CN111257171A - Method for testing workability of ultra-high performance concrete mixture - Google Patents
Method for testing workability of ultra-high performance concrete mixture Download PDFInfo
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- 239000000203 mixture Substances 0.000 title claims abstract description 107
- 239000011374 ultra-high-performance concrete Substances 0.000 title claims abstract description 50
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- 238000000034 method Methods 0.000 title claims abstract description 18
- 239000000835 fiber Substances 0.000 claims abstract description 44
- 238000011156 evaluation Methods 0.000 claims abstract description 23
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 22
- 239000010959 steel Substances 0.000 claims abstract description 22
- 238000005204 segregation Methods 0.000 claims description 21
- 238000002156 mixing Methods 0.000 claims description 17
- 239000004567 concrete Substances 0.000 claims description 13
- 239000002002 slurry Substances 0.000 claims description 11
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- G01N11/00—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties
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- G01N11/04—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties by measuring flow of the material through a restricted passage, e.g. tube, aperture
- G01N11/06—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties by measuring flow of the material through a restricted passage, e.g. tube, aperture by timing the outflow of a known quantity
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- G01N33/383—Concrete or cement
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N5/00—Analysing materials by weighing, e.g. weighing small particles separated from a gas or liquid
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- G—PHYSICS
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- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N5/00—Analysing materials by weighing, e.g. weighing small particles separated from a gas or liquid
- G01N5/04—Analysing materials by weighing, e.g. weighing small particles separated from a gas or liquid by removing a component, e.g. by evaporation, and weighing the remainder
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Abstract
The embodiment of the invention discloses a method for testing the workability of an ultra-high performance concrete mixture, wherein a transparent test box is placed on a flat ground, and a movable flashboard is arranged at the joint of a vertical flow passage and a horizontal flow passage formed in the test box; the movable flashboard is closed, the vertical runner is not communicated with the horizontal runner, the ultra-high performance concrete mixture to be measured is filled into the vertical runner, the movable flashboard is opened, the mixture starts to flow to the horizontal runner, the time and the total flow distance of the mixture flowing to the horizontal runner for a set distance are recorded, and the workability of the ultra-high performance concrete mixture is evaluated. The method disclosed by the invention is used for evaluating the workability of the ultra-high performance concrete mixture containing the steel fibers under different construction conditions for the first time in the industry, and provides specific evaluation indexes.
Description
Technical Field
The invention relates to the technical field of performance evaluation of concrete mixtures, in particular to a method for testing the workability of an ultrahigh-performance concrete mixture.
Background
The ultra-high performance concrete (UHPC) has many advantages that the compressive strength of the ultra-high performance concrete is generally higher than 150MPa, which is about 3 times more than that of the traditional concrete [1-2 ]. The fiber is added to ensure that the ultra-high performance concrete has excellent toughness and fracture energy, compared with the high performance concrete, the toughness of the ultra-high performance concrete is improved by more than 300 times, and is equivalent to some metals, so that a concrete structure has more excellent structural reliability under an overload environment or in an earthquake [3-4 ].
The concrete is composed of a plurality of raw materials which are not homogeneous, the mixing proportion of the raw materials can fluctuate, and the UHPC is complex in composition material and higher in sensitivity to the raw materials than ordinary concrete. Therefore, the quality of UHPC inevitably fluctuates to a greater extent than the properties of the raw materials used. In addition, the methods adopted for proportioning, mixing, transporting and pouring the concrete can bring large fluctuation to the performance of the ultra-high performance concrete mixture. The fluctuation can directly influence the quality of the ultra-high performance concrete mixture, further influence the quality of the hardened ultra-high performance concrete, and have important influence on the service performance of an engineering structure. According to the specifications of basic performance and test method of ultra-high performance concrete (T/CCPA-7-2018) and active powder concrete (GB/T31387-2015), at the present stage, the ultra-high performance concrete is mainly divided into three types of fiber-containing non-vibratile forming, fiber-containing vibratile forming and semi-dry hard ultra-high performance concrete, the test of slump expansion of the ultra-high performance concrete mixture in an ultra-high performance concrete production factory and a pouring site is a main way for production uniformity inspection, and other related tests only refer to the workability test of self-compacting concrete simply and cannot effectively guide the characteristics of the ultra-high performance concrete. Considering that the ultra-fine powder and the additive in the ultra-high performance concrete are extremely high in dosage, the rheological property of the mixture is obviously influenced by the fluctuation of the quality of the components, so that the fluidity and the segregation resistance of the mixture are obviously changed. Considering that the ultrahigh-performance concrete contains the steel fibers, the difference between the density of the steel fibers and the density of slurry is large, the rheological property of the mixture has important influence on the distribution state of the fibers in the mixture, and particularly the problem of uneven fiber distribution possibly occurs in the process of large slurry fluidity or vibration construction, so that the quality of the ultrahigh-performance concrete is obviously influenced.
