1. The rigid polymeric fiber for concrete crack resistance is characterized by comprising the following raw materials: 37-52% of polypropylene, 5-10% of blended resin, 5-10% of filler, 20-50% of fiber material and 3-7% of anti-cracking powder.

2. The rigid polymeric fiber for concrete crack resistance according to claim 1, wherein: the blended resin is selected from high density polyethylene.

3. The rigid polymeric fiber for concrete crack resistance according to claim 1, wherein: the filler is at least one selected from calcium silicate, wollastonite and calcium carbonate.

4. The rigid polymeric fiber for concrete crack resistance according to claim 1, wherein: the fiber material is selected from at least one of glass fiber, carbon fiber, asbestos fiber and metal fiber.

5. The rigid polymeric fiber for concrete crack resistance according to claim 1, wherein: the anti-cracking powder is prepared by mixing cement, a binder, sand, superfine fibers and a silane coupling agent in proportion.

6. The rigid polymeric fiber for concrete crack resistance according to claim 5, wherein: the superfine fiber in the anti-cracking agent is selected from superfine natural fiber, the superfine natural fiber is selected from at least one of animal fiber and plant fiber, and the monofilament fineness of the superfine fiber is 0.1-1.0 dtex.

7. The rigid polymeric fiber for concrete crack resistance according to claim 5, wherein: the mixing ratio of cement, binder, sand, superfine fiber and silane coupling agent in the anti-cracking powder is 5: 1-2: 5-10: 0.005-0.05: 0.0005: 0.01.

8. a process for producing a rigid polymeric fiber for concrete crack resistance, comprising the rigid polymeric fiber for concrete crack resistance of any one of claims 1 to 7, comprising the following steps of:

s1, adding cement, a binder, sand, superfine fibers and a silane coupling agent into a stirring kettle in proportion, adding water, stirring and mixing to obtain anti-cracking powder for later use;

s2, adding the polypropylene and the blending resin into a double-screw extruder, heating and melting, and stirring and mixing;

s3, adding a filling agent and a small amount of anti-cracking powder and mixing;

s4, slowly adding the fiber material, heating for plasticizing, finally extruding, drying and cutting into granules to obtain the polymer fiber;

s5, uniformly coating the anti-crack powder on the surface of the polymer fiber, heating and compacting, and repeatedly operating for 3-5 times to form the finished fiber.

9. The process for producing rigid polymeric fibers for concrete crack resistance according to claim 8, wherein: in the S3, the addition amount of the anti-crack powder is 1-5% of the total amount of the anti-crack powder.

10. The process for producing rigid polymeric fibers for concrete crack resistance according to claim 8, wherein: in the S5, the heating temperature is 190 ℃ to 220 ℃.

Background

The ultimate tensile rate of the concrete is low, generally 0.01-0.20%, while the tensile rate of the polypropylene fiber is up to 15-18%, the polypropylene monofilament fiber uniformly dispersed in the concrete not only prevents the sinking of aggregate, improves the workability and bleeding, reduces the segregation, but also effectively bears the tensile strain generated by the shrinkage of the concrete, delays or prevents the occurrence and development of micro cracks in the concrete and surface macro cracks, improves the impermeability of the concrete, prevents the expansion of concrete cracks when the polypropylene fiber concrete is subjected to impact load, improves the impact resistance, frost resistance, carbonization resistance and the like of the concrete;

however, the rigidity of the common polypropylene fiber is poor, and the crack resistance is general, so that the defects of the prior art are modified by a rigid polymer fiber for the crack resistance of concrete.

Disclosure of Invention

The invention aims to provide a production process of rigid polymeric fibers for concrete crack resistance, so as to solve the problems in the background technology.

In order to achieve the above objects, in one aspect, the present invention provides a rigid polymeric fiber for concrete crack resistance, comprising the following raw materials: 37-52% of polypropylene, 5-10% of blended resin, 5-10% of filler, 20-50% of fiber material and 3-7% of anti-cracking powder.

As a further improvement of the technical scheme, the blended resin is selected from high-density polyethylene, and the rigidity of polypropylene can be improved by blending with polypropylene.

As a further improvement of the technical scheme, the filler is selected from at least one of calcium silicate, wollastonite and calcium carbonate, and the rigidity of the polypropylene can be improved to a certain extent by filling modification, and meanwhile, the toughness is enhanced.

As a further improvement of the present technical solution, the fiber material is at least one selected from glass fiber, carbon fiber, asbestos fiber and metal fiber, and the mechanical properties of the modified polypropylene using the fiber material are improved.

