Fine aggregate saturated surface dry state identification and test device

Abstract

The utility model relates to the field of civil engineering, and provides a fine aggregate saturated surface dry state identification and testing device which comprises an electronic scale, a base and a support, the electronic scale is provided with the base and the support, the support is provided with a stirring assembly, the base is provided with a charging barrel, and the output end of the stirring assembly is arranged in the charging barrel and used for stirring fine aggregate in the charging barrel; the stirring assembly comprises a motor and a stirrer, the motor is arranged on the support, and the output end of the motor is connected with the stirrer which is located in the charging barrel. According to the utility model, the subjectivity of a manual test method can be eliminated, so that a test result has better accuracy and repeatability; according to the utility model, testing is carried out in a closed environment, the influence of factors such as a testing environment is eliminated, and the accuracy of measurement is ensured; the test time is greatly shortened, the water evaporation efficiency is improved, and the labor intensity of testers is reduced.

Description

Technical Field

[0001] The utility model relates to the field of civil engineering, in particular to a device for identifying and testing the saturated surface dry state of fine aggregates. Background Art

[0002] The relative density and water absorption rate of fine aggregates are two basic parameters required in the design of civil engineering fields such as highway and structural construction projects. In engineering, technicians are very concerned about a method and instrument that can accurately and quickly test the relative density and water absorption rate of fine aggregates. The relative density and water absorption rate of fine aggregates are important indicators reflecting the hydrophilic properties of fine aggregates.

[0003] The relative density of fine aggregates refers to the ratio of the mass of unit volume of fine aggregates at room temperature to the mass of the same volume of water. The relative density of fine aggregates includes the apparent relative density and the bulk relative density. The volume of the apparent relative density is the volume of the fine aggregates, excluding the void volume of the fine aggregates. The volume of the bulk relative density is the total volume, which includes, in addition to the volume of the fine aggregates, the void volume filled with water when the fine aggregates reach the saturated surface dry state.

[0004] In the current specification for measuring the water absorption rate of fine aggregates, for coarse and fine aggregates and fine aggregates, the surface moisture is first dried with a hair dryer and then the slump bucket method is used. Whether the saturated surface dry state is reached is judged by the slump degree of the fine aggregates, and the slump degree standards for natural sand, manufactured sand and stone chips are different. Therefore, this test is greatly affected by human factors, inconvenient to operate and difficult to reproduce, and there are great deviations in the judgment of the saturated surface dry state by different testers.

[0005] Therefore, in view of the above problems, a device for identifying and testing the saturated surface dry state of fine aggregates is proposed to solve the above problems. Content of the Utility Model

[0006] Aiming at the deficiencies of the prior art, the utility model develops a device for identifying and testing the saturated surface dry state of fine aggregates. The utility model can accurately, efficiently and conveniently test the density and water absorption rate of fine aggregates, making the test results have better accuracy and repeatability, and improving the reliability of the test.

[0007] The technical solution for the utility model to solve the technical problems is as follows: The utility model provides a device for identifying and testing the saturated surface dry state of fine aggregates, including an electronic scale, a base and a bracket. The base and the bracket are arranged on the electronic scale, a stirring assembly is arranged on the bracket, a material cylinder is arranged on the base, and the output end of the stirring assembly is arranged in the material cylinder to stir the fine aggregates in the material cylinder; the stirring assembly includes a motor and a stirrer. The motor is arranged on the bracket, the output end of the motor is connected to the stirrer, and the stirrer is located in the material cylinder.

[0008] As an optimization, a sealing plug is provided at the top of the barrel, and the stirrer passes through the sealing plug and extends into the barrel.

[0009] As an optimization, the stirrer includes a rotating shaft, an erasing component, and a stirring shaft. The rotating shaft is arranged at the output end of the motor. An erasing component is provided at the bottom of the rotating shaft, and a stirring shaft is provided below the erasing component.

