CN110482891B

CN110482891B - Anti-crack concrete and preparation method thereof

Info

Publication number: CN110482891B
Application number: CN201910817650.8A
Authority: CN
Inventors: 彭龙贵
Original assignee: Shaanxi Longbinlide New Material Technology Co ltd
Current assignee: Nantong Biomaterial Technology Co.,Ltd.
Priority date: 2019-08-30
Filing date: 2019-08-30
Publication date: 2022-03-22
Anticipated expiration: 2039-08-30
Also published as: CN110482891A

Abstract

The invention discloses anti-crack concrete and a preparation method thereof, wherein the anti-crack concrete comprises an anti-crack agent and a gel material, and the anti-crack agent comprises the following components in percentage by mass: the mass of the anti-cracking agent is 1-10% of the mass of the gel material; the anti-cracking agent comprises: 60-90% of polymer composite fiber, 3-8% of surfactant and the balance of filler; the polymer composite fiber is processed by a resin-based composite material of a fiber reinforcement body, and the polymer composite fiber is a composite fiber of which the surface of the fiber reinforcement body is wrapped with at least one layer of resin. The anti-crack concrete has good anti-crack performance and durability.

Description

Anti-crack concrete and preparation method thereof

Technical Field

The invention belongs to the technical field of concrete, and particularly relates to anti-crack concrete and a preparation method thereof.

Background

With the higher and higher requirements of modern civil engineering and construction engineering, high-performance concrete is widely applied. The core of high performance concrete is durability. The durability is insufficient, and extremely serious consequences can be caused to engineering construction. The service life of a common concrete project is about 50-100 years. The concrete engineering cannot meet the durability requirement due to the occurrence of cracks, which are mainly caused by drying shrinkage, self-shrinkage and cold shrinkage of concrete.

1) Shrinkage on drying

Drying shrinkage is the shrinkage of hardened concrete caused by the loss of capillary water. This shrinkage increases the tensile stress and can cause cracking of the concrete before it is subjected to any load. All cement concretes undergo drying shrinkage or changes in hydrate volume with age.

2) Self-shrinking

The self-shrinkage is the shrinkage caused by self-drying or the reduction of the relative humidity in the concrete, and is the phenomenon that the macroscopic volume of the concrete is reduced due to the hydration of cement under the conditions of constant temperature and no humidity of the concrete. That is, when unhydrated cement chemically reacts with water, the volume of the product is smaller than the sum of the two, and cracks occur.

3) Cold shrink

A large amount of heat is released in the cement hydration process, the heat dissipation conditions of the interior and the surface of the concrete are different mainly in the first 7 days, so that the temperature of the interior of the concrete is higher than that of the exterior of the concrete, a large temperature difference is formed, and when the temperature stress exceeds the internal and external constraint stresses of the concrete, cold shrinkage cracks are generated. In mass concrete engineering, cracking is more likely to be caused by cold shrinkage caused by heat dissipation and temperature reduction than by dry shrinkage, and the cold shrinkage and the dry shrinkage often occur simultaneously. Various cooling measures are often adopted in mass concrete engineering to reduce the temperature rise so as to reduce cold contraction, but the problem cannot be solved fundamentally.

With the rapid development of economy in China, resin-based composite materials with fiber reinforcements are widely used. According to the reports of China Association for composite industry, the total amount of leftover materials of resin matrix composites of fiber reinforcements produced in China every year is not less than 150 ten thousand tons, the total amount of waste materials is not less than 600 ten thousand tons, and the speed is increased by more than 10% every year. The traditional method for disposing the materials is incineration or landfill, which brings huge pollution and pressure to the environment and enterprise development. The method for applying the fiber reinforced resin matrix composite leftover materials and wastes in a large-scale, large-scale and high-value manner is an economic problem and an environmental problem and a social problem.

Disclosure of Invention

In order to solve the problems in the prior art, the invention aims to provide anti-cracking concrete and a preparation method thereof, and the invention can solve the technical problem of concrete cracking.

The technical scheme adopted by the invention is as follows:

the anti-crack concrete comprises an anti-crack agent and a gel material, and comprises the following components in percentage by mass:

the mass of the anti-cracking agent is 1-10% of the mass of the gel material;

the anti-cracking agent comprises: 60-90% of polymer composite fiber, 3-8% of surfactant and the balance of filler;

the polymer composite fiber is processed by a resin-based composite material of a fiber reinforcement body, and the polymer composite fiber is a composite fiber of which the surface of the fiber reinforcement body is wrapped with at least one layer of resin.

The surfactant is an anionic surfactant.

The surfactant is a polycarboxylic acid modified surfactant or a melamine resin modified surfactant.

The filler is one or a mixture of more of fly ash, mineral powder, calcium carbonate, kaolin and 4A zeolite.

The resin-based composite material of the fiber reinforcement comprises one or a mixture of several of glass fiber reinforced plastic products, scrapped fan blades, leftover materials for producing the glass fiber reinforced plastic products, glass felts and glass gridding cloth.

The length of the polymer composite fiber is 3 mm-10 mm.

