JP5103159B2 - Workability evaluation tester for asphalt mixture - Google Patents

Description

  The present invention relates to an asphalt mixture workability evaluation tester. Specifically, the characteristics of an asphalt mixture can be numerically displayed, and, for example, the characteristics of a virgin asphalt mixture are compared with the characteristics of a regenerated and heated asphalt mixture. The present invention relates to an asphalt mixture workability evaluation tester capable of evaluating the workability of an asphalt mixture.

  Asphalt mixtures are roughly classified into newly produced virgin asphalt mixtures and regenerated and heated asphalt mixtures. In recent years, the proportion of regenerated and heated asphalt mixtures has increased. This recycled and heated asphalt mixture is made by heating and regenerating asphalt pavement waste material excavated by road construction, etc., and the recovered pavement material is mechanically crushed or broken into pieces by heat, steam, etc. The material is produced by mixing the virgin asphalt mixture in a predetermined ratio.

  An asphalt mixed material production plant capable of heating and regenerating asphalt pavement waste is known from Patent Document 1, for example.

Japanese Utility Model Publication No. 6-63606

  However, since regenerated aggregates have various properties, it is known that workability greatly changes when mixed in a virgin asphalt mixture at a predetermined ratio as aggregate.

  Therefore, the amount of recycled aggregate is adjusted so that workability does not deteriorate, but this adjustment depends on the experience and intuition of experienced workers.

  On the other hand, demand for recycled and heated asphalt mixtures is expected to increase further as energy and resource savings are screamed and raw materials soar. Moreover, veteran workers are leaving the site due to aging, and the succession of technology is in danger.

  The problem to be solved by the present invention is to provide an asphalt mixture workability evaluation tester that can numerically display the characteristics of the asphalt mixture.

The invention according to claim 1 is a testing machine for evaluating workability of an asphalt mixture, a container for storing an asphalt mixture as a sample, temperature measuring means for measuring the temperature of the sample, and stirring the sample A paddle, a drive source for driving the paddle, load measuring means for measuring a load applied to the paddle during agitation, and a display recording means for displaying and storing the measured temperature and load . It is characterized by preparing multiple different ones, measuring the characteristics of each sample by changing the shape and combination of the paddles, and comparing the measurement results of each sample to evaluate the workability of the sample. To do.

  The present invention can numerically display the characteristics of the asphalt mixture. For example, the characteristics of the virgin asphalt mixture can be compared with the characteristics of the regenerated heated asphalt mixture. Therefore, based on this characteristic, the amount of recycled aggregate can be adjusted, and a recycled and heated asphalt mixture having excellent workability can be easily manufactured.

  Next, an embodiment of an asphalt mixture workability evaluation tester according to the present invention will be described with reference to the drawings. FIG. 1 is a front view of an asphalt mixture workability evaluation tester. FIG. 2 is a plan view of the same, and FIG. 3 is a right side view of the same.

  The asphalt mixture workability evaluation test machine 1 (hereinafter sometimes referred to as the test machine 1) has portability and enables a measurement test to be performed at the work site.

  The testing machine 1 includes a container 20 that contains an asphalt mixture that is a sample, and a container lifting / lowering device 30 that lifts and lowers the container 20 in the body. Examples of the sample include a virgin asphalt mixture and a regenerated and heated asphalt mixture.

  The container 20 is made of a material having excellent corrosion resistance, such as stainless steel, and has a capacity of about 5 to 10 liters. In addition, it is preferable that the shape of the container 20 is a cylindrical shape so that a staying portion does not occur when stirring by a paddle 40 described later.

  The container lifting / lowering device 30 lifts and lowers the container 20 inside the main body by rotating a handle 31 attached to the outside of the main body (frame 10). That is, the container attachment base 32 to which the container 20 is attached is configured to be movable up and down along the guide rod 33, and the container attachment base 32 and the handle 31 are connected by the gear mechanism 34. 2 and 3, the handle 31 is not shown.

  Therefore, when the handle 31 of the container lifting / lowering device 30 is manually rotated in a predetermined direction, the container mounting base 32 is guided to the guide rod 33 via the gear mechanism 34, and the container 20 is moved according to the rotation direction of the handle 31. Ascend or descend. Of course, the container 20 may be lifted and lowered automatically not only manually but also by a motor or the like.

