CN105823725A - Testing device and testing method for measuring road surface friction attenuation rate of snow-melting agent under low-temperature environment - Google Patents

Abstract

A device and test method for measuring the friction attenuation rate of snow-melting agent road surface under low-temperature environment. Determination of pavement friction attenuation rate. The test method uses the above-mentioned test device and follows three steps of test preparation, measurement and result arrangement. The test results obtained by the above-mentioned test device and test method are accurate, stable and reliable, and can more truly reflect the change of the anti-skid performance of the road surface after using the snow-melting agent, and the beneficial effect is remarkable. Traffic accidents are of great significance.

Description

A test device and test method for measuring the friction attenuation rate of snow-melting agent road surface in low temperature environment

technical field

The invention belongs to the technical field of snow melting and deicing for urban roads, airport roads, highways, etc., and specifically relates to a test that can quickly and accurately measure the road surface friction attenuation rate index that characterizes the influence of snow melting agents on the antiskid performance of road surfaces in low temperature environments Device and test method.

Background technique

Highways, urban roads and airport roads in most parts of my country will be affected by ice and snow in winter. The snow and ice on the road not only leads to traffic interruption, but also easily leads to traffic accidents, resulting in serious economic and loss of life and property. At present, the most widely used snow melting and deicing method in the world is to spread deicing agent. According to incomplete statistics, the world uses about 30 million tons of deicing agent every year, and the amount of deicing agent is still showing a gradual increase trend.

Sprinkling deicing agent will reduce the anti-skid performance of the road surface. In order to ensure driving safety, my country's national standard for road deicing and snow-melting agent (GB/T23851-2009) uses the index of friction attenuation rate of the road surface to characterize and standardize the effect of snow-melting agent on the anti-skid performance of the road surface. influences. Among them, the method of measuring the anti-slip attenuation rate of snow-melting agent pavement is to use a pendulum tribometer to measure the anti-skid value of on-site asphalt pavement, cement concrete pavement or indoor specimens before and after spraying snow-melting agent solution, and then calculate the anti-skid value of the pavement after spraying snow-melting agent solution. friction decay rate. On the basis of a large number of tests, the applicant analyzed the following defects in the above-mentioned test method: (1) The deicing agent is mainly used for snow melting and deicing on roads in winter, and the ambient temperature is low when used. temperature. The test data show that the ambient temperature has a significant impact on the skid resistance of the pavement after the deicing agent is sprayed. (2) In the test operation using the pendulum friction coefficient measuring instrument, since the moment the pendulum falls must be caught by hand, the whole device will vibrate, and the reading accuracy is greatly affected by the operator. In addition, there are difficulties in pressure calibration, Shortcomings such as poor reproducibility of test results.

Contents of the invention

For the problems existing in the above-mentioned test method, the purpose of this invention is to provide a kind of test device and test method capable of measuring the friction attenuation rate of snowmelting agent road surface under low temperature environment. Attenuation index of skid resistance performance after spraying deicing agent on road pavement.

In order to achieve the above object, the present invention is characterized in that the test device for measuring the attenuation rate of deicing agent road surface friction in a low temperature environment includes a test box capable of controlling the ambient temperature and a road surface friction coefficient measuring device. The bottom of the test chamber can be fixed with a pavement test bench, including two kinds of asphalt pavement and cement pavement test benches, which are the same as the materials used for the actual asphalt pavement or cement concrete pavement surface, and the pavement friction coefficient measuring device is placed on the pavement test bench.

The test box includes a control system, a motor, a liquid receiver, a compressor, a condenser, an evaporator, and a universal wheel at the bottom. The control system is placed inside the test box, and a display screen is installed on the left side of the test box. The motor is a servo motor, which is fixed on the left side of the bottom of the test box by bolts.

The pavement friction coefficient measuring device is composed of a pavement test bench, a tension meter, a slider, and a speed measuring and length measuring instrument. The size of the pavement test bench is 180cm*30cm*5cm, including two kinds of asphalt pavement and cement pavement, which are made of two different types of materials, namely asphalt mixture and cement concrete, and are the same as the actual road surface material and construction depth . The slider is a counterweight with a mass of 1 kg, one side is equipped with a hook, and the bottom of the slider is fixed with a rubber layer. The tension gauge is connected with the control system through a data line.

A test method for measuring the friction attenuation rate of snow-melting agent road surface under low temperature environment is characterized in that the above-mentioned test device is used to carry out according to the following steps:

(1) Test preparation

① Move the asphalt pavement test bench or cement pavement test bench to the test box, install and level it;

②Place the slider in the middle position on the right side of the road test bench, and connect the tension gauge.

(2) Determination

① Sprinkle 300ml of water on the road test bench, and scrape it flat with a rubber plate, so that the surface is evenly covered with a layer of water film;

②Set the running speed to 4m/min, start the test and record the friction force f ₁ when the slider reaches a constant speed, if the slider does not reach a uniform speed, adjust the running speed and try again;

③Wipe off the water on the surface of the road test bench and wait for it to dry completely;

④Set the temperature of the test chamber, prepare 300ml of deicing agent solution and pour it into a beaker, and place it in the test chamber for 30 minutes;

⑤ Sprinkle all the snow melting agent solution on the road test bench, and scrape it with a rubber plate to make it evenly covered;

⑥Set the running speed to 4m/min, start the test and record the friction force f ₂ when the slider reaches a constant speed, if the slider does not reach a uniform speed, adjust the running speed and try again.