The compressive strength of the anti-crack concrete 28d is 43.5-46.5 Mpa, and the compressive ratio is 103% -109%; the compression ratio of the anti-crack concrete 7d is 97-106%.

A preparation method of anti-crack concrete comprises the following steps:

uniformly mixing the polymer composite fiber, the filler and the surfactant to obtain the anti-cracking agent;

and adding the anti-cracking agent into the gel material, and uniformly mixing to obtain the anti-cracking concrete.

The invention has the following beneficial effects:

the anti-cracking concrete comprises an anti-cracking agent and a gel material, wherein the mass of the anti-cracking agent is 1-10% of that of the gel material in percentage by mass; the anti-cracking agent comprises: 60-90% of polymer composite fiber, 3-8% of surfactant and the balance of filler; the polymer composite fiber is a composite fiber of which the surface of a fiber reinforcement body is wrapped with at least one layer of resin, and the wrapped resin can prevent the fiber reinforcement body from further carrying out chemical reaction with alkali substances such as cement, an additive and an admixture in the gel material under certain conditions, so that the phenomena of expansion, cracking and even damage of the structure of the gel material can not be caused. In addition, the specific heat capacity of the polymer composite fiber is close to that of cement, expansion with heat and contraction with cold are almost synchronously carried out, and the polymer composite fiber is not easy to fall off in the later period, so that cracks caused by asynchronous contraction in the anti-crack concrete can be prevented, the anti-crack performance is good, and the durability of the anti-crack concrete is good. The surfactant can uniformly disperse the polymer composite fiber in the anti-crack concrete, so that the polymer composite fiber plays a supporting role in the anti-crack concrete, and the fluidity and the construction performance of the anti-crack concrete are not influenced. The filler has two aspects of chemical action and physical action in concrete: the chemical action is to improve the bonding of the slurry to the aggregate interface; the physical effect is mainly referred to the microaggregate effect and the morphological effect of the filler particles. Because the particles of the filler are mostly microbeads and the particle size is smaller than that of cement, the filler plays a more prominent role in compacting the filling, lubricating, deflocculating, dispersing water and the like in the concrete, the combined action of the two aspects reduces the water consumption of the concrete, improves the workability, and ensures that the concrete is uniform and compact, thereby improving the strength and the durability of the concrete. The polymer composite fiber is processed by the resin-based composite material of the fiber reinforcement, thereby realizing the reutilization of wastes and simultaneously reducing the pollution of solid wastes to the environment.

Furthermore, after the cement is hydrated, the coagulation is generated due to the van der Waals force action among ions and different charges of cement hydrated minerals and cement main minerals in the hydration process, so that the flocculation structure of the mortar is generated. The surfactant is an anionic surfactant, and negative ions-SO-, -COO-in the surfactant can be added into positive charge Ca of cement particles in mortar due to the doping of the anionic surfactant²⁺The slurry is adsorbed on cement particles under the action of (1) to form ion distribution of a diffusion electric double layer (Zeta potential), and the ion distribution of the diffusion electric double layer is formed on the surface, so that the cement particles are dispersed under the action of electrostatic repulsion, bound water in a space grid structure formed in the cement hydration process is released, and the mortar is fluidized. The larger the absolute value of Zeta potential is, the better the dispersing effect is. Polar hydrophilic groups of the anionic surfactant are directionally adsorbed on the surface of cement particles, are associated with water molecules in a hydrogen bond form and are associated with the water molecules in a hydrogen bond modeThe water film on the surface of cement particle can prevent the cement particles from contacting directly, increase the sliding capacity between cement particles, and lubricate the cement particles, so as to improve the flowability of slurry. The micro bubbles in the cement mortar are also wrapped by the directional adsorption polar groups of the surfactant, so that a plurality of micro beads are similarly added among cement particles due to the repulsion of like electricity among the bubbles and among the bubbles and the cement particles, the lubricating effect is also realized, the fluidity is improved, and the uniformity of the anti-crack concrete is ensured.

Furthermore, the filler is one or a mixture of more of fly ash, mineral powder, calcium carbonate, kaolin and 4A zeolite, so that the raw material source of the filler is wide, the filler is suitable for production in various places, and the cost can be reduced.

Furthermore, the resin-based composite material of the fiber reinforcement comprises one or a mixture of several of glass fiber reinforced plastic products, scrapped fan blades, leftover materials for producing the glass fiber reinforced plastic products, glass felts and glass gridding cloth, so that the invention can solve the problems of environmental pollution and resource waste caused by the waste leftover materials and wastes of the fiber reinforced resin-based composite material.

Furthermore, the length of the polymer composite fiber is 3 mm-10 mm, so that the polymer composite fiber can be better dispersed in concrete and plays a role in crack resistance enhancement.

The preparation method of the anti-crack concrete comprises the steps of uniformly mixing the polymer composite fiber, the filler and the surfactant to obtain the anti-crack agent, adding the anti-crack agent into the gel material, and uniformly mixing to obtain the anti-crack concrete.

