阅读说明：本技术 一种利用麦秸秆灰做集料的透水混凝土及其制备方法 (Pervious concrete using wheat straw ash as aggregate and preparation method thereof ) 是由 杨彬 张志萱 朱娜 林颖 马博 汪发红 刘玉娟 王梅节 王智强 于 2021-09-07 设计创作，主要内容包括：本发明涉及透水混凝土技术领域,公开了一种利用麦秸秆灰做集料的透水混凝土及其制备方法,其原料组分及其质量比例为：水泥(1.2～3.0)、回收碎骨料(1.0～2.5)、发泡剂(1.0～3.0)、水(1.0～2.8)和小麦秸秆灰(1.0～3.5)。本发明添加小麦秸秆灰以及将用于燃烧小麦秸秆灰产生的二氧化碳进行通入到混合罐内对回收碎骨料加水反应成碳酸钙从而增强混凝土的抗压、抗折以及空气污染的指数均提高,适合广泛推广和使用。(The invention relates to the technical field of pervious concrete, and discloses pervious concrete taking wheat straw ash as aggregate and a preparation method thereof, wherein the pervious concrete comprises the following raw material components in percentage by mass: 1.2-3.0 parts of cement, 1.0-2.5 parts of recycled crushed aggregate, 1.0-3.0 parts of foaming agent, 1.0-2.8 parts of water and 1.0-3.5 parts of wheat straw ash. The invention adds the wheat straw ash and introduces the carbon dioxide generated by burning the wheat straw ash into the mixing tank to react the recycled crushed aggregates with water to form calcium carbonate, thereby enhancing the indexes of compression resistance, fracture resistance and air pollution of the concrete and being suitable for wide popularization and use.)

1. The utility model provides an utilize pervious concrete of wheat straw ash as material that gathers materials which characterized in that: the raw material components and the mass ratio thereof are as follows:

1.2-3.0 parts of cement, 1.0-2.5 parts of recycled crushed aggregate, 1.0-3.0 parts of foaming agent, 1.0-2.8 parts of water and 1.0-3.5 parts of wheat straw ash.

2. The pervious concrete using wheat straw ash as aggregate according to claim 1, wherein: the raw material components and the mass ratio thereof are as follows:

cement, recycled crushed aggregate, foaming agent, water and wheat straw ash in a ratio of 2.2:1.8:1.6:1.9: 2.6.

3. The pervious concrete using wheat straw ash as aggregate according to claim 1, wherein: the cement is ordinary portland cement.

4. The pervious concrete using wheat straw ash as an aggregate applied to any one of claims 1 to 3, wherein the preparation method of the pervious concrete using wheat straw ash as an aggregate comprises the following steps:

s1: putting the recycled crushed aggregates into a mixing tank, adding quantitative water, and mixing and stirring for 20min for later use;

s2: putting the wheat straws into a combustion furnace for combustion, introducing flue gas generated by combustion into the mixing tank in the step (1), continuously stirring for 30min for standby use, and reacting carbon dioxide in the flue gas with lime water formed by mixing recycled aggregates and water in the mixing tank to form calcium carbonate;

s3: continuously adding the foaming agent into the mixing tank in the step 2, and mixing and stirring for 10 min;

s4: continuously adding the wheat straw ash and water into the mixing tank in the step 3, stirring for 25min, and then putting the mixture into a container for use;

s5: the prepared and poured concrete can be put into use after being naturally cured for 5 days.

5. The method for preparing the pervious concrete by using the wheat straw ash as the aggregate according to claim 4, which is characterized in that: the recycled crushed aggregates in the step 1 are crushed in advance and then screened by a stainless steel screen plate with 10 meshes.

6. The method for preparing the pervious concrete by using the wheat straw ash as the aggregate according to claim 4, which is characterized in that: and 2, arranging a combustion furnace for combusting the wheat straws beside the mixing tank, communicating an exhaust pipe of the combustion furnace with a side top cover of the mixing tank, and arranging a valve on the exhaust pipe.

7. The method for preparing the pervious concrete by using the wheat straw ash as the aggregate according to claim 4, which is characterized in that: the chemical reaction equation in the step 2 is as follows:

CO2+Ca(OH)2＝CaCO3↓+H2O。

8. the method for preparing the pervious concrete by using the wheat straw ash as the aggregate according to claim 4, which is characterized in that: the stirring speed in the steps 1 to 4 is 300 r/min.

