WO2017121357A1 - Asphalt pavement pore water pressure simulation test device and method - Google Patents

Abstract

An asphalt pavement pore water pressure simulation test device comprises at least two pressure vessels (63), each of which is provided with an asphalt concrete test piece (71); and an open container (62). Adhesive (101) is filled in between the bottom of the asphalt concrete test piece (71) and an open annular portion of the open container (62), and the side wall of the asphalt concrete test piece (71) is coated with the adhesive (101). The side wall of the pressure vessel (63) is provided with a first pressure sensor (52) for measuring the external water pressure of the asphalt concrete piece (71). The side wall of the open container (62) is provided with a second pressure sensor (53) for measuring the water pressure at the bottom of the asphalt concrete piece (71). Each open container (62) communicates through a pipe (83) which passes through the side wall of each pressure vessel (63). In the test method of the device, the test pieces (71) in each pressure vessel (63) are sequentially loaded by using a control flow which meets different wheel load characteristics, which can achieve the directional movement of the pore water, and the dynamic response of water pressure in asphalt concrete pores can be tested under the effect of the dynamically changing external water pressure.

Description

Asphalt pavement pore water pressure simulation test device and method [Technical Field]

The invention relates to hydraulic water pressure analysis of asphalt pavement, and particularly relates to an asphalt water pavement pore water pressure simulation test device and method.

【Background technique】

Patent CN101216401B, CN101210870B, CN102253187B, US8312776 and US6799471B1 propose a method or device for causing pore water flow of asphalt concrete specimen by applying external water pressure, but neither of the pore water pressure of the asphalt concrete is monitored, and some pores in the simulation test Non-directional flow of water, and some simulation tests also have the problem of low loading speed.

For the point-like porous area on the asphalt pavement with a plane area smaller than the ground contact area of the tire, the pore water of the pavement under the wheel load generally seeps downward; but the planar porous area on the asphalt pavement with a plane area larger than the ground contact area of the tire, such as asphalt The concrete grade is equipped with a thicker belt-shaped segregation zone, or the bottom of the asphalt layer with a large void ratio. Under the wheel load, the pore water flowing to the adjacent zone under the load of the wheel will occur after the wheel load moves to the adjacent zone. Reverse flow, that is, the pore water moves back and forth between adjacent areas of the road surface as the wheel load moves horizontally. A vehicle with multiple axles or multiple shafts drives over the planar porous area of the asphalt pavement, which may cause the pore water to flow back and forth between adjacent areas of the road surface several times in succession.

In the indoor simulation test, if the test method including the loading method is not designed, especially if the drainage condition of the boundary of the test piece is not limited, the special flow law of the pore water in the planar porous area of the asphalt pavement will not be met; and the pore water flow mode and The pore water pressure response is directly related. In the simulation test, the actual pore water flow pattern does not match the pore water pressure caused by the road surface. The compression of the gas will delay the flow rate of the water and delay the water pressure conduction. Therefore, when considering the compressibility of the unsaturated water, the application of dynamic and static loads will cause different pore water pressure responses. For the analysis of the pore water pressure of the asphalt pavement, it is very important to apply the instantaneous dynamic external pressure in accordance with the actual conditions of the road surface in the simulation test.

In summary, in the indoor experiment, the dynamic water pressure is simulated, and it is necessary to apply the instantaneous dynamic water pressure consistent with the actual road surface and the design test method to collect the pore water pressure.

[Summary of the Invention]

The technical problem to be solved by the present invention is to address the deficiencies of the prior art simulation method for high-speed moving loads on the surface pores of asphalt pavements, and to provide an external environment capable of realizing the directional flow of pore water of asphalt concrete specimens and testing instantaneous dynamic changes. Asphalt pavement pores with dynamic response of pore water pressure at the bottom of asphalt concrete specimen under water pressure The water pressure simulates the test device and provides a test method for the above device.

In order to solve the above technical problem, the present invention adopts the following technical solutions:

An asphalt pavement pore water pressure simulation test device comprises at least two pressure vessels, each of which is provided with an asphalt concrete test piece, an open container, a bottom of the asphalt concrete test piece and an open annular portion of the open container Interposed with an adhesive, the side wall of the asphalt concrete test piece is coated with an adhesive; the side wall of the open container is provided with a first pressure sensor for measuring the external water pressure of the asphalt concrete test piece and is provided for A second pressure sensor for measuring the water pressure at the bottom of the asphalt concrete test piece; each open container is connected by a pipe passing through the side wall of each pressure vessel.