[0010] As an optimization, the erasing component includes a support rod, a two-way cylinder, a connecting rod, and an erasing rod. The support rod and the two-way cylinder are horizontally arranged on the rotating shaft from top to bottom in sequence. A connecting rod is hinged to each end of the support rod. A slider one is hinged to each of the two output ends of the two-way cylinder. A chute one for the slider one to slide is formed along the length direction of the connecting rod inside the connecting rod. A slider two is hinged to each end of the two connecting rods away from the support rod. A chute two for the slider two to slide is formed along the horizontal direction on the erasing rod.

[0011] As an optimization, the erasing component further includes a telescopic rod. The two-way cylinder is connected to the erasing rod through the telescopic rod. Scrapers are provided at both ends of the erasing rod, and stoppers are provided at both ends of the chute two of the erasing rod.

[0012] As an optimization, a stirring shaft is provided at the bottom of the erasing rod. The stirring shaft includes a stirring main shaft, stirring blades, and sleeves. A number of sleeves are uniformly fixed along the axial direction of the stirring main shaft. A number of stirring blades are uniformly arranged on the outer wall of the sleeves, and the stirring blades are crescent-shaped.

[0013] As an optimization, a drain pipe is provided at the lower end of the barrel. A filter screen is provided at the connection between the drain pipe and the barrel. A control valve one is provided on the drain pipe; an air inlet pipe and a temperature sensor are provided on the barrel. A control valve three is provided on the air inlet pipe. A hot air blower is provided on the support, and the output end of the hot air blower is connected to the air inlet pipe.

[0014] As an optimization, an exhaust pipe is provided at the upper end of the barrel. A control valve two and an air humidity sensor are provided on the exhaust pipe; a water inlet pipe is provided at the top of the barrel. A control valve four is provided on the water inlet pipe.

[0015] As an optimization, scale lines are provided on the outer wall of the barrel. Sealing caps are also provided at the ends of the air inlet pipe, the exhaust pipe, the drain pipe, and the water inlet pipe.

[0016] The effects provided in the utility model content are only the effects of the embodiments, rather than all the effects of the utility model. The above technical solutions have the following advantages or beneficial effects:

[0017] The device realizes the identification and preparation of the saturated surface dry state of fine aggregates, and can complete the measurement of the apparent relative density, bulk relative density and water absorption related to the saturated surface dry state; effectively eliminates the subjectivity of the manual test method, making the test results have better accuracy and repeatability; the utility model conducts tests in a closed environment, eliminates the influence of factors such as the test environment, and ensures the accuracy of the measurement; greatly shortens the test time, improves the water evaporation efficiency, and reduces the labor intensity of the testers; at the same time, a wiping component is set to scrape the inner wall of the barrel, which is convenient to scrape the materials on the inner wall of the top of the barrel and improves the accuracy rate of the test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings are used to provide a further understanding of the present utility model, and constitute a part of the specification. Together with the embodiments of the present utility model, they are used to explain the present utility model, and do not constitute a limitation to the present utility model.

[0019] Figure 1 It is a schematic diagram of the internal structure of the present utility model;

[0020] Figure 2 It is a schematic diagram of the overall structure of the present utility model;

[0021] Figure 3 It is the front view of the stirrer of the present utility model;

[0022] Figure 4 It is a structural diagram of the stirring shaft of the utility model;

[0023] Figure 5 It is a change curve graph of the saturated surface dry point of the present utility model.

