CN201769264U - Device for preparing steel fiber reinforced cement-based materials in one-way distribution - Google Patents

Abstract

The utility model discloses equipment for preparing unidirectionally distributed steel fiber reinforced cement-based materials, which is composed of a vibrating table, a coil and a DC power supply. Among them, the vibrating table has no magnetic adsorption, its amplitude is 0.5±0.2mm, and the vibration frequency is 2850 times/min; the number of turns of the coil is 100-3000 turns, and the length is 100-550mm. The shape and size of the cavity in the skeleton are based on The shape and size of the non-metallic test mold poured into the steel fiber cement-based material mixture are determined. When the voltage is 1-30 volts and the current is 0.1-20 amperes. A magnetic field with a magnetic induction intensity of 1.0×10 ^-3 T to 20.0×10 ^-3 T will be generated in the hollow cavity. The unidirectional distributed steel fiber reinforced cement-based material prepared by this equipment has a flexural strength of 20%-100% higher than that of the steel fiber-reinforced cement-based material prepared by the existing method, or saves 25%-60% of steel fiber .

Description

Equipment for preparing unidirectional distributed steel fiber reinforced cement-based materials

technical field

The technical scheme of the utility model relates to steel fiber reinforced cement-based materials, in particular to equipment for preparing unidirectionally distributed steel fiber reinforced cement-based materials.

Background technique

Cement-based materials (including concrete, mortar and cement slurry, etc.) are the most widely used and one of the most important engineering materials in construction projects such as civil engineering, transportation and water conservancy. Cement-based materials are characterized by high compressive strength, low tensile strength, small ultimate strain and high brittleness. Due to these characteristics, cement-based materials have poor toughness and are prone to cracking. After cracking, the steel bars at the cracks cannot be effectively protected by cement-based materials, and may corrode prematurely, reducing the durability of the structure, which has become one of the most important factors affecting the quality of the project and the service life of the project. Adding steel fiber is one of the most effective methods to improve the crack resistance and toughness of cement-based materials and improve the tensile properties. After steel fibers are added to the cement-based material, the steel fibers in the same direction as the tensile stress can effectively share the tensile stress. For the cracks that have already occurred, the steel fibers across both sides of the crack can prevent the further development of the crack and reduce the width of the crack. Thereby improving the crack resistance of cement-based materials. However, the effect of steel fibers that are not completely consistent with the direction of tensile stress in improving the crack resistance of cement-based materials decreases with the deviation of the direction, and steel fibers perpendicular to the direction of tensile stress have little effect on improving the crack resistance of cement-based materials. .

The preparation process of the existing steel fiber reinforced cement-based material is to mix raw materials such as cement and steel fibers together, add mixing water and stir evenly, put it into a mold, vibrate and compact it, and harden it into an engineering material. In the steel fiber reinforced cement-based material formed according to this process, the steel fibers are randomly distributed in the cement-based material. Cement-based materials in actual engineering are subject to different directions of specific loads depending on the location. Often, some cement-based materials are under long-term compression and the other part is under long-term tension, and the stress direction generally does not change. Therefore, when the unidirectional distributed steel fiber reinforced cement-based material is prepared by the existing technology, only a small part of the steel fiber that is consistent with or close to the direction of the tensile stress plays the role of crack resistance. On the other hand, the distribution density of effective steel fibers must reach a certain value in order to truly resist cracking. To solve this problem, the method of increasing the overall content of steel fibers is generally adopted in engineering, so that even if they are randomly distributed, the steel along the direction of tensile stress There are still enough fibers to bear the corresponding load, and the performance of cement-based materials can be improved. The disadvantage of this is that the effective utilization efficiency of steel fibers in cement-based materials is very low, and most of the steel fibers cannot play their due role. At the same time, it also leads to a substantial increase in the cost of raw materials for steel fiber reinforced cement-based materials.

Utility model content

The technical problem to be solved by the utility model is: provide equipment for preparing unidirectionally distributed steel fiber reinforced cement-based material, and the unidirectionally distributed steel fiber reinforced cement-based material prepared by this equipment has a higher flexural strength than the existing method The prepared steel fiber reinforced cement base material increases by 20% to 100%, or saves steel fiber by 25% to 60%.

The technical solution adopted by the utility model to solve the technical problem is:

The equipment for preparing unidirectional distributed steel fiber reinforced cement-based materials consists of a vibrating table, a coil and a DC power supply.

The above-mentioned equipment for preparing unidirectionally distributed steel fiber reinforced cement-based materials, the vibrating table is a mechanical concrete vibrating table, a mechanical mortar vibrating table or a mechanical cement slurry vibrating table, wherein the mechanical concrete vibrating table has no magnetic adsorption, and its amplitude The vibration frequency is 0.5±0.2mm, and the vibration frequency is 2850 times/min, which is in line with the regulations of "Vibrating Table for Concrete Test" (JGT 3020-94) or other relevant industry standards; the mechanical mortar shaking table has no magnetic adsorption, and its amplitude is 0.5±0.2 mm, the vibration frequency is 2850 times/min, which conforms to the regulations of "Cement Physical Test Instruments for Plastic Sand Vibration Table" (JCT723-2005) or other relevant industry standards; the mechanical cement slurry vibration table has no magnetic adsorption, and its amplitude is 0.5±0.2mm , The vibration frequency is 2850 times/min, which is in line with the regulations of "Cement Physical Testing Instrument Mortar Vibrating Table" (JCT723-2005) or other relevant industry standards.

The above-mentioned equipment for preparing unidirectional distributed steel fiber reinforced cement-based materials, the number of turns of the coil is 100 to 3000 turns, and the length is 100 to 550mm. The shape and size of the non-metallic test mold of the steel fiber concrete mixture are determined, and the non-metallic test mold poured into the steel fiber cement-based material mixture is allowed to be placed in it. When the DC current is 0.1-20 A, a magnetic field with a magnetic induction intensity of 1.0×10 ^-3 T-20.0×10 ^-3 T will be generated in the hollow cavity of the coil.

For the above-mentioned equipment for preparing unidirectionally distributed steel fiber reinforced cement-based materials, the DC power supply can provide an output DC voltage of 0-30 volts and a DC current of 0-20 A.