As a further improvement to the above device:

The adhesive is an epoxy resin or a phenolic resin, and the probe of the second pressure sensor is located in a hollow sensor rod member provided with an external thread, and the open container is tightly connected to the pressure vessel through the sensor carrier rod member. .

The asphalt pavement pore water pressure simulation test apparatus further includes a first connecting pipe located at the top of the side wall of the pressure vessel, and the top cover of the pressure vessel is embedded in the pressure vessel in a boss shape.

A piston is further disposed between the top cover of the pressure vessel and the asphalt concrete test piece, and the piston is provided with an exhaust hole communicating with the upper and lower surfaces of the piston.

The asphalt pavement pore water pressure simulation test device further includes a first exhaust gas control valve and a second connecting pipe, wherein the pressure vessel is connected to the air compressor through the first connecting pipe; the second connecting pipe is symmetric with the first connecting pipe Provided on a side wall of the pressure vessel, the first exhaust gas is connected to the pressure vessel through a second connecting pipe.

The asphalt pavement pore water pressure simulation test device further includes an air compressor, a pressure reducing valve, a first intake control valve and a second intake control valve, and the pressure vessel is connected to the air compressor through the first connecting pipe. The first connecting pipe is sequentially provided with a first intake air control valve, a second intake air control valve and a pressure reducing valve in a direction from the pressure vessel to the air compressor, and the top cover of the pressure vessel is provided for Manual valve for exhaust.

The first pressure sensor and the second pressure sensor are dynamic pressure sensors with an operating frequency of 50 kHz or more, the first pressure sensor has a range of 0 MPa to 1.0 MPa, and the second pressure sensor has a range of -0.1 MPa to 1.0 MPa.

As a general inventive concept, the present invention also provides a test method for the above-mentioned asphalt pavement pore water pressure simulation test device, comprising the following steps:

S1, the prepared asphalt concrete test piece having a diameter of not less than 100 mm and not exceeding 155 mm is placed in an open container pre-filled with gravel;

S2, the bottom of the asphalt concrete test piece and the open annular portion of the open container are filled with an adhesive bond, and the side wall of the asphalt concrete test piece is coated with an adhesive. After the adhesive is sufficiently dried and solidified, An asphalt concrete test piece bonded to the open container is placed in the pressure vessel to connect and lock the open container and the pressure vessel;

S3, installing a first pressure sensor and a second pressure sensor, filling the pressure vessel with water to a set water level, installing a piston, sealing the pressure vessel, and being a programmable controller, an air compressor, a first pressure sensor, and a second pressure sensor Connect the power supply and turn on the air compressor;

S4, setting the number of times the data acquisition instrument needs to be collected is t0;

S5, the selection control process starts the test, and the data of the first pressure sensor and the second pressure sensor are collected by the data acquisition instrument, and the current collection time t1 of the data acquisition instrument is updated;

S6. When t1<t0, the looping step S5 is terminated when t1=t0.

As a further improvement to the above test method:

The specific steps of the control flow in the step S5 are as follows:

S5-1, controlling the cross-opening and closing of the first intake control valve and the second intake control valve by the programmable controller, charging one of the pressure vessels with compressed air, and controlling the fourth by the programmable controller The intake control valve and the third intake control valve are cross-opened and closed, and the other pressure vessel is filled with compressed air to apply positive pressure to the water and asphalt concrete test piece until the pressure in the pressure vessel reaches the set pressure. Target pressure value;

S5-2, controlling the cross opening and closing of the first exhaust control valve and the second exhaust control valve by the programmable controller, and releasing the pressure vessel to atmospheric pressure.

The sequence of the step of opening and closing the step S5 is as follows: opening the first intake control valve, opening the fourth intake control valve, opening the second intake control valve, and closing the first intake control valve simultaneously Opening the third intake control valve and the first exhaust control valve, closing the fourth intake control valve and simultaneously opening the second exhaust control valve, closing the second intake control valve, and closing the third intake The control valve and the first exhaust control valve close the second exhaust control valve.