Drawings

FIG. 1 is a schematic structural diagram of a separation and dissociation apparatus used in the present invention;

FIG. 2 is an exploded view of the inner arc spherical gland, the inner spiral conical cylinder and the conical spiral shaft in the separation and dissociation device adopted by the invention;

FIG. 3 is a schematic structural view of an inner helical conical cylinder in the separation and dissociation device adopted in the present invention;

FIG. 4 is a front view of a conical screw shaft in the separation and dissociation device employed in the present invention;

FIG. 5 is a left side view of a conical screw shaft in the separation and dissociation device employed in the present invention;

FIG. 6 is a perspective view of a conical screw shaft in the separation and dissociation device used in the present invention;

FIG. 7 is a schematic structural view of an inner arc spherical gland in the separation and dissociation device of the present invention;

FIG. 8 is a laser micrograph of a chopped polymer composite fiber fines prepared in example 1;

FIG. 9 is a laser micrograph of a chopped polymer composite fiber fines prepared in example 1;

FIG. 10 is a scanning electron micrograph of a chopped polymer composite fiber fines prepared in example 1;

fig. 11 is a scanning electron microscope image of the anti-crack concrete added with the anti-crack agent prepared in example 1.

In the figure: 1-an equipment base; 2-an electric motor; 3-a first coupling; 4-gear speed reducer; 5-a second coupling; 6-anti-loose round nut; 7-bearing gland; 8-bearing seats; 9-feeding and feeding bin; 10-conical screw shaft, 10-1-first boss, 10-1-1-transition part, 10-2-second boss and 10-3-first spiral line; 11-internal helical line conical cylinder; 11-1-second helix; 12-inner arc spherical gland, 12-1-third boss, 12-2-discharge port; 13-cooling water jacket; 14-outer cladding sheet.

Detailed Description

The invention is further described below with reference to the figures and examples.

The anti-crack concrete comprises an anti-crack agent and a gel material, and the anti-crack agent comprises the following components in percentage by mass:

the mass of the anti-cracking agent is 1-10% of the mass of the gel material;

the anti-cracking agent comprises: 60-90% of polymer composite fiber, 3-8% of surfactant and the balance of filler; the polymer composite fiber is processed by a resin-based composite material of a fiber reinforcement body, and the polymer composite fiber is a composite fiber of which the surface of the fiber reinforcement body is wrapped with at least one layer of resin.

As a preferred embodiment of the present invention, the surfactant is an anionic surfactant.

As a preferred embodiment of the present invention, the surfactant is a polycarboxylic acid-modified surfactant or a melamine resin-modified surfactant.

As a preferred embodiment of the invention, the filler is one or a mixture of more of fly ash, mineral powder, calcium carbonate, kaolin and 4A zeolite.

As a preferred embodiment of the invention, the resin-based composite material of the fiber reinforcement comprises one or a mixture of several of glass fiber reinforced plastic products, scrapped fan blades, leftover materials for producing the glass fiber reinforced plastic products, glass felts and glass gridding cloth.

As a preferred embodiment of the present invention, the length of the polymer composite fiber is 3mm to 10 mm.

The preparation method of the anti-cracking agent comprises the following steps:

and uniformly mixing the polymer composite fiber, the filler and the surfactant to obtain the anti-cracking agent, adding the anti-cracking agent into the gel material, and uniformly mixing to obtain the anti-cracking concrete, wherein the mixing and mixing methods are common physical mixing methods.

Referring to fig. 1, the polymer composite fiber of the present invention is processed by a separation and dissociation device, the separation and dissociation device comprises a driving device, a bearing seat 8, a feeding bin 9, a conical screw shaft 10, an internal screw conical cylinder 11 and an internal arc spherical gland 12, one end of the conical screw shaft 10 is connected with the driving device through the bearing seat 8, the driving device can drive the conical screw shaft 10 to rotate, a feeding port is arranged on a bin body of the feeding bin 9, the feeding bin 9 is sleeved on the conical screw shaft 10, one end of the feeding bin 9 is arranged on the bearing seat 8, the internal screw conical cylinder 11 is sleeved on the conical screw shaft 10, one end of the internal screw conical cylinder 11 is arranged at the other end of the feeding bin 9, the internal arc spherical gland 12 is arranged at the other end of the internal screw conical cylinder 11, the conical screw shaft 10 extends out of the internal screw conical cylinder 11 and extends into the internal arc spherical gland 12, a discharge hole is arranged on the inner arc spherical gland 12; the outer part of the inner spiral line conical cylinder body 11 is provided with a cooling device, and the cooling device can adopt a cooling water jacket 13. Referring to fig. 2, 4-6, a plurality of convex first helical lines 10-3 are arranged on the conical screw shaft 10, the conical screw shaft 10 is in a cone shape, one end of the conical screw shaft 10 connected with the driving device is a big end, and the other end is a small end. Referring to fig. 2 and 3, the inner cavity of the inner spiral conical cylinder 11 is in a circular truncated cone shape, one end of the inner spiral conical cylinder 11, which is mounted with the feeding bin 9, is a big end, and the other end is a small end; the inner surface of the inner spiral line conical barrel body 11 is provided with a plurality of convex second spiral lines 11-1; a gap is left between the second spiral line 11-1 and the first spiral line 10-3. Referring to fig. 2 and 4-6, a plurality of second bosses 10-2 are uniformly distributed on the end surface of one end of the conical screw shaft 10 close to the inner arc spherical gland 12. Referring to fig. 2 and 7, the inner surface of the inner arc spherical gland 12 close to the end of the conical screw shaft 10 is an inner concave surface adapted to the end of the conical screw shaft 10, a plurality of third bosses 12-1 are uniformly distributed on the inner concave surface, and a preset gap is reserved between the second boss 10-2 and the third bosses 12-1.

