CN110658117A - Coarse aggregate corner angle evaluation device and method - Google Patents
Coarse aggregate corner angle evaluation device and method Download PDFInfo
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Abstract
The invention discloses a coarse aggregate angularity evaluation device and method, which comprises an image acquisition system and an image data processing system, wherein the image acquisition system comprises a camera bellows, a digital camera, a coarse aggregate containing plate and a backlight lamp, the digital camera, the coarse aggregate containing plate and the backlight lamp are all arranged in the camera bellows, the digital camera is arranged above the coarse aggregate containing plate, the backlight lamp is arranged below the coarse aggregate containing plate, and the image data processing system is connected with the digital camera. The method can directly and quantitatively represent the edge angle of the coarse aggregate, has the characteristics of simple operation, clear detection target, high testing speed and accurate measurement result, and effectively avoids errors caused by artificial operation factors in the traditional indirect measurement method.
Description
Technical Field
The invention particularly relates to a device and a method for evaluating the edge angle performance of coarse aggregates.
Background
The aggregate is a material with the largest use amount in highway and urban road engineering, and the mass ratio of the aggregate in asphalt pavements and cement pavements can respectively reach more than 90 percent and 70 percent. The quality of bituminous and cement pavements is therefore determined to a large extent by the quality of the aggregate, in terms of the material mass ratio. Among mineral aggregates, the shape, angularity, surface texture, and the like of coarse aggregates have a significant influence on the performance of asphalt pavements. Among the above three properties of aggregates investigated in the american highway strategic research (SHRP) program, the angularity of coarse aggregates is considered to be the most important characteristic. In view of this, the properties of the aggregate, particularly the angularity of the coarse aggregate, have a significant impact on the performance of asphalt concrete pavements. At present, the evaluation method and the evaluation index of the angularity of the coarse aggregate are not listed in relevant specifications in China. Generally speaking, there are two methods for quantitatively evaluating the angularity of coarse aggregates, namely an indirect measurement method and a direct measurement method, and although the indirect measurement method is simple to operate, the method has the disadvantages of low accuracy and poor representativeness of the measurement result. And the edge angle of the coarse aggregate can be intuitively, quickly and accurately evaluated by using a direct measurement method.
In view of the important significance of the angular research of coarse aggregates and the limitations of the existing methods, many foreign scholars apply the digital image processing technology (DIP) to the microscopic research of aggregates and obtain a series of important achievements. Compared with the traditional indirect measurement method, the digital image processing technology has higher measurement precision, better flexibility and higher visualization degree, and can carry out complex nonlinear operation. Therefore, based on the digital image processing technology, the device and the method for evaluating the edge angle of the coarse aggregate, which are simple to operate and high in detection precision, are developed, and have important significance for saving stone resources, improving the production and processing quality of the aggregate, improving the design method of the asphalt mixture and the like.
Disclosure of Invention
The invention aims to solve the technical problem that aiming at the defects in the prior art, the invention provides the device and the method for evaluating the edge angle of the coarse aggregate, which can directly and quantitatively represent the edge angle of the coarse aggregate, have the characteristics of simple operation, clear detection target, high test speed and accurate measurement result, and effectively avoid errors caused by artificial operation factors in the traditional indirect measurement method.
The technical scheme adopted by the invention for solving the technical problems is as follows:
a coarse aggregate angular character evaluation device comprises an image acquisition system and an image data processing system,
the image acquisition system comprises a camera bellows, a digital camera, a coarse aggregate containing plate and a backlight lamp, wherein the digital camera, the coarse aggregate containing plate and the backlight lamp are all arranged in the camera bellows, the digital camera is arranged above the coarse aggregate containing plate, the backlight lamp is arranged below the coarse aggregate containing plate, and the image data processing system is connected with the digital camera.
According to the technical scheme, the illuminating lamp is further arranged in the camera bellows, the illuminating lamp is arranged above the coarse aggregate containing plate, and the opening and closing door is arranged on the camera bellows.
According to the technical scheme, a plurality of grooves are distributed on the coarse aggregate containing plate, and each groove is used for correspondingly containing particles of a coarse aggregate; the groove is used for placing each particle of the coarse aggregate in a separated way.