As a further improvement of the technical scheme, the anti-cracking powder is prepared by mixing cement, a binder, sand, superfine fibers and a silane coupling agent in proportion.

As a further improvement of the technical scheme, the superfine fibers in the anti-cracking agent are selected from superfine natural fibers, the superfine natural fibers are selected from at least one of animal fibers and plant fibers, and the monofilament fineness of the superfine fibers is 0.1-1.0 dtex.

As a further improvement of the technical scheme, the mixing ratio of the cement, the binder, the sand, the superfine fiber and the silane coupling agent in the anti-cracking powder is 5: 1-2: 5-10: 0.005-0.05: 0.0005: 0.01, has the advantages of strong adhesive force, good water retention, high strength, excellent tear resistance and strong seepage-proofing capability.

In the invention, the added blending resin can not only improve the rigidity of the polypropylene, but also can be mixed with calcium silicate, wollastonite and calcium carbonate in the filler, thereby supplementing the lost tensile strength and impact strength after blending the polypropylene and the polyethylene and further improving the tensile strength and the impact strength;

in the invention, in order to avoid the problem of poor compatibility between the polypropylene and the blending resin and the filler, the surface of the filler is coated by the anti-permeability powder to improve the cohesiveness, so that the anti-permeability powder can be better bonded with the polypropylene and the blending resin.

In another aspect, the present invention provides a process for producing a rigid polymeric fiber for concrete crack resistance, including any one of the above rigid polymeric fibers for concrete crack resistance, including the following steps:

s1, adding cement, a binder, sand, superfine fibers and a silane coupling agent into a stirring kettle in proportion, adding water, stirring and mixing to obtain anti-cracking powder for later use;

s2, adding the polypropylene and the blending resin into a double-screw extruder, heating and melting, and stirring and mixing;

s3, adding a filling agent and a small amount of anti-cracking powder and mixing;

s4, slowly adding the fiber material, heating for plasticizing, finally extruding, drying and cutting into granules to obtain the polymer fiber;

s5, uniformly coating the anti-crack powder on the surface of the polymer fiber, heating and compacting, and repeatedly operating for 3-5 times to form the finished fiber.

Preferably, in S3, the addition amount of the anti-cracking powder is 1-5% of the total amount of the anti-cracking powder, so as to avoid that the addition amount is too much to hinder the production of the polymeric fiber and greatly increase the anti-cracking performance of the polymeric fiber.

Preferably, in the S5, the heating temperature is 190-220 ℃.

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

1. in the production process of the rigid polymeric fiber for concrete crack resistance, the added blending resin is selected from high-density polyethylene, the rigidity of polypropylene can be improved by blending with polypropylene, and the rigidity of polypropylene can be improved to a certain extent by filling modification of the added filler, and meanwhile, the toughness is enhanced.

2. In the production process of the rigid polymeric fiber for concrete crack resistance, crack resistance of finished fiber can be improved by coating crack resistance powder on the surface of the prepared polymeric fiber, and when the rigid polymeric fiber is added into concrete for stirring, the rigid polymeric fiber can be separated from the surface of the polymeric fiber and blended with the concrete, so that the crack resistance of the concrete is improved.

Drawings

FIG. 1 is an overall flow diagram of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the 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.

Example 1 a process for producing rigid polymeric fibers for use in crack resistance in concrete, comprising:

preparation of anti-cracking powder

Firstly, cement, a binder, sand, superfine fibers and a silane coupling agent are mixed according to the proportion of 5: 1-2: 5-10: 0.005-0.05: 0.0005: 0.01, adding the mixture into a stirring kettle in sequence, adding water, stirring and mixing to prepare anti-cracking powder for later use, wherein the superfine natural fiber is selected from at least one of animal fiber and plant fiber, and the monofilament fineness of the superfine fiber is 0.1-1.0 dtex;

preparation of Di-and poly-fibers

Adding 37% of polypropylene and 5% of blending resin into a double-screw extruder, heating and melting, and stirring and mixing; then 5% of filling agent and a small amount of anti-cracking powder are added and mixed, the addition amount of the anti-cracking powder is 1-5% of the total amount of the anti-cracking powder, so that the phenomenon that the production of the polymeric fiber is hindered due to excessive addition amount is avoided, and meanwhile, the anti-cracking performance of the polymeric fiber is greatly increased; slowly adding 50% of fiber material into the mixture, heating and plasticizing, finally extruding, drying and granulating to obtain the polymer fiber.

