阅读说明：本技术 一种高性能抗裂抗冲击改性混凝土及其制备方法 (High-performance anti-cracking impact-resistant modified concrete and preparation method thereof ) 是由 季汉琪 于 2020-05-30 设计创作，主要内容包括：本发明公开了一种高性能抗裂抗冲击改性混凝土及其制备方法,混凝土中掺入了增强纤维,所述增强纤维由尺寸不同的改性聚丙烯粗纤维和改性聚丙烯腈纤维组成。本发明中,改性聚丙烯腈纤维可以提高早期混凝土抵抗应力的能力,阻止早期裂缝产生,提高混凝土早期的抗裂性能,且改性聚丙烯腈纤维可对外增加应力能量的吸收,提高整体混凝土对冲击能量的吸收,从而提高混凝土的抗冲击能力,改性聚丙烯粗纤维增加了其与混凝土的接触面积,粗糙的纤维表面使得改性混凝土在后期破坏的过程中吸收更多的能量,从而达到增韧的目的,实现混凝土从脆性破坏到韧性破坏的改变,两种纤维在普通混凝土中发挥不同作用,最终通过得到抗裂抗冲击性能好的改性混凝土。(The invention discloses high-performance anti-cracking impact-resistant modified concrete and a preparation method thereof. According to the invention, the modified polyacrylonitrile fiber can improve the stress resistance of early concrete, prevent early cracks from being generated and improve the early crack resistance of the concrete, the modified polyacrylonitrile fiber can increase the absorption of stress energy to the outside and improve the absorption of impact energy of the whole concrete, so that the impact resistance of the concrete is improved, the contact area of the modified polypropylene coarse fiber and the concrete is increased, the rough fiber surface enables the modified concrete to absorb more energy in the later-stage damage process, so that the toughening purpose is achieved, the change of the concrete from brittle damage to ductile damage is realized, the two fibers play different roles in the common concrete, and finally the modified concrete with good crack resistance and impact resistance is obtained.)

1. A high-performance anti-cracking and impact-resistant modified concrete and a preparation method thereof are disclosed, wherein reinforcing fibers are doped in the concrete to improve the anti-cracking and impact-resistant capability of the concrete, and the high-performance anti-cracking and impact-resistant modified concrete is characterized in that the reinforcing fibers consist of modified polypropylene coarse fibers and modified polyacrylonitrile fibers with different sizes.

2. The concrete of claim 1, wherein the modified polypropylene coarse fibers have a length of 45-55mm and a diameter of 1.0-1.5 mm.

3. The concrete of claim 1, wherein the modacrylic fiber has a length of 6-8mm and a diameter of 0.06-0.09 mm.

4. The concrete of claim 1, wherein the modified polypropylene fiber is present in the concrete in an amount of 5kg/m³-10kg/m³The content of the modified polyacrylonitrile fiber in the concrete is 0kg/m³-5kg/m³。

5. The concrete of claim 1, wherein the modified polypropylene coarse fibers are obtained by chemically surface-modifying polypropylene particles with one or more of organic modifiers, silane coupling agents, and non-polar modified fillers.

6. The concrete of claim 5, wherein the organic modifier is one or more of maleic anhydride grafted polypropylene, maleic anhydride grafted polyethylene and polyethylene glycol, the coupling agent is one or more of silane coupling agent Si-69, KH570, KH550, KH151, silica gel anti-blocking agent and Tetraethoxysilane (TEOS), and the inorganic modified filler is one or more of talc powder, kaolin, silica, diatomite, montmorillonite and hydrotalcite.

7. The high-performance anti-cracking impact-resistant modified concrete and the preparation method thereof according to claim 1, wherein the modified polyacrylonitrile fiber is prepared by mixing starch, cerium oxide nano powder, dimethyl sulfoxide, polyacrylonitrile, dimethylformamide, graphene nano powder and powdered activated carbon in proportion, spinning by a wet spinning method, and placing in an electric field of 3-18 KV/cm.

8. The preparation method of the high-performance anti-cracking impact-resistant modified concrete according to claim 1, comprising the following steps:

s1, mixing one or more of organic modifier, silane coupling agent and inorganic modified filler with polypropylene particles in proportion, and performing melt stretching to prepare modified polypropylene fibers;

s2, firstly, dissolving fully dried starch and cerium oxide in dimethyl sulfoxide according to a mass ratio to prepare a solution A, secondly, dissolving polyacrylonitrile in dimethyl formamide to form a solution B, then, mixing the solution A and the solution B in proportion to obtain a solution C, then, adding graphene nano powder and powdered activated carbon into the solution C to obtain a solution D, and finally, spinning the solution D by a wet spinning method, wherein an electric field of 3-18KV/cm is additionally applied during spinning;

s3, after the modified polypropylene crude fiber and the modified polyacrylonitrile fiber are prepared according to the method, the modified polypropylene crude fiber and the modified polyacrylonitrile fiber are put into concrete and fully stirred until the mixture is uniform, and the modified concrete is obtained.