According to the technical scheme, the coarse aggregate edge angle performance evaluation device comprises a plurality of coarse aggregate containing plates, the size of a groove in each coarse aggregate containing plate is adapted to the size of the particle diameter of corresponding coarse aggregate, and the diameter range of the groove is 4.75-26.5 mm.
According to the technical scheme, the coarse aggregate containing plate is a white light-transmitting plastic plate.
The edge angle detection method adopting the coarse aggregate edge angle evaluation device comprises the following steps:
1) placing the coarse aggregates on a coarse aggregate placing plate, and keeping a certain gap between particles of each coarse aggregate;
2) placing the coarse aggregate containing plate containing the coarse aggregate in a dark box, and closing the dark box;
3) the image data processing system acquires images of the particles of the coarse aggregate through a digital camera;
4) after the image data processing system processes the acquired image, the edge angle of each particle of the coarse aggregate is obtained;
5) and the image data processing system carries out statistical analysis according to the obtained edge angle performance of each coarse aggregate particle to obtain a representative value of the edge angle performance of the coarse aggregate.
According to the above technical solution, in the step 4), the processing process of the image data processing system on the acquired image is as follows: and sequentially carrying out median filtering, image sharpening, image binarization, image morphology processing, image pit filling and coarse aggregate particle external polygon processing on the image.
According to the technical scheme, in the step 4), the angularity of the coarse aggregate particles is as follows:
wherein CA represents the angularity of a single aggregate, A2Represents the area of the coarse aggregate circumscribed polygon, A1Representing the raw profile area of the coarse aggregate particles.
According to the technical scheme, in the step 5), the representative value of the angularity of the coarse aggregate is as follows:
wherein I represents a representative value of angularity of the coarse aggregate, CAiIndicating the angularity of the individual coarse aggregates and n indicating the number of coarse aggregate particles.
According to the technical scheme, the method also comprises the following steps before the step 1): selecting a coarse aggregate sample to be tested, sieving the sample, cleaning the sample by using clear water, and then putting the sample into an oven for drying to obtain the coarse aggregate sample with single grain size and clean surface.
The invention has the following beneficial effects:
the coarse aggregate containing plate is used for containing the particles of the coarse aggregates in the camera bellows, the particles of the coarse aggregates are distributed on the coarse aggregate containing plate at intervals, the reverse light is irradiated from the lower part of the coarse aggregate containing plate, the digital camera collects the particle images of the coarse aggregates from the upper part of the coarse aggregate containing plate, and transmits the image to an image data processing system, after the image data processing system processes the image, obtaining the edge angle performance of each coarse aggregate, finally, carrying out statistical analysis on the edge angle performance of the coarse aggregate particles obtained by calculation by an image data processing system to obtain a representative value of the edge angle performance of the coarse aggregate, compared with the traditional indirect measurement method, the device and the method for evaluating the edge angle of the coarse aggregate can directly and quantitatively characterize the edge angle of the coarse aggregate, have the characteristics of simple operation, clear detection target, high test speed and accurate measurement result, errors caused by human operation factors in the traditional indirect measurement method can be effectively avoided.
Drawings
FIG. 1 is a schematic structural view of an apparatus for evaluating the angularity of coarse aggregate in an embodiment of the present invention;
FIG. 2 is a front view of a coarse aggregate containment plate in an embodiment of the invention;
FIG. 3 is a top view of FIG. 2;
FIG. 4 is a schematic structural diagram of a backlight lamp according to an embodiment of the present invention;
FIG. 5 is a schematic diagram of an image processing flow according to an embodiment of the present invention;
FIG. 6 is an original image of coarse aggregate particles in an embodiment of the invention;
FIG. 7 is an image of a circumscribed polygon of coarse aggregate particles in an embodiment of the present invention;
in the figure, 1-an image acquisition system, 2-1-a first opening and closing door, 2-2-a second opening and closing door, 3-a digital camera, 4-a lighting lamp, 5-a coarse aggregate containing plate, 6-a reverse light lamp, 6-1-a high-brightness LED lamp, 6-2-a light-gathering lampshade and 7-an image data processing system.
