CN106018463A - Evaluation method for low temperature crack resistance of asphalt - Google Patents
Evaluation method for low temperature crack resistance of asphalt Download PDFInfo
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- CN106018463A CN106018463A CN201610377177.2A CN201610377177A CN106018463A CN 106018463 A CN106018463 A CN 106018463A CN 201610377177 A CN201610377177 A CN 201610377177A CN 106018463 A CN106018463 A CN 106018463A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N25/00—Investigating or analyzing materials by the use of thermal means
- G01N25/14—Investigating or analyzing materials by the use of thermal means by using distillation, extraction, sublimation, condensation, freezing, or crystallisation
Abstract
The invention discloses an evaluation method for the low temperature crack resistance of asphalt. The method includes the steps of: taking or preparing a pedestal and a non-expansive circular ring, wherein the middle of the pedestal is provided with an annular groove, the non-expansive circular ring is closely sleeved on the inner ring wall of the annular groove, the pedestal is equipped with a synapse on the outer ring wall of the annular groove, and the synapse is a cylindrical synapse horizontally disposed on the outer ring wall of the annular groove; heating asphalt, pouring the asphalt into an annular space between the non-expansive circular ring and the outer ring wall of the annular groove, and performing cooling molding to obtain an asphalt circular ring; conducting cooling till the asphalt circular ring fractures, detecting and recording the temperature value and the instantaneous strain value of the non-expansive circular ring at a position corresponding to the synapse. The method performs approximate simulation of a corresponding maximum fracture strain during pavement fracture, establishes correlation with the pavement mixture actual low temperature condition, can realize fixed-point fracture, and can measure the strength value of a fracture part specifically. By means of the method, the measured ring fracture temperature has good correlation with TSRST fracture temperature, and the method has good accuracy and repeatability.
Description
Technical field
The invention belongs to asphalt performance assessment technique field, particularly relate to the evaluation side of a kind of Colophonium crack resistance at low-temperature
Method.
Background technology
The cracking of bituminous paving is domestic and international road circle question of common concern, and its harm is to make moisture immerse along crack
Inside pavement structure, so that sub-surface and roadbed feel like jelly, pavement structure depression of bearing force, produce under Driving Loading
Purt mud, washing away, boundary layer occurs coming to nothing in local, ultimately results in road surface and check crack and pit occur, severely impact the traveling of vehicle
Quality, greatly reduces the service life on road surface.
The crack of bituminous paving includes load Crack and non-loaded deformation.The crack produced by load is in some overload of China
Serious high-grade highway runway is often met, existing many to control fatigue rupture as core content.And another kind of crack, the most non-
Reflection crack caused by the low-temperature shrink crack of load type and semi-rigid type base the most generally exists, and has caused suitable pass
Note, it is well known that both cracks are closely related with the cracking resistance of Colophonium and asphalt.In recent years, carry out both at home and abroad
More research work, wherein, a lot of researchs are main is main goal in research with asphalt surface course cold cracking.
Take the lead in since the cold shrinkage crack to asphalt surface course carries out systematic investigation and study from Canada's sixties in 20th century, road surface
Cracking resistance and material at low temperature performance indications are always the important research content of international road educational circles, at research and application neck over nearly 20 years
Territory achieves breakthrough progress especially.Achieved with common recognition: control the cryogenic property of Colophonium and asphalt, set up phase
Close cryogenic property index and feasible value, be the key measure of asphalt surface course cold cracking design.And the anti-low-temperature cracking of bituminous paving
Performance depends primarily on the cryogenic tensile characteristic of asphalt binder, and the performance of asphalt binder plays a part particular importance, phase
Pass document shows, its contribution rate to 90%, and therefore the research to asphalt surface course cold cracking should be with Colophonium cryogenic property index
Control be main.
By the analysis to domestic and international Colophonium low temperature evaluation index, current Conventional cryogenic index is in mechanical mechanism, test
Fruiting area indexing and still suffer from certain deficiency with the aspect such as road surface degree of association, a lot of aspects are unreasonable；SHRP index can be relatively
The good cryogenic property evaluating matrix pitch, and modified pitch can not be made well evaluation, and SHRP index uses
Creep properties carrys out classification, it is believed that croop property can substitute destructive characteristics, but research shows the phase of croop property and destructive characteristics
Closing property is not fine.In present stage, the cryogenic property of Colophonium can not be made comparisons clear and definite table by currently existing low temperature index
Levying, asphalt performance is evaluated by the easiest index intuitively of necessary proposition one.
