate water reducer available on the market, and is specifically available from easter, Suzhou.

Preferably, the recycled aggregate is 6 parts by weight, the steel slag is 27 parts by weight, the steel slag aggregate is 4 parts by weight, and the fine sand is 3 parts by weight.

In one embodiment, the steel slag contains less than 5% of free calcium, and the particle size ranges from 5mm to 15 mm.

Preferably, the content of free calcium in the steel slag is less than 3 percent, so that the influence on the volume stability of the steel slag concrete can be avoided.

In this embodiment, the steel slag is commercially available conventional steel slag, and is specifically available from shanghai metallurgical environmental engineering technology ltd.

In one embodiment, the steel slag aggregate has a particle size in the range of 0.8-3 mm. The steel slag aggregate with the grain size range of 0.8-3mm can fill the pores of the steel slag and the recycled aggregate, and improve the strength of the concrete.

In this embodiment, the steel slag aggregate is a commercially available steel slag aggregate, which can be purchased from shanghai metallurgical environmental engineering technologies, ltd.

In one embodiment, the recycled aggregate has a particle size in the range of 5-10 mm. The particle size of the recycled aggregate is similar to that of the steel slag, and the recycled aggregate has a good synergistic effect on a concrete framework.

In this embodiment, the recycled aggregate is a commercially available recycled aggregate, and the recycled aggregate can be obtained by treating construction waste, and specifically can be purchased from zheng koffda limited.

In one embodiment, the fine sand has a particle size in the range of 0.5 to 1 mm.

In the present embodiment, the fine sand is commercially available conventional fine sand, and is specifically available from Shanghai Yusha industries, Ltd.

In a third aspect of the present invention, there is provided a method for preparing the steel slag pervious concrete of the second aspect, the method comprising the steps of:

1) uniformly dividing the cementing material into two parts according to the proportion, and mixing one part of the cementing material with the substrate material to obtain primary steel slag concrete;

2) and (3) mixing and stirring the other part of the cementing material, the primary steel slag concrete, the water reducer and water in the step 1) to obtain the steel slag permeable concrete.

In the step 1), the cement, the mineral powder and the anhydrite ground powder are respectively weighed according to a preset proportion and are put into a closed container to be uniformly mixed to obtain a gel material, the steel slag aggregate, the regenerated aggregate, the fine sand and the gel material are respectively weighed according to the preset proportion according to the mass of the required steel slag concrete, the gel material is uniformly divided into two parts, and one part of the gel material is mixed with the substrate material to obtain the primary steel slag concrete.

In the step 2), the other part of the cementing material is mixed with the primary steel slag concrete in the step 1), and the water reducer and the water are mixed according to the mass of the required steel slag concrete and the mixture ratio to obtain the steel slag concrete.

In the invention, the loose cementing material is added for the first time, the steel slag aggregate is wrapped by a layer of cementing material to form a thick cement paste shell, and the mortar formed by adding the loose cementing material particles and water for the second time is filled in the bonding position of the steel slag and the recycled aggregate, so that the bleeding and the segregation of the concrete can be prevented, the bonding force between the mortar and the aggregate is improved, and the strength of the concrete is improved. The water reducing agent is added in the step 2) and can be fully and uniformly mixed with water to obtain a good effect.

In one embodiment, in step 1), the steel slag in the base material is pre-wetted in advance.

Preferably, the steel slag is pre-wetted 1 hour in advance.

The steel slag has more micro pores inside, the pre-wetted steel slag is prevented from absorbing mixing water, the water adding amount is not easy to control, and the pre-wetted steel slag aggregate surface is beneficial to wrapping a cementing material.

Example 1

The process flow for preparing concrete comprises the following steps:

(1) metering and homogenizing: weighing cement, mineral powder and anhydrite ground powder according to a given proportion, and placing the ground powder into a closed container for pre-mixing for 25-40 seconds until the ground powder is in a uniform state;

(2) stirring: the steel slag is prewetted 1 hour in advance, the steel slag aggregate, the regenerated aggregate, the fine sand and a half of the cementing material are weighed, mixed and stirred for 15-30 seconds by a small horizontal stirrer, then the other half of the cementing material and the water reducing agent are added, water is added at a constant speed, and the stirring mode is adopted, so that the materials are uniformly stirred, and the aggregate agglomeration is prevented.