The above-mentioned equipment for preparing unidirectionally distributed steel fiber reinforced cement-based materials, the DC power supply, coil and vibrating table are all commonly used equipment in this technical field, which can be made by those skilled in the art or purchased commercially.

The above-mentioned equipment for preparing unidirectional distribution steel fiber reinforced cement-based material is used for the method of preparing unidirectional distribution steel fiber reinforced cement-based material as follows:

The first step is to prepare the steel fiber cement-based material mixture

According to the mixing ratio of the steel fiber cement-based material components determined by known design methods, the required amount of ordinary cement-based material raw materials and steel fibers during actual operation are weighed, and the weighed ordinary cement-based material raw materials and steel fibers are weighed. Put it into the mixer and mix evenly to prepare the steel fiber cement-based material mixture;

The second step, pouring into the test mold

Pour the steel fiber cement-based material mixture prepared in the first step into the non-metallic test mold;

The third step is to apply a magnetic field

The non-metallic test mold poured into the steel fiber cement-based material mixture prepared in the first step obtained in the second step is placed in the hollow cavity of the coil of the equipment for preparing unidirectionally distributed steel fiber reinforced cement-based materials, Then place the coil and the trial mold together on the vibrating table of the above-mentioned equipment, turn on the DC power supply of the above-mentioned equipment to energize the coil to form a magnetic field, so as to apply a magnetic field to the steel fiber cement-based material mixture prepared in the first step, the direction of the magnetic field Keep consistent with the direction of the tensile stress during the test or working state of the specimen, the magnetic induction intensity in the above coil is 1.0×10 ^-3 T～20.0×10 ^-3 T, turn on the vibration table of the above equipment to vibrate for 30 to 300 seconds, and then Turn off the vibrating table of the above-mentioned equipment in turn, cut off the DC power supply of the above-mentioned coil, and move the non-metallic test mold poured with the steel fiber cement-based material mixture prepared in the first step out of the hollow cavity of the coil skeleton, and place it on the ground or on the bench;

The fourth step, demoulding and maintenance

Gently smooth the surface of the steel fiber cement-based material mixture specimen in the non-metallic test mold after applying the magnetic field in the third step, let it stand, remove the formwork, and obtain the unidirectional distribution steel fiber reinforced cement-based material after curing .

The above-mentioned equipment for preparing unidirectionally distributed steel fiber reinforced cement-based materials, specifically, is the equipment for preparing unidirectionally distributed steel fiber reinforced concrete, the equipment for preparing unidirectionally distributed steel fiber reinforced mortar, or the equipment for preparing unidirectionally distributed steel fiber reinforced Equipment for grout.

The above-mentioned equipment for preparing unidirectional distribution steel fiber reinforced cement-based material is used for the method of preparing unidirectional distribution steel fiber reinforced cement-based material, specifically, it is a method for preparing unidirectional distribution steel fiber A method for fiber-reinforced mortar or a method for preparing unidirectionally distributed steel fiber-reinforced cement slurry.

The beneficial effects of the utility model are:

(1) Principle

A magnetic field is applied to the steel fiber cement-based material mixture, and the fibrous steel will be magnetized in a strong magnetic field. When the fiber direction is not perpendicular to the magnetic field direction, a magnetic S pole and a magnetic N pole are formed at both ends of the fiber. The external magnetic field magnetizes the steel fibers in the cement-based material mixture into small magnets with two poles at both ends, and then under the action of the directional magnetic field, the two ends of the magnetized steel fibers are respectively subjected to equal and opposite forces. When the mixture is in a liquefied state during the vibration process, the steel fibers in it will rotate under the action of the magnetic field, and the direction tends to be consistent with the direction of the magnetic field, thus forming a unidirectional or directional distribution. It can be seen that the method and equipment for preparing unidirectionally distributed steel fiber reinforced cement-based materials in the present invention completely overcome the steel fiber reinforced cement-based materials formed by the prior art process, the steel fibers are randomly distributed in the cement-based materials, and the cement-based materials The effective utilization efficiency of the steel fiber in the material is very low, and a large part of the steel fiber cannot play its due role. At the same time, it also leads to a substantial increase in the raw material cost of the steel fiber reinforced cement-based material, which has outstanding substantive characteristics.

(2) practice

After a lot of research, the inventor has developed equipment for preparing unidirectionally distributed steel fiber reinforced cement-based materials. During the application process, the voltage and current of the DC power supply are adjusted according to the workability of the fresh cement-based material and the size and shape of the steel fiber to control the magnetic induction intensity in the inner space of the coil. Practice has proved that the better the workability of the steel fiber cement-based material mixture, the smaller the magnetic induction intensity of the required magnetic field. On the contrary, the worse the workability of the mixture, the need to increase the current and increase the magnetic induction intensity of the magnetic field.

(3) Effect

Compared with the steel fiber cement-based material prepared by the method of the prior art: if the raw material mixing ratio is exactly the same, the flexural strength of the unidirectionally distributed steel fiber cement-based material prepared by the method and equipment of the present invention is increased by 20% to 100% %; if the product flexural strength is the same, prepare unidirectionally distributed steel fiber cement-based material with the method and equipment of the present invention, wherein the consumption of steel fibers reduces by 25% to 60%, as can be seen, the present invention has significant advantages compared with the prior art improvement.

Description of drawings

Below in conjunction with accompanying drawing and embodiment the utility model is further described.

Fig. 1 is a structural schematic diagram of the equipment for preparing unidirectionally distributed steel fiber reinforced cement-based materials according to the present invention.

Fig. 2 is a schematic diagram of a DC power supply of the equipment for preparing unidirectionally distributed steel fiber reinforced cement-based materials according to the present invention.

Fig. 3 is a coil schematic diagram of the equipment for preparing unidirectionally distributed steel fiber reinforced cement-based materials according to the present invention.

Fig. 4 is a coil cross-sectional schematic diagram of the equipment for preparing unidirectionally distributed steel fiber reinforced cement-based materials according to the present invention.

Fig. 5 is a schematic diagram of a vibrating table of the equipment for preparing unidirectionally distributed steel fiber reinforced cement-based materials according to the present invention.

