CN-119322086-B - Device and method for testing duration time and condensation strength of black ice on phase-change asphalt pavement

CN119322086BCN 119322086 BCN119322086 BCN 119322086BCN-119322086-B

Abstract

The invention provides a device and a method for testing the duration time and the coagulation strength of black ice on a phase-change asphalt pavement, and belongs to the technical field of road surface anti-icing performance testing. The device comprises a pressure head unit, a water bin unit and an acquisition unit, wherein the pressure head unit comprises a hollow circular tube, a concentric reducing special tube, a circular disc, a steel ball, a circular rod, a cylinder and a spring, the water bin unit comprises a fan-shaped water bin, a plastic film, a screw, a level bar and a screw type horizontal adjustment foot, and the acquisition unit comprises a conductivity meter and a pressure meter. The test method comprises the steps of unfolding freeze thawing tests on phase-change asphalt mixtures with water films of different thicknesses on the bottom surfaces, testing the coagulation time, melting time and duration of black ice of different thicknesses according to a conductivity-time curve, pressing the black ice of different thicknesses until the black ice is broken, and testing the coagulation strength of the black ice of different thicknesses.

Inventors

YE HAIHANG
WEN DONGHUI
CHEN JUN
LI YUNPENG
FU JIAJING
DONG ZHENHAI
LIN CHUANXIANG

Assignees

河海大学
水电十三局天津勘测设计研究院有限公司

Dates

Publication Date: 20260508
Application Date: 20241121

Claims (4)

1. The device for testing the duration time and the condensation strength of black ice on the phase-change asphalt pavement comprises a pressure head unit, a water sump unit and an acquisition unit; the upper part of the pressure head unit is a hollow circular tube with the length of 6cm and the outer diameter of 1.95cm, a through hole with the aperture of 5mm is formed on the side surface 1cm away from the top, and threads are arranged in the range 1cm away from the bottom on the inner wall of the circular tube; the lower part of the pressure head is a concentric variable-diameter special pipe, the outer side surface of the small-aperture circular pipe is provided with threads, the threads extend into the hollow circular pipe and are screwed with the threads on the inner wall of the hollow circular pipe, the outer diameter of the large-aperture circular pipe is the same as the outer diameter of the hollow circular pipe, 8 equal-depth cuts are formed in the side surface along the height direction, the threads are arranged in the range of 1cm from the upper edge of the cuts on the inner wall of the large-aperture circular pipe, a wafer capable of being screwed with the large-aperture circular pipe is arranged, the side surface and the bottom surface of the wafer are respectively carved with external threads and a cross-shaped groove, and the bottom surface of the wafer is flush with the upper edge of the cuts after the wafer is screwed; the structure comprises a steel ball, a round rod, a cylinder and a spring, wherein the steel ball is provided with a through hole passing through the center of the sphere and sleeved on the round rod, two ends of the round rod are fixed on the inner wall of the cylinder, two cylinders are in a group and connected through the spring, two ends of the spring are fixed on the bottom surfaces of the two cylinders, the two round rods in the two cylinders are mutually parallel after being fixed, the inside of the pressure head is provided with a conductivity probe, the probe enters the pressure head from the through hole which is 1cm away from the top on a hollow round tube, the bottom of the probe is flush with the lower edge of a notch, the water bin unit consists of 4 open fan-shaped water bins with the same horizontal area, the depth of each fan-shaped water bin is 1mm, 2mm, 3mm and 4mm, the thickness of the bottom plate of each fan-shaped water bin is 2cm, the two through holes are arranged on the bottom plate, the aperture is 2cm, the inner wall of the hole is provided with threads, the collecting unit comprises a conductivity meter and a pressure meter, wherein the conductivity meter and the pressure meter are respectively used for collecting conductivity signals and pressure signals so as to determine the duration time of the black ice and characterize the condensation strength of the black ice, the water bin is made of stainless steel, and glass wool with low heat conductivity coefficient is adhered to the outer side surface of the water bin.
2. The device for testing the duration and the condensation strength of black ice on the phase-change asphalt pavement according to claim 1, wherein the pressure head unit consists of 4 groups of 2 pressure heads, and the depths of side cuts of the large-aperture circular tubes in each group of pressure heads are respectively 1mm, 2mm, 3mm and 4mm.
3. The device for testing the duration and the condensation strength of black ice on the phase-change asphalt pavement according to claim 1, wherein the distance between the centers of two through holes on the bottom plate of the fan-shaped water bin and the vertex of the fan is 4.36cm, and the vertical distance between the centers of two through holes and the nearest radius of the fan-shaped water bin is 1.67cm.
4. A method for testing the duration and the setting strength of black ice on a phase-change asphalt pavement, which is characterized by using the testing device for the duration and the setting strength of black ice on the phase-change asphalt pavement according to any one of claims 1 to 3, and comprising the following steps: S1, cutting a phase-change asphalt mixture Marshall test piece along the radial direction to obtain a disc sample with the thickness of 4cm, marking 8 points which are 4.5cm away from the center of the top surface and are distributed in a central symmetry manner on the top surface of the sample, and drilling 8 through round holes with the aperture of 2cm along the thickness direction of the sample by taking the 8 points as the center; S2, taking out the testing device and the disc samples from the incubator, injecting a water sample with the initial conductivity of more than 50 mu S/cm at 20 ℃ into the four water bins after leveling, enabling the upper surface of the water film to be flush with the upper edges of the water bins, and respectively forming water films with the thickness of 1mm, 2mm, 3mm and 4mm in the four water bins; s3, transferring the assembled sample and device to a refrigerator at the temperature of minus 5 ℃, connecting a conductivity meter, drawing conductivity and time relation curves of water films with the thickness of 4 respectively after 12 hours, taking the final moment of a conductivity sudden drop as the initial condensation moment t 0i (min) of black ice, wherein i=1, 2, 3 and 4; S4, putting the sample and the device into a refrigerator at the temperature of minus 5 ℃, screwing out 0.5 cm-1 cm of black ice with the thickness of 1mm, 2mm, 3mm and 4mm from one through hole of each fan-shaped water bin at the time (t 01 +30)min、(t 02 +30)min、(t 03 +30)min、(t 04 +30) min, pressing a pressure head on the through hole by using a pressure gauge until the black ice is broken, obtaining the condensation strength S 0i of the black ice, screwing out the other through hole of each fan-shaped water bin after 12h, and measuring the condensation strength S 1i of the black ice with the thickness of 4 pieces by using the pressure gauge.