The working principle of the invention is: when the asphalt concrete test piece is immersed in water, the asphalt concrete test piece is subjected to the dynamic pressure conforming to the actual road surface in the vertical axial direction by applying a positive pressure to the pressure vessel filled with one of the pressure vessels. . Due to the external water pressure of the asphalt concrete specimen, the residual air in the void of the asphalt concrete specimen is compressed, and the water is further filled with the pores of the asphalt concrete specimen and the void under the asphalt concrete specimen, and when the pore is saturated with water, the water It flows to the gap under the bottom of the asphalt concrete test piece in another pressure vessel and then flows into the pores of the asphalt concrete test piece. When air pressure is applied to another pressure vessel, that is, water pressure is applied to another asphalt concrete test piece, the water flows in the opposite direction, and water pressure is applied to the two asphalt concrete test pieces to simulate the road surface moving load, and the water flow simulates the asphalt. The actual situation in the pavement gap. When the external water pressure is applied, the pore water pressure response lags due to the non-saturated pore water; when the external water pressure is suddenly released, the gas pressure in the pore will have an impact effect.

Compared with the prior art, the present invention has the following advantages and effects:

(1) The asphalt pavement pore water pressure simulation test device of the present invention is filled with an adhesive between the asphalt concrete test piece and the open annular portion of the open container, and the side wall of the asphalt concrete test piece is coated with an adhesive seal, Asphalt coagulation The boundary drainage condition of the soil test piece is limited to guide the pore water to flow downward, so that the pore water flows back and forth in the vertical direction to ensure that there is no gap between the adhesive and the asphalt concrete test piece sidewall after sealing, and the pore water pressure and external pressure are utilized. The difference causes the pore water to flow, instead of artificially setting the pressure to drive the pore water, so as to measure the pressure conduction law of the directional flow of the pore water of the asphalt concrete, and the open containers are connected through a pipe passing through the side walls of the pressure vessels to guide the pore water. Directional flow between asphalt concrete specimens.

(2) The probe of the second pressure sensor of the present invention is located in a hollow sensor rod member provided with an external thread, and the open container is tightly coupled to the pressure vessel through the sensor carrier rod member, thereby preventing water in the inside and outside of the open container from passing through The concrete specimens are directly connected by pores.

(3) The connecting pipe of the present invention is disposed at the top of the pressure vessel, and the top cover of the pressure vessel is thickly embedded in the pressure vessel, and the space above the water surface in the pressure vessel is reduced, and the amount of inflation required to achieve the target pressure is reduced, and the test frequency is increased.

(4) The second control valve or the like of the present invention is connected to the side wall of the pressure vessel instead of the top cover of the pressure vessel, so that the opening and closing of the pressure vessel is lighter; the first pressure sensor, the second pressure sensor, and the third The pressure sensor and the fourth pressure sensor have high acquisition frequency, high precision and sufficient range of ranges to meet the needs of water pressure monitoring.

(5) The invention can be loaded independently, can be loaded instantaneously and repeatedly loaded without relying on large-scale dynamic loading test equipment, all the accessories are localized, the maintenance is convenient, and the purchase and maintenance cost is relatively low.

(6) The test method of the present invention connects the first intake control valve and the second intake control valve in series and the opening time crosses, greatly shortening the pressurization time, increasing the loading speed, and avoiding the first intake control. The effect of the opening and closing time of the valve and the second intake control valve on the loading speed.

(7) The test method of the present invention alternately applies a cyclically varying instantaneous external water pressure to the asphalt concrete test piece, causing seepage and reverse seepage in the pores of the asphalt concrete test piece, and applying a periodic dynamic change pole to the asphalt concrete test piece. Short-term external water pressure, real-time monitoring of external water pressure and pore water pressure of asphalt concrete specimens, and the water pressure in the pores changes dynamically and lags behind the external water pressure changes, which is consistent with the variation of the pore water pressure of the pavement, so that the asphalt can be simulated. The actual working condition of the pavement, that is, the effect of the pore water pressure caused by the simulated moving wheel load, can analyze the impact of the road surface on traffic load and environmental factors, and overcome the shortcomings of the existing test techniques.

[Description of the Drawings]

1 is a schematic structural view of a pore water pressure simulation test device for an asphalt pavement according to Embodiment 1 of the present invention.

Fig. 2 is a schematic view showing the sealing mode and force of the asphalt concrete test piece according to the first embodiment of the present invention.