In the figure, 1. DC power supply, 2. Coil, 3. Vibration table, 4. Current control knob, 5. Switch.

Detailed ways

The embodiment shown in Fig. 1 shows that the equipment for preparing unidirectional distributed steel fiber reinforced cement-based materials in the present invention is composed of a DC power supply 1, a coil 2 and a vibrating table 3, wherein the DC power supply 1 has an alternating current (AC) input terminal and a direct current output terminal, the DC output terminal is connected to the coil 2, the switch 5 of the DC power supply 1 controls whether to provide DC power for the coil 2, and the current control knob 4 of the DC power supply 1 controls the voltage and current of the coil 2 to provide DC power; the coil 2 is placed on on shaker 3.

The embodiment shown in Figure 2 shows that the DC power supply 1 of the equipment for preparing unidirectional distributed steel fiber reinforced cement-based materials of the present invention is provided with an alternating current (AC) input terminal, a direct current output terminal, a switch 5 and a current control knob 4.

The embodiment shown in Figure 3 shows that the utility model prepares the coil 2 of the equipment for unidirectionally distributed steel fiber reinforced cement-based materials, the number of turns is 100-3000 turns, and the length 1 is 100-550mm, which is guaranteed to be longer than the skeleton placed in the coil The length of the non-metallic test mold in the hollow cavity. The coil 2 is connected to the direct current output terminal (DC) of the direct current power source 1 .

The embodiment shown in Fig. 4 shows that the utility model prepares the coil 2 of the equipment for unidirectionally distributed steel fiber reinforced cement-based materials, wherein the cavity cross section is square, and the size is determined according to the test mold inserted.

The embodiment shown in Fig. 5 shows that the vibrating table 3 of the equipment for preparing unidirectionally distributed steel fiber reinforced cement-based materials according to the present invention is of a size that can place coils and test molds.

Example 1

The first step is to prepare the steel fiber concrete mixture

According to known design methods, the strength grade determined by the known design method is that the mass mix ratio of the concrete components of C40 is water: cement: fly ash: sand: stone: high-efficiency water reducer: steel fiber=180: 375: 75: 780 : 990: 2.2: 47 Weigh the required amount of water, cement, fly ash, sand, stone, high-efficiency water reducer and steel fiber, the steel fiber used is made of low carbon steel material by cutting technology, with a diameter of 0.5mm, The aspect ratio is 40. Put the weighed cement, fly ash, sand and stone into the dry material of the mixer and mix evenly, then put in all the weighed steel fibers while stirring until evenly mixed, then add the weighed mixing water and high-efficiency water reducing agent, continue to stir for 90 seconds, and the slump of the concrete mixture is 160mm;

The second step, pouring into the test mold

Pour the steel fiber concrete mixture prepared in the first step into a non-metallic test mold of 100mm×100mm×400mm;

The third step is to apply a magnetic field

The non-metallic test mold obtained in the second step and poured with the steel fiber concrete mixture prepared in the first step is placed in the hollow cavity of the coil skeleton of the equipment for preparing unidirectional distribution steel fiber reinforced concrete, and then the coil Put it together with the test mold on the vibrating table of the above-mentioned equipment, turn on the DC power supply of the above-mentioned equipment to energize the coil to form a magnetic field, so as to apply a magnetic field to the steel fiber concrete mixture prepared in the first step, the direction of the magnetic field is the same as that of the test piece or work The direction of the tensile stress in the state is consistent or determined according to the design requirements. The magnetic induction intensity in the above coil is 3.0×10 ^-3 T. Turn on the vibrating table of the above equipment to vibrate for 90 seconds, then turn off the vibrating table of the above equipment in sequence, and cut off the above The DC power supply of the coil, and the non-metallic test mold poured with the steel fiber concrete mixture prepared in the first step is removed from the hollow cavity of the coil skeleton and placed on the ground or on the test bench;

The fourth step, demoulding and maintenance

After applying the magnetic field in the third step, the surface of the steel fiber concrete mixture specimen in the non-metallic test mold is lightly smoothed and placed in the indoor environment, the surface is covered with plastic film, the mold is removed after 24 hours, and it is moved into the curing room for curing , keep the temperature at 20+2°C, relative humidity ≥90%, take the specimen out of the curing room when it is cured to the specified 28d age, and obtain unidirectional distribution of steel fiber reinforced concrete, according to GBJ 81-1985 "Mechanical Properties of Ordinary Concrete Test method "The measured flexural strength is 8.70MPa.

Comparative Example 1

Except the lack of the third step in Example 1, other processes are the same as Example 1.

When curing to the specified age of 28 days, the specimens were taken out from the curing room to obtain steel fiber reinforced concrete with non-unidirectional distribution. According to GBJ 81-1985 "Test Methods for Mechanical Properties of Ordinary Concrete", the flexural strength was 6.95MPa. .

Example 1 and Comparative Example 1 have the same raw material ratio and steel fiber consumption, and the 28d flexural strength of the unidirectionally distributed steel fiber reinforced concrete obtained in Example 1 is higher than that of the non-unidirectionally distributed steel fiber obtained in Comparative Example 1 The 28d flexural strength of reinforced concrete is increased by 25%.

Example 2

The first step is to prepare the steel fiber concrete mixture

According to the known design method, the mass mix ratio of the concrete components whose strength grade is C55 is water: cement: fly ash: sand: stone: superplasticizer: steel fiber=170:385:95:775 : 980: 3.0: 117 Weigh the required amount of water, cement, fly ash, sand, stone, high-efficiency water reducer and steel fiber, the steel fiber used is made of low carbon steel material by cutting technology, with a diameter of 0.5mm, The aspect ratio is 40. Put the weighed cement, fly ash, sand and stone into the dry material of the mixer and mix evenly, then put in all the weighed steel fibers while stirring until evenly mixed, then add the weighed mixing water and high-efficiency water reducing agent, continue stirring for 300 seconds, and the slump of the concrete mixture is 40mm;

The second step, pouring into the test mold

Pour the steel fiber concrete mixture prepared in the first step into a non-metallic test mold of 100mm×100mm×400mm;