Detailed Description
The present invention will be described in detail below with reference to the accompanying drawings and examples.
Referring to fig. 1 to 7, in an embodiment of the present invention, an apparatus for evaluating the angularity of coarse aggregate includes an image acquisition system 1 and an image data processing system 7,
the image acquisition system 1 comprises a camera bellows, a digital camera 3, a coarse aggregate containing plate 5 and a backlight lamp 6, wherein the digital camera 3, the coarse aggregate containing plate 5 and the backlight lamp 6 are all arranged in the camera bellows, the digital camera 3 is arranged above the coarse aggregate containing plate 5, the backlight lamp 6 is arranged below the coarse aggregate containing plate 5, and an image data processing system 7 is connected with the digital camera 3; coarse aggregate holds board 5 and is used for holding the granule of coarse aggregate in the camera bellows, the granule interval distribution of coarse aggregate holds board 5 in coarse aggregate, backlight 6 shines from the below of coarse aggregate holds board 5, digital camera 3 gathers the granule image of each coarse aggregate from coarse aggregate holds board 5 top, and transmit the image to image data processing system 7, image data processing system 7 handles the back to the image, obtain the edges and corners nature of each coarse aggregate, image data processing system 7 carries out statistical analysis to the edges and corners nature of the coarse aggregate granule that the calculation obtained at last, obtain the representative value of coarse aggregate edges and corners nature.
Further, the digital camera 3, the illuminating lamp 4, the coarse aggregate containing plate 5, the backlight lamp 6 and the light-gathering lampshade are all installed in a light-tight cabinet in a cubic shape to form a 'dark box' capable of sealing external light so as to avoid adverse effects of the external light on image quality during image acquisition.
The image data processing system 7 is composed of a computer and a display screen, and may be replaced by a personal PC. The image acquisition system 1 is connected with the image data processing system 7 through a data line, and the image data processing system 7 issues an instruction to control the image acquisition system 1 to perform image acquisition operation. And after the Image is collected, processing and analyzing the collected Image by using Image Pro Plus software through a computer to obtain the edge angle of each coarse aggregate. And finally, carrying out statistical analysis on the edge angle performance of the coarse aggregate particles obtained by calculation through a computer to obtain a representative value of the edge angle performance of the coarse aggregate.
Further, still be equipped with light 4 in the camera bellows, light 4 sets up in the top of coarse aggregate holding plate 5, is equipped with the door that opens and shuts on the camera bellows.
Further, the backlight lamp 6 comprises a high-brightness LED lamp and a spotlight cover, and the high-brightness LED lamp is arranged in the spotlight cover; the condensing lampshade gathers the optical fibers of the high-brightness LED lamp and emits the optical fibers to the coarse aggregate containing plate 5.
Further, a coarse aggregate holding plate 5 is horizontally placed in the dark box.
Furthermore, a plurality of grooves are distributed on the coarse aggregate containing plate 5, and each groove is correspondingly used for containing particles of a coarse aggregate; the groove is used for placing each particle of the coarse aggregate in a separated way.
Further, coarse aggregate angular character evaluation device include a plurality of coarse aggregate and hold board 5, the recess size adaptation corresponding coarse aggregate particle size on each coarse aggregate holds board 5, the diameter range of recess is 4.75 ~ 26.5 mm.
Furthermore, the coarse aggregate containing plate 5 is a white light-transmitting plastic plate, and the coarse aggregate containing plate 5 with different groove sizes of 4.75-26.5 mm is manufactured according to the grain size specification of common coarse aggregates. The purpose of arranging the grooves is to provide convenience for test personnel to place coarse aggregate.
Further, the coarse aggregate containing plate 5 is a white light-transmitting plastic plate.
The edge angle detection method adopting the coarse aggregate edge angle evaluation device comprises the following steps:
1) placing coarse aggregates on the coarse aggregate placing plate 5, and leaving a certain gap between particles of each coarse aggregate;
2) placing the coarse aggregate containing plate 5 containing the coarse aggregate in a dark box, and closing the dark box; the illuminating lamp 4 is turned off, and the opening and closing door of the coarse aggregate image acquisition system 1 is closed, so that the coarse aggregate image is not adversely affected by external light when the coarse aggregate image is acquired;
3) the image data processing system 7 acquires images of the particles of the coarse aggregate through the digital camera 3;
4) after the image data processing system 7 processes the acquired image, the edge angle of each particle of the coarse aggregate is obtained;
5) the image data processing system 7 performs statistical analysis based on the obtained edge angle characteristics of each coarse aggregate particle to obtain a representative value of the edge angle characteristics of the coarse aggregate.