[0024] In the figure, 1, electronic scale; 2, base; 3, barrel; 4, filter screen; 5, control valve 1; 6, drain pipe; 7, stirrer; 71, rotating shaft; 72, stirring shaft; 721, stirring main shaft; 722, stirring blade; 723, sleeve; 731, support rod; 732, double-acting cylinder; 733, connecting rod; 734, wiping rod; 735, slider 1; 736, slider 2; 737, chute 2; 738, chute 1; 739, stop block; 74, scraper; 75, telescopic rod; 8, exhaust pipe; 9, control valve 2; 10, sealing plug; 11, air humidity sensor; 12, motor; 13, temperature sensor; 15, intake pipe; 16, bracket; 17, control valve 3; 18, hot air blower; 19, scale line; 20, water inlet pipe; 21, control valve 4; 22, sealing cap. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] In order to clearly illustrate the technical features of this solution, the following will elaborate on the present utility model in detail through specific embodiments and in conjunction with its attached drawings. The following disclosure provides many different embodiments or examples for implementing different structures of the present utility model. To simplify the disclosure of the present utility model, the components and settings of specific examples are described below. In addition, the present utility model may repeat reference numerals and / or letters in different examples. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. It should be noted that the components illustrated in the drawings are not necessarily drawn to scale. The present utility model omits the description of well-known components, processing technologies and processes to avoid unnecessarily limiting the present utility model. The orientation or positional relationship indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present utility model. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance. In the description of the present utility model, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0026] As Figures 1 to 4 shown, a device for identifying and testing the saturated surface-dry state of fine aggregates includes an electronic scale 1, a base 2 and a bracket 16. The base 2 and the bracket 16 are arranged on the electronic scale 1, a stirring assembly is arranged on the bracket 16, a material cylinder 3 is arranged on the base 2, and the output end of the stirring assembly is arranged inside the material cylinder 3 to stir the fine aggregates in the material cylinder 3; the stirring assembly includes a motor 12 and a stirrer 7. The motor 12 is arranged on the bracket 16, the output end of the motor 12 is connected to the stirrer 7, and the stirrer 7 is located inside the material cylinder 3.

[0027] In this embodiment, a sealing plug 10 is arranged at the top of the material cylinder 3, and the stirrer 7 passes through the sealing plug 10 and extends into the material cylinder 3.

[0028] In this embodiment, the stirrer 7 includes a rotating shaft 71, a wiping assembly and a stirring shaft 72. The rotating shaft 71 is arranged at the output end of the motor 12, the wiping assembly is arranged at the bottom of the rotating shaft 71, and the stirring shaft 72 is arranged below the wiping assembly.

[0029] The erasing assembly includes a support rod 731, a double-acting cylinder 732, a connecting rod 733 and an erasing rod 734. The rotating shaft 71 is horizontally provided with the support rod 731 and the double-acting cylinder 732 from top to bottom in sequence. Two connecting rods 733 are respectively hinged at both ends of the support rod 731. Two sliders 735 are respectively hinged at the two output ends of the double-acting cylinder 732. A first chute 738 for the slider 735 to slide is formed in the connecting rod 733 along the length direction of the connecting rod 733. Two sliders 736 are respectively hinged at the ends of the two connecting rods 733 away from the support rod 731. A second chute 737 for the slider 736 to slide is formed in the erasing rod 734 along the horizontal direction.

[0030] The erasing assembly further includes a telescopic rod 75. The double-acting cylinder 732 is connected to the erasing rod 734 through the telescopic rod 75. Scrapers 74 are arranged at both ends of the erasing rod 734. Stoppers 739 are arranged at both ends of the second chute 737 of the erasing rod 734. The telescopic rod 75 plays a role in support and guidance. The distance between the two scrapers 74 is adapted to the inner diameter of the barrel 3.

[0031] A stirring shaft 72 is arranged at the bottom of the erasing rod 734. The stirring shaft 72 includes a stirring main shaft 721, stirring blades 722 and sleeves 723. A plurality of sleeves 723 are uniformly fixed along the axial direction of the stirring main shaft 721. A plurality of stirring blades 722 are uniformly arranged on the outer wall of the sleeve 723. The stirring blades 722 are in a crescent shape. During use, the motor 12 is started, and the motor drives the rotating shaft 71 to rotate, thereby driving the stirring main shaft 721 to rotate. The fine aggregate in the barrel 3 is stirred by the stirring blades 722. By setting the erasing assembly, the double-acting cylinder 732 is started, and the rod end of the cylinder 732 extends or retracts, driving the slider 735 to move in the first chute 738, so that the connecting rod 733 rotates around the hinge joint between the connecting rod 733 and the support rod 731, and then driving the slider 736 to move in the second chute 737, driving the erasing rod 734 to move up or down. While the erasing rod 734 moves up and down, it will rotate driven by the motor 12, so that the scraper 74 scrapes the inner wall of the barrel 3, facilitating the scraping of the material on the inner wall of the top of the barrel 3 and improving the accuracy of the experimental results.