Summary of the invention
The technical problem to be solved is to provide the evaluation methodology of a kind of Colophonium crack resistance at low-temperature.
The technical solution used in the present invention is:
The evaluation methodology of a kind of Colophonium crack resistance at low-temperature, comprises the following steps:
S1: take or prepare base and the most swollen annulus, has a cannelure in the middle of described base, the most swollen described annulus closely overlaps
On the internal ring wall of described cannelure, described base is provided with a synapse on the external annulus of described cannelure, and described synapse is water
The flat cylindrical synapse being arranged on the external annulus of described cannelure；
S2: heated asphalt, poured into described in annular space between the most swollen annulus and described cannelure external annulus, cooling
Molding, obtains Colophonium annulus；
S3: cooling, until the fracture of described Colophonium annulus, detects and records temperature value and the most swollen annulus position in corresponding synapse
The instantaneous strain value put.
In some specific embodiments, be additionally included between described S1 and S2 described in the most swollen annulus lateral wall and
The step of the medial wall uniform application lubricant of described cannelure.
In some specific embodiments, described S3 concretely comprises the following steps: the most swollen described in relative with described synapse
On the medial wall of annulus, strain transducer is set, base arranges temperature sensor, by base, the most swollen annulus together with described drip
Blue or green annulus is put in heat sink together, preheating, then controls heat sink and lowers the temperature with steady rate, until described Colophonium annulus
Fracture, detects and records temperature value and the most swollen annulus instantaneous strain value in the position of corresponding synapse.
In further preferred embodiment, after described S3, also include S4: draw instantaneous strain value that detection obtains with
Temperature variation curve, when instantaneous strain value occurs to jump, corresponding temperature value is the temperature during fracture of asphalt material, i.e. ring
Split temperature.
In some specific embodiments, the diameter of described cylindrical synapse can determine according to public formula (I):
In formula, S represents the diameter of described cylindrical synapse, and h represents the height of described cylindrical synapse；R1Described in expression not
The outer shroud radius of swollen annulus；Described H represents the height of described Colophonium annulus；D determines according to public formula (II):
In formula, αDripLinear expansion coefficient for Colophonium；αNECRLinear expansion coefficient for the most swollen annulus；Δ T is cooling extent；R1
Outer shroud radius for the most swollen described annulus；R2Outer shroud radius for described Colophonium annulus；In formula, parameter εATrue by public formula (III)
Fixed:
εA=(αDrip+M·αCollection) Δ T M εCollection (III)
In formula, Δ T is cooling extent；αDripLinear expansion coefficient for Colophonium；M is the length ratio gathering materials one-dimensional with Colophonium；αCollection
For the linear expansion coefficient gathered materials；εCollectionFor the strain gathered materials.
In some specific embodiments, linear expansion coefficient≤5 × 10 of the most swollen described annulus-6mm/mm/℃。
In some specific embodiments, the material of the most swollen described annulus is quartz glass, invar alloy, pottery and steel
In any one.
In some specific embodiments, the material of the most swollen described annulus is quartz glass.
In some specific embodiments, the material of described base is any one in steel, ferrum, aluminum.
In some specific embodiments, the cooling rate scope in described S3 is 1～30 DEG C/h.
The invention has the beneficial effects as follows: the invention provides the evaluation methodology of a kind of Colophonium crack resistance at low-temperature, by system
Standby base and the most swollen annulus, have a cannelure in the middle of described base, the most swollen described annulus closely surrounds the interior of described cannelure
On ring wall, described base is provided with a synapse on the external annulus of described cannelure, and described synapse is for being horizontally placed on described annular
Cylindrical synapse on the external annulus of groove, heated asphalt, poured into described between the most swollen annulus and described cannelure outer shroud
Annular space, cool down molding, obtain Colophonium annulus, cooling, until described Colophonium annulus fracture, detect and record temperature value and
The most swollen annulus is in the instantaneous strain value of the position of corresponding synapse.This method is by controlling the continuous decrease of temperature, and Colophonium annulus is not
Disconnected cooling is shunk, and the most swollen annulus is the least with temperature shrinkage amount, is kept approximately constant, and produces so that Colophonium ring specimen is internal
Temperature stress, and constantly increase with continued down, during until temperature is down to certain value, Colophonium annulus ruptures, due at described ring
Being provided with synapse on the external annulus of shape groove, make Colophonium annulus cross-sectional area at synapse minimum, stress suffered by synapse is maximum,
So the point control that can be ruptured at low temperatures by Colophonium annulus is at synapse, it is achieved selective cleavage；Due to Colophonium annulus and not
The interaction force of swollen annulus is equal, so the strain value that Colophonium annulus is at synapse and the most swollen annulus are at synapse correspondence position
Strain value is equal, so detected instantaneous strain value is Colophonium annulus instantaneous strain value at synapse, records instantaneous
Strain value and temperature value, when instantaneous strain value is undergone mutation, now Colophonium annulus fracture, corresponding temperature value is ring crack temperature
TFrac(temperature during fracture of Colophonium annulus), corresponding instantaneous strain value is ring crack strain value, by stress-strain relation, i.e.