The third step is to apply a magnetic field

The non-metallic test mold obtained in the second step and poured with the steel fiber concrete mixture prepared in the first step is placed in the hollow cavity of the coil skeleton of the equipment for preparing unidirectional distribution steel fiber reinforced concrete, and then the coil Put it together with the test mold on the vibrating table of the above-mentioned equipment, turn on the DC power supply of the above-mentioned equipment to energize the coil to form a magnetic field, so as to apply a magnetic field to the steel fiber concrete mixture prepared in the first step, the direction of the magnetic field is the same as that of the test piece or work The direction of the tensile stress in the state is consistent or determined according to the design requirements. The magnetic induction intensity in the above-mentioned coil is 12.0×10 ^-3 T. Turn on the vibrating table of the above-mentioned equipment to vibrate for 180 seconds, then turn off the vibrating table of the above-mentioned equipment in sequence, and cut off the above-mentioned The DC power supply of the coil, and the non-metallic test mold poured with the steel fiber concrete mixture prepared in the first step is removed from the hollow cavity of the coil skeleton and placed on the ground or on the test bench;

The fourth step, demoulding and maintenance

After applying the magnetic field in the third step, the surface of the steel fiber concrete mixture specimen in the non-metallic test mold is lightly smoothed and placed in the indoor environment, the surface is covered with plastic film, the mold is removed after 24 hours, and it is moved into the curing room for curing , keep the temperature at 20±2°C, relative humidity ≥90%, take the specimen out of the curing room when it is cured to the specified age of 28 days, and obtain unidirectional distributed steel fiber reinforced concrete, according to GBJ 81-1985 "Mechanical Properties of Ordinary Concrete Test method "The measured flexural strength is 20.4MPa.

Comparative Example 2

Except lacking the third step in embodiment 2, other processes are identical with embodiment 2.

When curing to the specified age of 28 days, the specimen was taken out from the curing room to obtain steel fiber reinforced concrete with non-unidirectional distribution. According to GBJ 81-1985 "Test Method for Mechanical Properties of Ordinary Concrete", its flexural strength was 11.2MPa. .

Embodiment 2 and comparative example 2 have the same raw material ratio and steel fiber consumption, and the 28d flexural strength of the unidirectionally distributed steel fiber reinforced concrete obtained in embodiment 2 is higher than that of the non-unidirectionally distributed steel fiber reinforced concrete obtained in comparative example 2. The 28d flexural strength of fiber reinforced concrete is increased by 100%.

Example 3

The first step is to prepare the steel fiber concrete mixture

According to the known design method, the mass ratio of the concrete components whose strength grade is C45 is water: cement: fly ash: sand: stone: superplasticizer: steel fiber=165:430:0:815: 970:3.2:47 Weigh the required amount of water, cement, fly ash, sand, stone, high-efficiency water reducer and steel fiber. The steel fiber used is made of low carbon steel material by cutting process, with a diameter of 0.5mm and a length of The diameter ratio is 40. Put the weighed cement, fly ash, sand and stone into the dry material of the mixer and mix evenly, then put in all the weighed steel fibers while stirring until evenly mixed, then add the weighed mixing water and high-efficiency water reducing agent, continue to stir for 180 seconds, and the slump of the concrete mixture is 135mm;

The second step, pouring into the test mold

Pour the steel fiber concrete mixture prepared in the first step into a non-metallic test mold of 100mm×100mm×400mm;

The third step is to apply a magnetic field

The non-metallic test mold obtained in the second step and poured with the steel fiber concrete mixture prepared in the first step is placed in the hollow cavity of the coil skeleton of the equipment for preparing unidirectional distribution steel fiber reinforced concrete, and then the coil Put it together with the test mold on the vibrating table of the above-mentioned equipment, turn on the DC power supply of the above-mentioned equipment to energize the coil to form a magnetic field, so as to apply a magnetic field to the steel fiber concrete mixture prepared in the first step, the direction of the magnetic field is the same as that of the test piece or work The direction of the tensile stress in the state is consistent or determined according to the design requirements. The magnetic induction intensity in the above coil is 10.0×10 ^-3 T. Turn on the vibration table of the above equipment to vibrate for 240 seconds, and then turn off the vibration table of the above equipment in sequence, cut off the above The DC power supply of the coil, and the non-metallic test mold poured with the steel fiber concrete mixture prepared in the first step is removed from the hollow cavity of the coil skeleton and placed on the ground or on the test bench;

The fourth step, demoulding and maintenance

After applying the magnetic field in the third step, the surface of the steel fiber concrete mixture specimen in the non-metallic test mold is lightly smoothed and placed in the indoor environment, the surface is covered with plastic film, the mold is removed after 24 hours, and it is moved into the curing room for curing , keep the temperature at 20+1°C, relative humidity ≥95%, take the specimen out of the curing room when it is cured to the specified 28d age, and obtain unidirectional distributed steel fiber reinforced concrete, according to GBJ 81-1985 "Mechanical Properties of Ordinary Concrete Test method "The measured flexural strength is 9.7MPa.

Comparative Example 3

Except that the prescribed mass ratio of raw materials used in the first step is: water: cement: fly ash: sand: stone: superplasticizer: steel fiber=165: 430: 0: 805: 940: 3.2: 117 and lack of embodiment Except the 3rd step in 3, other technology is identical with embodiment 3.

When curing to the specified age of 28 days, the specimen was taken out from the curing room to obtain steel fiber reinforced concrete with non-unidirectional distribution. According to GBJ 81-1985 "Test Method for Mechanical Properties of Ordinary Concrete", its flexural strength was 9.6MPa. .

The 28d flexural strength of Example 3 is basically the same as that of Comparative Example 3, and the steel fiber consumption of the unidirectionally distributed steel fiber reinforced concrete obtained in Example 3 is only the non-unidirectionally distributed steel fiber reinforced concrete obtained in Comparative Example 3 Half of the steel fiber consumption is reduced by 60%.