(3) Molding: and (3) feeding the stirred material into a 100 x 100 concrete test mould, inserting and smashing the material for 6 to 10 seconds by using an iron rod, placing the material on a vibration table, vibrating the material for 4 to 8 seconds, and vibrating the material for 3 to 5 seconds by using a flat plate vibrator.

(4) And (5) maintenance: and (5) putting the concrete test block into a curing kiln along with the mould for curing. The temperature is controlled to be higher than 20 ℃, and the humidity is higher than 75%.

Example 2

PII 52.5 grade portland cement: 6 wt%; mineral powder: 9 wt% of a base; grinding anhydrite into fine powder: 4% of the total amount of the cementing material; polycarboxylic acid water reducing agent: 1.5% of the total amount of the gel material; fine sand: 6 wt%; 5-10mm recycled aggregate: 12 wt%; 0.8-3mm steel slag: 8 wt%; 5-15mm steel slag: 54 wt%; a proper amount of water.

Weighing and premixing the gelled material according to the process flow, adding coarse and fine aggregates, adding a water reducing agent and a proper amount of water, uniformly stirring, sending the stirred material into a 100 x 100 concrete test mould, inserting and smashing for 6-10 seconds by using an iron bar, vibrating on a vibrating table for 4-8 seconds, and vibrating by using a flat plate vibrator for 3-5 seconds for forming. And feeding the concrete test block into a curing kiln along with the mould for curing.

Example 3

PII 52.5 grade portland cement: 7 wt%; mineral powder: 8 wt%; grinding anhydrite into fine powder: 4% of the total amount of the cementing material; polycarboxylic acid water reducing agent: 1.5% of the total amount of the gel material; fine sand: 6 wt%; 5-10mm recycled aggregate: 12 wt%; 0.8-3mm steel slag: 8 wt%; 5-15mm steel slag: 54 wt%; a proper amount of water.

The stirring, molding and curing processes were the same as in example 1.

Example 4:

PII 52.5 grade portland cement: 8 wt%; mineral powder: 7 wt%; grinding anhydrite into fine powder: 4% of the total amount of the cementing material; polycarboxylic acid water reducing agent: 1.5% of the total amount of the gel material; fine sand: 6 wt%; 5-10mm recycled aggregate: 12 wt%; 0.8-3mm steel slag: 8 wt%; 5-15mm steel slag: 54 wt%; a proper amount of water.

The stirring, molding and curing processes were the same as in example 1.

Example 5:

PII 52.5 grade portland cement: 9 wt%; 6 wt% of mineral powder; polycarboxylic acid water reducing agent: 1.5% of the total amount of the gel material; fine sand: 6 wt%; 5-10mm recycled aggregate: 12 wt%; 0.8-3mm steel slag: 8 wt%; 5-15mm steel slag: 54 wt%; a proper amount of water.

The stirring, molding and curing processes were the same as in example 1.

Comparative example 1:

PII 52.5 grade portland cement: 16 wt%; polycarboxylic acid water reducing agent: 1.5% of the total amount of the gel material; fine sand: 6 wt%; 5-10mm recycled aggregate: 12 wt%; 0.8-3mm steel slag: 8 wt%; 5-15mm steel slag: 54 wt%; a proper amount of water.

The stirring, molding and curing processes were the same as in example 1.

Comparative example 2:

mineral powder: 16 wt%; polycarboxylic acid water reducing agent: 1.5% of the total amount of the gel material; fine sand: 6 wt%; 5-10mm recycled aggregate: 12 wt%; 0.8-3mm steel slag: 8 wt%; 5-15mm steel slag: 54 wt%; a proper amount of water.

The stirring, molding and curing processes were the same as in example 1.

And (3) detecting the compressive strength and the water permeability coefficient of the test group samples 7d and 28d by referring to a GB/T50081 common concrete mechanical property test method and GB/T25993 water permeable pavement bricks and water permeable pavement slabs.

The detection result is as follows:

in conclusion, the present invention effectively overcomes various disadvantages of the prior art and has high industrial utilization value.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.