(3) Result sorting

Before and after spraying the deicing agent, the friction coefficient of the road surface is measured in μ and calculated according to the following formula:

$\mathrm{<span\; class="notranslate">\; \&mu;</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; f</span>}}{\mathrm{<span\; class="notranslate">\; 9.8</span>}}$

In the formula:

μ - road surface friction coefficient;

f - measured friction force

The pavement friction attenuation rate of deicing agent is calculated in M and calculated according to the following formula:

$\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; 100</span>}\mathrm{<span\; class="notranslate">\; \%</span>}$

In the formula:

M-the road surface friction attenuation rate of snow melting agent;

f ₁ - friction force determined by spraying water;

f ₂ - friction force measured by spraying deicing agent solution.

The traditional pendulum tribometer is made according to the principle that "the potential energy loss of the pendulum is equal to the work done by overcoming the friction of the road surface when the rubber sheet installed at the end of the swing arm slides across the road". The measurement result is the pendulum value (BPN), Divide by 100 to get the friction coefficient value; and the present invention is made according to the principle of "friction force is proportional to positive pressure and dynamic friction coefficient", by measuring the friction force and the slide block when relative sliding occurs between the slide block and the test bench The ratio of the weight is the coefficient of friction of the road surface. Compared with the pendulum friction coefficient meter, the present invention has the characteristics of simple operation, high measurement accuracy and fast speed:

(1) By controlling the test temperature in the test chamber, the friction attenuation rate of the road surface can be measured in a low temperature environment, which is more consistent with the actual use environment of the snow melting agent, and the test results are more meaningful;

(2) Using the servo motor to pull the slider, the speed and precision of the slider can be precisely controlled, and it has the characteristics of instant start and quick stop, which makes the measurement result of the friction coefficient more accurate.

Description of drawings

Fig. 1 is a schematic structural view of the present invention's test device for measuring deicing agent pavement friction attenuation rate in a low temperature environment; Fig. 2 is a front view of the pavement friction coefficient measuring device; Fig. 3 is a top view of the pavement friction coefficient measuring device; Fig. 4 is a slider Schematic diagram of the structure. Among them: 1 display screen; 2 control system; 3 motor; 4 liquid reservoir; 5 universal wheel; 6 speed measuring instrument; 7 road surface model; 8 compressor; 9 leveling screw; 10 condenser; 12 rubber layer; 13 drainage hole; 14 counterweight; 15 data line; 16 insulation layer; 17 evaporator.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

As shown in Fig. 1, the structure schematic diagram of the device for measuring the friction attenuation rate of snow-melting agent road surface in the present invention is provided, including a test box and a road surface friction coefficient measuring device for providing a low temperature test environment. The test chamber includes a control system 2, a motor 3, a liquid receiver 4, a compressor 8, a condenser 10, and an evaporator 17, and a universal wheel 5 is provided at the bottom, and the control system 2 is placed inside the test chamber , and a display screen 1 is provided on the left side of the test box, the liquid receiver 4, compressor 8, and condenser 10 are placed on the bottom plate of the test box cabinet, and the evaporator 17 is placed on the back of the test box working room , the motor 3 is placed on the left side of the bottom of the working chamber of the test box, and an insulation layer 16 is arranged between the working room, and the speed measuring and length measuring sensor 6 is placed at the bottom of the working room of the test box. Flat screw 9, bottom right side is provided with drainage hole 13.

As shown in Fig. 2 and Fig. 3, the front view and top view of the pavement friction coefficient measuring device are given respectively, including the pavement model 7, the tension meter 11, the data line 15, the breeding speed 14 and the rubber layer 12. The size of the pavement model 7 is 180cm*30*5cm. It is paved with asphalt mixture and cement concrete. It is placed on the 6 leveling screws 9 at the bottom of the working room of the test box. 15 is connected with control system 2.

As shown in FIG. 4 , a schematic structural view of the slider is provided. The slider is a counterweight 14 with a mass of 1 kg. A rubber layer 12 is arranged at the bottom of the slider to simulate the effect of a car tire.

When carrying out the test, the motor 3 starts quickly after receiving the signal, and the traction slider 14 moves toward the motor 3 at a constant speed. During 25cm, motor 3 stops working, and slide block 14 stops sliding.

Implementation of the test method:

In order to verify the reliability and beneficial effect of the test device and test method for the friction attenuation rate of snowmelting agent road surface under low temperature environment of the present invention, the present invention will be further described in detail below in conjunction with the examples, but the present invention is not limited to the following examples.

The specific test steps are as follows:

(1) Test preparation

① Move the asphalt pavement test bench or cement pavement test bench to the test box, install and level it;

②Place the slider in the middle position on the right side of the road test bench, and connect the tension gauge.