Fig. 3 is a partially enlarged view showing the mounting manner of the first pressure sensor in the first embodiment of the present invention.

Fig. 4 is a partially enlarged view showing the mounting manner of the second pressure sensor in the first embodiment of the present invention.

Figure 5 is a flow chart showing a test method of Embodiment 2 of the present invention.

illustration:

1, programmable controller; 21, the first solid state relay; 22, the second solid state relay; 23, the third solid state relay; 24, the fourth solid state relay; 25, the fifth solid state relay; 3, air compressor; a first intake control valve; 42, a second intake control valve; 43, a third intake control valve; 44, a fourth intake control valve; 45, a first exhaust control valve; Second exhaust control valve; 47, manual valve; 48, pressure reducing valve; 51, pressure gauge; 52, first pressure sensor; 53, second pressure sensor; 61, piston; 62, open container; Container; 64, top cover; 71, asphalt concrete test piece; 81, first connecting pipe; 82, second connecting pipe; 83, pipe; 9, data collecting instrument; 101, binder; 111, sensor carrier rod .

【detailed description】

The present invention will be further described in detail below with reference to the embodiments and drawings, but the embodiments of the present invention are not limited thereto.

Embodiment 1

As shown in FIGS. 1 to 4, an asphalt pavement pore water pressure simulation test device includes at least two pressure vessels 63, each of which is provided with an asphalt concrete test piece 71, an open container 62, and an asphalt concrete test piece. The bottom of the 71 and the open annular portion of the open container 62 are filled with an adhesive 101 (the adhesive 101 in the embodiment is specifically an epoxy resin, and the phenolic resin can achieve the same technical effect), and the side wall of the asphalt concrete test piece 71 The adhesive 101 is coated; the lower portion of the side wall of the open container 62 is symmetrically provided with two mounting holes, one of which is provided with a first pressure sensor 52 for measuring the external water pressure of the asphalt concrete test piece 71, and the other A second pressure sensor 53 for measuring the water pressure at the bottom of the asphalt concrete test piece 71 is provided in the mounting hole; each of the open containers 62 communicates through a duct 83 passing through the side wall of each pressure vessel 63. The asphalt pavement pore water pressure simulation test device of the present invention is filled with an adhesive 101 between the asphalt concrete test piece 71 and the open annular portion of the open container 62, and the side wall of the asphalt concrete test piece 71 is coated with the adhesive 101 to be sealed. The boundary drainage condition of the asphalt concrete test piece 71 is limited, and the pore water is deflected downward to make the pore water reciprocate in the vertical direction, so that the adhesive 101 and the asphalt concrete test piece 71 have no gap on the side wall after the sealing, and the pores are utilized. The difference between the water pressure and the external pressure causes the pore water to flow, instead of artificially setting the pressure to drive the pore water, thereby measuring the pressure conduction law of the directional flow of the pore water of the asphalt concrete, and the respective open containers 62 pass through a side wall passing through the pressure vessels 63. The pipe 83 communicates to guide the directional flow of the pore water between the asphalt concrete test pieces 71.

In the present embodiment, the probe of the second pressure sensor 53 is located in the hollow sensor carrier rod member 111 with internal and external threads, and the open container 62 is tightly coupled to the pressure vessel 63 via the sensor carrier rod member 111. The second pressure sensor 53 is installed at the bottom of the asphalt concrete test piece 71, so that the water between the pressure vessel 63 and the open container 62 is prevented from directly communicating without passing through the pores of the asphalt concrete test piece 71.

In this embodiment, the asphalt pavement pore water pressure simulation test device further includes a first connecting pipe 81, the first connecting pipe 81 is located at the top of the side wall of the pressure vessel 63, and the top cover 64 of the pressure vessel 63 has a boss-like thickening embedded pressure. In the container 63, a gap is provided between the side wall of the pressure vessel 63 and the top cover 64.

In the present embodiment, a piston 61 is attached below the top cover 64 of the pressure vessel 63 and above the asphalt concrete test piece 71. The piston 61 is used to prevent the water mist from being discharged during the exhausting, thereby causing the water surface in the pressure vessel 63 to be lowered. The piston 61 is slidably connected to the side wall of the pressure vessel 63 through a rubber ring. The piston 61 is provided with an exhaust hole communicating with the upper and lower surfaces of the piston 61. After the piston 61 is attached to the water surface, a bolt is installed to block the exhaust hole, and the piston 61 is provided. The top surface is flush with the bottom surface of the first connecting duct 81.