Technical Field

The invention relates to the technical field of concrete modification, in particular to high-performance anti-cracking impact-resistant modified concrete and a preparation method thereof.

Background

The concrete is a general term for engineering composite materials formed by cementing aggregate into a whole by cementing materials, and the term concrete generally refers to cement concrete which is prepared by mixing cement as the cementing material, sand and stone as the aggregate and water (with or without additives and admixtures) according to a certain proportion, stirring, molding and curing, and is also called ordinary concrete.

However, since the properties of concrete such as crack resistance and impact resistance are related to the engineering quality of building construction, in order to further improve the service performance and construction quality of concrete, a modifier is added to improve certain properties (strength) of concrete according to the use requirement, so that the concrete has excellent properties, and the obtained modified concrete meets the actual building construction requirement, therefore, a high-performance modified concrete is needed to improve the crack resistance and impact resistance of common concrete.

Disclosure of Invention

The invention aims to solve the problems and provides high-performance anti-cracking and anti-impact modified concrete and a preparation method thereof.

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

a high-performance anti-cracking and impact-resistant modified concrete and a preparation method thereof are disclosed, wherein reinforcing fibers are doped in the concrete to improve the anti-cracking and impact-resistant capability of the concrete, and the reinforcing fibers are composed of modified polypropylene coarse fibers and modified polyacrylonitrile fibers with different sizes.

As a further description of the above technical solution:

the modified polypropylene crude fiber has the length of 45-55mm and the diameter of 1.0-1.5 mm.

As a further description of the above technical solution:

the length of the modacrylic fiber is between 6 and 8mm, and the diameter of the modacrylic fiber is between 0.06 and 0.09 mm.

As a further description of the above technical solution:

the content of the modified polypropylene fiber in concrete is 5kg/m³-10kg/m³The modified polyacrylonitrile fiber is in concreteIs 0kg/m³-5kg/m³。

As a further description of the above technical solution:

the modified polypropylene crude fiber is obtained by chemically surface-modifying polypropylene particles through one or more than one of organic modifier, silane coupling agent and electrodeless modified filler.

As a further description of the above technical solution:

the organic modifier is one or more than one mixture of maleic anhydride grafted polypropylene, maleic anhydride grafted polyethylene and polyethylene glycol, the coupling agent is one or more than one mixture of silane coupling agent Si-69, KH570, KH550, KH151, silica gel anti-blocking agent and Tetraethoxysilane (TEOS), and the inorganic modified filler is one or more than one mixture of talcum powder, kaolin, silica, diatomite, montmorillonite and hydrotalcite.

As a further description of the above technical solution:

the modified polyacrylonitrile fiber is prepared by mixing starch, cerium oxide nano powder, dimethyl sulfoxide, polyacrylonitrile, dimethylformamide, graphene nano powder and powdered activated carbon in proportion, spinning by a wet spinning method, and placing in an electric field of 3-18 KV/cm.

As a further description of the above technical solution:

a preparation method of high-performance anti-cracking impact-resistant modified concrete comprises the following steps:

s1, mixing one or more of organic modifier, silane coupling agent and inorganic modified filler with polypropylene particles in proportion, and performing melt stretching to prepare modified polypropylene fibers;

s2, firstly, dissolving fully dried starch and cerium oxide in dimethyl sulfoxide according to a mass ratio to prepare a solution A, secondly, dissolving polyacrylonitrile in dimethyl formamide to form a solution B, then, mixing the solution A and the solution B in proportion to obtain a solution C, then, adding graphene nano powder and powdered activated carbon into the solution C to obtain a solution D, and finally, spinning the solution D by a wet spinning method, wherein an electric field of 3-18KV/cm is additionally applied during spinning;

s3, after the modified polypropylene crude fiber and the modified polyacrylonitrile fiber are prepared according to the method, the modified polypropylene crude fiber and the modified polyacrylonitrile fiber are put into concrete and fully stirred until the mixture is uniform, and the modified concrete is obtained.

In summary, due to the adoption of the technical scheme, the invention has the beneficial effects that: modified polypropylene crude fibers and modified polyacrylonitrile fibers with different sizes are added into common concrete and are uniformly stirred to obtain modified concrete, wherein, the modified polyacrylonitrile fiber can improve the stress resistance of the early concrete, thereby preventing the generation of early cracks and improving the early crack resistance of the concrete, and the modified polyacrylonitrile fiber can increase the absorption of stress energy to the outside, improve the absorption of impact energy by the whole concrete, thereby improving the shock resistance of the concrete, increasing the contact area of the modified polypropylene coarse fibers and the concrete, absorbing more energy in the later damage process of the modified concrete due to the rough fiber surface, thereby achieving the purpose of toughening, realizing the change of the concrete from brittle failure to ductile failure, and finally obtaining the modified concrete with good crack resistance and impact resistance by the two fibers playing different roles in the common concrete.

Detailed Description

The technical solutions in the embodiments of the present invention are 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. 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.