[0032] In this embodiment, a drain pipe 6 is arranged at the lower end of the barrel 3. A filter screen 4 is arranged at the connection between the drain pipe and the barrel 3. A control valve 5 is arranged on the drain pipe 6; an air inlet pipe 15 and a temperature sensor 13 are arranged on the barrel 3. A control valve 17 is arranged on the air inlet pipe 15. A hot air blower 18 is arranged on the bracket 16. The output end of the hot air blower 18 is connected to the air inlet pipe 15. The mesh hole of the filter screen 4 is 0.05 mm.

[0033] An exhaust pipe 8 is arranged at the upper end of the barrel 3. A control valve 9 and an air humidity sensor 11 are arranged on the exhaust pipe 8; a water inlet pipe 20 is arranged at the top of the barrel 3. A control valve 21 is arranged on the water inlet pipe 20.

[0034] A scale line 19 is provided on the outer wall of the barrel 3, and sealing caps 22 are also provided at the ends of the air inlet pipe 15, the exhaust pipe 8, the drain pipe 6 and the water inlet pipe 20.

[0035] This device realizes the identification and preparation of the saturated surface-dry state of fine aggregates, and can also complete the measurement of parameters related to the saturated surface-dry state of fine aggregates, including apparent relative density, bulk relative density and water absorption rate; effectively eliminates the subjectivity of the manual test method, making the test results have better accuracy and repeatability; this utility model conducts tests in a closed environment, eliminates the influence of factors such as the test environment, and ensures the accuracy of the measurement; greatly shortens the test time, improves the water evaporation efficiency, and reduces the labor intensity of the testers; adopts an electronic control system, improves the reliability of the test, and is more convenient to operate.

[0036] A method for identifying and testing the saturated surface-dry state of fine aggregates, applicable to the device described in any one of the above, adopts the following steps.

[0037] S1: After drying the fine aggregates to a constant weight, add them to the barrel and weigh; take a certain amount of fine aggregates and put them into the barrel 3 from above. Insert the stirrer 7 and connect it to the motor 12, then fasten the sealing plug 10. Connect the air inlet pipe 15, the exhaust pipe 8 to the corresponding control valve three 17 and control valve two 9. Turn on the hot air blower 18 and the motor 12. After drying the fine aggregates to a constant weight, zero the electronic scale 1. Turn off the motor 12 and the hot air blower 18, disconnect the control valve three 17 and control valve two 9 of the air inlet pipe 15 and the exhaust pipe 7, and replace them with sealing caps 22. Start the test program, and the instrument will automatically weigh the dry mass of the fine aggregates. .

[0038] S2: Add water to the barrel to make the fine aggregates supersaturated; connect the water inlet pipe 20 and the drain pipe 6 to the corresponding control valve four 21 and control valve one 5 with the barrel 3. Open the control valve four 21 to inject a certain amount of water into the barrel 3 so that it submerges the fine aggregates to a certain depth. After standing for 24 hours, make the fine aggregates reach the saturated state. Open the control valve one 4 to drain most of the excess water.

[0039] S3: Dry the supersaturated fine aggregates and plot the curve of air humidity and mass change during the drying process; subject the supersaturated fine aggregates to saturated surface dry treatment, and under hot air and stirring, let the moisture be carried away. The computer will automatically plot the curve of air humidity and the mass change of the fine aggregates; connect the stirrer 7 to the motor 12, remove the sealing caps at the air inlet pipe 15 and the exhaust pipe 7 and replace them with control valves, connect the air inlet pipe 15 and the exhaust pipe 7 to the barrel 3, turn on the motor 12 and the hot air blower 18, slowly stir the fine aggregates under certain hot air conditions to carry away the surface moisture, and judge through the temperature sensor 13 and keep the temperature in the whole barrel 3 constant. At the same time, detect the air humidity with the air humidity sensor 10, and analyze the air humidity data in real time through the computer. When it reaches the mutation point, it is considered that the fine aggregates reach the saturated surface dry state. After reaching the saturated surface dry state, turn off the motor 12 and the hot air blower 18, disconnect the connection between the stirrer 7 and the motor 12, disconnect the air inlet and outlet pipes and the water inlet and outlet pipes from the barrel 3, and replace the control valve with the sealing cap 22;