In this embodiment, the asphalt pavement pore water pressure simulation test device further includes a second connecting duct 82 symmetrically disposed on the side wall of the pressure vessel 63 and the first exhausting control valve 45 passing through the second connecting duct 82. It is connected to the pressure vessel 63.

In this embodiment, the asphalt pavement pore water pressure simulation test apparatus further includes an air compressor 3, a pressure reducing valve 48, a first intake control valve 41, and a second intake control valve 42, and the pressure vessel 63 passes through the first connection. The duct 81 is connected to the air compressor 3, and the first connecting duct 81 is sequentially provided with a first intake air control valve 41, a second intake air control valve 42 and a lower order in the direction from the pressure vessel 63 to the air compressor 3. The pressure valve 48, the top cover 64 of the pressure vessel 63 is provided with a pressure gauge 51 and a manual valve 47. During the test, the pressure in the pressure vessel 63 can be understood by the pressure gauge 51 or the reading of the first pressure sensor 52 can be checked to avoid abnormal air pressure. Not promptly detected; during the test, a temporary interruption test is required to open the pressure vessel 63, which can be manually vented by the manual valve 47.

In the present embodiment, the first connecting duct 81 is sequentially provided with a third intake air control valve 43, a fourth intake air control valve 44, and a pressure reducing valve in the direction from the other pressure vessel 63 to the air compressor 3. 48. The second exhaust control valve 46 is connected to the other pressure vessel 63 through the second connecting duct 82.

In the present embodiment, the air compressor 3 is of a normally open type; the first intake control valve 41, the second intake control valve 42, the fourth intake control valve 44, and the third intake control valve 43, The first exhaust control valve 45 and the second exhaust control valve 46 are both normally closed.

In the present embodiment, the pressure reducing valve 48 is used to adjust the output pressure of the air compressor 3 so that the pressure in the pressure vessel 63 reaches the target value. The first pressure sensor 52 tests the external water pressure above the top surface of the asphalt concrete test piece 71 in the pressure vessel 63. The second pressure sensor 53 tests the pore water pressure at the bottom of the asphalt concrete test piece 71.

The embodiment further includes a programmable controller 1, a first solid state relay 21, a second solid state relay 22, a third solid state relay 23, a fourth solid state relay 24, and a fifth solid state relay 25, and the programmable controller 1 passes the first The solid state relay 21, the second solid state relay 22, the third solid state relay 23, the fourth solid state relay 24, and the fifth solid state relay 25 are respectively connected to the first intake control valve 41, the second intake control valve 42, and the fourth intake The gas control valve 44, the third intake control valve 43, and the first exhaust control valve 45 are connected; the fourth solid state relay 24 is also connected to the first exhaust control valve 45; and the fifth solid state relay 25 is also connected to An exhaust control valve 45 and a second exhaust control valve 46 are connected to each other.

The programmable controller 1 is used to set the time by controlling the first solid state relay 21, the second solid state relay 22, The third solid state relay 23, the fourth solid state relay 24, and the fifth solid state relay 25 respectively control the first intake control valve 41, the second intake control valve 42, the fourth intake control valve 44, and the third intake The control valve 43 and the first exhaust control valve 45 supply and receive power, the fourth solid state relay 24 also controls the supply and de-energization of the first exhaust control valve 45; and the fifth solid state relay 25 controls the second exhaust. Supply and disconnection of the control valve 46.

In this embodiment, the first pressure sensor 52 and the second pressure sensor 53 are dynamic pressure sensors having an operating frequency of 50 kHz or more, the range of the first pressure sensor 52 is 0 MPa to 1.0 MPa, and the range of the second pressure sensor 53 is -0.1. MPa ~ 1.0MPa.