Among the above-mentioned embodiments 1-3: the number of turns of the coil of the equipment used to prepare unidirectional distributed steel fiber reinforced concrete is selected within the range of 300-1000 turns and the length l is 100-550 mm, so as to ensure that it is longer than the skeleton placed in the coil The length of the non-metallic test mold in the hollow cavity, the shape and size of the cavity in its skeleton is determined according to the shape and size of the non-metallic test mold poured into the steel fiber concrete mixture, allowing the pouring The non-metallic test mold of the steel fiber concrete mixture is placed in it; the vibration table of the equipment for preparing unidirectional distribution steel fiber reinforced concrete is a mechanical concrete vibration table without magnetic adsorption, and its amplitude is 0.5 ± 0.2mm, The vibration frequency is 2850 times/min, which complies with the regulations of "Vibrating Table for Concrete Test" (JGT 3020-94) or other relevant industry standards.

Example 4

The first step is to prepare the steel fiber mortar mixture

According to the known design method, the mass ratio of the mortar composition components determined by the strength grade of M5 is water: cement: sand: superplasticizer=0.56: 1: 3: 0.003, and the required amount during actual operation is weighed Water: cement and sand, and steel fibers with a volume content of 1.5% are added to ordinary mortar (the densities of steel, cement, and water are 7800kg/m ³ , 3100kg/m ³ , and 1000kg/m ³ respectively, according to This determines the required steel fiber quality), the steel fiber used is a steel wire cut-off steel fiber, the length is 13mm, and the aspect ratio is 40. First put the weighed cement and sand into the dry material of the mortar mixer and stir evenly, then put in the weighed steel fiber while stirring, then add the weighed mixing water and high-efficiency water reducer, continue stirring for 60 seconds and then discharge , the measured consistency of the steel fiber mortar mixture is 120mm;

The second step, pouring into the test mold

Pour the steel fiber mortar mixture prepared in the first step into a non-metallic test mold of 40mm×40mm×160mm;

The third step is to apply a magnetic field

Place the non-metallic test mold poured into the steel fiber mortar mixture prepared in the first step obtained in the second step in the hollow cavity of the coil of the equipment for preparing unidirectional distribution steel fiber reinforced mortar, and then the coil Put it together with the test mold on the vibrating table of the above-mentioned equipment, turn on the DC power supply of the above-mentioned equipment to energize the coil to form a magnetic field, so as to apply a magnetic field to the steel fiber mortar mixture prepared in the first step, the direction of the magnetic field is the same as that of the test piece or work The direction of the tensile stress in the state is consistent or determined according to the design requirements. The magnetic induction intensity in the above-mentioned coil is 1.0×10 ^-3 T. Turn on the vibrating table of the above-mentioned equipment for 30 seconds, and then turn off the vibrating table of the above-mentioned equipment in sequence, and cut off the above-mentioned The DC power supply of the coil, and the non-metallic test mold poured with the steel fiber mortar mixture prepared in the first step is removed from the hollow cavity of the coil skeleton and placed on the ground or on the test bench;

The fourth step, demoulding and maintenance

Gently smooth the surface of the steel fiber mortar mixture specimen in the non-metallic test mold after applying the magnetic field in the third step, then place it in the indoor environment, cover the surface with plastic film, remove the mold after 24 hours, and move it into the curing room for curing , keep the temperature at 20+2°C, relative humidity ≥90%, take the specimen out of the curing room when it is cured to the specified 28d age, and obtain unidirectional distributed steel fiber reinforced mortar, according to GB/T 17671 "Cement mortar strength Inspection method "The measured flexural strength is 7.65MPa.

Comparative Example 4

Except lacking the third step in embodiment 4, other processes are identical with embodiment 4.

When curing to the specified age of 28 days, the test piece is taken out from the curing room to obtain a non-unidirectional distribution of steel fiber reinforced mortar. According to GB/T 17671 "Cement Mortar Strength Test Method", its flexural strength is 6.10MPa .

Example 4 and Comparative Example 4 have the same raw material ratio and steel fiber consumption, and the 28d flexural strength of the unidirectionally distributed steel fiber reinforced mortar obtained in Example 4 is higher than that of the non-unidirectionally distributed steel fiber obtained in Comparative Example 4 The 28d flexural strength of the reinforced mortar is increased by 25%.

Example 5

The first step is to prepare the steel fiber mortar mixture

According to the known design method, the mass ratio of the mortar components whose strength grade is M10 is water: cement: sand: high-efficiency water reducing agent = 0.3: 1: 1.5: 0.006. Water: cement and sand, and steel fibers with a volume content of 1.5% are added to ordinary mortar (the densities of steel, cement, and water are 7800kg/m ³ , 3100kg/m ³ , and 1000kg/m ³ respectively, according to This determines the required steel fiber quality), the steel fiber used is a steel wire cut-off steel fiber, the length is 13mm, and the aspect ratio is 40. Put the weighed water into the mixer first, then put in the weighed cement, turn on the mixer and stir for 20 seconds, add the weighed sand while stirring, then add the weighed steel fiber while stirring, and continue stirring for 180 seconds , the measured consistency of the steel fiber mortar mixture is 40mm;

The second step, pouring into the test mold

Pour the steel fiber mortar mixture prepared in the first step into a non-metallic test mold of 40mm×40mm×160mm;

The third step is to apply a magnetic field

Place the non-metallic test mold obtained in the second step into the steel fiber mortar mixture prepared in the first step in the hollow cavity of the coil of the equipment for preparing unidirectional distribution steel fiber reinforced mortar, and then the coil and Put the test mold together on the vibrating table of the above-mentioned equipment, turn on the DC power supply of the above-mentioned equipment to energize the coil to form a magnetic field, so as to apply a magnetic field to the steel fiber mortar mixture prepared in the first step, the direction of the magnetic field is consistent with the test or working state of the specimen The direction of the tensile stress is consistent or determined according to the design requirements. The magnetic induction intensity in the above coil is 10.0×10 ^-3 T. Turn on the vibration table of the above equipment to vibrate for 300 seconds, and then turn off the vibration table of the above equipment in order to cut off the above coil DC power supply, and the non-metallic test mold poured with the steel fiber mortar mixture prepared in the first step is removed from the hollow cavity of the coil skeleton and placed on the ground or on the test bench;

The fourth step, demoulding and maintenance

Gently smooth the surface of the steel fiber mortar mixture specimen in the non-metallic test mold after applying the magnetic field in the third step, then place it in the indoor environment, cover the surface with plastic film, remove the mold after 24 hours, and move it into the curing room for curing , keep the temperature at 20±2°C, relative humidity ≥90%, take the specimen out of the curing room when it is cured to the specified age of 28 days, and obtain unidirectional distributed steel fiber reinforced mortar, according to GB/T 17671 "Strength of cement mortar Inspection method "The measured flexural strength is 21.20MPa.

