阅读说明：本技术 一种耐久性的钢渣混凝土及其制备工艺 (Durable steel slag concrete and preparation process thereof ) 是由 高增民 于 2020-12-31 设计创作，主要内容包括：本申请涉及混凝土路面施工领域,具体公开了一种耐久性的钢渣混凝土及其制备工艺,钢渣混凝土包括以下质量份数的原料通过搅拌混合得到：水泥200-220份,钢渣250-260份,水120-180份,粉煤灰50-60份,尼龙66 18-25份,所述尼龙66的粒径为200-300μm,钢渣混凝土制备方法为,将混凝土原料尼龙66、水泥、水、钢渣等进行搅拌混合最终得到钢渣混凝土,本申请的钢渣混凝土组合物可用于铺设路面,本申请具有提高钢渣混凝土耐久性的优点。(The application relates to the field of concrete pavement construction, and particularly discloses durable steel slag concrete and a preparation process thereof, wherein the steel slag concrete is prepared by stirring and mixing the following raw materials in parts by mass: the concrete comprises, by weight, 220 parts of cement, 260 parts of steel slag, 180 parts of water, 120 parts of flyash and 6618-25 parts of nylon, wherein the particle size of the nylon 66 is 200-300 mu m, and the preparation method of the steel slag concrete comprises the steps of stirring and mixing concrete raw materials of nylon 66, cement, water, steel slag and the like to finally obtain the steel slag concrete.)

1. A durable steel slag concrete is characterized in that: the material is prepared by stirring and mixing the following raw materials in parts by weight:

200 portions of cement and 220 portions of cement,

250 portions of steel slag and 260 portions of steel slag,

120 portions of water and 180 portions of water,

50-60 parts of fly ash,

nylon 6618-25 parts, the particle size of nylon 66 is 200-.

2. A durable steel slag concrete according to claim 1, characterized in that: the nylon 66 is modified nylon 66, and the modified nylon 66 is prepared by the following steps:

s1: uniformly mixing nylon 66 and an amine chain extender at a high speed to obtain a premix;

s2: adding the premix into a double-screw extruder, and carrying out melt reaction and extrusion to obtain the modified nylon 66.

3. A durable steel slag concrete according to claim 2, characterized in that: 3-5 parts of amine chain extender, wherein the amine chain extender is amino-terminated trimethylolpropane tripolypropylene glycol ether.

4. A durable steel slag concrete according to claim 1, characterized in that: the concrete raw material also comprises 10-20 parts of a dispersing agent.

5. A durable steel slag concrete according to claim 4, characterized in that: the dispersant is sodium hexametaphosphate.

6. A durable steel slag concrete according to claim 1, characterized in that: the concrete raw material also comprises 10-16 parts of a toughening agent.

7. A durable steel slag concrete according to claim 6, characterized in that: the toughening agent is chlorinated polyethylene.

8. A process for the preparation of a durable steel slag concrete according to any one of claims 1 to 7, characterized in that: the method comprises the following steps:

a1: the concrete raw material nylon 66, cement, water, steel slag and the like are stirred and mixed to finally obtain the steel slag concrete.

Technical Field

The application relates to the field of concrete pavement construction, in particular to durable steel slag concrete and a preparation process thereof.

Background

The steel slag is the waste slag discharged in the steel-making process, and is a composite solid solution mainly composed of slag-forming materials, smelting reactants, an erosion-falling furnace body, a fettling material, impurities brought by metal furnace burden and slag-forming materials added for adjusting the properties of the steel slag, and the amount of the steel slag laid by China at present reaches 1.8 multiplied by 10⁷Tons, and are now also growing at a rate of millions of tons per year. The steel slag is solid waste produced in the steel-making industry, and is characterized by high yield and low utilization rate, and the main disposal means at present is fieldThe land is piled up, a large amount of land is occupied, steel slag discharge amount is increased day by day along with the vigorous development of the steel industry, and the newly-built and expanded steel slag field seriously damages the air water quality. The utilization rate of the steel slag in China is only about 30%, the steel slag is mainly used as a backfill material, and how to better utilize the residual steel slag is a difficult problem to be solved urgently.