Embodiment 2

As shown in FIG. 5, the specific process of the method for testing by using the apparatus described in Embodiment 1 is as follows:

(1) indoor preparation or drilling on the road surface to obtain an asphalt concrete test piece 71 having a diameter of not less than 100 mm and not exceeding 155 mm;

(2) filling a cylindrical open container 62 having the same outer diameter as that of the asphalt concrete test piece 71 and having a sensor mounting hole on one side, filling the gravel of the 13.2 mm to 16 mm standard square sieve and filling it with water;

(3) The bottom portion of the asphalt concrete test piece 71 and the top open annular portion of the cylindrical open container 62 filled with crushed stone are cemented with the adhesive 101, and the sidewall of the asphalt concrete test piece 71 is coated with the adhesive 101. And let it flow naturally until the adhesive 101 is applied to the outer side wall of the asphalt concrete test piece 71 and the open container 62, and keep the sensor mounting hole without the adhesive 101;

(4) After the adhesive 101 is sufficiently dried and solidified to form strength, the asphalt concrete test piece 71 firmly bonded to the cylindrical open container 62 is placed in the pressure vessel 63 to be a sensor carrier rod with external threads. 111 is connected to the locking opening container 62 and the pressure container 63, the first pressure sensor 52 and the second pressure sensor 53 are installed, the pressure container 63 is filled with water to the bottom surface of the first connecting pipe 81, and the piston 61 is slidably connected to the pressure through the rubber ring. On the side wall of the container 63, when the piston 61 is attached to the water surface, the mounting bolt is used to block the vent hole, and the top cover 64 of the pressure container 63 is covered;

(5) tightening the screw to compress the rubber pad between the top cover 64 of the pressure vessel 63 and the side wall to seal the pressure vessel 63, closing the manual valve 47;

(6) For the programmable controller 1, the air compressor 3, the first pressure sensor 52 and the second pressure sensor 53, respectively, the power source is connected, and the air compressor 3 is turned on, then the control flow can be selected to start the water washing test, and the water washing is performed. The data collecting instrument 9 collects data of the first pressure sensor 52 and the second pressure sensor 53 during the process;

Control flow: the first intake control valve 41 is opened by the programmable controller 1 for 0.25 s, and the second intake control valve 42 is opened for 0.25 s at 0.15 s, that is, at the first intake control valve 41 and The second intake control valve 42 applies pressure to the 0.1s inward water and the asphalt concrete test piece 71 which are simultaneously opened; the fourth intake control valve 44 is opened for 0.25s in 0.1s, and the third intake control valve is 0.25s. 43 open for 0.25s; the first exhaust control valve 45 at 0.25s The pressure vessel 63 is vented to atmospheric pressure for 0.25 s, and the second exhaust control valve 46 is opened for 0.25 s at 0.35 s to vent another pressure vessel 63 to atmospheric pressure;

Table 1 Example 2 control process schedule

	0s	0.1s	0.15s	0.25s	0.35s	0.4s	0.5s	0.6s
First intake control valve 41	Open			shut down
Second intake control valve 42			Open			shut down
Fourth intake control valve 44		Open			shut down
Third intake control valve 43				Open			shut down
First exhaust control valve 45				Open			shut down
Second exhaust control valve 46					Open			shut down

According to the control process, a cyclically varying instantaneous external water pressure is applied to the asphalt concrete test piece 71 to simulate the process of scouring the dynamic water pressure of the asphalt pavement; or the same process cycle after the end of the control process, in this embodiment, the number of cycles For one time.

The time when the first intake control valve 41 and the second intake control valve 42 are simultaneously opened, or the time when the fourth intake control valve 44 and the third intake control valve 43 are simultaneously opened and the selected air compressor Related to the 3rd component, it can be determined according to the data collected by the first pressure sensor 52 and the second pressure sensor 53; the water temperature control during the test can be realized by adjusting the temperature of the periphery of the pressure vessel 63.

For the asphalt concrete test piece 71 with a certain void ratio, when the loading speed is constant, the critical height of the asphalt concrete test piece 71 causing the pore water pressure to 0 is determined by the water pressure-time relationship curve obtained by testing the asphalt concrete test piece 71 of different heights. When the height of the asphalt concrete test piece 71 is constant, the water pressure-time relationship curve obtained by the test of different loading speeds determines the critical loading speed which causes the pore water pressure to be zero.

(7) After the simulated hydrodynamic pressure flushing is completed, the programmable controller 1 is turned off, the air compressor 3 is turned off; the manual valve 47 is opened to discharge the residual gas in the pressure vessel 63; and the screw is opened to open the top cover 64 of the pressure vessel 63, The asphalt concrete test piece 71 was taken out.