  The paddle 40 is connected to a driving source 50 to be described later via a coupling 51, and is preferably close to the touch when an operator actually works with a shovel, and uses one or a plurality of paddles. Also, it is preferable to prepare a plurality of paddles 40 having different shapes and use them in combination.

  An example of the paddle 40 is shown in FIGS. First, the paddle 40 shown in FIG. 4 includes a flat stirring portion 41a. That is, a mounting cylindrical portion 43 provided with an insertion port 42 for inserting the rotating shaft 52 is provided in the central column portion, and a flat plate-like stirring portion 41a extends from the mounting cylindrical portion 43 in the diameter direction. (Hereinafter, this paddle 40 may be referred to as a flat paddle 40A). Further, in the paddle 40 shown in FIG. 5, a stirring portion 41b having a substantially triangular cross section extends from the mounting cylindrical portion 43 in the diameter direction (hereinafter, the paddle 40 may be referred to as a triangular paddle 40B). ).

  In order to attach such a paddle 40 to the rotating shaft 52, the rotating shaft 52 may be inserted into the insertion opening 42 of the mounting cylindrical portion 43 from the tip portion and fixed by the mounting screw 44. Although not shown, the mounting screw 44 is also provided on the opposite side surface of the mounting cylindrical portion 43 and is fixed by a pair of mounting screws 44 opposed in the diameter direction.

  Such paddles 40 can be used alone, but may be used in appropriate combinations. That is, for example, as shown in FIG. 6, a triangular paddle 40, that is, a triangular paddle 40B is attached to the lower stage, and a flat paddle 40, that is, a flat paddle 40A, is attached to the middle stage and the upper stage at appropriate intervals. A total of three paddles 40 are arranged so as to be orthogonal to each other. It should be noted that the triangular paddle 40B attached to the lower stage has an action of lifting the sample.

  In the example of the combination of paddles 40 shown in FIG. 7, a total of four paddles 40 including three flat paddles 40 </ b> A and one triangular paddle 40 </ b> B are attached to the rotating shaft 52. That is, the triangular paddle 40B is attached to the lowermost stage, and the flat paddles 40A are attached to the upper, middle, and lower stages, respectively, and a total of four paddles 40 are arranged so as to be orthogonal to each other.

  Further, as shown in FIG. 8, two flat paddles 40A can be attached so as to be orthogonal to each other. In this case, it is preferable that the depth of the sample is shallow, that is, it is used for the shallow dish type container 20. In any case, the number and interval of the paddles 40 or the deployment angle can be adjusted as appropriate. Furthermore, a screw-shaped paddle can also be used.

  On the other hand, the drive source 50 for rotationally driving the paddle 40 is, for example, a motor that uses 200V three-phase AC as a power source, and the rotation by this motor is decelerated by the built-in ring cone continuously variable transmission and output. Removed from the shaft. And the output shaft of this ring cone continuously variable transmission will rotate at 5-10 rpm, for example. The ring cone continuously variable transmission is fixed to the upper surface of the frame 10.

  The ring cone continuously variable transmission includes a sun cone fitted to an input shaft (motor shaft) and a plurality of planetary cones that are in pressure contact with the sun cone. Driven (rotated). Each planetary cone revolves while rotating the inner peripheral surface of the ring with the other conical surface pressed against the inner peripheral surface of the ring. The ring cone continuously variable transmission is configured such that this revolution speed is transmitted to the output shaft by the planetary cone holder.

  The drive source 50, in other words, the output shaft of the ring cone continuously variable transmission is connected via a coupling 51 to an input shaft of a digital torque meter 60 (described later) constituting load measuring means. The digital torque meter 60 is also fixed to the upper surface of the frame 10 in the same manner as the ring cone continuously variable transmission.

  The digital torque meter 60 for measuring the load applied to the paddle 40 measures a torsion angle generated in the power transmission shaft in proportion to the transmitted torque. In other words, the digital torque meter 60 includes the power transmission shaft by means of gears in which the torsion angle generated in the power transmission shaft is fixed at two locations on the shaft and an electromagnetic detector arranged to face each gear. Is a contact torque measuring device that takes out a phase difference between two AC voltage signals in a non-contact manner and measures the phase difference by digital processing based on a highly accurate and highly stable clock pulse of a crystal oscillator.