In the prior art, the steel slag is used for replacing aggregate, the preparation of concrete is an effective way for improving the utilization rate of the steel slag, the concrete produced by taking the steel slag as a raw material is mainly used for repairing a road surface, the steel slag can generate a carbonization reaction with carbon dioxide in the air at the later stage of the use of the steel slag concrete, and the defect that the service life of the road surface paved with the steel slag concrete is short due to the poor carbonization resistance of the steel slag concrete exists.

Disclosure of Invention

In order to improve slag concrete and lay road surface life, this application provides a slag concrete of durability.

In order to obtain durable steel slag concrete, the application provides a preparation process of the durable steel slag concrete.

In a first aspect, the present application provides a durable steel slag concrete, which adopts the following technical scheme:

the durable steel slag concrete is prepared by stirring and mixing the following raw materials in parts by weight:

200 portions of cement and 220 portions of cement,

250 portions of steel slag and 260 portions of steel slag,

120 portions of water and 180 portions of water,

50-60 parts of fly ash,

nylon 6618-25 parts, the particle size of nylon 66 is 200-.

By adopting the technical scheme, compared with expansion, the shrinkage of the steel slag concrete is more easily caused by cracking of the concrete in the later use period, and the shrinkage of the concrete is caused by a plurality of reasons such as drying shrinkage, carbonization, shrinkage, plastic shrinkage and the like, and the early shrinkage of the concrete can be reduced by adding the steel slag, mainly because the steel slag contains a certain amount of magnesium oxide and calcium oxide, the substances form magnesium hydroxide and calcium hydroxide to slightly expand in the cement hydration process, has little compensation effect on the early shrinkage of the concrete, the nylon 66 is added, the nylon 66 can absorb water and expand in the later period of the concrete, when the particle diameter of the nylon 66 is 200-300 mu m, more even when can making nylon 66 and concrete mix, nylon 66 can reduce the diffusion rate of carbon dioxide in the concrete for the later stage concrete is difficult to shrink the fracture, thereby improves the durability of concrete.

Preferably, the nylon 66 is modified nylon 66, and the modified nylon 66 is prepared by the following steps:

s1: uniformly mixing nylon 66 and an amine chain extender at a high speed to obtain a premix;

s2: adding the premix into a double-screw extruder, and carrying out melt reaction and extrusion to obtain the modified nylon 66.

By adopting the technical scheme, the nylon 66 reacts with the amine chain extender, and the reason for causing the cracking of the steel slag concrete is that the alkali in the concrete and the carbon dioxide in the environment react to generate calcium carbonate, and the amine chain extender can absorb the carbon dioxide in the air after modifying the nylon 66, so that the possibility of the carbonization of the steel slag concrete is reduced, the carbonization resistance of the steel slag concrete is improved, and the durability of the concrete is improved.

Preferably, the amine chain extender is amino-terminated trimethylolpropane tripolypropylene glycol ether.

By adopting the technical scheme, the amino-terminated trimethylolpropane tripolypropylene glycol ether has an amino functional group, and the amino functional group can react with carbon dioxide to absorb the carbon dioxide, so that the carbon dioxide in the air is absorbed, the possibility of carbonization between the carbon dioxide and the steel slag concrete is reduced, the carbonization resistance of the steel slag concrete is improved, and the durability of the steel slag concrete is improved.

Preferably, the concrete raw material also comprises 10-20 parts of a dispersing agent.

Through adopting above-mentioned technical scheme, nylon 66 carries out the mixing process with the concrete raw materials in, has the inhomogeneous phenomenon of mixing, can make nylon 66 and slag concrete intensive mixing even after adding the dispersant to avoid appearing the condition of local fracture, make nylon 66 mixing degree more even, improve slag concrete's durability.

Preferably, the dispersant is sodium hexametaphosphate.