Thirdly, preparation of finished fiber

And (3) uniformly coating the anti-cracking powder on the surface of the polymer fiber, heating to 190-220 ℃ for compaction, and repeatedly operating for 3-5 times to form the finished fiber.

Example 2 a process for producing rigid polymeric fibers for use in crack resistance in concrete, comprising:

preparation of anti-cracking powder

Firstly, cement, a binder, sand, superfine fibers and a silane coupling agent are mixed according to the proportion of 5: 1-2: 5-10: 0.005-0.05: 0.0005: 0.01, adding the mixture into a stirring kettle in sequence, adding water, stirring and mixing to prepare anti-cracking powder for later use, wherein the superfine natural fiber is selected from at least one of animal fiber and plant fiber, and the monofilament fineness of the superfine fiber is 0.1-1.0 dtex;

preparation of Di-and poly-fibers

Adding 41% of polypropylene and 7% of blending resin into a double-screw extruder, heating and melting, and stirring and mixing; then 7% of filling agent and a small amount of anti-cracking powder are added and mixed, the addition amount of the anti-cracking powder is 1-5% of the total amount of the anti-cracking powder, so that the phenomenon that the production of the polymeric fiber is hindered due to excessive addition amount is avoided, and meanwhile, the anti-cracking performance of the polymeric fiber is greatly increased; and slowly adding 42.5% of fiber material into the mixture, heating and plasticizing, finally extruding, drying and granulating to obtain the polymer fiber.

Thirdly, preparation of finished fiber

And (3) uniformly coating the anti-cracking powder on the surface of the polymer fiber, heating to 190-220 ℃ for compaction, and repeatedly operating for 3-5 times to form the finished fiber.

Example 3 a process for producing a rigid polymeric fiber for crack resistance in concrete, comprising:

preparation of anti-cracking powder

Firstly, cement, a binder, sand, superfine fibers and a silane coupling agent are mixed according to the proportion of 5: 1-2: 5-10: 0.005-0.05: 0.0005: 0.01, adding the mixture into a stirring kettle in sequence, adding water, stirring and mixing to prepare anti-cracking powder for later use, wherein the superfine natural fiber is selected from at least one of animal fiber and plant fiber, and the monofilament fineness of the superfine fiber is 0.1-1.0 dtex;

preparation of Di-and poly-fibers

Adding 45% of polypropylene and 8% of blending resin into a double-screw extruder, heating and melting, and stirring and mixing; then 8% of filling agent and a small amount of anti-cracking powder are added and mixed, the addition amount of the anti-cracking powder is 1-5% of the total amount of the anti-cracking powder, so that the phenomenon that the production of the polymeric fiber is hindered due to excessive addition amount is avoided, and meanwhile, the anti-cracking performance of the polymeric fiber is greatly increased; slowly adding 35% of fiber material into the mixture, heating and plasticizing, finally extruding, drying and granulating to obtain the polymer fiber.

Thirdly, preparation of finished fiber

And (3) uniformly coating the anti-cracking powder on the surface of the polymer fiber, heating to 190-220 ℃ for compaction, and repeatedly operating for 3-5 times to form the finished fiber.

Example 4 a process for producing rigid polymeric fibers for use in crack resistance in concrete, comprising:

preparation of anti-cracking powder

Firstly, cement, a binder, sand, superfine fibers and a silane coupling agent are mixed according to the proportion of 5: 1-2: 5-10: 0.005-0.05: 0.0005: 0.01, adding the mixture into a stirring kettle in sequence, adding water, stirring and mixing to prepare anti-cracking powder for later use, wherein the superfine natural fiber is selected from at least one of animal fiber and plant fiber, and the monofilament fineness of the superfine fiber is 0.1-1.0 dtex;

preparation of Di-and poly-fibers

Adding 49% of polypropylene and 9% of blending resin into a double-screw extruder, heating and melting, and stirring and mixing; then 9% of filling agent and a small amount of anti-cracking powder are added and mixed, the addition amount of the anti-cracking powder is 1-5% of the total amount of the anti-cracking powder, so that the phenomenon that the production of the polymeric fiber is hindered due to excessive addition amount is avoided, and meanwhile, the anti-cracking performance of the polymeric fiber is greatly increased; and slowly adding 27.5% of fiber material into the mixture, heating and plasticizing, finally extruding, drying and granulating to obtain the polymer fiber.

Thirdly, preparation of finished fiber

And (3) uniformly coating the anti-cracking powder on the surface of the polymer fiber, heating to 190-220 ℃ for compaction, and repeatedly operating for 3-5 times to form the finished fiber.