Comparative Example 5

Except lacking the third step in embodiment 5, other processes are identical with embodiment 5.

When curing to the specified age of 28 days, the test piece is taken out from the curing room to obtain a non-unidirectional distribution of steel fiber reinforced mortar. According to GB/T 17671 "Cement Mortar Strength Test Method", its flexural strength is 11.15MPa .

Example 5 and Comparative Example 5 have the same raw material ratio and steel fiber consumption, and the 28d flexural strength of the unidirectional distribution steel fiber reinforced mortar obtained in Example 5 is the same as that of the non-unidirectional distribution steel fiber obtained in Comparative Example 5 The 28d flexural strength of the reinforced mortar is nearly twice that of the 28d, which is nearly 100% higher.

Example 6

According to the known design method, the mass ratio of the mortar components whose strength grade is M7.5 is water: cement: sand: high-efficiency water reducer = 0.42: 1: 2: 0.004. Amount of water: cement and sand, and steel fibers with a volume content of 0.5% added to ordinary mortar (the densities of steel, cement, and water are respectively 7800kg/m ³ , 3100kg/m ³ , and 1000kg/m ³ , According to this, the required steel fiber quality can be determined), the steel fiber used is steel wire cut steel fiber, the length is 13mm, and the aspect ratio is 40. Put the weighed water and superplasticizer into the mixer first, then put in the weighed cement, turn on the mixer and stir for 120 seconds, add the weighed sand while stirring, and then put in the weighed steel fiber while stirring , continue to stir for 300 seconds, and measure the consistency of the steel fiber mortar mixture to be 80mm;

The second step, pouring into the test mold

Pour the steel fiber mortar mixture prepared in the first step into a non-metallic test mold of 40mm×40mm×160mm;

The third step is to apply a magnetic field

Place the non-metallic test mold obtained in the second step into the steel fiber mortar mixture prepared in the first step in the hollow cavity of the coil of the equipment for preparing unidirectional distribution steel fiber reinforced mortar, and then the coil and Put the test mold together on the vibrating table of the above-mentioned equipment, turn on the DC power supply of the above-mentioned equipment to energize the coil to form a magnetic field, so as to apply a magnetic field to the steel fiber mortar mixture prepared in the first step, the direction of the magnetic field is consistent with the test or working state of the specimen When the tensile stress direction is consistent or determined according to the design requirements, the magnetic induction intensity in the above coil is 6.0×10 ^-3 T, the vibrating table of the above equipment is turned on for 120 seconds, and then the vibrating table of the above equipment is turned off in sequence, and the above coil is cut off. DC power supply, and the non-metallic test mold poured with the steel fiber mortar mixture prepared in the first step is removed from the hollow cavity of the coil skeleton and placed on the ground or on the test bench;

The fourth step, demoulding and maintenance

Gently smooth the surface of the steel fiber mortar mixture specimen in the non-metallic test mold after applying the magnetic field in the third step, then place it in the indoor environment, cover the surface with plastic film, remove the mold after 24 hours, and move it into the curing room for curing , keep the temperature at 20±2°C, relative humidity ≥90%, take the specimen out of the curing room when it is cured to the specified age of 28 days, and obtain unidirectional distributed steel fiber reinforced mortar, according to GB/T 17671 "Strength of cement mortar Inspection method "The measured flexural strength is 9.05MPa.

Comparative Example 6

Except that the raw materials used in the first step are determined by known design methods, the mass ratio of the mortar components whose strength grade is M7.5 is water: cement: sand: high-efficiency water reducer=0.42: 1: 2: 0.004, Take by weighing the water of required amount during actual operation: cement and sand, then take the steel fiber that admixture is 1.0% steel fiber and lack the 3rd step in the embodiment 6 in common mortar again, other technology and embodiment 6 is the same.

When curing to the specified age of 28 days, the test piece was taken out from the curing room to obtain a non-unidirectional distribution of steel fiber reinforced mortar. According to GB/T 17671 "Cement Mortar Strength Test Method", its flexural strength was 9.15MPa. .

The 28d flexural strength of Example 6 is basically the same as that of Comparative Example 6, and the steel fiber dosage of the unidirectionally distributed steel fiber reinforced mortar obtained in Example 6 is only the non-unidirectionally distributed steel fiber reinforced mortar obtained in Comparative Example 6 Half of the steel fiber consumption is reduced by 60%.

Among the above-mentioned embodiments 4-6: the number of turns of the coil of the equipment used to prepare the unidirectional distributed steel fiber reinforced mortar is selected within the range of 100-3000 turns and the length l is 100-160mm, so as to ensure that it is longer than the skeleton placed in the coil The length of the non-metallic test mold in the hollow cavity, the shape and size of the hollow cavity of its skeleton are determined according to the shape and size of the non-metallic test mold poured into the steel fiber mortar mixture, allowing the poured The non-metallic test mold of the steel fiber mortar mixture is placed in it; the vibration table of the equipment for preparing unidirectional distribution steel fiber reinforced mortar is a mechanical mortar vibration table without magnetic adsorption, and its amplitude is 0.85 ± 0.05mm. The frequency is 2850 times/min, which complies with the regulations of "Physical Testing Instruments for Cement Mortar Vibrating Table" (JCT723-2005) or other relevant industry standards.