By adopting the technical scheme, sodium hexametaphosphate is used as a dispersing agent, the dispersing effect is better, and the sodium hexametaphosphate can improve the strength of the steel slag concrete, so that the durability of the steel slag concrete is improved.

Preferably, the concrete raw material also comprises 10-16 parts of a toughening agent.

By adopting the technical scheme, cracks are easy to generate in the concrete shrinkage process, the toughening agent can improve the toughness of the concrete, reduce the possibility of concrete shrinkage cracking and improve the durability of the steel slag concrete.

Preferably, the toughening agent is chlorinated polyethylene.

Through adopting above-mentioned technical scheme, chlorinated polyethylene can improve the toughness of slag concrete, and chlorinated polyethylene can improve the ageing resistance of concrete, has good compatibility with the slag concrete to improve the durability of slag concrete.

In a second aspect, the present application provides a method for preparing durable steel slag concrete, which adopts the following technical scheme: a preparation method of durable steel slag concrete comprises the following steps,

a1: the concrete raw material modified nylon 66, cement, water, a dispersing agent, a toughening agent and the like are stirred and mixed to finally obtain the steel slag concrete.

By adopting the technical scheme, the concrete raw materials are uniformly mixed, and finally the durable steel slag concrete is obtained.

In summary, the present application has the following beneficial effects:

1. because the nylon 66 is adopted, the nylon 66 has water-absorbing expansibility, so that the concrete is not easy to shrink and crack in the later period, and the durability effect of the concrete is improved;

2. the modified nylon 66 is preferably adopted in the application, and because the amino-terminated trimethylolpropane tripolypropylene glycol ether contains an amino functional group, the amino functional group can react with carbon dioxide to absorb the carbon dioxide, so that the carbon dioxide in the air is absorbed, the possibility of carbonization between the carbon dioxide and the steel slag concrete is reduced, and the durability effect of the steel slag concrete is improved;

3. according to the method, the steel slag concrete is finally obtained by stirring and mixing the concrete raw material modified nylon 66, the cement, the water, the dispersing agent, the toughening agent and the like, so that a durable steel slag concrete effect is obtained.

Detailed Description

The raw material sources are as follows:

the cement is a customized commercial product of Jinan Sensen chemical Co., Ltd, the granularity is 325 meshes, the mark is 1344-09-8, and the cement strength grade is 42.5;

the steel slag is a customized commercial product of Hebei Jie Gui mineral products GmbH;

the fly ash is a customized commercial product of a Lingshu county Taiyue mineral product processing factory;

nylon 66 is a custom-made commercially available product from Huatai Nylon, Inc., Yixing, Inc., where Nylon 66 is a commercially available product;

the amino-terminated trimethylolpropane tripolypropylene glycol ether is a customized commercial product of Hubei Shinshun Biotechnology Limited;

the sodium hexametaphosphate is a customized commercial product of Yichangjiamao chemical Co., Ltd;

chlorinated polyethylene is a customized commercial product of Weifang City Huichhang waterproof materials Co.

Example 1

The durable steel slag concrete is prepared by stirring and mixing the following raw materials in parts by weight:

210 parts of cement, namely cement, wherein the cement is selected from the group consisting of,

255 parts of steel slag, namely 255 parts of steel slag,

150 parts of water, namely adding 150 parts of water,

55 parts of fly ash, namely 55 parts of fly ash,

nylon 6622, wherein nylon 66 is modified nylon 66, and the particle size of modified nylon 66 is 250 μm.

The amine chain extender is preferably 4 parts of amino-terminated trimethylolpropane tripolypropylene glycol ether,

the dispersant is preferably 15 parts of sodium hexametaphosphate,

the toughening agent is preferably chlorinated polyethylene 13 parts,

the preparation of the modified nylon 66 comprises the following steps:

s1: uniformly mixing nylon 66 and amino-terminated trimethylolpropane tripolypropylene glycol ether at a high speed for 30min to obtain a premix;

s2: and adding the premix into a double-screw extruder, and performing melt reaction and extrusion at the extrusion temperature of 260 ℃ to obtain the modified nylon 66.