As the preferred embodiment of the invention, the taper of the inner cavity of the conical cylinder body 11 of the internal spiral line is the same as that of the conical spiral shaft 10.

As a preferred embodiment of the invention, the second helix 11-1 has the opposite direction of helix to the first helix 10-3, see fig. 2, which results in better shearing.

Referring to fig. 2, 4-6, as a preferred embodiment of the present invention, a first helical line 10-3 of the conical helical shaft 10 near one end of the inner arc spherical gland 12 gradually transitions to be parallel to the axis of the conical helical shaft 10 and extends to the end of the conical helical shaft 10.

Referring to fig. 2, 4-6, as a preferred embodiment of the present invention, the first helical lines 10-3 gradually transition to a portion parallel to the axis of the conical helical shaft 10, first bosses 10-1 for splitting flow parallel to the axis of the conical helical shaft 10 are uniformly distributed on the conical helical shaft 10 between the adjacent first helical lines 10-3, and the first bosses 10-1 extend to the end of the conical helical shaft 10.

As a preferred embodiment of the invention, referring to fig. 2 and fig. 4 to fig. 6, a section of smooth arc-shaped transition part 10-1-1 is arranged at one end of the first boss 10-1 far away from the end part of the conical spiral shaft 10, the transition part 10-1-1 is spirally distributed on the conical spiral shaft 10, and the rotation direction of the transition part 10-1-1 is the same as that of the first spiral line 10-3.

Referring to fig. 4 and 5, as a preferred embodiment of the present invention, starting points of two adjacent first spiral lines among the plurality of first spiral lines 10-3 are different by a predetermined distance in the axial direction of the conical screw shaft 10.

As a preferred embodiment of the present invention, the tops of all the second bosses 10-2 are located on the same spherical surface, the tops of all the third bosses 12-1 are located on the same spherical surface, and the radius of the spherical surface on which the tops of the second bosses 10-2 are located is the same as the radius of the spherical surface on which the tops of the third bosses 12-1 are located.

Referring to fig. 2, 5 and 7, as a preferred embodiment of the present invention, the second bosses 10-2 and the third bosses 12-1 are each in a tapered tooth shape.

As a preferred embodiment of the present invention, a gasket is provided between the inner arc spherical gland 12 and the inner helical conical cylinder 11, and the gasket is used for making a gap between the end of the conical helical shaft 10 and the inner arc spherical gland 12.

As a preferred embodiment of the invention, the driving device comprises a motor 2, a first coupling 3, a gear reducer 4, a second coupling 5 and a locknut 6, wherein the motor 1, the gear reducer 2 and a feeding bin 9 are respectively arranged on the equipment base 1; an output shaft of the motor 2 is connected with an input shaft of a gear speed reducer 4 through a first coupler 3, and an output shaft of the gear speed reducer 4 is connected with one end of a conical spiral shaft 10 through a second coupler 5 and a locknut 6. The bearing seat 8 is coupled with the bearing gland 7.

The working principle of the separation and dissociation device is as follows: the motor 2 transmits power to the gear reducer 4 through the first coupler 3, the gear reducer 4 is directly connected with the conical screw shaft 10 to rotate, the resin-based composite material of the fiber reinforcement enters from the feeding bin 9, the resin-based composite material of the resin-based composite material fiber reinforcement of the fiber reinforcement is continuously pushed forward under the driving force of the conical screw shaft 10 in the feeding bin 9 and is compressed, the resin-based composite material of the fiber reinforcement is contacted with the inner wall of the inner spiral conical barrel 11 to generate a working state of kneading, shearing and separating effects while the resin-based composite material of the fiber reinforcement advances in a compression direction, the resin-based composite material of the fiber reinforcement synchronously generates a normal shearing force taking the axial force direction as an axis while being subjected to an axial extrusion force, and separation cracks between the resin matrix with brittle characteristic and the fiber reinforcement with toughness characteristic are spread from the interface of the two materials to extend from inside to outside under the combined action of the two forces, finally separating and dissociating the fiber reinforcement from the matrix, wherein the fiber reinforcement is coated with at least one layer of resin in the Shanghai; the invention adjusts the axial length of the separation and dissociation by adjusting the size of the gap between the end part of the conical screw shaft and the spherical gland of the inner arc spherical surface. This is in contrast to conventional pulverizing mechanisms which rely on random forces of impact or separation to pulverize both matrix and fiber materials in the same proportion, at the same latitude, and at the same particle size.

When the fineness of the product needs to be adjusted, a gasket is additionally arranged between the inner arc spherical gland 12 and the inner spiral conical cylinder 11, so that the gap between the end part of the conical spiral shaft and the spherical surface of the inner arc spherical gland is adjusted, the treatment capacity is large and the fiber length is long when the gap is large, and the powder treatment capacity is small and the fiber length is short when the gap is small.