Example 5 a process for producing a rigid polymeric fiber for crack resistance in concrete, comprising:

preparation of anti-cracking powder

Firstly, cement, a binder, sand, superfine fibers and a silane coupling agent are mixed according to the proportion of 5: 1-2: 5-10: 0.005-0.05: 0.0005: 0.01, adding the mixture into a stirring kettle in sequence, adding water, stirring and mixing to prepare anti-cracking powder for later use, wherein the superfine natural fiber is selected from at least one of animal fiber and plant fiber, and the monofilament fineness of the superfine fiber is 0.1-1.0 dtex;

preparation of Di-and poly-fibers

Adding 52% of polypropylene and 10% of blending resin into a double-screw extruder, heating and melting, and stirring and mixing; then 10% of filling agent and a small amount of anti-cracking powder are added and mixed, the addition amount of the anti-cracking powder is 1-5% of the total amount of the anti-cracking powder, so that the phenomenon that the production of the polymeric fiber is hindered due to excessive addition amount is avoided, and meanwhile, the anti-cracking performance of the polymeric fiber is greatly increased; slowly adding 20% of fiber material into the mixture, heating and plasticizing, finally extruding, drying and granulating to obtain the polymer fiber.

Thirdly, preparation of finished fiber

And (3) uniformly coating the anti-cracking powder on the surface of the polymer fiber, heating to 190-220 ℃ for compaction, and repeatedly operating for 3-5 times to form the finished fiber.

In the above, the blending resin is selected from high density polyethylene, and the rigidity of polypropylene can be improved by blending with polypropylene;

the filler is selected from at least one of calcium silicate, wollastonite and calcium carbonate, and the rigidity of the polypropylene can be improved to a certain extent through filling modification, and meanwhile, the toughness is enhanced;

the fiber material is selected from at least one of glass fiber, carbon fiber, asbestos fiber and metal fiber, and the mechanical property of the modified polypropylene adopting the fiber material is improved;

the added blending resin can not only improve the rigidity of the polypropylene, but also can be mixed with calcium silicate, wollastonite and calcium carbonate in the filler, thereby supplementing the lost tensile strength and impact strength after blending the polypropylene and the polyethylene and further improving the tensile strength and the impact strength;

in order to avoid the problem of poor compatibility between the polypropylene and the blended resin and the filler, the surface of the filler is coated with the impervious powder to improve the cohesiveness, so that the impervious powder can be better bonded with the polypropylene and the blended resin.

The rigid polymeric fiber for concrete crack resistance prepared by the invention has better crack resistance and mechanical property, and the method shows the relevant indexes of the rigid polymeric fiber for concrete crack resistance, and concretely shows that the indexes are shown in the following table 1:

TABLE 1

	Crack resistance Strength (MPa)	Compressive strength (MPa)	Tensile Strength (MPa)	Modulus of elasticity (GPa)
					Example 1	7.5	30.1	403	4.2
Example 2	8.1	32.0	439	3.9
					Example 3	9.6	35.7	453	3.5
Example 4	7.9	29.8	431	3.7
					Example 5	7.1	31.7	401	4.1

According to table 1, the rigid polymeric fibers for concrete crack resistance prepared by the invention have better mechanical properties in examples 1-5, and when 45% of polypropylene, 8% of blending resin, 8% of filler and 35% of fiber material are used, the mechanical properties and crack resistance of the polymeric fibers are optimal, so that the rigid polymeric fibers for concrete crack resistance prepared by using the material in example 3 have better comprehensive properties.

Comparative example 1 a process for producing a rigid polymeric fiber for concrete crack resistance, comprising:

preparation of polymeric fibers

Adding 45% of polypropylene and 8% of blending resin into a double-screw extruder, heating and melting, and stirring and mixing; then adding 8% of filling agent; slowly adding 35% of fiber material into the mixture, heating and plasticizing, finally extruding, drying and granulating to obtain the polymer fiber.