Example 7

The first step is to prepare the steel fiber cement slurry mixture

According to the mass ratio of water: cement: superplasticizer = 0.60: 1: 0 to form cement slurry, add steel fiber with a volume content of 0.3% in the cement slurry, first put the weighed mixing water into the mixer, Then put in the weighed cement and stir for 20 seconds, then slowly put in the weighed steel fiber while keeping the mixer continuously stirring, keep the mixer continuously stirring during the steel fiber feeding process, and continue stirring for 60 seconds after the steel fiber feeding is completed. Material, the measured fluidity of the steel fiber cement slurry mixture is 180mm;

The second step, pouring into the test mold

Pour the steel fiber cement slurry mixture prepared in the first step into a non-metallic test mold of 40mm×40mm×160mm;

The third step is to apply a magnetic field

The non-metallic test mold poured into the steel fiber cement slurry mixture prepared in the first step obtained in the second step is placed in the hollow cavity of the coil skeleton of the equipment for preparing unidirectional distribution steel fiber reinforced cement slurry, and the coil generates a magnetic field The direction of the coil is consistent with the direction of the long axis of the test piece, and then the coil and the test mold are placed on the vibration table of the above-mentioned equipment, and the DC power supply of the above-mentioned equipment is turned on to energize the coil to form a magnetic field, so as to stabilize the steel fiber cement prepared in the first step. A magnetic field is applied to the slurry mixture, and the direction of the magnetic field is consistent with the tensile stress direction of the test piece or in the working state or determined according to the design requirements. The magnetic induction intensity in the above-mentioned coil is 1.0×10 ^-3 T, and the vibrating table of the above-mentioned equipment is turned on to vibrate for 30 Seconds, then turn off the vibrating table of the above equipment in sequence and remove it from the test mold, cut off the DC power supply of the above coil and move out the non-metallic test mold poured into the steel fiber cement slurry mixture prepared in the first step a cavity in the bobbin of the coil;

The fourth step, demoulding and maintenance

After applying the magnetic field in the third step, the surface of the steel fiber cement slurry mixture specimen in the non-metallic test mold is lightly smoothed and placed in the indoor environment. The surface is covered with plastic film. After 24 hours, the mold is removed and moved into the curing room. Curing, keep the temperature at 20±2°C, relative humidity ≥90%, take the test piece out of the curing room when it reaches the specified age of 28 days, and obtain unidirectional distribution of steel fiber reinforced cement slurry, according to GB/T 17671 "Cement Adhesive Sand strength test method "measured its flexural strength to be 6.96MPa.

Comparative Example 7

Except lacking the third step in embodiment 7, other processes are identical with embodiment 7.

When curing to the specified age of 28 days, the test piece is taken out from the curing room to obtain a non-unidirectional distribution of steel fiber reinforced cement slurry. According to GB/T 17671 "Cement Mortar Strength Test Method", its flexural strength is 5.81. MPa.

Embodiment 7 and comparative example 7 have the same raw material ratio and steel fiber consumption, and the 28d flexural strength of the unidirectional distribution steel fiber reinforced cement slurry obtained in embodiment 7 is higher than that of the non-unidirectional distribution steel obtained in comparative example 7. The 28d flexural strength of fiber-reinforced cement paste increased by 20%.

Example 8

The first step is to prepare the steel fiber cement slurry mixture

According to the mass ratio of water: cement: high-efficiency water reducer = 0.20:1:0.0075 to form cement slurry, add steel fiber with a volume content of 1.0% in the cement slurry, first mix the weighed mixing water and high-efficiency water reducer Put the water agent into the mixer, then put in the weighed cement and stir for 120 seconds, then slowly put in the weighed steel fiber while keeping the mixer continuously stirring, keep the mixer continuously stirring during the steel fiber feeding process, and continue to stir after the steel fiber feeding is completed After stirring for 300 seconds, the material is discharged, and the fluidity of the steel fiber cement slurry mixture is determined to be 90mm;

The second step, pouring into the test mold

Pour the steel fiber cement slurry mixture prepared in the first step into a non-metallic test mold of 40mm×40mm×160mm;

The third step is to apply a magnetic field

The non-metallic test mold poured into the steel fiber cement slurry mixture prepared in the first step obtained in the second step is placed in the hollow cavity of the coil skeleton of the equipment for preparing unidirectional distribution steel fiber reinforced cement slurry, and the coil generates a magnetic field The direction of the coil is consistent with the direction of the long axis of the test piece, and then the coil and the test mold are placed on the vibration table of the above-mentioned equipment, and the DC power supply of the above-mentioned equipment is turned on to energize the coil to form a magnetic field, so as to stabilize the steel fiber cement prepared in the first step. A magnetic field is applied to the slurry mixture, and the direction of the magnetic field is consistent with the direction of the tensile stress of the test piece or in the working state or determined according to the design requirements. The magnetic induction intensity in the above coil is 10.0×10 ^-3 T, and the vibrating table of the above equipment is turned on to vibrate for 300 Seconds, then turn off the vibrating table of the above equipment in sequence and remove it from the test mold, cut off the DC power supply of the above coil and move out the non-metallic test mold poured into the steel fiber cement slurry mixture prepared in the first step a cavity in the bobbin of the coil;

The fourth step, demoulding and maintenance

After applying the magnetic field in the third step, the surface of the steel fiber cement slurry mixture specimen in the non-metallic test mold is lightly smoothed and placed in the indoor environment. The surface is covered with plastic film. After 24 hours, the mold is removed and moved into the curing room. Curing, keep the temperature at 20±2°C, relative humidity ≥90%, take the test piece out of the curing room when it reaches the specified age of 28 days, and obtain unidirectional distribution of steel fiber reinforced cement slurry, according to GB/T 17671 "Cement Adhesive Sand strength test method "measured its flexural strength to be 20.65MPa.

Comparative Example 8

Except the lack of the third step in Example 8, other processes are the same as Example 8.

When curing to the specified age of 28 days, the test piece is taken out from the curing room to obtain a non-unidirectional distribution of steel fiber reinforced cement slurry, and its flexural strength is 10.30 according to GB/T 17671 "Cement Mortar Strength Test Method" MPa.

Embodiment 8 and comparative example 8 have the same raw material ratio and steel fiber consumption, and the 28d flexural strength of the unidirectional distribution steel fiber reinforced cement slurry obtained in embodiment 8 is higher than that of the non-unidirectional distribution steel obtained in comparative example 8. The 28d flexural strength of fiber-reinforced cement paste was increased by 100%.