  The torsion angle detection method includes a method in which a torque detector is inserted between the power transmission shafts and a method in which a detector is attached to the actual moving shaft and the detection is performed directly. The rotating hollow cylinder of the torque detector is rotated by the motor attached to the detector, and the internal toothed wheel integrated therewith is always rotated, so even if the shaft (external gear) is stationary, There is a relative speed between the internal gears. Therefore, each time the internal gear rotates through the gear pitch, the coil receives a change in magnetic flux and generates a sinusoidal AC voltage, so that the torque applied to the stationary shaft can also be measured.

  On the other hand, the torque measured by the digital torque meter 60 is numerically visually displayed and recorded by a display recording means (not shown). This display recording means is constituted by a personal computer (hereinafter referred to as a personal computer) in this embodiment. Then, the personal computer is connected to the digital torque meter 60 and the like through an appropriate interface.

  Furthermore, the load shaft of the digital torque meter 60 is connected to the gear box 70 via the coupling 53. The gear box 70 is a device that changes the transmission direction of rotation by a shaft, and includes shafts that are orthogonal to each other. That is, it has a horizontal axis and a vertical axis. The rotating shaft 52 to which the paddle 40 is attached is connected to the vertical axis of the gear box 70. The gear box 70 is also fixed on the frame 10. Further, the horizontal axis and the vertical axis may be configured to rotate at a constant speed, or may be configured to decelerate.

  On the other hand, the container 20 is provided with a temperature measuring means (not shown) for measuring the temperature of the sample, and the measured temperature is displayed and recorded on a personal computer as the display recording means according to the elapsed time. For example, a thermocouple thermometer or the like is inserted into the sample and directly measured. The measurement position may be measured at a plurality of locations such as the upper stage, middle stage, and lower stage of the sample. The measurement position is preferably a position that does not hinder the rotation of the paddle 40, but the measurement may be performed with the rotation of the paddle 40 stopped during measurement.

  In the illustrated embodiment, the container 20 is lifted by the container lifting device 30 in order to insert the paddle 40 into the container 20 into which the sample has been put. However, when the paddle 40 is inserted, the container 20 is framed. 10, and the rotary shaft 52 to which the paddle 40 is fixed can be moved up and down.

  Next, the usage method of the workability evaluation test machine 1 of the asphalt mixture comprised as mentioned above is demonstrated. First, a heat-regenerated asphalt mixture as a sample is put into the container 20, and the container 20 is set in the testing machine 1. Then, the handle 31 is turned to raise the container 20 so that the paddle 40 is immersed in the sample.

  Therefore, when the motor as the drive source 50 is turned on, the rotation is transmitted by the ring cone continuously variable transmission and the gear box 70, and the paddle 40 rotates at, for example, about 5 to 10 rpm. The rotational speed is adjusted according to the ring position of the ring cone continuously variable transmission.

  When the paddle 40 rotates, resistance due to the sample is added to the paddle 40. Therefore, this resistance, in other words, “return”, is measured by the digital torque meter 60 as torque applied to the shaft, and is visually displayed and recorded on a personal computer.

  The measurement is performed when the paddle 40 is rotated. Therefore, if the paddle 40 is rotated, the torque change can be continuously measured and recorded. However, if the paddle 40 is continuously rotated, the sample in the container 20 is stirred, and the aggregate Sedimentation may be accelerated. When the aggregate settles, the distribution of the aggregate is different between the upper layer and the lower layer of the sample, and the resistance actually applied to the paddle 40 is different. For this reason, an error may occur in the torque measured on the shaft. Therefore, the rotation of the paddle 40, in other words, the torque is preferably measured at an appropriate interval so that the aggregate is uniformly distributed in the container 20.

  And when time passes and the temperature of a sample falls, what was recorded by measuring temperature and torque at an appropriate interval is a graph of the workability evaluation test results shown in FIGS. That is, torque and temperature were measured under the following conditions.