Description

Device and method for testing duration time and condensation strength of black ice on phase-change asphalt pavement Technical Field The invention belongs to the technical field of road surface anti-icing performance test, and particularly relates to a detection device for determining a black ice coagulation state of a phase-change asphalt road surface. Background Mountain roads, wet roads, bridge deck pavement sections, back-to-shade surfaces and land low sections are extremely prone to black ice in autumn and winter. On the one hand, the black ice on the road surface greatly reduces the friction coefficient between the vehicle tyre and the road surface, which leads to easy slipping and difficult control of the vehicle and obviously increases the driving danger of the vehicle, and on the other hand, the black ice is very thin, the black color of the road surface asphalt can be transmitted out from the road surface, which leads to very low visibility of the ice surface, and is difficult to be found and effectively early-warned. Therefore, the black ice on the road surface is delayed, the melting of the black ice is quickened, and the method is a problem of continuous attention of road workers. In order to achieve delayed coagulation and fusion promotion of pavement, researchers have developed low freezing point technologies represented by salt-accumulating asphalt pavement. The technology is to mix the admixture containing chlorine salt into the surface layer of the road surface, typical products of the technology are imported MFL, homemade LX and the like, and the sustained release of the chlorine salt in rainy and snowy weather reduces the freezing point of the road surface and delays the freezing of the road surface. At present, the production of salt storage additive, the composition design of salt storage asphalt concrete, the construction process of salt storage asphalt pavement and the like are mature, a certain number of salt storage asphalt pavement test sections are paved at home and abroad, and good retarder performance is shown in ice and snow weather. However, engineering practice finds that the retarding function of the salt-accumulating asphalt pavement can only last for 2-4 years, and the main reason is that in spring and summer, the chlorine salt of the pavement is still separated out and released, so that the chlorine salt of the pavement is continuously reduced along with the extension of time. Aiming at the problem of short duration of the retarding function of the salt storage pavement technology, the technology represented by the phase change pavement begins to appear in recent years, the technology is to mix a low-temperature phase change material (the phase change temperature is between 0 ℃ and 5 ℃) into the pavement, and the purpose of retarding the pavement surface is realized by storing heat during phase transition and reducing the dropping rate of the pavement temperature when the air temperature drops. At present, the technology obtains series achievements in the aspects of low-temperature phase-change material screening, phase-change asphalt concrete mechanical property, road performance evaluation and the like, but in the low-temperature phase-change asphalt concrete, the influence rule of the type and the doping amount of the phase-change material on the condensation time, the melting time and the condensation strength of the thin ice is not clear, so that the type and the doping amount of the suitable low-temperature phase-change material are difficult to determine in different climates, and the application of the low-temperature phase-change asphalt concrete in a road section easy to generate black ice is greatly hindered. The fundamental reasons of the unknown influence of the type and the doping amount of the phase change material on the black ice coagulation time, the melting time and the coagulation strength are that the device and the method for quantitatively testing the black ice coagulation time, the melting time and the coagulation strength are lack at present, and are mainly characterized in that (1) the thickness of the black ice within 1-4 mm is difficult to judge coagulation and melting through the temperature test by a thermometer, an ice crystal catalyst is doped, and the method for judging the coagulation time by artificially observing the color change also has great subjectivity, and the moment of icing and melting the ice by water is determined by adopting a high-precision method. (2) The small thickness of the black ice makes it difficult to test the strength of the black ice or the bonding strength of the black ice and asphalt concrete by conventional test means such as compression, drawing and the like, and the novel method is to comprehensively evaluate the coagulation strength of the black ice. Disclosure of Invention Aiming at the defects in the prior art, the device and the method for testing the duration and the condensation strength of the black ic