Example 9

The first step is to prepare the steel fiber cement slurry mixture

According to the mass ratio of water: cement: high-efficiency water reducer = 0.35:1:0.004 to form cement slurry, in this cement slurry, add steel fiber with a volume content of 0.4%, first mix the weighed water and high-efficiency water reducer Put the water agent into the mixer, then put in the weighed cement and stir for 120 seconds, then slowly put in the weighed steel fiber while keeping the mixer continuously stirring, keep the mixer continuously stirring during the steel fiber feeding process, and continue to stir after the steel fiber feeding is completed After stirring for 300 seconds, the material is discharged, and the fluidity of the steel fiber cement slurry mixture is determined to be 135mm;

The second step, pouring into the test mold

Pour the steel fiber cement slurry mixture prepared in the first step into a non-metallic test mold of 40mm×40mm×160mm;

The third step is to apply a magnetic field

The non-metallic test mold poured into the steel fiber cement slurry mixture prepared in the first step obtained in the second step is placed in the hollow cavity of the coil skeleton of the equipment for preparing unidirectional distribution steel fiber reinforced cement slurry, and the coil generates a magnetic field The direction of the coil is consistent with the direction of the long axis of the test piece, and then the coil and the test mold are placed on the vibration table of the above-mentioned equipment, and the DC power supply of the above-mentioned equipment is turned on to energize the coil to form a magnetic field, so as to stabilize the steel fiber cement prepared in the first step. A magnetic field is applied to the slurry mixture, and the direction of the magnetic field is consistent with the tensile stress direction of the test piece or in the working state or determined according to the design requirements. The magnetic induction intensity in the above-mentioned coil is 5.0×10 ^-3 T, and the vibrating table of the above-mentioned equipment is turned on to vibrate for 90 Seconds, then turn off the vibrating table of the above equipment in sequence and remove it from the test mold, cut off the DC power supply of the above coil and move out the non-metallic test mold poured into the steel fiber cement slurry mixture prepared in the first step a cavity in the bobbin of the coil;

The fourth step, demoulding and maintenance

After applying the magnetic field in the third step, the surface of the steel fiber cement slurry mixture specimen in the non-metallic test mold is lightly smoothed and placed in the indoor environment. The surface is covered with plastic film. After 24 hours, the mold is removed and moved into the curing room. Curing, keep the temperature at 20±2°C, relative humidity ≥90%, take the test piece out of the curing room when it reaches the specified age of 28 days, and obtain unidirectional distribution of steel fiber reinforced cement slurry, according to GB/T 17671 "Cement Adhesive Sand strength test method "measured its flexural strength to be 7.85MPa.

Comparative Example 9

Except that the raw materials used in the first step are composed of water: cement: high-efficiency water reducer=0.35: 1: 0.004 to form cement slurry, in this cement slurry, add steel fibers with a volumetric dosage of 0.8% and lack the third in Example 9. Except step, other processes are identical with embodiment 9.

When curing to the specified age of 28 days, the specimen is taken out from the curing room to obtain steel fiber reinforced cement slurry with non-unidirectional distribution. According to GB/T 17671 "Cement Mortar Strength Test Method", its flexural strength is 7.80 MPa.

The 28d flexural strength of embodiment 9 is basically the same as that of comparative example 9, and the steel fiber dosage of the unidirectionally distributed steel fiber reinforced cement slurry obtained in embodiment 9 only has the non-unidirectionally distributed steel fiber reinforced by comparative example 9 The amount of steel fiber in cement slurry is reduced by 60% by half.

Among the above-mentioned embodiments 7-9: the number of turns of the coil of the equipment used to prepare unidirectional distributed steel fiber reinforced cement slurry is selected in the range of 100-3000 turns and length l is 100-160mm, to ensure that it is longer than the coil placed in the coil. The length of the non-metallic test mold in the cavity in the skeleton, the shape and size of the cavity in the skeleton is determined according to the shape and size of the non-metallic test mold poured into the steel fiber cement slurry mixture, allowing the The non-metallic test mold poured with the steel fiber cement slurry mixture is placed in it; the vibrating table is a mechanical cement slurry vibrating table without magnetic adsorption, its amplitude is 0.5±0.2mm, and the vibration frequency is 2850 times/min , in line with the "cement physical testing instrument plastic sand shaker" (JCT723-2005) or other industry-related standards; steel fibers are made in accordance with construction steel standards.

Claims (4)

1. the equipment of preparation unidirectionally-distributed steel fiber reinforced cement sill is characterized in that: be made of shake table (3), coil (2) and dc source (1); Dc source (1) is provided with alternating current input, DC output end, switch (5) and Current Control knob (4); The number of turn of coil (2) is 100～3000 circles, length is 100～550mm, cavity shape in its skeleton and size determine that according to shape that is placed into the nonmetal die trial that has poured into steel fiber feinforced cement sill mixture wherein and size the nonmetal die trial that permission will pour into the steel fiber reinforced concrete mixture is placed in one; The DC output end of dc source (1) is connected to coil (2), and coil (2) is placed on the shake table (3).

2. according to the equipment of the described preparation unidirectionally-distributed steel fiber reinforced cement of claim 1 sill, it is characterized in that: shake table (3) is mechanical type concrete vibrating stand, mechanical type mortar shake table or mechanical cement slurry shake table, wherein the mechanical type concrete vibrating stand does not have magnetic force absorption, its amplitude is 0.5 ± 0.2mm, and vibration frequency is 2850 times/minute; Mechanical type mortar shake table does not have magnetic force absorption, and its amplitude is 0.5 ± 0.2mm, and vibration frequency is 2850 times/minute; The mechanical cement slurry shake table does not have magnetic force absorption, and its amplitude is 0.5 ± 0.2mm, and vibration frequency is 2850 times/minute.

3. according to the equipment of the described preparation unidirectionally-distributed steel fiber reinforced cement of claim 1 sill, it is characterized in that: the cavity cross section of coil (2) is square.

4. according to the equipment of the described preparation unidirectionally-distributed steel fiber reinforced cement of claim 1 sill, it is characterized in that: the size of shake table (3) is can place coil and die trial is as the criterion.

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