<Measurement 1>
Paddle Arrangement 1: Upper = flat paddle 40A, middle = flat paddle 40A, lower = triangular paddle 40B (arrangement shown in FIG. 6)
Sample 1: Regenerated and heated asphalt mixture (regenerated dense granules 13, R ratio 75%)
Control 1: Virgin asphalt mixture (virgin dense 13)
The result of measurement 1 is shown in FIG.
The R rate is a recycling rate and is a weight percentage of the recycled aggregate.

<Measurement 2>
Paddle arrangement 2: Upper stage = flat paddle 40A, middle stage = flat paddle 40A, lower stage = flat paddle 40A, bottom stage = triangular paddle 40B (arrangement shown in FIG. 7)
Sample 2: Regenerated and heated asphalt mixture (regenerated dense granules 13, R ratio 55%)
Control 2: Virgin asphalt mixture (Virgin dense granules 13)
The result of measurement 2 is shown in FIG.

  As a result of the measurement, as is clear from both figures, the regeneratively heated asphalt mixture tends to have a greater increase in torque due to the temperature drop than the virgin asphalt mixture. That is, workability is not greatly reduced in a range where the temperature drop is small. In other words, if the work is performed before the temperature drops, workability is hardly impaired.

  On the other hand, it is also possible to bring the characteristics of the regenerated and heated asphalt mixture closer to those of the virgin asphalt mixture by changing the regenerated dense grains or increasing or decreasing the recycling rate. That is, it is possible to obtain a regenerated and heated asphalt mixture having workability similar to that of a virgin asphalt mixture by adjusting the regenerated dense granules and the recycle rate.

  By the way, when the paddle is added, that is, when the area of the paddle is increased, a larger resistance is applied, and a larger torque is applied to the rotating shaft. Therefore, measurement is performed in a wide torque range, and more accurate measurement is possible.

  According to the workability evaluation tester for asphalt mixtures according to the present invention, various asphalt mixture characteristics can be measured and visually displayed. On the other hand, the virgin asphalt mixture is not always the best in workability. Therefore, if an asphalt mixture excellent in workability is applied to this test machine to measure the characteristics, and a regenerated and heated asphalt mixture close to this characteristic is prepared, a regenerated asphalt mixture excellent in workability can be easily obtained. .

  Although the present invention has been described with reference to the illustrated embodiments, the present invention is not limited to the above-described embodiments, and can be appropriately implemented without changing the configuration described in the claims. For example, not only the ring cone continuously variable transmission but also other types of transmissions may be used for deceleration of the drive source. Also, a dedicated monitor and recorder can be used as the display recording means.

It is a front view which shows one Example of the workability | operativity evaluation test machine of an asphalt mixture. It is a top view which shows one Example of the workability | operativity evaluation test machine of an asphalt mixture. It is a right view which shows one Example of the workability evaluation test machine of an asphalt mixture. It is a perspective view which shows an example of a paddle shape. It is a perspective view which shows another example of a paddle shape. It is a perspective view which shows an example of the combination of a paddle. It is a perspective view which shows another example of the combination of a paddle. It is a perspective view which shows another example of the combination of a paddle. It is a graph which shows workability | operativity evaluation test result. It is a graph which shows another workability | operativity evaluation test result.

Explanation of symbols

1 Workability Evaluation Tester 10 Frame 20 Container 30 Container Lifting Device 31 Handle 32 Container Mounting Base 33 Guide Shaft 34 Gear Mechanism 40 Paddle 40A Flat Paddle 40B Triangular Paddle 41a Stirring Portion 41b Stirring Portion 42 Insertion Port 43 Mounting Cylindrical Portion 44 Mounting Screw 50 Drive source 51 Coupling 52 Rotating shaft 53 Coupling 60 Digital torque meter 70 Gear box

Claims (1)

A testing machine for evaluating workability of an asphalt mixture,
A container for storing an asphalt mixture as a sample, a temperature measuring means for measuring the temperature of the sample, a paddle for stirring the sample, a drive source for driving the paddle, and a load measuring means for measuring a load applied to the paddle during stirring Display recording means for displaying and storing the measured temperature and load, and
Prepare a plurality of paddles with different shapes, change the shape and combination of the paddles, measure the characteristics of each sample, and compare the measurement results of each sample to evaluate the workability of the sample workability evaluating tester of asphalt mixture, wherein the thing.

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