Therefore, the distribution uniformity of the fibers in the mixture has an extremely important influence on the ultra-high performance concrete, only a small amount of methods for evaluating the fiber distribution of the hardened slurry exist [5], and the related stability test of the mixture is still blank, so that the mixing ratio correction during construction is difficult to be quickly guided, and the quality fluctuation is reduced.
Primary references
[1]Ye Shi,Guangcheng Long,et al,Design and preparation of ultra-highperformance concrete with low environmental impact,Journal of CleanerProduction 214(2019)633-643。
[2] Chenbao Chun, Jitao, Huang Qing Wei, etc. research on ultra-high performance concrete reviews [ J ] Proc. Rev. architectural sciences and engineering, 2014,31(3): 1-24.
[3]Yoo D Y,Yoon Y S.A Review on Structural Behavior,Design,andApplication of Ultra-High-Performance Fiber-Reinforced Concrete[J].International Journal of Concrete Structures&Materials,2016,10(2):125-142。
[4] Zhang Yunsheng, Zhang Wenhua, Chengshengyu, comprehensive theory of ultra-high performance concrete, design preparation, microstructure, mechanics and durability, engineering application [ J ] material guide, 2017,31(23) is 1-16.
[5]Rui Wang,Xiaojian Gao,et al,Influence of rheological properties ofcement mortar on steel fiber distribution in UHPC,Construction and BuildingMaterials 144(2017)65–73。
Disclosure of Invention
The embodiment of the application aims at solving at least one technical problem existing in the prior art. Therefore, one of the objectives of the embodiments of the present invention is to provide a testing method capable of quickly and accurately evaluating the workability of an ultra-high performance concrete mixture.
In order to solve the technical problem, the embodiment of the invention adopts the following technical scheme:
a method for testing the workability of an ultra-high performance concrete mixture comprises the following steps:
step 1, placing a transparent test box on a flat ground, wherein an L-shaped flow passage with a uniform cross section is formed in the test box; the L-shaped flow passage consists of a vertical flow passage and a horizontal flow passage, and a movable flashboard is arranged at the joint of the vertical flow passage and the horizontal flow passage;
step 2, closing the movable flashboard to ensure that the vertical runner is not communicated with the horizontal runner, and filling the ultra-high performance concrete mixture to be tested into the vertical runner and fully standing;
step 4, workability evaluation
(1) Fluidity of the resin
The fluidity is evaluated by T and L, and the shorter the flow time T is, the larger the flow distance L is, the better the fluidity of the mixture is;
(2) resistance to segregation
Judging the segregation resistance of the mixture by observing the state of the mixture in the flowing process, and if aggregates or fibers are found to be stacked in a vertical flow channel or a horizontal flow channel area close to the vertical flow channel and more slurry is separated out at the edge of the finally expanded concrete, indicating that the segregation resistance of the mixture is poor;
(3) stability of
Dividing the horizontal flow channel into N sections of horizontal flow channel segments with equal length, respectively collecting and weighing the mass of the mixture in each segment, and recording the mass of the mixture collected by each segment as mi，i＝1、2、3…N；
Separating the steel fibres from the collected mixture, drying and weighing the corresponding steel fibres in the mixture collected at each sectionMass mfi，i＝1、2、3…N；
The stability evaluation index DM of the ultra-high performance concrete mixture is obtained by the following formulaiAnd DM, DMiAnd lower DM indicates better stability of the blend:
DM＝∑DMi
wherein: a is the mass ratio of the steel fibers to the mixture in the designed mixing ratio.