Technical Field

The invention relates to the technical field of pervious concrete, in particular to pervious concrete taking wheat straw ash as aggregate and a preparation method thereof.

Background

The ecological concrete is also called porous concrete, and the ecological concrete has characteristics of good rainwater permeability, sound absorption, suitability for growth of herbaceous plants and the like due to a porous structure, and is widely concerned, and the permeable concrete is also called porous concrete and is a building material which is formed by mixing aggregate, a cementing material, water, an additive and the like, and the strength of the porous concrete is formed by binding the aggregate by the hardened cementing material wrapped on the surface of the aggregate. The pervious concrete has good pervious and noise-reducing performances and is mainly used for paving road shoulders, partition boards and the like of dams, revetments, sidewalks, large squares and green buildings.

China is a big agricultural country and has rich agricultural crop resources. However, with the continuous increase of agricultural output, agricultural wastes are increased, according to statistics, the annual average production of crop biomass-straw in China reaches 6.4 hundred million tons, except a small part of the biomass-straw is used for papermaking and plate processing, most of straw resources are wasted or burned on site, the produced straw ash not only occupies the land, but also produces a large amount of smoke dust and CO2, which causes serious influence on the local ecological environment, and compared with other biomasses, the wheat straw harvesting season has high temperature, is easy to dry and collect; the wheat straw ash has the characteristics of less impurities, pure quality, no toxic or harmful components, high activity, low price, high stability and the like, and can be used as a raw material for producing and processing building materials. Researches also find that the thermal resistance of the concrete doped with a certain amount of straw ash is higher than that of common concrete, and the self-heat-preservation function of the concrete can be realized.

The retrieval publication No. CN 107573009A discloses ecological water-permeable foam concrete and a preparation method thereof, and the ecological water-permeable foam concrete comprises the following components in parts by weight: 15-36 parts of cement, 5-15 parts of iron tailing slag micro powder, 10-25 parts of sludge hollow ceramsite, 12-40 parts of regenerated lightweight aggregate, 0.1-0.6 part of modified straw fiber, 0.1-2 parts of modified foaming agent, 0.2-1 part of thickening agent and 10-30 parts of water. According to the invention, by adopting the modified foaming agent, the bubbles which have a thin-wall structure and are in a metastable state reach a stable state with surrounding adjacent bubbles under the combined action of the combination heat, gravity, surface tension and capillary effect before the cement slurry is hardened, and the permeable foam concrete is formed after the cement slurry is hardened. Although the concrete has larger communicated porosity, high permeability can be realized, the fluidity is good, the construction surface is smooth, the construction is convenient and fast, and the construction efficiency is high.

However, the inventor finds that the technical scheme still has at least the following defects:

firstly, in the technical scheme, waste recycled lightweight aggregate is directly used as a base material to be mixed with other materials, but the strength and the hardness of the recycled lightweight aggregate are weak due to long service time of the recycled lightweight aggregate, and the problem of reduction of the compressive strength and the flexural strength of the whole concrete is inevitably caused if the recycled lightweight aggregate is directly used;

secondly, although wheat straw ash is used as aggregate in the technical scheme, a large amount of carbon dioxide gas is inevitably generated by burning wheat straws, so that the air pollution is serious, and the environmental protection property of concrete production is not facilitated.

Disclosure of Invention

The invention aims to provide pervious concrete using wheat straw ash as aggregate and a preparation method thereof, and solves the problems in the background art.

In order to achieve the purpose, the invention provides the following technical scheme: the pervious concrete using the wheat straw ash as the aggregate comprises the following raw material components in percentage by mass:

1.2-3.0 parts of cement, 1.0-2.5 parts of recycled crushed aggregate, 1.0-3.0 parts of foaming agent, 1.0-2.8 parts of water and 1.0-3.5 parts of wheat straw ash.

As a preferred embodiment of the invention, the raw material components and the mass ratio thereof are as follows:

cement, recycled crushed aggregate, foaming agent, water and wheat straw ash in a ratio of 2.2:1.8:1.6:1.9: 2.6.

As a preferred embodiment of the present invention, the cement is ordinary portland cement.