The polymer composite fiber is processed by adopting a separation dissociation device, and the first spiral line with a plurality of bulges is arranged on the conical spiral shaft, so that the glass fiber reinforced plastic raw material can be pushed to advance in the rotating process of the conical spiral shaft, and the aim of continuous feeding is fulfilled; the conical screw shaft is in a cone shape, and the inner cavity of the conical cylinder body of the inner screw line is in a cone shape, so that the glass fiber reinforced plastic raw material can be compressed under the thrust action of the conical screw shaft in the process that the conical screw shaft pushes the glass fiber reinforced plastic raw material; the inner surface of the conical cylinder body with the inner spiral line is provided with a plurality of second convex spiral lines; a gap is reserved between the second spiral line and the first spiral line, so that the glass fiber reinforced plastic raw material is in a working state of rubbing, shearing and separating effects when being compressed and moving forward and is in contact with the inner wall of the conical cylinder of the inner spiral line, the glass fiber reinforced plastic raw material synchronously generates normal shearing force taking the axial force direction as an axis when being subjected to axial extrusion force, the glass fiber reinforced plastic raw material is torn and dissociated under the combined action of the two forces, the polymer composite fiber with at least one layer of resin coated on the surface of the glass fiber is obtained, and the polymer composite fiber can be ground between the end part of the conical spiral line and the inner arc spherical gland by utilizing the second boss and the third boss, so that the polymer composite fiber reaches the preset fineness; the obtained polymer composite fiber with the preset fineness is extruded from a discharge hole on the inner arc spherical gland. According to the invention, the cooling device is arranged outside the inner spiral line conical cylinder body, so that the obtained polymer composite fiber can be prevented from being agglomerated into balls at times due to high temperature generated in processing. The glass fiber reinforced plastic separation and dissociation device has simple structure and good separation effect, and has completely different crushing mechanism of matrix and fiber materials with the same proportion, the same latitude and the same grain diameter by the random force of collision or separation compared with the traditional crushing mechanical device. In conclusion, the glass fiber reinforced plastic separation and dissociation device can solve the difficult problem of dissociation of the matrix and the fibers in the processes of processing the recycled glass fiber reinforced plastic products and the glass fiber reinforced plastic production edges and corners, achieves the purpose of recovering a useful fiber structure with a certain length from the glass fiber reinforced plastic, and can be used as an additive to improve the service performance of the matrix, so that the high-valued recovery and utilization of the recycled glass fiber reinforced plastic products and the glass fiber reinforced plastic production edges and corners are achieved.

The first spiral line of one end of the conical spiral shaft, which is close to the inner arc spherical gland, is gradually transited to be parallel to the axis of the conical spiral shaft and extends to the end part of the conical spiral shaft. Because first helix passes through gradually to the axis parallel part with the toper screw axis for its spiral part interval grow, is unfavorable for the evenly distributed of glass steel raw materials, and then makes the powder fineness that obtains at last unable assurance, consequently sets up first boss, shunts the material in toper screw axis and the interior spiral line toper barrel cavity through first boss for glass steel raw materials evenly distributed guarantees the grinding effect. The first boss is provided with a section of smooth arc-shaped transition part, the transition part is spirally distributed on the conical spiral shaft, and the rotating direction of the transition part is the same as that of the first spiral line; the transition portion of this structure can further make glass steel raw materials evenly distributed, guarantees to grind the effect. In the axial direction of the conical spiral shaft, starting points of two adjacent first spiral lines in the plurality of first spiral lines have a difference of a preset distance; the fineness of the glass fiber reinforced plastic raw material is gradually reduced in the processes of extrusion, kneading and shearing, so that the overall volume is gradually reduced, and the defect of poor extrusion, kneading and shearing effects caused by insufficient filling of a cavity between the conical screw shaft and the conical cylinder of the inner spiral line due to the reduction of the volume of the processed raw material can be overcome by the preset distance difference between the starting points of the two adjacent first spiral lines; meanwhile, the problem that the processing effect is affected due to local material shortage caused by the fact that raw materials are easily accumulated and effective feeding is difficult to carry out due to the fact that the spiral part of the first spiral line is dense and the glass fiber reinforced plastic raw materials with large fineness are more when the processing is started is also avoided. The conical screw shaft is provided with second bosses, the inner arc spherical gland is provided with third bosses, the tops of all the second bosses are positioned on the same spherical surface, the tops of all the third bosses are positioned on the same spherical surface, and the radius of the spherical surface where the tops of the second bosses are positioned is the same as that of the spherical surface where the tops of the third bosses are positioned; the structure realizes the structural matching between the end part of the conical screw shaft and the inner arc spherical gland, and can realize the grinding of the processed material through the second boss and the third boss, thereby ensuring the grinding effect. The second boss and the third boss are distributed in the shape of oblique cone teeth, and the structure can enable the processed material to be ground in the part, so that the grinding path is lengthened, and the grinding effect is further ensured. A gasket is arranged between the inner arc spherical gland and the inner spiral conical cylinder and is used for adjusting the gap between the end part of the conical spiral shaft and the inner arc spherical gland; by adjusting the gap, the length of the processed polymer composite fiber can be adjusted.