Fracture strength σ of Colophonium can be calculatedFrac.Use this method to carry out the evaluation of Colophonium crack resistance at low-temperature, have following excellent
Point: 1) can the fracture of approximate simulation road surface time corresponding maximum breaking strain, low-temperature condition actual with road surface is set up and is associated；2) may be used
Realizing selective cleavage, the cylinder synapse point on Colophonium annulus, i.e. at stress maximum suffered by Colophonium, controlled fracturing blasting is sent out herein
Raw (this point is corresponding with the fracture of actual road surface), and routine is frozen to break and tested, test previous as indefinite breakaway poing position, this is not only
Improve the effective control to test, facilitate the measurement to breaking strength values herein the most targetedly；3) for different blended
Closing type and the proportion of composing of material, the size of joint base can simulate calculating, and the cross-sectional area adjusting cylindric synapse is (logical
Cross and change different cylinder synapse types), cryogenic property test can be carried out by the dissimilar compound of road pavement targetedly,
To accomplish to be more nearly with road surface actual state, the current any Colophonium crack resistance at low-temperature evaluation of this point all cannot be accomplished；4)
Obtain ring crack temperature TFracWhile, also measure corresponding fracture strength σFrac；5) described Colophonium cryogenic property is used to comment
Valency structure monitoring to ring crack temperature and TSRST breaking temperature there is preferable dependency, and evaluation methodology of the present invention is accurate
Really property and reproducible.
Accompanying drawing explanation
Fig. 1 is the top view of base；
Fig. 2 is Section A-A sectional view in Fig. 1；
Fig. 3 is unlike material and the pictorial diagram of the most swollen various sizes of annulus；
Fig. 4 is the pictorial diagram of various sizes of synapse；
Fig. 5 is that Colophonium ring crack freezes disconnected disc structure top view；
Fig. 6 is section B-B sectional view in Fig. 5；
Fig. 7 is Colophonium low temperature ring crack tester structural representation.
Fig. 8 is bituminous paving model schematic；
Fig. 9 is pavement asphalt mixture check model figure；
Figure 10 is pavement cracking schematic illustration of strain；
Figure 11 is Colophonium annulus and the most swollen annulus force balance schematic diagram；
Figure 12 is strain variation schematic diagram before and after Colophonium annulus is lowered the temperature with the most swollen annulus；
Figure 13 is nonuniform section Colophonium annulus equivalent schematic；
Figure 14 is the correlation analysis figure of quartz glass the most swollen annulus gained ring crack temperature and TSRST breaking temperature；
Figure 15 is the correlation analysis figure of invar alloy the most swollen annulus gained ring crack temperature and TSRST breaking temperature；
Figure 16 is the correlation analysis figure of the most swollen annulus gained ring crack temperature of pottery and TSRST breaking temperature；
Figure 17 varies with temperature curve by one the most swollen annulus material is strained；
Figure 18 is different pitches material correspondence rate of temperature fall and ring crack temperature relation figure.
Description of reference numerals:
1-base；2-cannelure；3-internal ring wall；4-external annulus；5-synapse；6-is the most swollen annulus；7-Colophonium annulus；8-is circular
Depression；9-strain transducer；10-temperature sensor；11-closes accommodation space；12-temperature acquisition processor；13-strain acquirement
Processor；14-liquid nitrogen cooling system；15-material height temperature tester.