Further, in the step 4), the processing process of the image data processing system 7 on the acquired image is as follows: and sequentially carrying out median filtering, image sharpening, image binarization, image morphology processing, image pit filling and coarse aggregate particle external polygon processing on the image.
Further, in the step 4), the angularity of the coarse aggregate particles is:
wherein CA representsAngularity of individual aggregates, A2Represents the area of the coarse aggregate circumscribed polygon, A1Representing the raw profile area of the coarse aggregate particles.
Further, in the step 5), the representative value of the angularity of the coarse aggregate is as follows:
wherein I represents a representative value of angularity of the coarse aggregate, CAiIndicating the angularity of the individual coarse aggregates and n indicating the number of coarse aggregate particles.
Further, the step 1) is preceded by the following steps: selecting a coarse aggregate sample to be tested, sieving the sample, cleaning the sample by using clear water, and then putting the sample into an oven for drying to obtain the coarse aggregate sample with single grain size and clean surface.
Further, a lighting lamp 4 of the coarse aggregate image acquisition system 1 is turned on, the lighting lamp 4 is a common LED lamp, and the lighting lamp is mainly used for providing necessary lighting conditions for installation of the coarse aggregate containing plate 5 and placement of the coarse aggregates. The coarse aggregate holding plate 5 is installed above the inverse lamp 6.
Further, in the step 1), according to the different particle sizes of the coarse aggregate particles, selecting a coarse aggregate containing plate 5 with a proper groove size corresponding to the coarse aggregate particles; placing the coarse aggregates in corresponding grooves of the coarse aggregate containing plate 5 in order, and leaving proper gaps among coarse aggregate particles; and image processing at the later stage is facilitated.
Further, after the image data processing system 7 issues an instruction, the digital camera 3 in the image acquisition system 1 starts to perform image acquisition operation on the coarse aggregate. After the acquisition is completed, the image data processing system 7 automatically saves the acquired picture. The image acquisition system 1 comprises a digital camera 3, a lighting lamp 4, a coarse aggregate containing plate 5, a backlight lamp 6, a light-gathering lampshade and the like, and all the devices are arranged in a shell formed by a lightproof black plastic plate to form a 'dark box' capable of sealing external light. Compared with the image acquired under natural light, the contrast and the definition of the image acquired under the 'dark box' environment are obviously improved, and the later-stage image processing is facilitated.
The working principle of the invention is as follows:
the invention is composed of an image acquisition system 1 and an image data processing system 7. The image acquisition system 1 comprises digital camera 3, light 4, coarse aggregate holding plate 5, backlight 6, spotlight cover etc. and above equipment all is installed in the light-tight cabinet of a cube shape, forms a "camera bellows" that can seal external light to avoid when carrying out image acquisition, external light causes harmful effects to image quality. The image data processing system 7 is composed of a computer and a display screen, and can be replaced by a personal PC. The image acquisition system 1 is connected with the image data processing system 7 through a data line, and the image data processing system 7 issues an instruction to control the image acquisition system 1 to perform image acquisition operation. And after the Image is collected, processing and analyzing the collected Image by using Image Pro Plus software through a computer to obtain the edge angle of each coarse aggregate. And finally, carrying out statistical analysis on the edge angle performance of the coarse aggregate particles obtained by calculation through a computer to obtain a representative value of the edge angle performance of the coarse aggregate.
The method comprises the following specific operation steps:
the method comprises the following steps: selecting a coarse aggregate sample to be tested, sieving the sample, cleaning the sample by using clear water, and then putting the sample into an oven for drying to obtain the coarse aggregate sample with single grain size and clean surface.