Embodiment 3

The specific process of the method for testing by using the device in the first embodiment is the same as that in the second embodiment. The difference is that the control process used in this embodiment is as follows:

The first intake control valve 41 is controlled to be opened by the programmable controller 1 for 0.25 s, and the second intake control valve 42 is opened for 0.25 s at 0.15 s, that is, the first intake control valve 41 and the second intake. Gas control valve 42 is simultaneously turned on for 0.1s The inward asphalt concrete test piece 71 applies pressure; the first exhaust gas control valve 45 is opened for 0.25 s at 0.25 s, and the pressure vessel 63 is exhausted to atmospheric pressure; at 0.1 s, the fourth intake air control valve 44 is opened for 0.25 s. At 0.25 s, the third intake control valve 43 is opened for 0.25 s; at 0.35 s, the second exhaust control valve 46 is opened for 0.3 s to exhaust the pressure vessel 66 to atmospheric pressure; Each time the valve 46 is spaced apart by 0.1 s, the other control valves are cycled several times (0.1 times in this embodiment) after each interval of 0.15 s, thereby applying a periodic change moment to the two asphalt concrete test pieces 71. External water pressure simulates the process of scouring the dynamic pressure of asphalt pavement.

Table 2 Example 3 control process schedule

	0s	0.1s	0.15s	0.25s	0.35s	0.4s	0.5s	0.65s
First intake control valve 41	Open			shut down
Second intake control valve 42			Open			shut down
Fourth intake control valve 44		Open			shut down
Third intake control valve 43				Open			shut down
First exhaust control valve 45				Open			shut down
Second exhaust control valve 46					Open			shut down

It has been found that, when static water pressure is applied to the top of the side wall and bottom closed asphalt concrete test piece 71, the internal water pressure (i.e., pore water pressure) of the asphalt concrete test piece 71 will gradually become equal to the external water pressure; The asphalt concrete test piece 71 applies an instantaneously dynamic water pressure, and the internal water pressure of the asphalt concrete test piece 71 is always smaller than the external water pressure due to the hysteresis of the pore water pressure transmission. Therefore, it is necessary to apply an externally varying external water pressure equivalent to the wheel load frequency in the indoor simulation test.

While the invention has been described above in the preferred embodiments, it is not intended to limit the invention. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention by using the above-disclosed technical contents, or modify the equivalent implementation of equivalent changes without departing from the scope of the technical solutions of the present invention. example. Therefore, any simple modifications, equivalent changes, and modifications to the above embodiments in accordance with the teachings of the present invention should fall within the scope of the present invention.

Claims (10)

1. An asphalt pavement pore water pressure simulation test device comprises at least two pressure vessels (63), each of which is provided with an asphalt concrete test piece (71) and an open container (62), characterized in that: An adhesive (101) is filled between the bottom of the asphalt concrete test piece (71) and the open annular portion of the open container (62), and the side wall of the asphalt concrete test piece (71) is coated with an adhesive. (101); a side wall of the open container (62) is provided with a first pressure sensor (52) for measuring the external water pressure of the asphalt concrete test piece (71) and a bottom water for measuring the asphalt concrete test piece (71) A second pressure sensor (53) for pressure; each open vessel (62) is in communication through a conduit (83) that passes through the side walls of each pressure vessel (63).
2. The asphalt pavement pore water pressure simulation test apparatus according to claim 1, wherein the binder (101) is an epoxy resin or a phenolic resin, and the probe of the second pressure sensor (53) is hollow and In the externally threaded sensor carrier rod (111), the open container (62) is lockedly connected to the pressure vessel (63) via a sensor carrier rod (111).
3. The asphalt pavement pore water pressure simulation test device according to claim 1 or 2, wherein the asphalt pavement pore water pressure simulation test device further comprises a first connecting pipe (81), and the first connecting pipe (81) is located At the top of the side wall of the pressure vessel (63), the top cover (64) of the pressure vessel (63) is embedded in the pressure vessel (63) in a boss shape.
4. The asphalt pavement pore water pressure simulation test apparatus according to claim 3, wherein a piston (61) is further disposed between the top cover (64) of the pressure vessel (63) and the asphalt concrete test piece (71). The piston (61) is provided with a vent hole for communicating the upper and lower surfaces of the piston (61).
5. The asphalt pavement pore water pressure simulation test device according to claim 3, wherein the asphalt pavement pore water pressure simulation test device further comprises a first exhaust control valve (45) and a second connecting conduit (82). The pressure vessel (63) is connected to the air compressor (3) through a first connecting pipe (81); the second connecting pipe (82) is symmetrically disposed on the side of the pressure vessel (63) with the first connecting pipe (81) The wall, the first exhaust control valve (45) is connected to the pressure vessel (63) through a second connecting conduit (82).
6. The asphalt pavement pore water pressure simulation test device according to claim 5, wherein the asphalt pavement pore water pressure simulation test device further comprises an air compressor (3), a pressure reducing valve (48), and a first intake air control device. a valve (41) and a second intake control valve (42), the pressure vessel (63) being connected to the air compressor (3) through a first connecting pipe (81), the first connecting pipe (81) being a first intake control valve (41), a second intake control valve (42), and a pressure reducing valve (48) are sequentially disposed in the direction from the pressure vessel (63) to the air compressor (3). Pressure vessel (63) The top cover (64) is provided with a manual valve (47) for exhausting.
7. The asphalt pavement pore water pressure simulation test apparatus according to claim 6, wherein the first pressure sensor (52) and the second pressure sensor (53) are dynamic pressure sensors having an operating frequency of 50 kHz or more, the A pressure sensor (52) has a range of 0 MPa to 1.0 MPa, and a second pressure sensor (53) has a range of -0.1 MPa to 1.0 MPa.
8. A test method for an asphalt pavement pore water pressure simulation test device according to claim 7, comprising the steps of:

   S1, the prepared asphalt concrete test piece (71) having a diameter of not less than 100 mm and not exceeding 155 mm is placed in an open container (62) prefilled with gravel;

   S2, bonding the bottom of the asphalt concrete test piece (71) and the open annular portion of the open container (62) with a filling adhesive (101), and coating the side wall of the asphalt concrete test piece (71) with a binder (101), after the adhesive (101) is sufficiently dried and solidified, the asphalt concrete test piece (71) bonded to the open container (62) is placed in the pressure container (63), and the open container is connected and locked ( 62) with a pressure vessel (63);

   S3, installing a first pressure sensor (52) and a second pressure sensor (53), filling the pressure vessel (63) with water to a set water level, installing a piston (61), and sealing the pressure vessel (63) for programmable control The air compressor (3), the air compressor (3), the first pressure sensor (52) and the second pressure sensor (53) are connected to the power source, and the air compressor (3) is turned on;

   S4, setting the number of times the data acquisition instrument (9) needs to be collected is t0;

   S5, the selection control process starts the test, and the data of the first pressure sensor (52) and the second pressure sensor (53) are collected by the data acquisition instrument (9), and the current acquisition number t1 of the data acquisition instrument (9) is updated;

   S6. When t1<t0, the looping step S5 is terminated when t1=t0.
9. The method for testing a pore water pressure simulation test device for an asphalt pavement according to claim 8, wherein the specific steps of the control flow in the step S5 are as follows:

   S5-1, controlling the cross opening and closing of the first intake control valve (41) and the second intake control valve (42) by the programmable controller (1) to charge one of the pressure vessels (63) The compressed air is introduced, and the fourth intake control valve (44) and the third intake control valve (43) are controlled to open and close by the programmable controller (1), and are charged to the other pressure vessel (63). Into the compressed air, apply a positive pressure to the water and asphalt concrete test piece (71) until the pressure in the pressure vessel (63) reaches the set target pressure value;

   S5-2, controlling the cross opening and closing of the first exhaust control valve (45) and the second exhaust control valve (46) by the programmable controller (1), releasing the pressure vessel (63) to atmospheric pressure .
10. The method for testing an asphalt pavement pore water pressure simulation test device according to claim 9, wherein the step of opening and closing the step S5 is in turn: turning on the first intake control valve (41), opening The fourth intake control valve (44) opens the second intake control valve (42), closes the first intake control valve (41), and simultaneously opens the third intake control valve (43) and the first row. The gas control valve (45) closes the fourth intake control valve (44) and simultaneously opens the second exhaust control valve (46), closes the second intake control valve (42), and closes the third intake The control valve (43) and the first exhaust control valve (45) close the second exhaust control valve (46).

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