Detailed description of the invention
The present invention relates to a ring crack and freeze disconnected disc structure and a Colophonium low temperature ring crack tester.A kind of Colophonium ring crack is frozen
Disconnected disc structure, including base 1 and the most swollen annulus 6.It is the top view of base with reference to Fig. 1, Fig. 1, in the middle of described base 1, has one
Cannelure 2, described base 1 is provided with a synapse 5 on the external annulus 4 of described cannelure 2, is that in Fig. 1, A-A cuts with reference to Fig. 2, Fig. 2
Face sectional view, described synapse 5 is the cylindrical synapse being horizontally placed on the external annulus 4 of described cannelure 2.Described base 1
Centre be provided with a circular depressed 8, described circular depressed 8 is concentric with described cannelure 2, and the radius of described circular depressed 8 is equal to
Internal ring wall 3 radius of described cannelure 2, the degree of depth of described circular depressed 8 is less than the degree of depth of described cannelure 2.The most swollen described circle
The material of ring 6 need to vary with temperature and change in volume is the least, linear expansion coefficient≤5 × 10 of the most swollen described annulus 6-6mm/mm/
℃.In a preferred embodiment, the material of described the most swollen annulus 6 is quartz glass.The material of described base 1 is in steel, ferrum, aluminum
Any one.
Quartz glass, pottery, invar alloy, four kinds of different materials of ordinary steel are the most respectively used with reference to Fig. 3, Fig. 3 a
The most swollen annulus that matter makes, Fig. 3 b is the most swollen annulus of various sizes of quartz glass material.
With reference to the pictorial diagram that Fig. 4, Fig. 4 are various sizes of synapse, described synapse 5 includes the first end and the second end, described
First end is cylindrical, and the cylindrical size of described first end can regulate, to simulate road pavement inhomogeneity pointedly
Type compound carry out cryogenic property test, can accomplish to be more nearly with road surface actual state, described second end is embedded in institute
State in the external annulus 4 of cannelure 2.
With reference to Fig. 5, the most swollen described annulus 6 closely surrounds on the internal ring wall 3 of described cannelure 2, outside the most swollen described annulus 6
Forming an annular accommodation space between wall and described cannelure 2, described annular accommodation space is used for placing Colophonium, at test process
In, first Colophonium is heated, then poured into described annular accommodation space, cool down molding, obtain Colophonium annulus 7, described temperature
Acquisition Instrument includes temperature sensor 10 and temperature acquisition processor 12 two parts, and it is recessed that described temperature sensor 10 is placed in described circle
Falling into the center of 8, the temperature of described base 1 is i.e. regarded as the temperature of described Colophonium annulus 7, and described temperature sensor 10 is used for
Test ring crack freezes the temperature of Colophonium ring in disconnected disk.The height of described cylindrical synapse is equal to the outer shroud 4 half of described cannelure 2
The difference of the outer shroud radius of footpath and the most swollen described annulus 6.Described strain acquirement instrument includes strain transducer 9 and and strain acquirement process
Device 13 two parts, described strain transducer 9 is located on the inwall of described synapse 5 described the most swollen relative annulus 6, due to the described end
There is described circular depressed 8, so facilitating the setting of described strain transducer 9 in seat 1.
With reference to Fig. 6, the bottom of described cannelure 2 is level.The width of described the most swollen annulus 6 is equal to described cannelure 2
The degree of depth.
With reference to Fig. 7, present invention also offers a kind of Colophonium low temperature ring crack tester, freeze including Colophonium ring crack as above
Disconnected disc structure, described Colophonium low temperature ring crack tester also includes heat sink, temperature sensor and strain acquirement instrument, described fall
Temperature device has a closing accommodation space that can accommodate described Colophonium cryogenic property evaluation structure, described temperature sensor bag
Including the temperature sensor 10 and temperature acquisition processor 12 being connected, described temperature sensor 10 is located at described Colophonium ring crack and is frozen disconnected
On the base 1 of disc structure, described strain acquirement instrument includes strain transducer 9 and the strain acquirement processor 13 being connected, should
Become sensor 9 to be located on the inwall relative with described synapse 5 of the most swollen annulus 6.In the present embodiment, Colophonium low temperature ring crack test
Instrument includes that Colophonium ring crack freezes disconnected disc structure, material height temperature tester 15, temperature sensor (by temperature sensor 10 and temperature
Acquisition Processor 12 two parts form, both are connected by data wire), strain acquirement instrument (strain transducer 9 and and strain acquirement
Processor 13 two parts form, connected by data wire), liquid nitrogen cooling system 14 5 part composition.Material height temperature tester
15 are provided with single-stage cooling compressor, and material height temperature tester 15 has closing accommodation space 11.Liquid nitrogen cooling system
The Main Function of 14 is on the basis of the single stage compress heat sink of material height temperature tester 15, takes liquid nitrogen cooling measure
Test is lowered the temperature further strengthening.