Furthermore, the ultrahigh-performance concrete mixture is provided with a plurality of groups by changing the water-cement ratio, the mixing amount of the water reducing agent or the cement-sand ratio, and the steps 1 to 4 are repeated to obtain the workability evaluation indexes of the mixtures with different components, so that the mixture component proportion is guided by combining the evaluation indexes.
Further, the comparative analysis of the workability evaluation indexes of the mixtures with different components can show that:
the reduction of the rubber-sand ratio can lead to the improvement of the fluidity of the mixture without obvious influence on the segregation resistance of the mixture, but can greatly influence the distribution state of the fibers and can generate the phenomenon of fiber sedimentation;
the fluidity of the mixture can be improved by increasing the mixing amount of the water reducing agent, but when the mixing amount of the water reducing agent is too high, slurry and aggregate are separated, so that the serious segregation problem is caused, and meanwhile, the fiber stability is also poor;
along with the continuous improvement of the water-cement ratio, the fluidity of the mixture can be continuously improved, the water-cement ratio is improved within a certain range, the anti-segregation performance of the mixture can not be influenced, and the uniform dispersion of the fibers is facilitated.
Further, the steel fiber is separated through a separation and recovery cylinder, the separation and recovery cylinder comprises a conical cylinder, a round hole sieve and a magnet, the round hole sieve is transversely arranged in the conical cylinder, and the magnet is arranged at the small-diameter end of the conical cylinder, so that the fiber loss can be effectively prevented.
Further, the diameter of the outer part of the round hole sieve is 30cm, and the sieve hole is 10 meshes.
Further, the inner diameter of the large proximal end of the conical barrel is 32cm, and the inner diameter of the small proximal end of the conical barrel is 10 cm.
Further, the magnet is a magnetic ring with the outer diameter of 13 cm.
Furthermore, a vibrating motor for providing a vibrating force in the vertical direction is arranged in the middle of the vertical flow channel on the transparent test box.
Further, the length of the vertical flow channel is 100mm, the width of the vertical flow channel is 100mm, and the height of the vertical flow channel is 300 mm.
Further, the length of the horizontal flow channel is 1000 mm.
Compared with the prior art, the embodiment of the invention has the technical effects that:
the method can evaluate the workability of the concrete mixture with the ultrahigh performance and containing the steel fibers for the first time in the industry, can meet the evaluation of the workability of the mixture under the application conditions of vibration construction, non-vibration construction and the like, and provides specific evaluation indexes.
Drawings
FIG. 1 is a schematic structural diagram of a transparent test box in an embodiment;
FIG. 2 is a schematic view of the separation and recovery cylinder in the embodiment.
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.
A method for testing the workability of an ultra-high performance concrete mixture comprises the following steps:
step 1, placing a transparent test box on a flat ground, wherein an L-shaped flow passage with a uniform cross section is formed in the test box; the L-shaped flow passage consists of a vertical flow passage and a horizontal flow passage, and a movable flashboard is arranged at the joint of the vertical flow passage and the horizontal flow passage;
step 2, closing the movable flashboard to ensure that the vertical runner is not communicated with the horizontal runner, continuously and uniformly filling the ultra-high performance concrete mixture to be tested into the vertical runner, and fully standing;
step 4, workability evaluation
(1) Evaluation of flowability
The fluidity is evaluated by T and L, and the shorter the flow time T is, the larger the flow distance L is, the better the fluidity of the mixture is;
(2) evaluation of resistance to isolation
Judging the segregation resistance of the mixture by observing the state of the mixture in the flowing process, and if aggregates or fibers are found to be stacked in a vertical flow channel or a horizontal flow channel area close to the vertical flow channel and more slurry is separated out at the edge of the finally expanded concrete, indicating that the segregation resistance of the mixture is poor;
(3) evaluation of stability
Dividing the horizontal flow channel into N sections of horizontal flow channel segments with equal length, respectively collecting and weighing the mass of the mixture in each segment, and recording the mass of the mixture collected by each segment as mi，i＝1、2、3…N；
Separating the steel fibers from the collected mixture, drying and weighing, wherein the mass of the corresponding steel fibers in the mixture collected by each section is mfi，i＝1、2、3…N；
The stability evaluation index DM of the ultra-high performance concrete mixture is obtained by the following formulaiAnd DM, DMiLower DM indicates stability of the blendThe better:
DM＝∑DMi
wherein: a is the mass ratio of the steel fibers to the mixture in the designed mixing ratio.