[0040] S4: Judge the saturated surface dry point through the plotted curve; record the saturated mass of the fine aggregates in the saturated surface dry state at this time ;

[0041] For the discrimination of the saturated surface dry state, it is mainly based on the principles of thermodynamics and the mass change law of aggregates. The principles are as follows:

[0042] Based on the basic principles of thermodynamics, when a well-soaked fine aggregate specimen is uniformly dried by hot air, the first to be evaporated is the free moisture on the surface of the fine aggregates, and then the moisture absorbed by the fine aggregates. The difficulty of evaporation between the two is not the same. It is more difficult to evaporate the moisture in the internal voids of the fine aggregates. Therefore, when the fine aggregates are uniformly dried, there will be a mutation point on the curve of the relationship between the air humidity at the outlet and time. At this time, the fine aggregates reach the saturated surface dry state: for the mass of the evaporated fine aggregates, its mass change will also have an obvious law. When there is a large amount of free water in the instrument, its mass reduction speed is very fast. As the free water evaporates, it is more difficult to evaporate the water inside the aggregates, and its mass reduction speed will slow down; combining the air humidity change and the mass change, plot a change curve as shown in Figure 5 to accurately find out the saturated surface dry point of the fine aggregates.

[0043] S5: Add water to the barrel to the scale line and record the total mass at this time; then add water to the barrel 3 to the scale line 19, disconnect the connection between the water inlet pipe 20 and the control valve four 21, replace it with the sealing cap 22, and measure its mass with the electronic scale 1 ;

[0044] S6: After emptying the barrel completely, wash the barrel and refill it with water up to the graduation line, and record the mass at this time. After taking out all the fine aggregates and cleaning the barrel, reconnect the water inlet pipe 20 and the control valve four 21, add water to the barrel 3 up to the graduation line 19, and after disconnecting the water inlet pipe 20 and the control valve four 21, measure its mass at this time as ;

[0045] S7: The apparent relative density, bulk relative density and water absorption of the fine aggregates can be calculated based on the above masses.

[0046] S8: Correct the relative density and water absorption according to the test temperature.

[0047] Based on the various masses, test temperatures and other data obtained above, the apparent relative density, bulk relative density and water absorption of the fine aggregates can be calculated, and the test results can be corrected according to the test temperature.

[0048] In the present utility model, the relative density and water absorption of the fine aggregates can be obtained through the following formulas.

[0049]

[0050]

[0051]

[0052] Where:

[0053] is the mass of the dried fine aggregates (g);

[0054] is the mass of the saturated surface dry specimen of the fine aggregates (g);

[0055] is the total mass of the saturated surface dry specimen and water (g);

[0056] is the mass of only adding water (g);

[0057] is the apparent dry relative density of the fine aggregates, dimensionless;

[0058] is the bulk relative density of the fine aggregates, dimensionless;

[0059] is the water absorption of the fine aggregates, %.

[0060] At this time, the test results obtained according to the above formula are the relative density and water absorption at the test temperature. The test temperature can be corrected according to the test temperature to obtain the relative density and water absorption of the fine aggregate at the standard temperature.

[0061] Although the specific implementation manners of the utility model are described above in conjunction with the accompanying drawings, it is not a limitation on the protection scope of the utility model. Based on the technical solution of the utility model, various modifications or deformations that can be made by those skilled in the art without creative efforts are still within the protection scope of the utility model.