The invention provides the evaluation methodology of a kind of Colophonium crack resistance at low-temperature, comprise the following steps: S1: take or prepare the end
Seat 1 and the most swollen annulus 2 (No Expansion Circle Ring is called for short NECR), described base 1 and described the most swollen annulus 2 are tied
Structure above-mentioned ring crack freeze base 1 described in disconnected disc structure and as described in the most swollen annulus 2, described the most swollen annulus 2 is little with temperature
Change and there is change in volume, the shape of described base 1 can be arbitrary shape, such as rectangle, circle, ellipse etc., preferably
Embodiment described in base 1 generally circular in shape, there is in the middle of described base 1 cannelure 2, the most swollen described annulus 6 is nested
On the internal ring wall 3 of described cannelure 2, described base 1 is provided with a synapse 5, described synapse 5 on the external annulus 4 of described cannelure 2
For being horizontally placed on the cylindrical synapse on the external annulus 4 of described cannelure 2；S2: in the lateral wall of the most swollen described annulus 6 and
The medial wall uniform application lubricant of described cannelure 2, so that will not adhere to the most swollen annulus at temperature-fall period medium pitch, it is to avoid
Produce abnormal reading strain, affect test data；S3: heated asphalt, poured into described in the most swollen annulus 6 and described cannelure 2
External annulus 4 between annular space, cool down molding, obtain Colophonium annulus 7；S4: the most swollen described in relative with described synapse 5
Strain transducer 9 is set on the medial wall of annulus 6, base 1 arranges temperature sensor 10, by base 1, the most swollen annulus 6 even
Put in the closing accommodation space 11 of material height temperature tester 15 together with described Colophonium annulus 7,0 DEG C of preheating 30min, then
Controlling heat sink to lower the temperature with steady rate, rate of temperature fall scope is 1-30 DEG C/h, until described Colophonium annulus 7 ruptures,
Detect and record temperature value and the most swollen annulus 6 instantaneous strain value in the position of corresponding synapse 5；S5: draw the wink that detection obtains
Time strain value vary with temperature curve, when instantaneous strain value occurs to jump, the most swollen circle when corresponding strain value is Colophonium fracture
Ring is in the strain value of synapse correspondence position, the mutual extruding produced in cooling contraction process due to Colophonium annulus and the most swollen annulus
It is active force and counteracting force, i.e. FThe most swollen annulus=FDrip, parameter ε that obtained by testStrain jump valueWith ess-strain formula F=ε
E·ASectional area, F can be obtainedThe most swollen annulus, obtain directed force F suffered by Colophonium annulusDrip.Then F is passed throughDrip=σDrip·ADrip, obtain asphalt material
Ring crack intensity σDrip, i.e. σFrac.And the corresponding temperature value that ruptures at this moment is temperature when described Colophonium annulus 7 ruptures,
I.e. ring crack temperature TFrac.In a preferred embodiment, cooling rate can be 10 DEG C/h.The linear expansion coefficient of described the most swollen annulus 2
≤5×10-6mm/mm/℃.The material of described the most swollen annulus 2 is any one in quartz glass, invar alloy, pottery and steel.Institute
The material stating base is any one in steel, ferrum, aluminum.
Principle Analysis:
Below the mechanism of ring crack test is analyzed.In process of the test, annular freezes what disconnected disk was tested as ring crack
Important composition parts, its internal composition is as shown in Figure 5.Internal ring is that (No Expansion Circle Ring is called for short the most swollen annulus
NECR, linear contractive quotiety is the least, generally (0～5) × 10-6Mm/mm/ DEG C), outer shroud is that (linear contractive quotiety α is the biggest for Colophonium ring
In 200 × 10-6Mm/mm/ DEG C), bi-material α difference is relatively big, about two orders of magnitude.Carrying out testing in temperature-fall period,
Colophonium produces with the most swollen annulus temperature influence and shrinks, the length reduction amount produced in the unit interval by variations in temperature because of Colophonium ring
Bigger than the most swollen annulus, make asphalt material and the most swollen annulus directly all create phase in annulus tangential direction and vertical tangent lines direction
Mutual squeezing action power, along with the continuous decline of temperature, asphalt material constantly shrinks under the effect of stress, when (the drip of Colophonium ring
Green material itself) institute's tension stress is when reaching tensile strength of its fracture, Colophonium ring fracture (therefore claim ring crack test).