As a preferred embodiment of the present invention, there is also provided a method for preparing the pervious concrete using wheat straw ash as an aggregate, comprising the steps of:

s1: putting the recycled crushed aggregates into a mixing tank, adding quantitative water, and mixing and stirring for 20min for later use;

s2: putting the wheat straws into a combustion furnace for combustion, introducing flue gas generated by combustion into the mixing tank in the step (1), continuously stirring for 30min for standby use, and reacting carbon dioxide in the flue gas with lime water formed by mixing recycled aggregates and water in the mixing tank to form calcium carbonate;

s3: continuously adding the foaming agent into the mixing tank in the step 2, and mixing and stirring for 10 min;

s4: continuously adding the wheat straw ash and water into the mixing tank in the step 3, stirring for 25min, and then putting the mixture into a container for use;

s5: the prepared and poured concrete can be put into use after being naturally cured for 5 days.

In a preferred embodiment of the present invention, the recycled crushed aggregates in step 1 are crushed in advance and then screened through a 10-mesh stainless steel screen.

In a preferred embodiment of the present invention, the combustion furnace for combusting wheat straw in step 2 is disposed beside the mixing tank, an exhaust pipe of the combustion furnace is disposed to communicate with the side top cover of the mixing tank, and a valve is disposed on the exhaust pipe.

As a preferred embodiment of the present invention, the chemical reaction equation in step 2 is:

CO2+Ca(OH)2＝CaCO3↓+H2O。

in a preferred embodiment of the present invention, the stirring rate in step 1 to step 4 is 300 r/min.

Compared with the prior art, the invention has the following beneficial effects:

the invention improves indexes of compression resistance, folding resistance and air pollution of the concrete by adding the wheat straw ash and introducing carbon dioxide generated by burning the wheat straw ash into the mixing tank to react the recycled crushed aggregate with water to form calcium carbonate, and solves the problems that the waste recycled lightweight aggregate is directly adopted as the base material to be mixed and stirred with other materials in the technical scheme in the prior art, but the strength and the hardness of the aggregate are weaker because the recycled lightweight aggregate is used for a longer time, and the compression strength and the folding resistance of the whole concrete are inevitably reduced if the recycled lightweight aggregate is directly used; meanwhile, the problem that in the prior art, wheat straw ash is used as aggregate, but a large amount of carbon dioxide gas is inevitably generated by burning wheat straws, so that the air pollution is serious, and the environmental protection property of concrete production is not facilitated is solved.

Detailed Description

In order to make the technical means, the creation characteristics, the achievement purposes and the effects of the invention easy to understand, the invention is further described with the specific embodiments.

Example 1:

the invention provides a technical scheme that: the pervious concrete using the wheat straw ash as the aggregate comprises the following raw material components in percentage by mass: cement, recycled crushed aggregate, foaming agent, water and wheat straw ash in a ratio of 1.6:2.0:1.2:1.9: 2.8.

The embodiment also provides a preparation method of the pervious concrete by using the wheat straw ash as the aggregate, which comprises the following steps:

s1: putting the recycled crushed aggregates into a mixing tank, adding quantitative water, and mixing and stirring for 20min for later use;

s2: putting the wheat straws into a combustion furnace for combustion, introducing flue gas generated by combustion into the mixing tank in the step (1), continuously stirring for 30min for standby use, and reacting carbon dioxide in the flue gas with lime water formed by mixing recycled aggregates and water in the mixing tank to form calcium carbonate;

s3: continuously adding the foaming agent into the mixing tank in the step 2, and mixing and stirring for 10 min;

s4: continuously adding the wheat straw ash and water into the mixing tank in the step 3, stirring for 25min, and then putting the mixture into a container for use;

s5: the prepared and poured concrete can be put into use after being naturally cured for 5 days.

Further, the recycled crushed aggregates in the step 1 are crushed in advance and then screened by a stainless steel screen plate with 10 meshes, and the cement is ordinary portland cement.

Furthermore, the combustion furnace for combusting the wheat straws in the step 2 is arranged beside the mixing tank, an exhaust pipe of the combustion furnace is communicated with the side top cover of the mixing tank, and a valve is arranged on the exhaust pipe.

Further, the chemical reaction equation in step 2 is:

CO2+ ca (oh)2 ═ CaCO3 ↓ + H2O, the stirring rate in steps 1 to 4 was 300 r/min.

The concrete properties of this example are shown in Table 1:

the ecological water-permeable foam concrete prepared by the embodiment has the compression strength of 39MPa in 28 days, the breaking strength of 31MPa and the permeability coefficient of 0.9 cm/s.