And (3) setting a plurality of groups of the ultra-high performance concrete mixture by changing the water-cement ratio, the mixing amount of the water reducing agent or the cement-sand ratio, repeating the steps 1 to 4 to obtain the workability evaluation indexes of the mixtures with different components, and then combining the evaluation indexes to guide the component proportion of the mixtures. The comparative analysis of the workability evaluation indexes of the mixtures with different components can show that: the reduction of the rubber-sand ratio can lead to the improvement of the fluidity of the mixture without obvious influence on the segregation resistance of the mixture, but can greatly influence the distribution state of the fibers and can generate the phenomenon of fiber sedimentation; the fluidity of the mixture can be improved by increasing the mixing amount of the water reducing agent, but when the mixing amount of the water reducing agent is too high, slurry and aggregate are separated, so that the serious segregation problem is caused, and meanwhile, the fiber stability is also poor; along with the continuous improvement of the water-cement ratio, the fluidity of the mixture can be continuously improved, the water-cement ratio is improved within a certain range, the anti-segregation performance of the mixture can not be influenced, and the uniform dispersion of the fibers is facilitated.
The method can evaluate the workability of the concrete mixture with the ultrahigh performance and containing the steel fibers for the first time in the industry, can meet the evaluation of the workability of the mixture under the application conditions of vibration construction, non-vibration construction and the like, and provides specific evaluation indexes.
Referring to fig. 1 and 2, the test box is composed of an upright cylinder 1 and a horizontal cylinder 2, wherein an equal-section vertical flow passage 101 is formed in the upright cylinder 1, an equal-section horizontal flow passage 202 is formed in the horizontal cylinder 2, the vertical flow passage and the horizontal flow passage are communicated to form an equal-section L-shaped flow passage, the upright cylinder 1 and the horizontal cylinder 2 are both made of hard non-water-absorbing materials, the length and the width of the upright cylinder 1 are both 100mm and 300mm, a movable gate plate 3 is arranged at the position, close to the horizontal cylinder 2, of the upright cylinder 1, the width of the gate plate is 100mm, the length of the gate plate is 110mm, and the thickness of the gate plate is 2 mm. Upright section of thick bamboo 1 and horizontal cylinder 2 intercommunication, the intercommunication size is the same with 2 cross-sections of horizontal cylinder, and 2 cross-sections of horizontal cylinder are the square of 100mm of length of side, and 2 length of horizontal cylinder are 1000mm, and 2 upper end openings of horizontal cylinder, the side that the upright section of thick bamboo was kept away from to horizontal cylinder 2 are the encapsulated situation, and vibrating motor 4 installs in 1 intermediate position of upright section of thick bamboo, provides the effect of vibrating of a vertical direction.
Referring to fig. 2, the steel fibers are separated by a separation and recovery cylinder consisting of a round screen 5, a conical cylinder 6 and a magnet 7. The inner diameter of the large-diameter section end of the conical cylinder 6 is 320mm, and the inner diameter of the small-diameter section end is 100 mm. The outside diameter of the round hole sieve 5 is 300mm, the sieve holes are 10 meshes, the sieves with different sieve holes can be replaced according to the maximum aggregate particle size of the actual construction mixing proportion to adapt to the actual situation, and the size of the sieve holes is slightly larger than the maximum aggregate particle size. The round hole sieve is arranged at the big circle of the conical cylinder. The magnet is placed inside the conical barrel near the end of the large-diameter section. The magnet is a ring magnet with an outer diameter of 130 mm.
Application example
Preparing the ultra-high performance concrete according to the mixing ratio in the table 1, putting all dry materials into a stirrer, dry-mixing until the materials are uniform, slowly adding water and a water reducing agent, continuously stirring until a uniform mixture is formed, putting a workability test box on a solid and flat ground, closing a movable flashboard 3 of a vertical cylinder 1 to ensure that the vertical cylinder 1 is not communicated with a horizontal cylinder 2, wetting the workability test box by using wet cloth to ensure that the inside of the workability test box is free from clear water, and continuously and uniformly filling the ultra-high performance concrete mixture to be tested into the vertical cylinder 1 to ensure that the surface of the mixture is level with the upper opening of the vertical cylinder.