The processing process of the polymer composite fiber comprises the following steps:

the driving device drives the conical screw shaft 10 to rotate, resin-based composite materials of the fiber reinforcement are added into the feeding bin 9, the resin-based composite materials of the fiber reinforcement are conveyed into the inner spiral line conical barrel 11 from the feeding bin 9 by the rotating conical screw shaft 10, and in the inner spiral line conical barrel 11, the resin-based composite materials of the fiber reinforcement are repeatedly extruded, kneaded, sheared and separated by the first spiral line 10-3 and the second spiral line 11-1 between the conical screw shaft 10 and the inner spiral line conical barrel 11, so that the resin-based composite materials of the fiber reinforcement are dissociated to obtain polymer composite fibers; grinding the polymer composite fiber between the end part of the conical screw shaft 10 and the inner arc spherical gland 12 by using a second boss 10-2 and a third boss 12-1 to enable the polymer composite fiber to reach a preset fineness; the obtained polymer composite fiber is extruded from a discharge hole on the inner arc spherical gland 12.

From the above results, it can be seen that the surface of the fiber reinforcement of the polymer composite fiber processed by the present invention is coated with at least one layer of resin.

The preparation method of the anti-cracking agent is preferably as follows: the leftover material of the resin-based composite material of the fiber reinforcement is firstly subjected to primary treatment by a jaw crusher and the like to reduce the volume of the material, and then is subjected to fine powder by a separation and dissociation device, wherein the leftover material of the resin-based composite material of the fiber reinforcement can be any leftover material of a glass fiber reinforced plastic product.

The anti-cracking agent is added into the anti-cracking concrete.

In a preferred embodiment, the addition amount of the anti-cracking agent in the anti-cracking concrete is 1 to 10 percent of the mass of the gel material.

The following non-limiting examples are presented to enable those of ordinary skill in the art to more fully understand the present invention and are not intended to limit the invention in any way.

Example 1

In this embodiment, the preparation method of the polymer composite fiber includes the following steps:

the resin-based composite material of the fiber reinforcement adopts leftover materials of glass fiber reinforced plastic products.

Preparing primary powder of polymer composite fiber: crushing leftover materials of the resin-based composite material of the fiber reinforcement, cutting a large resin-based composite material of the fiber reinforcement into small pieces, and putting the small pieces into a crusher to obtain the primarily crushed polymer composite fiber;

preparation of polymer composite fiber fine powder: the polymer composite fiber primary powder is added into the separation and dissociation device for processing to obtain fine powder, and the fine powder can be used as the fine powder of the polymer composite fiber which can be used in the anti-cracking agent.

Referring to fig. 8, taking the processing of the fiber glass reinforced plastic leftover material in example 1 as an example, it can be seen that the surface of the fiber reinforcement (i.e. the glass fiber) is covered with at least one layer of resin in the polymer composite fiber obtained by the separation and dissociation device of the present invention.

Referring to fig. 9, it can be seen from the processing of the glass fiber reinforced plastic trim that there is a layer of wrinkles on the surface of the glass fiber in the upper left corner of fig. 9, which is formed by the thermosetting resin on the surface of the glass fiber not completely separated from the glass fiber.

Referring to fig. 10, polymer composite fibers obtained by passing glass fiber reinforced plastic scraps through the separation and dissociation device of the present invention are heated to 200 ℃, and depressions are formed on the surfaces of the glass fibers, which are formed by ablation of the thermosetting resin on the surfaces of the glass fibers.

The preparation of the anti-cracking agent in the embodiment: the fine powder of the polymer composite fiber, the fly ash and the polycarboxylic acid modified surfactant obtained above are uniformly mixed in a mixer to obtain the anti-cracking agent of the embodiment, and the anti-cracking agent contains 90% of the fine powder of the polymer composite fiber, 5% of the fly ash and 5% of the polycarboxylic acid modified surfactant in percentage by mass.

The anti-cracking agent obtained in the embodiment is added to the gel material according to 1%, 5% and 10% of the mass of the concrete gel material, the anti-cracking concrete of the embodiment is obtained by uniformly mixing, the obtained anti-cracking concrete is tested, and the test results are shown in table 1:

TABLE 1

As can be seen from Table 1, the compressive strength and the crack resistance of the crack-resistant concrete are improved with the increase of the addition amount of the crack-resistant agent.

Referring to fig. 11, in the anti-crack concrete of the present invention in example 1, the polymer composite fibers are uniformly dispersed, such that the cement hydration product has a more complete crystal form, a more compact structure, and improved mechanical properties.

Example 2

preparation of polymer composite fiber fine powder: the polymer composite fiber primary powder is added into the separation and dissociation device for processing to obtain fine powder, and the fine powder can be used as the fine powder of the polymer composite fiber which can be used in the anti-crack agent.