A preparation method of durable steel slag concrete comprises the following steps:

a1: the concrete raw material modified nylon 66, cement, water, a dispersing agent and a toughening agent are put into a small concrete mixer with the rated volume of 60L to be stirred for 30 minutes and are uniformly mixed to obtain the steel slag concrete.

The production of a durable steel slag concrete was carried out according to the above-mentioned preparation process, the raw material amounts were changed to prepare examples 2 to 5, and the remaining operation steps and parameters were the same as those of example 1, thereby obtaining steel slag concretes of examples 1 to 5, wherein the specific amounts of examples 1 to 5 are shown in table 1 below.

Table 1, examples 1-5 specific raw material usage tables.

The steel slag concretes obtained in examples 1 to 5 were tested.

1. And (3) a carbonization resistance test, namely placing the cubic test piece in a carbonization box with the carbon dioxide content of 20 +/-3 percent, the temperature of 20 +/-2 ℃ and the relative humidity of 70 +/-5 percent according to the specification, taking out the test pieces (3 test pieces in each group) when the carbonization time is 3 days, 7 days, 14 days and 28 days, spraying phenolphthalein alcohol (the concentration is 1 percent) on a cut surface in a broken mode, and measuring the depth after 30 seconds. Along the side not coated with paraffin, the slices were cut, ground into powder, poured into a small beaker, added with distilled water (water-to-solid ratio 1:3), stirred, and the pH was measured after stabilization with a pH meter.

2. And (3) testing the durability: according to the method specified in GB/T50081-2019, after steel slag concrete with the size of 150mm x 150mm is subjected to standard culture for 28d, the compressive strength of the steel slag concrete is tested, and then the steel slag concrete is placed outdoors for weathering experiments, and after 6 months, the compressive strength of the steel slag concrete is tested.

The test results are as follows.

Table 2, results of the anti-carbonization performance test of examples 1 to 5.

Table 3, results of durability test of examples 1-5.

As can be seen from Table 2, the pH values of the concretes of examples 1 to 5 all showed a downward trend, and from Table 2, it can be seen that the pH value of the steel slag concrete prepared in example 1 was more moderate, less affected by carbon dioxide, and better in anti-carbonation property.

As is clear from Table 3, the 28d compressive strength and the 6-month compressive strength of the steel slag concrete in example 1 are both higher than those in examples 2 to 5, and the durability of example 1 is better.

Comparative example 1

A durable steel slag concrete is based on the concrete of the embodiment 1, nylon 66 is not added into the concrete raw material, and the rest operation steps and parameters are the same as the embodiment 1.

Comparative example 2

The durable steel slag concrete is based on the concrete in the embodiment 1, nylon 66 is not pretreated and modified, and the rest operation steps and parameters are the same as those in the embodiment 1.

Comparative example 3

A durable steel slag concrete is based on the concrete of the embodiment 1, no dispersing agent is added into the concrete raw materials, and the rest operation steps and parameters are the same as the embodiment 1.

Comparative example 4

Based on the concrete of the embodiment 1, a durable steel slag concrete is prepared, wherein no toughening agent is added into the concrete raw materials, and the rest operation steps and parameters are the same as those of the embodiment 1.

Example 6

A durable steel slag concrete is based on example 1, N-di (2-hydroxypropyl) aniline is selected as an amine chain extender, and the rest operation steps and parameters are the same as those in example 1.

Example 7

Based on the embodiment 1, 3' -dichloro-4, 4-diamino-diphenylmethane is selected as an amine chain extender, and the rest operation steps and parameters are the same as those in the embodiment 1.

Example 8

The durable steel slag concrete is based on the embodiment 1, the dispersant is selected from polyacrylamide, and the rest operation steps and parameters are the same as those of the embodiment 1.

Example 9

The durable steel slag concrete is based on the concrete in example 1, the dispersant is methyl amyl alcohol, and the rest operation steps and parameters are the same as those in example 1.