TABLE 1 example ultra high performance concrete mix proportions
| Numbering | Cement | Fly ash | Silica fume | Water (W) | Water reducing agent | Quartz sand | Steel fiber |
| 1 | 700 | 145 | 211 | 179 | 23 | 1160 | 160 |
| 2 | 700 | 145 | 211 | 190 | 23 | 1160 | 160 |
| 3 | 700 | 145 | 211 | 201 | 23 | 1160 | 160 |
| 4 | 700 | 145 | 211 | 211 | 23 | 1160 | 160 |
| 5 | 700 | 145 | 211 | 211 | 32 | 1160 | 160 |
| 6 | 790 | 153 | 237 | 225 | 26 | 1000 | 160 |
| 7 | 880 | 161 | 263 | 248 | 29 | 850 | 160 |
Standing for 5 minutes after standing a vertical section of thick bamboo 1 is full of the mixture, standing and opening movable flashboard 3 after the completion, opening vibrating motor 4 simultaneously, making the mixture begin to flow in horizontal cylinder 2, vibrating motor work closes after 45 seconds, and the record flows time T and total flow distance L to 2 middle sections 500mm departments of horizontal cylinder in the process, and flow time T is shorter more, and flow distance L is bigger then the mobility of mixture is better.
The segregation resistance of the mixture is judged by observing the state of the mixture in the flowing process, and if aggregates or fibers are found to be stacked in the vertical cylinder or the horizontal cylinder 2 area close to the vertical cylinder 1 and more slurry is separated out from the finally expanded concrete edge, the segregation resistance of the mixture is poor.
Taking the position of the horizontal cylinder 2 close to the vertical cylinder 1 as an original point, dividing the horizontal cylinder 2 into 3 sections of horizontal flow passage segments with equal length, taking out and weighing the mixture to respectively obtain the mixture mass m of each section1、m2And m3。
And placing the weighed mixture into a separating cylinder, placing a circular hole sieve 5 in a conical cylinder 6, placing a magnet 7 close to a small circular opening in the cylinder, washing the mixture with clear water, and sieving to remove slurry and aggregate. Air drying and dewatering the steel fiber adsorbed by the magnet and the surplus by a blower, weighing the mass of the steel fiber by balance to be accurate to 0.1g, and respectively obtaining the mass m of the steel fiber in each section of mixturef1、mf2And mf3。
The stability evaluation index DM of the ultra-high performance concrete mixture is obtained by the following formulaiAnd DM. The lower the index is, the better the stability of the ultra-high performance concrete is, and the DM is generally requirediThe maximum value should be less than 15% and the DM should be less than 12%.
DM＝∑DMi
Wherein A is the mass ratio of the steel fibers in the mixture in the designed mixing ratio.
TABLE 2 test results for the respective mixing ratios
| Numbering | L(mm) | T(s) | Resistance to segregation | DM1 | DM2 | DM3 | DM |
| 1 | 415 | - | Does not segregate | 1％ | 5％ | 3％ | 3％ |
| 2 | 540 | 30 | Does not segregate | 4％ | 2％ | 3％ | 3％ |
| 3 | 720 | 17 | Does not segregate | 5％ | 2％ | 4％ | 4％ |
| 4 | 930 | 8 | Does not segregate | 9％ | 7％ | 12％ | 9％ |
| 5 | 1000 | 4 | Isolation of | 16％ | 14％ | 19％ | 16％ |
| 6 | 830 | 12 | Does not segregate | 13％ | 8％ | 16％ | 12％ |
| 7 | 950 | 7 | Does not segregate | 28％ | 31％ | 37％ | 32％ |
From the results in Table 2, it can be seen that when the water-cement ratio of the ultra-high performance concrete is gradually increased from 0.17 to 0.2 (groups 1 to 4 in Table 1), other composition parameters are kept unchanged, the L value of the ultra-high performance concrete is continuously increased, and the T value is continuously decreased, which indicates that the fluidity of the ultra-high performance concrete is continuously improved, and the ultra-high performance concrete has better segregation resistance and the evaluation index DM of the stability of the mixtureiAnd DM were both low, only within experimental system error, indicating that the fibers were uniformly dispersed.