Comparative example 2 a process for producing a rigid polymeric fiber for concrete crack resistance, comprising:

preparation of anti-cracking powder

Firstly, cement, a binder, sand, superfine fibers and a silane coupling agent are mixed according to the proportion of 5: 1-2: 5-10: 0.005-0.05: 0.0005: 0.01, adding the mixture into a stirring kettle in sequence, adding water, stirring and mixing to prepare anti-cracking powder for later use, wherein the superfine natural fiber is selected from at least one of animal fiber and plant fiber, and the monofilament fineness of the superfine fiber is 0.1-1.0 dtex;

preparation of Di-and poly-fibers

Adding 45% of polypropylene into a double-screw extruder, heating and melting, and stirring and mixing; then 8% of filling agent and a small amount of anti-cracking powder are added and mixed, the addition amount of the anti-cracking powder is 1-5% of the total amount of the anti-cracking powder, so that the phenomenon that the production of the polymeric fiber is hindered due to excessive addition amount is avoided, and meanwhile, the anti-cracking performance of the polymeric fiber is greatly increased; slowly adding 35% of fiber material into the mixture, heating and plasticizing, finally extruding, drying and granulating to obtain the polymer fiber.

Thirdly, preparation of finished fiber

And (3) uniformly coating the anti-cracking powder on the surface of the polymer fiber, heating to 190-220 ℃ for compaction, and repeatedly operating for 3-5 times to form the finished fiber.

Comparative example 3 a process for producing a rigid polymeric fiber for concrete crack resistance, comprising:

preparation of anti-cracking powder

Firstly, cement, a binder, sand, superfine fibers and a silane coupling agent are mixed according to the proportion of 5: 1-2: 5-10: 0.005-0.05: 0.0005: 0.01, adding the mixture into a stirring kettle in sequence, adding water, stirring and mixing to prepare anti-cracking powder for later use, wherein the superfine natural fiber is selected from at least one of animal fiber and plant fiber, and the monofilament fineness of the superfine fiber is 0.1-1.0 dtex;

preparation of Di-and poly-fibers

Adding 45% of polypropylene and 8% of blending resin into a double-screw extruder, heating and melting, and stirring and mixing; slowly adding 35% of fiber material into the mixture, heating and plasticizing, finally extruding, drying and granulating to obtain the polymer fiber.

Thirdly, preparation of finished fiber

And (3) uniformly coating the anti-cracking powder on the surface of the polymer fiber, heating to 190-220 ℃ for compaction, and repeatedly operating for 3-5 times to form the finished fiber.

Comparative example 4 a process for producing a rigid polymeric fiber for concrete crack resistance, comprising:

preparation of anti-cracking powder

Firstly, cement, a binder, sand, superfine fibers and a silane coupling agent are mixed according to the proportion of 5: 1-2: 5-10: 0.005-0.05: 0.0005: 0.01, adding the mixture into a stirring kettle in sequence, adding water, stirring and mixing to prepare anti-cracking powder for later use, wherein the superfine natural fiber is selected from at least one of animal fiber and plant fiber, and the monofilament fineness of the superfine fiber is 0.1-1.0 dtex;

preparation of Di-and poly-fibers

Adding 45% of polypropylene and 8% of blending resin into a double-screw extruder, heating and melting, and stirring and mixing; then adding 8% of filling agent; slowly adding 35% of fiber material into the mixture, heating and plasticizing, finally extruding, drying and granulating to obtain the polymer fiber.

Thirdly, preparation of finished fiber

And (3) uniformly coating the anti-cracking powder on the surface of the polymer fiber, heating to 190-220 ℃ for compaction, and repeatedly operating for 3-5 times to form the finished fiber.

The rigid polymeric fiber for concrete crack resistance prepared by the invention has better mechanical property and crack resistance, has a larger relationship with crack resistance powder, blending resin and filler added into the rigid polymeric fiber, and in order to verify the related technical scheme, the applicant performs the following tests:

comparative examples 1 to 3: by adopting the method of embodiment 3, the relevant indexes of the prepared polymeric fiber are detected under the condition of removing the anti-cracking powder, the blending resin and the filler;

comparative example 4: by adopting the method of example 3, the relevant indexes of the prepared polymeric fiber are detected under the condition that the added anti-cracking powder is removed in the polymeric fiber preparation process, and are specifically shown in table 2:

TABLE 2

As shown in Table 2, the crack resistance of the polymeric fiber is minimized in comparative example 1 in case of removing the crack resistant powder, the compressive strength and tensile strength of the polymeric fiber are minimized and the elastic modulus is increased in comparative examples 2 to 3 in case of removing the blended resin, and the compressive strength and tensile strength of the polymeric fiber are reduced to various degrees in comparative example 4 in case of removing the added crack resistant powder in the process of preparing the polymeric fiber, so that it can be seen that the rigid polymeric fiber for concrete crack resistance prepared by using the material of the present invention is superior in mechanical properties and crack resistance.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and the preferred embodiments of the present invention are described in the above embodiments and the description, and are not intended to limit the present invention. The scope of the invention is defined by the appended claims and equivalents thereof.