One, road surface virtual condition is analyzed
The design Elasticity based on material of this test method and strength failure are theoretical.
With reference to Fig. 8, as shown in Figure 8, this figure is bituminous paving model schematic to bituminous paving practical situation, takes one of them
Fritter asphalt is analyzed, road surface Asphalt Mixture check model figure such as Fig. 9, conventional pavement asphalt mixture by
Colophonium, gather materials and space composition, gather materials the most of the total volume 83～85%, Colophonium of the total volume 10～12%, voidage
Account for 4～5%.
Account for the 85% of volume assuming that gather materials, Colophonium of the total volume 15%, both volume ratios are 5.7:1, and research first wouldn't
Consider the volume in space, the cube grid of upper figuredGather materials=0.9473, dColophonium=1-dGather materials=0.0527, gather materials with
The one-dimensional length of Colophonium represents than for 18:1, proportionality coefficient M, i.e. M=18.
As shown in Figure 10, Figure 10 is pavement cracking schematic illustration of strain, and under the conditions of being in microthermal climate, bituminous paving just starts
Low-temperature shrink, and due to the effect of contraction of road surface longitudinal direction, limit the length change on road surface, add road surface cryogenic conditions lower aprons
For elastomer, road surface just occurs in that elastic shrinkage deforms, balances produced temperature stress with this.
Now, the satisfied strain stress relation formula as shown in formula (1.1) in the most uncracked road surface:
(αDrip+M·αCollection) Δ T=εDrip (road surface)+M·εCollection (1.1)
Two, the lab simulation of evaluation methodology of the present invention and mechanical analysis
It is Colophonium annulus and the most swollen annulus force balance schematic diagram with reference to Figure 11, Figure 11, lowered the temperature carrying out laboratory test
Cheng Zhong, Colophonium annulus produces with the most swollen annulus temperature influence and shrinks, because Colophonium annulus is produced in the unit interval by variations in temperature
Length reduction amount bigger than the most swollen annulus, make asphalt material and the most swollen annulus directly in annulus tangential direction and vertical tangent lines side
To all creating mutual squeezing action power, i.e. during this, Colophonium annulus not yet ruptures and is always maintained at the equilibrium-like of stress before
State, satisfied equilibrium relation as shown in formula (2.1), (2.2):
PDrip=PNECR (2.1)
P ＇Drip=PN＇ECR (2.2)
In formula, PDripThe interaction force of tangential direction suffered by Colophonium annulus；PNECRTangential direction suffered by the most swollen annulus
Interaction force；P ＇DripIt is perpendicular to the interaction force of tangential direction, P suffered by Colophonium annulusN＇ECRSuffered by the most swollen annulus
It is perpendicular to the interaction force of tangential direction.
As shown in Figure 11, Colophonium annulus and the most swollen annulus are in contraction process, and Colophonium annulus contracted length is in the unit interval
It is greater than the most swollen annulus, and poised state to be kept, need to support by the elastic strain of Colophonium with the most swollen annulus.Such as Fig. 7 institute
Showing, Fig. 7 is strain variation schematic diagram before and after Colophonium annulus is lowered the temperature with the most swollen annulus, if described Colophonium annulus is uniform cross-section,
Colophonium annulus meets with the strain of the most swollen annulus with relational expression as shown in formula (2.3):
(αDripαNECR) Δ T=εDrip (indoor)+εNECR (2.3)
In formula, αDripLinear expansion coefficient for Colophonium；αNECRLinear expansion coefficient for the most swollen annulus；Δ T is cooling extent；
εDrip (indoor)For testing the strain of medium pitch；εNECRStrain for the most swollen annulus.