(2) Determination

① Sprinkle 300ml of water on the road test bench, and scrape it flat with a rubber plate, so that the surface is evenly covered with a layer of water film;

②Set the running speed to 4m/min, start the test and record the friction force f ₁ when the slider reaches a constant speed, if the slider does not reach a uniform speed, adjust the running speed and try again;

③Wipe off the water on the surface of the road test bench and wait for it to dry completely;

④Set the temperature of the test chamber, prepare 300ml of deicing agent solution and pour it into a beaker, and place it in the test chamber for 30 minutes;

⑤ Sprinkle all the snow melting agent solution on the road test bench, and scrape it with a rubber plate to make it evenly covered;

⑥Set the running speed to 4m/min, start the test and record the friction force f ₂ when the slider reaches a constant speed, if the slider does not reach a uniform speed, adjust the running speed and try again.

(3) Result sorting

20% sodium chloride, 20% potassium acetate and a liquid deicing agent were used to test three different deicing agents, and the pavement friction attenuation rate was calculated according to the following formula:

$\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; 100</span>}\mathrm{<span\; class="notranslate">\; \%</span>}$

In the formula:

M-the road surface friction attenuation rate of snow melting agent;

f ₁ - friction force determined by spraying water;

f ₂ - friction force measured by spraying deicing agent solution.

The test results of road surface friction attenuation rate of various deicing agents are shown in Table 1.

Table 1. Test results of road surface friction attenuation rate of deicing agent

The test results show that the pavement friction attenuation rate of the same snow-melting agent is different under different ambient temperatures, and the ambient temperature has a significant impact on the friction coefficient of the pavement after spraying the snow-melting agent; the pavement friction attenuation rate of different types of snow-melting agents is different. The test device and the test method of the present invention measure the road surface friction attenuation rate of the deicing agent, which can reflect the influence of the deicing agent on the antiskid performance of the pavement, and the test result is accurate, stable, reliable and highly distinguishable. The test device and the test method of the present invention can optimize the deicing agent which has less influence on the antiskid performance of the road surface, improve the snow melting and deicing efficiency, and ensure road driving safety.

It should be noted that the above embodiment is only for understanding the present invention, and the present invention is not limited to this embodiment, and any addition, equivalent replacement or modification of technical features made on the basis of the technical solution of the present invention shall be regarded as the present invention. protection scope of the invention.

Claims (4)

1. one kind measures the device of Snow Agent pavement friction attenuation rate under low temperature environment, it is characterised in that be made up of the proof box and surface friction coefficient determinator that can control ambient temperature.

Proof box the most according to claim 1, it is characterised in that include control system, motor, reservoir, compressor, condenser, vaporizer, bottom is provided with universal wheel, and described control system is placed in inside proof box, and is provided with display screen on the left of proof box.Described motor uses servomotor, adopts and is bolted to proof box bottom left.

Surface friction coefficient determinator the most according to claim 1, it is characterised in that be made up of pavement test platform, strain gauge, slide block, the horizontal metroscope that tests the speed.The size of described pavement test platform is 180cm*30cm*5cm, including bituminous paving and cement pavement two types, is made up of asphalt and two kinds of different kind of material of cement concrete respectively, identical with real road surface layer material therefor, construction depth.Described slide block is balancing weight, and quality is 1kg, and side is furnished with hook, and slider bottom is fixed with rubber layer.Described strain gauge is connected with control system by data wire.

4. one kind measures the test method of Snow Agent pavement friction attenuation rate under low temperature environment, it is characterised in that utilizes assay device, follows the steps below:

(1) test prepares

1. bituminous paving testing stand or cement pavement testing stand are moved in proof box, install and leveling；

2. slide block is placed in centre position on the right side of pavement test platform, connects strain gauge.

(2) measure

1. by 300ml water spread on pavement test platform, blend rubber plate strikes off so that it is surface uniform fold water membrane；

2. the speed of service is set as 4m/min, starts test and record frictional force f when slide block reaches at the uniform velocity₁, as slide block does not reaches at the uniform velocity, the speed of service need to be adjusted and again test；

3. the water on pavement test platform surface is cleaned, and treat that it is completely dried；

4. setting proof box temperature, preparation 300ml Snow Agent solution is also poured in beaker, places 30min in proof box；

5., by whole for Snow Agent solution spreads on pavement test platform, strike off with rubber slab, be allowed to uniform fold；

6. the speed of service is set as 4m/min, starts test and record frictional force f when slide block reaches at the uniform velocity₂, such as slide block the most at the uniform velocity, the speed of service need to be adjusted and again test.

(3) result arranges

Before and after spread Snow Agent, the coefficient of friction on road surface, in terms of μ, calculates as follows:

$\mathrm{\&mu;}=\frac{f}{9.8}$

In formula:

μ-surface friction coefficient；

The frictional force that f-measures

The pavement friction attenuation rate of Snow Agent, in terms of M, calculates as follows:

$M=(1-\frac{f_2}{f_1})\&times;100\%$

In formula:

The pavement friction attenuation rate of M-Snow Agent；

f₁The frictional force that-spray water measures；

f₂The frictional force that-spraying snow-melting agent solution measures.