The preparation of the anti-cracking agent in the embodiment:

the preparation of the anti-cracking agent in the embodiment: the fine powder of the polymer composite fiber, the mineral powder and the polycarboxylic acid modified surfactant obtained above are uniformly mixed in a mixer to obtain the anti-cracking agent of the embodiment, and the anti-cracking agent contains 60% of the fine powder of the polymer composite fiber, 32% of the mineral powder and 8% of the polycarboxylic acid modified surfactant in percentage by mass.

The anti-cracking agent obtained in the embodiment is added to the gel material according to 1%, 5% and 10% of the mass of the gel material, the anti-cracking concrete of the embodiment is obtained by uniformly mixing, the obtained anti-cracking concrete is tested, and the test results are shown in table 2:

TABLE 2

As can be seen from Table 2, the compressive strength and the crack resistance of the crack-resistant concrete are improved with the increase of the addition amount of the crack-resistant agent.

Example 3

the resin-based composite material of the fiber reinforcement adopts the leftover material for producing the glass fiber reinforced plastic pipeline.

The preparation of the anti-cracking agent in the embodiment: the fine powder of the polymer composite fiber obtained above, kaolin and melamine resin modified surfactant were uniformly mixed in a mixer to obtain the anti-cracking agent of the present example, which contains, by mass, 75% of the fine powder of the polymer composite fiber, 17% of kaolin and 8% of melamine resin modified surfactant.

The anti-cracking agent obtained in the embodiment is added to the gel material according to 1% and 10% of the mass of the gel material, the anti-cracking concrete of the embodiment is obtained by uniformly mixing, the obtained anti-cracking concrete is tested, and the test results are shown in table 3:

TABLE 3

As can be seen from Table 3, the compressive strength and the crack resistance of the crack-resistant concrete are improved with the increase of the addition amount of the crack-resistant agent.

Example 4

the resin-based composite material of the fiber reinforcement adopts the production of glass fiber reinforced plastic leftover materials.

The preparation of the anti-cracking agent in the embodiment: the fine powder of the polymer composite fiber obtained above, kaolin and a melamine resin modified surfactant were uniformly mixed in a mixer to obtain the anti-cracking agent of the present example, which contains, by mass, 80% of the fine powder of the polymer composite fiber, 12% of kaolin and 8% of the surfactant.

The anti-cracking agent obtained in the embodiment is added to the gel material according to 1% and 10% of the mass of the gel material, the anti-cracking concrete of the embodiment is obtained by uniformly mixing, the obtained anti-cracking concrete is tested, and the test results are shown in table 4:

TABLE 4

As can be seen from Table 4, the compressive strength and the crack resistance of the crack-resistant concrete are improved with the increase of the addition amount of the crack-resistant agent.

Example 5

The preparation of the anti-cracking agent in the embodiment: the fine powder of the polymer composite fiber obtained above, kaolin and a melamine resin modified surfactant were uniformly mixed in a mixer to obtain the anti-cracking agent of the present example, which contains, by mass, 85% of the fine powder of the polymer composite fiber, 10% of kaolin and 5% of the surfactant.

The anti-cracking agent obtained in the embodiment is added to the gel material according to 1% and 10% of the mass of the gel material, the anti-cracking concrete of the embodiment is obtained by uniformly mixing, the obtained anti-cracking concrete is tested, and the test results are shown in table 5:

TABLE 5

As can be seen from Table 5, the compressive strength and the crack resistance of the crack-resistant concrete are improved with the increase of the addition amount of the crack-resistant agent.

In conclusion, the beneficial effects of the invention are as follows:

1) the invention can take leftover waste generated in the production process of waste polymer composite fiber products as raw materials, realizes the reutilization of waste, and simultaneously reduces the pollution of solid waste to the environment.

2) The surface of the polymer composite fiber obtained by the invention is wrapped with at least one layer of resin, thereby providing protection for later use of the fiber reinforcement.

3) The filler adopted by the invention can be fly ash, mineral powder, calcium carbonate, kaolin, 4A zeolite and the like. The raw materials have wide sources, are suitable for production in various places, and reduce the cost.

4) The fine powder of the polymer composite fiber prepared by the invention can replace the application of polypropylene fiber, lignin fiber and rock wool in anti-cracking agents.

5) The anti-cracking agent prepared by the invention can effectively improve the strength and the viscosity of concrete, reduce the consumption of cement concrete and reduce the cost of construction units.

6) The specific heat capacity of the polymer composite fiber used in the invention is similar to that of cement, the expansion with heat and the contraction with cold are almost synchronously carried out, and the polymer composite fiber is not easy to fall off in the later period.

The anti-cracking agent for concrete provided by the invention has the advantages of strong adhesive force, heat resistance and excellent anti-cracking performance. The polymer composite fiber added into the concrete has higher temperature resistance, non-combustion, corrosion resistance, good heat insulation and sound insulation, high tensile strength and reduced creep compared with organic fiber. At least one layer of resin is coated on the surface of the fiber reinforcement, so that the further chemical reaction of specific components in the glass fiber and alkali substances in cement, additives, admixtures and the like in concrete under certain conditions can be prevented, and the phenomena of expansion, cracking and even damage of an anti-crack concrete structure can not be caused. The surfactant is added into the anti-cracking agent, so that the polymer composite fiber can be uniformly dispersed in the anti-cracking concrete, the polymer composite fiber can play a good supporting role in the anti-cracking concrete, and the fluidity and the construction performance of the anti-cracking concrete cannot be influenced.