Example 10

Based on the embodiment 1, the high-strength steel slag concrete has the particle size of 2mm nylon 66, and the rest of the operation steps and parameters are the same as those of the embodiment 1.

Example 11

Based on the embodiment 1, the high-strength steel slag concrete has the advantages that the particle size of nylon 66 is 6mm, and the rest operation steps and parameters are the same as those of the embodiment 1.

Example 12

Based on the embodiment 1, the toughening agent is polyvinyl acetate, and the rest operation steps and parameters are the same as those of the embodiment 1.

Example 13

Based on the embodiment 1, the toughening agent is chlorosulfonated polyethylene, and the rest operation steps and parameters are the same as those of the embodiment 1.

Comparative examples 1-4 and examples 6-13 were tested.

The test results are given in the table below.

Table 4, comparative examples 1 to 4 and examples 6 to 13 results of the anti-carbonization property and durability test.

As can be seen from the test results in table 4, in comparative example 1 and comparative example 1, when nylon 66 was not added to the steel slag concrete, the anti-carbonation performance and durability test of the steel slag concrete were both low, and the PH difference in the anti-carbonation test was large, so that the anti-carbonation performance and durability of the steel slag concrete could be improved by adding nylon 66.

As can be seen from comparison between example 1 and comparative example 2, when nylon 66 in the steel slag concrete is not modified, the carbonization resistance of the prepared steel slag concrete is low, but the reduction trend is slow, and the durability is not greatly influenced, so that the carbonization resistance of the steel slag concrete can be obviously improved by modifying the nylon 66.

As can be seen from comparison between example 1 and comparative example 3, when no dispersant is added to the steel slag concrete, the compressive strength of the prepared steel slag concrete is too different from that of example 1, so that the compressive strength of the steel slag concrete can be effectively improved by adding the dispersant to the steel slag concrete.

As can be seen from the comparison between example 1 and comparative example 4, when no toughening agent is added to the steel slag concrete, the compressive strength of the prepared steel slag concrete is lower, and the strength of the steel slag concrete tested after 6 months is lower, so that the compressive strength of the steel slag concrete can be obviously improved by adding the toughening agent to the steel slag concrete.

From examples 1 and 6 to 7, it is understood that when the amino-terminated trimethylolpropane tripropylene glycol ether is replaced by N, N-bis (2-hydroxypropyl) aniline and 3, 3' -dichloro-4, 4-diamino-diphenylmethane as amine chain extenders to modify nylon 66, the carbonization resistance of the steel slag concrete is not greatly affected, but the compressive strength of the steel slag concrete is reduced, so that the compressive strength of the steel slag concrete can be obviously improved by using the amine chain extenders, preferably the amino-terminated trimethylolpropane tripropylene glycol ether.

As can be seen from the examples 1 and 8-9, when the dispersant is selected from polyacrylamide or methylpentanol, the carbonization resistance of the steel slag concrete is greatly influenced, the PH value of the carbonization resistance test is reduced at a high speed, and the influence on the compression resistance of the steel slag concrete is small, so that the preferable sodium hexametaphosphate as the dispersant not only can improve the carbonization resistance of the concrete, but also can improve the compression strength of the concrete, thereby improving the durability of the concrete.

As is clear from examples 1 and 10 to 11, when the particle size of nylon 66 is 200 or 300. mu.m, the compressive strength of the steel slag concrete is low, so that when the particle size of nylon 66 is 250. mu.m, the anti-carbonization performance of the steel slag concrete can be improved, and the compressive strength of the concrete can be improved, thereby improving the durability of the steel slag concrete.

It is understood from examples 1 and 12 to 13 that, when polyvinyl acetate and chlorosulfonated polyethylene are used as the toughening agent, the influence on the carbonization resistance of the steel slag concrete is large, and the influence on the pressure resistance is not large, so that the toughening agent is preferably chlorinated polyethylene, and the durability of the steel slag concrete can be improved.

The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.