Comparing the mix proportion of 4 and 5, the water reducing agent mixing amount of the ultra-high performance concrete is increased to 3% from 2.2% of the total mass of the cementing material, the fluidity of the ultra-high performance concrete is further improved, but slurry and aggregate are separated, so that a serious segregation problem is caused, and the fiber stability at the moment also has a certain problem.
The contrast mix proportion 3, 6 and 7, the glue sand ratio of ultra high performance concrete constantly reduces will improve the mobility of mixture to a certain extent, does not have apparent influence to its anti segregation ability, but can greatly influence the distribution state of fibre, will present apparent fibre settlement phenomenon.
The above examples are merely illustrative for clearly illustrating the present invention and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. Nor is it intended to be exhaustive of all embodiments. And obvious variations or modifications of the invention may be made without departing from the scope of the invention.
Claims (8)
1. The method for testing the workability of the ultra-high performance concrete mixture is characterized by comprising the following steps of:
step 1, placing a transparent test box on a flat ground, wherein an L-shaped flow passage with a uniform cross section is formed in the test box; the L-shaped flow passage consists of a vertical flow passage and a horizontal flow passage, and a movable flashboard is arranged at the joint of the vertical flow passage and the horizontal flow passage;
step 2, closing the movable flashboard to ensure that the vertical runner is not communicated with the horizontal runner, and filling the ultra-high performance concrete mixture to be tested into the vertical runner and fully standing;
step 3, opening the movable flashboard after the standing is finished, enabling the mixture to start to flow to the horizontal flow channel, and recording the time T and the total flow distance L of the mixture flowing to the horizontal flow channel for the set distance K;
step 4, workability evaluation
(1) Fluidity of the resin
The fluidity is evaluated by T and L, and the shorter the flow time T is, the larger the flow distance L is, the better the fluidity of the mixture is;
(2) resistance to segregation
Judging the segregation resistance of the mixture by observing the state of the mixture in the flowing process, and if aggregates or fibers are found to be stacked in a vertical flow channel or a horizontal flow channel area close to the vertical flow channel and more slurry is separated out at the edge of the finally expanded concrete, indicating that the segregation resistance of the mixture is poor;
(3) stability of
Dividing the horizontal flow channel into N sections of horizontal flow channel segments with equal length, respectively collecting and weighing the mass of the mixture in each segment, and recording the mass of the mixture collected by each segment as mi，i＝1、2、3…N；
Separating the steel fibers from the collected mixtureAnd dry weighing, the mass of the corresponding steel fiber in the mixture collected by each segment is mfi，i＝1、2、3…N；
The stability evaluation index DM of the ultra-high performance concrete mixture is obtained by the following formulaiAnd DM, DMiAnd lower DM indicates better stability of the blend:
DM＝∑DMi
wherein: a is the mass ratio of the steel fibers to the mixture in the designed mixing ratio.
2. The test method of claim 1, wherein: the steel fiber is separated by a separation and recovery cylinder, the separation and recovery cylinder consists of a conical cylinder, a circular hole sieve and a magnet, the circular hole sieve is transversely arranged in the conical cylinder, and the magnet is arranged at the small-diameter end of the conical cylinder.
3. The test method of claim 2, wherein: the outside diameter of the round hole sieve is 30cm, and the sieve hole is 10 meshes.
4. The test method of claim 3, wherein: the inner diameter of the large proximal end of the conical barrel is 32cm, and the inner diameter of the small proximal end of the conical barrel is 10 cm.
5. The test method of claim 4, wherein: the magnet is a magnetic ring with the outer diameter of 13 cm.
6. The test method according to any one of claims 1 to 5, wherein: and a vibrating motor for providing a vibrating force in the vertical direction is arranged in the middle of the vertical flow channel on the transparent test box.
7. The test method according to any one of claims 1 to 5, wherein: the length of the vertical runner is 100mm, the width is 100mm, and the height is 300 mm.
8. The test method according to any one of claims 1 to 5, wherein: the length of the horizontal flow channel is 1000 mm.
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