Step two: depending on the size of the coarse aggregate particles, a coarse aggregate holding plate 5 having an appropriate groove size is selected to fit the coarse aggregate particles. The coarse aggregate containing plate 5 is a white light-transmitting plastic plate, and the coarse aggregate containing plate 5 with different groove sizes of 4.75-26.5 mm is manufactured according to the grain size specification of common coarse aggregates. The purpose of arranging the grooves is to provide convenience for test personnel to place coarse aggregate.
Step three: and turning on an illuminating lamp 4 of the coarse aggregate image acquisition system 1, wherein the illuminating lamp 4 is a common LED lamp and mainly has the function of providing necessary illuminating conditions for installation of the coarse aggregate containing plate 5 and placement of the coarse aggregates. The coarse aggregate holding plate 5 is installed above the inverse lamp 6. The reverse-light lamp 6 is composed of a high-brightness LED lamp and a spotlight cover.
Step four: the coarse aggregates are placed in the corresponding grooves of the coarse aggregate containing plate 5 in order, and appropriate gaps are reserved among the coarse aggregates, so that image processing can be performed conveniently in the later period.
Step five: the illuminating lamp 4 is turned off, the opening and closing door of the coarse aggregate image acquisition system 1 is closed, and it is guaranteed that when coarse aggregate image acquisition is carried out, external light cannot have adverse effects on the coarse aggregate image.
Step six: after the image data processing system 7 issues an instruction, the digital camera 3 in the image acquisition system 1 starts to perform image acquisition operation on the coarse aggregate. After the acquisition is completed, the image data processing system 7 automatically saves the acquired picture. The image acquisition system 1 comprises a digital camera 3, a lighting lamp 4, a coarse aggregate containing plate 5, a backlight lamp 6, a light-gathering lampshade and the like, and all the devices are arranged in a shell formed by a lightproof black plastic plate to form a 'dark box' capable of sealing external light. Compared with the image acquired under natural light, the contrast and the definition of the image acquired under the 'dark box' environment are obviously improved, and the later-stage image processing is facilitated.
Step seven: the image data processing system 7 performs image processing on the acquired coarse aggregate image, and the image processing flow is as follows: coarse aggregate original image → median filtering → image sharpening → image binarization → image morphological processing → image hole filling → coarse aggregate external polygon processing. The graphics and data processing system consists of a computer and a display screen and can be replaced by a personal PC.
The image acquisition system 1 is connected with the image data processing system 7 through a data line.
Preferably, the Image processing software is Image Pro Plus software.
Step eight: the evaluation index of the edge angle performance of the coarse aggregate is determined by the ratio of the difference between the original outline area of the coarse aggregate particles and the area of the polygon externally connected with the coarse aggregate particles to the outline area of the original coarse aggregate particles. The calculation formula is shown in the following formula.
Wherein CA represents the angularity of a single aggregate;
A2representing the area of a polygon circumscribed by the coarse aggregate;
A1representing the coarse aggregate particle raw profile area;
it is preferable that the index of the angularity evaluation of the coarse aggregate is independent of the size of the coarse aggregate particles and is related only to the degree of projection on the contour of the coarse aggregate particles, that is, only to the angularity of the coarse aggregate.
Since the angularity of the coarse aggregate is characterized by the area index, the calculation of the overall angularity of the coarse aggregate by area weighting is not necessary. The representative value of the angularity of the coarse aggregates can be obtained from the average value of all the coarse aggregate particles. The representative value of the angularity of the coarse aggregate can be obtained by the following formula:
wherein I represents a representative value of angularity of the coarse aggregate;
CAirepresenting the angularity of individual coarse aggregates
n represents the number of coarse aggregate particles.
Preferably, when the number of coarse aggregate samples exceeds 100, the arrangement of the coarse aggregate particles does not significantly affect the representative value of the angularity of the coarse aggregate. Therefore, when the image information of the coarse aggregates is acquired, in order to improve the efficiency of image information acquisition, the image information of each aggregate on one placing surface is acquired.
In one embodiment of the invention, basalt coarse aggregates from the same production site, the same production batch, are selected. The particle sizes are respectively 4.75-9.5 mm, 9.5-13.2 mm and 13.2-16 mm, hereinafter referred to as 4.75mm, 9.5mm and 13.2 mm.