Claims

1. A device for identifying and testing the saturated surface dry state of fine aggregate, characterized by: The electronic scale (1) comprises an electronic scale (1), a base (2) and a bracket (16); the base (2) and the bracket (16) are arranged on the electronic scale (1); a stirring assembly is arranged on the bracket (16); a barrel (3) is arranged on the base (2); an output end of the stirring assembly is arranged in the barrel (3) to stir fine aggregate in the barrel (3); the stirring assembly comprises a motor (12) and a stirrer (7); the motor (12) is arranged on the bracket (16); the output end of the motor (12) is connected to the stirrer (7); and the stirrer (7) is located in the barrel (3).

2. The fine aggregate saturated surface dry state identification and testing device according to claim 1 is characterized by: A sealing plug (10) is arranged at the top of the barrel (3), and the agitator (7) passes through the sealing plug (10) and extends into the barrel (3).

3. The fine aggregate saturated surface dry state identification and testing device according to claim 2 is characterized by: The stirrer (7) comprises a rotating shaft (71), an erasing component and a stirring shaft (72); the rotating shaft (71) is arranged at the output end of the motor (12); the erasing component is arranged at the bottom of the rotating shaft (71); and the stirring shaft (72) is arranged below the erasing component.

4. The fine aggregate saturated surface dry state identification and testing device according to claim 3 is characterized by: The erasing assembly comprises a support rod (731), a two-way cylinder (732), a connecting rod (733) and an erasing rod (734); the support rod (731) and the two-way cylinder (732) are horizontally arranged in sequence from top to bottom on the rotating shaft (71); two ends of the support rod (731) are respectively hinged with a connecting rod (733); two output ends of the two-way cylinder (732) are respectively hinged with a slider 1 (735); a slide groove 1 (738) for the slider 1 (735) to slide is provided in the connecting rod (733) along the length direction of the connecting rod (733); a slider 2 (736) is respectively hingedly provided at one end of the two connecting rods (733) away from the support rod (731); and a slide groove 2 (737) for the slider 2 (736) to slide is provided on the erasing rod (734) in the horizontal direction.

5. The fine aggregate saturated surface dry state identification and testing device according to claim 4 is characterized in that: The erasing assembly further comprises a telescopic rod (75), the bidirectional cylinder (732) and the erasing rod (734) are connected via the telescopic rod (75), scrapers (74) are arranged at both ends of the erasing rod (734), and stoppers (739) are arranged at both ends of the second slide groove (737) of the erasing rod (734).

6. The fine aggregate saturated surface dry state identification and testing device according to claim 4 is characterized in that: A stirring shaft (72) is arranged at the bottom of the rod (734), and the stirring shaft (72) comprises a stirring main shaft (721), stirring blades (722) and a sleeve (723). The stirring main shaft (721) is evenly and fixedly provided with a plurality of sleeves (723) along the axial direction, and an outer wall of the sleeve (723) is evenly provided with a plurality of stirring blades (722), and the stirring blades (722) are crescent-shaped.

7. The fine aggregate saturated surface dry state identification and testing device according to claim 1 is characterized by: A drainage pipe (6) is provided at the lower end of the barrel (3), a filter screen (4) is provided at the connection between the drainage pipe and the barrel (3), and a control valve 1 (5) is provided on the drainage pipe (6); an air intake pipe (15) and a temperature sensor (13) are provided on the barrel (3), a control valve 3 (17) is provided on the air intake pipe (15), and a hot air blower (18) is provided on the bracket (16), and an output end of the hot air blower (18) is connected to the air intake pipe (15).

8. The fine aggregate saturated surface dry state identification and testing device according to claim 7 is characterized by: An exhaust pipe (8) is arranged at the upper end of the barrel (3), and a second control valve (9) and an air humidity sensor (11) are arranged on the exhaust pipe (8); a water inlet pipe (20) is arranged at the top end of the barrel (3), and a fourth control valve (21) is arranged on the water inlet pipe (20).

9. The fine aggregate saturated surface dry state identification and testing device according to claim 8 is characterized by: The outer wall of the barrel (3) is provided with scale lines (19), and sealing caps (22) are also provided at the ends of the air inlet pipe (15), the exhaust pipe (8), the drain pipe (6) and the water inlet pipe (20).

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