Claims

1. The preparation method of the anti-crack concrete is characterized by comprising the following steps:

adding the anti-cracking agent into a gel material of concrete, and uniformly mixing to obtain the anti-cracking concrete;

the components of the anti-crack concrete comprise an anti-crack agent and a gel material, and the mass percentage of the components is as follows:

the mass of the anti-cracking agent is 1% -10% of that of the gel material;

the polymer composite fiber is processed by a resin-based composite material of a fiber reinforcement body, and the surface of the fiber reinforcement body is coated with at least one layer of resin;

the polymer composite fiber is processed by adopting a separation and dissociation device, the separation and dissociation device comprises a driving device, a bearing seat (8), a feeding bin (9), a conical screw shaft (10), an inner spiral conical barrel body (11) and an inner arc spherical gland (12), the conical screw shaft (10) is connected with the driving device through the bearing seat (8), the driving device can drive the conical screw shaft (10) to rotate, the feeding bin (9) is sleeved on the conical screw shaft (10), one end of the feeding bin (9) is installed on the bearing seat (8), the inner spiral conical barrel body (11) is sleeved on the conical screw shaft (10), one end of the inner spiral conical barrel body (11) is installed at the other end of the feeding bin (9), the inner arc spherical gland (12) is installed at the other end of the inner spiral conical barrel body (11), the conical screw shaft (10) extends out of the inner spiral conical barrel body (11) and extends into the inner arc spherical gland (12), a discharge hole is arranged on the inner arc spherical gland (12); a cooling device is arranged outside the inner spiral line conical barrel (11); a plurality of convex first spiral lines (10-3) are arranged on the conical spiral shaft (10), the conical spiral shaft (10) is in a round table shape, one end of the conical spiral shaft (10) connected with the driving device is a large end, and the other end of the conical spiral shaft is a small end; the inner cavity of the inner spiral line conical cylinder body (11) is in a round table shape, one end of the inner spiral line conical cylinder body (11) which is installed with the feeding bin (9) is a large end, and the other end of the inner spiral line conical cylinder body is a small end; a plurality of raised second spiral lines (11-1) are arranged on the inner surface of the inner spiral line conical barrel body (11); a gap is reserved between the second spiral line (11-1) and the first spiral line (10-3); a plurality of second bosses (10-2) are uniformly distributed on the end face of one end, close to the inner arc spherical gland (12), of the conical screw shaft (10), a plurality of third bosses (12-1) are uniformly distributed on the inner surface, close to the end part of the conical screw shaft (10), of the inner arc spherical gland (12), and a preset gap is reserved between the second bosses (10-2) and the third bosses (12-1);

the driving device drives the conical screw shaft (10) to rotate, resin-based composite materials of the fiber reinforcement are added into the feeding bin (9), the resin-based composite materials of the fiber reinforcement are conveyed into the inner spiral line conical barrel (11) from the feeding bin (9) by the rotating conical screw shaft (10), and in the inner spiral line conical barrel (11), the resin-based composite materials of the fiber reinforcement are repeatedly extruded, kneaded, sheared and separated by the first spiral line (10-3) and the second spiral line (11-1) between the conical screw shaft (10) and the inner spiral line conical barrel (11), so that the resin-based composite materials of the fiber reinforcement are dissociated, and the polymer composite fibers with at least one layer of resin wrapped on the surfaces of the glass fiber are obtained; grinding the polymer composite fiber between the end part of the conical screw shaft (10) and the inner arc spherical gland (12) by utilizing a second boss (10-2) and a third boss (12-1) to enable the polymer composite fiber to reach a preset fineness; the obtained polymer composite fiber with the preset fineness is extruded out from a discharge hole on the inner arc spherical gland (12).

2. The method of claim 1, wherein the surfactant is an anionic surfactant.

3. The method for preparing anti-crack concrete according to claim 1 or 2, wherein the surfactant is a polycarboxylic acid modified surfactant or a melamine resin modified surfactant.

4. The method for preparing anti-crack concrete according to claim 1, wherein the filler is one or a mixture of more of fly ash, mineral powder, calcium carbonate, kaolin and 4A zeolite.

5. The method for preparing the anti-crack concrete according to claim 1, wherein the resin-based composite material of the fiber reinforcement comprises one or a mixture of several of glass fiber reinforced plastic products, scrapped fan blades, leftover materials for producing the glass fiber reinforced plastic products, glass felts and glass meshes.

6. The method for preparing the anti-crack concrete according to claim 1, wherein the length of the polymer composite fiber is 3 mm-10 mm.

7. An anti-crack concrete, characterized in that the anti-crack concrete is prepared by the method of any one of claims 1 to 6.

8. The anti-crack concrete according to claim 7, wherein the anti-crack concrete 28d has a compressive strength of 43.5-46.5 MPa and a compressive ratio of 103-109%; the compression ratio of the anti-crack concrete 7d is 97-106%.