Basalt coarse aggregates with particle sizes of 4.75mm, 9.5mm and 13.2mm were abraded at 0r, 400r, 800r and 1200r, respectively, using a los angeles abrader to form coarse aggregates with different angularity. And after the abrasion is finished, sieving the coarse aggregates with different particle sizes and abrasion revolution numbers respectively, screening out the coarse aggregates which do not belong to respective particle size ranges, and finally, screening to obtain the coarse aggregates with single particle size. In order to avoid crushing the aggregate by the steel ball during abrasion, the steel ball is not put in the test during abrasion, and the aggregate is abraded only by collision and friction between the aggregate and the cylinder wall and between the aggregate. Preferably, the LR-T0317 Lorata abrader is selected for this test.
In order to avoid the adverse effect of the dust generated after abrasion on the test results, all aggregates were washed with clean water to remove surface dust and dried in an oven before image acquisition.
And (3) carrying out image acquisition, image processing and data analysis on the edge angle property of the coarse aggregate sample by using a coarse aggregate edge angle property evaluation device. The device for evaluating the edge angle of the coarse aggregate is composed of an image acquisition system 1 and an image data processing system 7 as shown in fig. 1.
According to the different sizes of the coarse aggregates, selecting the coarse aggregate containing plate 5 with the proper groove size, wherein the coarse aggregate containing plate 5 is a white light-transmitting plastic plate as shown in figure 2, and according to the size specification of the common coarse aggregates, the coarse aggregate containing plate 5 with the different groove sizes of 4.75-26.5 mm is manufactured. The purpose of arranging the grooves is to provide convenience for test personnel to place coarse aggregate. A side view of the coarse aggregate containment plate 5 is shown in figure 3.
And turning on an illuminating lamp 4 of the coarse aggregate image acquisition system, wherein the illuminating lamp is a common LED lamp and is mainly used for providing necessary illuminating conditions for installation of the coarse aggregate containing plate 5 and placement of the coarse aggregates. The coarse aggregate holding plate 5 is installed above the inverse lamp 6. The reverse light lamp consists of a high-brightness LED lamp 6-1 and a light-gathering lampshade 6-2.
The coarse aggregates are placed in the corresponding grooves of the coarse aggregate containing plate 5 in order, and appropriate gaps are reserved among the coarse aggregates, so that image processing can be performed conveniently in the later period.
And closing the illuminating lamp 4, and closing the opening and closing door of the coarse aggregate image acquisition system, wherein the opening and closing door comprises a first opening and closing door 2-1 and a second opening and closing door 2-2, so that the coarse aggregate image acquisition is ensured that the external light cannot generate adverse effects on the coarse aggregate image.
After the image data processing system 1 gives an instruction, the digital camera 3 in the image acquisition system starts to perform image acquisition operation on the coarse aggregate. After the acquisition is completed, the image data processing system 7 automatically saves the acquired picture. The image acquisition system 1 is composed of a digital camera 3, a lighting lamp 4, a coarse aggregate containing plate 5, a backlight lamp 6 and the like.
The image data processing system carries out image processing on the acquired coarse aggregate image, and the image processing flow is as follows: coarse aggregate original image → median filtering → image sharpening → image binarization → image morphological processing → image hole filling → coarse aggregate external polygon processing. The image processing flow is shown in fig. 5.
The evaluation index of the edge angle performance of the coarse aggregate is determined by the ratio of the difference between the original outline area of the coarse aggregate particles and the area of the polygon externally connected with the coarse aggregate particles to the outline area of the original coarse aggregate particles. The calculation formula is shown as the following formula, and the calculation schematic diagram is shown in fig. 6.
Wherein CA represents the angularity of a single aggregate;
A2representing the area of a polygon circumscribed by the coarse aggregate;
A1representing the coarse aggregate particle raw profile area;
the representative value of the whole coarse aggregate is obtained from the average value of all the coarse aggregate particles. The representative value of the angularity of the coarse aggregate can be obtained by the following formula:
wherein I represents a representative value of angularity of the coarse aggregate;
CAirepresenting the angularity of individual coarse aggregates
n represents the number of coarse aggregate particles.