Example 2:

the invention provides a technical scheme that: the pervious concrete using the wheat straw ash as the aggregate comprises the following raw material components in percentage by mass: the cement, recycled broken aggregates, foaming agent, water and wheat straw ash are 1.4:1.8:2.1:1.7: 2.2.

The embodiment also provides a preparation method of the pervious concrete by using the wheat straw ash as the aggregate, which comprises the following steps:

s1: putting the recycled crushed aggregates into a mixing tank, adding quantitative water, and mixing and stirring for 20min for later use;

s2: putting the wheat straws into a combustion furnace for combustion, introducing flue gas generated by combustion into the mixing tank in the step (1), continuously stirring for 30min for standby use, and reacting carbon dioxide in the flue gas with lime water formed by mixing recycled aggregates and water in the mixing tank to form calcium carbonate;

s3: continuously adding the foaming agent into the mixing tank in the step 2, and mixing and stirring for 10 min;

s4: continuously adding the wheat straw ash and water into the mixing tank in the step 3, stirring for 25min, and then putting the mixture into a container for use;

s5: the prepared and poured concrete can be put into use after being naturally cured for 5 days.

The ecological water-permeable foam concrete prepared by the embodiment has the compression strength of 39MPa in 28 days, the breaking strength of 34MPa and the permeability coefficient of 1.1 cm/s.

Example 3:

the invention also provides a technical scheme that: the pervious concrete using wheat straw ash as aggregate comprises the following raw material components in percentage by mass: cement, recycled crushed aggregate, foaming agent, water and wheat straw ash in a ratio of 2.2:1.8:1.6:1.9: 2.6.

The embodiment also provides a preparation method of the pervious concrete by using the wheat straw ash as the aggregate, which comprises the following steps:

s1: putting the recycled crushed aggregates into a mixing tank, adding quantitative water, and mixing and stirring for 20min for later use;

s2: putting the wheat straws into a combustion furnace for combustion, introducing flue gas generated by combustion into the mixing tank in the step (1), continuously stirring for 30min for standby use, and reacting carbon dioxide in the flue gas with lime water formed by mixing recycled aggregates and water in the mixing tank to form calcium carbonate;

s3: continuously adding the foaming agent into the mixing tank in the step 2, and mixing and stirring for 10 min;

s4: continuously adding the wheat straw ash and water into the mixing tank in the step 3, stirring for 25min, and then putting the mixture into a container for use;

s5: the prepared and poured concrete can be put into use after being naturally cured for 5 days.

The ecological water-permeable foam concrete prepared by the embodiment has the compression strength of 40MPa in 28 days, the breaking strength of 37MPa and the permeability coefficient of 1.4 cm/s.

Comparative example:

the pervious concrete using the wheat straw ash as the aggregate comprises the following raw material components in percentage by mass: cement, recycled aggregate, foaming agent and water in a ratio of 1.4:1.8:2.1: 1.7.

The embodiment also provides a preparation method of the pervious concrete by using the wheat straw ash as the aggregate, which comprises the following steps:

s1: putting the recycled crushed aggregates into a mixing tank, adding quantitative water, and mixing and stirring for 20min for later use;

s2: continuously adding the foaming agent into the mixing tank in the step 1, and mixing and stirring for 10 min;

s3: adding water into the mixing tank in the step 2, stirring for 25min, and then putting the water into the mixing tank for use;

s4: the prepared and poured concrete can be put into use after being naturally cured for 5 days.

The ecological water-permeable foam concrete prepared by the embodiment has the compression strength of 22MPa in 28 days, the breaking strength of 20MPa and the permeability coefficient of 0.1 cm/s.

Concrete properties are as in table 1:

TABLE 1

It can be understood from table 1 that the indexes of the concrete for enhancing the compression resistance, the bending resistance and the air pollution by adding the wheat straw ash and introducing the carbon dioxide generated by burning the wheat straw ash into the mixing tank to react the recycled crushed aggregates with water into calcium carbonate are obviously improved compared with the indexes of the concrete prepared by not adding the wheat straw ash and the carbon dioxide in the comparative example.

The invention relates to pervious concrete using wheat straw ash as aggregate and a preparation method thereof, wherein each part is a universal standard part or a part known by the technical personnel in the field, and the structure and the principle of the pervious concrete can be known by the technical manual or the conventional experimental method.

While there have been shown and described what are at present considered the fundamental principles and essential features of the invention and its advantages, it will be apparent to those skilled in the art that the invention is not limited to the details of the foregoing exemplary embodiments, but is capable of other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.