The present invention was used to measure the angularity of basalt coarse aggregates of 4.75mm, 9.5mm and 13.2mm after abrasion of 0r, 400r, 800r and 1200r, respectively, and the test results are shown in table 1 below.
TABLE 1 coarse aggregate angularity measurement results
| 4.75mm | 9.5mm | 13.2mm | |
| 0r | 5.50 | 5.24 | 6.81 |
| 400r | 3.06 | 4.18 | 5.86 |
| 800r | 2.61 | 3.76 | 4.89 |
| 1200r | 2.06 | 3.59 | 4.61 |
As can be seen from Table 1, the coarse aggregates of each grade of particle size were reduced in their angularity with the increase in the number of abrasion revolutions, but were reduced to different degrees.
The above is only a preferred embodiment of the present invention, and certainly, the scope of the present invention should not be limited thereby, and therefore, the present invention is not limited by the scope of the claims.
Claims (10)
1. A coarse aggregate angular character evaluation device is characterized by comprising an image acquisition system and an image data processing system,
the image acquisition system comprises a camera bellows, a digital camera, a coarse aggregate containing plate and a backlight lamp, wherein the digital camera, the coarse aggregate containing plate and the backlight lamp are all arranged in the camera bellows, the digital camera is arranged above the coarse aggregate containing plate, the backlight lamp is arranged below the coarse aggregate containing plate, and the image data processing system is connected with the digital camera.
2. The apparatus for evaluating the angularity of coarse aggregate according to claim 1, wherein an illumination lamp is further provided in the black box, the illumination lamp is provided above the coarse aggregate holding plate, and the black box is provided with an opening and closing door.
3. The apparatus for evaluating angularity of coarse aggregates according to claim 1, wherein a plurality of grooves are distributed on the coarse aggregate holding plate, and each groove is used for holding a particle of the coarse aggregate.
4. The coarse aggregate angularity evaluation device according to claim 1, wherein the coarse aggregate angularity evaluation device comprises a plurality of coarse aggregate containing plates, the size of the groove on each coarse aggregate containing plate is adapted to the size of the corresponding coarse aggregate particle size, and the diameter of the groove ranges from 4.75mm to 26.5 mm.
5. The apparatus for evaluating the angularity of coarse aggregates according to claim 1, wherein the coarse aggregate holding plate is a white light-transmitting plastic plate.
6. A method for detecting the edge angle of coarse aggregate by using the apparatus for evaluating the edge angle of coarse aggregate according to claim 1, comprising the steps of:
1) placing the coarse aggregates on a coarse aggregate placing plate, and keeping a certain gap between particles of each coarse aggregate;
2) placing the coarse aggregate containing plate containing the coarse aggregate in a dark box, and closing the dark box; 3) the image data processing system acquires images of the particles of the coarse aggregate through a digital camera;
4) after the image data processing system processes the acquired image, the edge angle of each particle of the coarse aggregate is obtained;
5) and the image data processing system carries out statistical analysis according to the obtained edge angle performance of each coarse aggregate particle to obtain a representative value of the edge angle performance of the coarse aggregate.
7. The method according to claim 6, wherein in the step 4), the image data processing system processes the acquired image by: and sequentially carrying out median filtering, image sharpening, image binarization, image morphology processing, image pit filling and coarse aggregate particle external polygon processing on the image.
8. The method according to claim 6, wherein in the step 4), the angularity of the coarse aggregate particles is:
wherein CA represents the angularity of a single aggregate, A2Represents the area of the coarse aggregate circumscribed polygon, A1Representing the raw profile area of the coarse aggregate particles.
9. The method for detecting angular characteristics of a coarse aggregate according to claim 6, wherein in the step 5), the representative value of angular characteristics of the coarse aggregate is:
wherein I represents a representative value of angularity of the coarse aggregate, CAiIndicating the angularity of the individual coarse aggregates and n indicating the number of coarse aggregate particles.
10. The method according to claim 6, further comprising, before the step 1), the step of: selecting a coarse aggregate sample to be tested, sieving the sample, cleaning the sample by using clear water, and then putting the sample into an oven for drying to obtain the coarse aggregate sample with single grain size and clean surface.
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