Indoor ring crack test is carried out simulated roadway freezing crack situation, selects σDrip (indoor)=σDrip (road surface)Or εDrip (indoor)=
εDrip (road surface), wherein, σDrip (indoor)Stress suffered by test medium pitch, σDrip (road surface)Stress suffered by the medium pitch of actual road surface, εDrip (indoor)For examination
Test the strain of medium pitch, εDrip (road surface)For the strain of actual road surface medium pitch, be i.e. equivalent to this ring crack tester and actual road surface one
Rise and be placed in same cooling environment, make the fracture planting Colophonium together farthest keep consistent with pavement behavior.
The present invention is provided with a synapse on the external annulus of described cannelure, and described synapse is for being horizontally placed on described cannelure
External annulus on cylindrical synapse, by arranging this synapse so that Colophonium annulus reduced cross-sectional area at synapse,
Because on Colophonium annulus, pressure (i.e. direct with the most swollen annulus interaction force) keeps constant, so Colophonium at this synapse
Suffered ess-strain is maximum, makes Colophonium annulus be fixed on and ruptures herein, it is achieved selective cleavage, such that it is able to fixed point detection is disconnected
Split place's strain value.
The present invention can also be by adjusting the size of cylinder synapse, as shown in Figure 4, so that suffered by this Colophonium annulus inside
The breaking strain of breaking strain compound actual with road surface keeps the consistent of approximation.Colophonium annulus cross-sectional area at synapse is become
Little it is equivalent to nonuniform section as shown in fig. 13 that, position at synapse is equivalent to Figure 13 medium pitch annulus cross-sectional area minimum
Place, i.e. at AD line segment.Select the A point (strain maximum of points) on nonuniform section Colophonium annulus as object of study so that it is with
Pavement strain opening relationships εA=εDrip (road surface), wherein εAFor the strain of A point Colophonium, εDrip (road surface)Strain for actual road surface medium pitch.
Then under the conditions of nonuniform section, formula (2.3) can be converted into formula (2.4)
(αDripαNECR) Δ T=εDrip (nonuniform section)+εNECR (2.4)
Wherein, εDrip (nonuniform section)Dependent variable produced by nonuniform section Colophonium annulus entirety.
Assume that cross-sectional length d in Figure 13 is being continually changing, R1Outer shroud radius for the most swollen described annulus；R2For described drip
The outer shroud radius of blue or green annulus；Angle changing value is θ.
The material modulus selected because of the most swollen annulus is very big, the ε of generationNECRThe least, first assume εNECR≈0。
As shown in figure 13, so it is believed that under identical cooling situation, constantly adjust Colophonium toroid size to making
εAMeet εA=εDrip (road surface)While, whole Colophonium annulus keeps constant, i.e. because of the overall strain amount produced by variations in temperature
In formula: ε1ForThe internal strain of Colophonium annulus in angle；
ε2ForThe internal strain of Colophonium annulus in angle；
And
Then
In formula: R1For the outer shroud radius of the most swollen described annulus, mm；R2For the outer shroud radius of described Colophonium annulus, mm；αDripFor
The linear expansion coefficient of Colophonium；αNECRFor the linear expansion coefficient of the most swollen annulus, mm/mm/ DEG C；αCollectionFor the linear expansion coefficient gathered materials；ΔT
For cooling extent, DEG C；M is the length ratio gathering materials one-dimensional with Colophonium；It is known.
By the calculating of formula (2.7), simplifying formula (2.6), formula (2.6) can be converted into formula (2.8),
Wherein,
Have already mentioned above, make Colophonium annulus selectively while fracture, also make the chi by adjusting cylinder synapse at A
It is very little so that this breaking strain suffered by Colophonium annulus inside (takes a εA) and the breaking strain ε of the actual compound in road surfaceDrip (road surface)(formula
(1.1) shown in) keep the consistent, i.e. as shown in following formula (2.9) of approximation.
εA=εDrip (road surface)=(αDrip+M·αCollection) Δ T M εCollection (2.9)
Calculated by simultaneous formula (2.8), formula (2.9), i.e. can get formula (II):
In formula, αDripLinear expansion coefficient for Colophonium；αNECRLinear expansion coefficient for the most swollen annulus；Δ T is cooling extent；R1
Outer shroud radius for the most swollen described annulus；R2Outer shroud radius for described Colophonium annulus；In formula, parameter εATrue by public formula (III)
Fixed:
εA=(αDrip+M·αCollection) Δ T M εCollection (III)
In formula, Δ T is cooling extent；αDripLinear expansion coefficient for Colophonium；M is the length ratio gathering materials one-dimensional with Colophonium；αCollection
For the linear expansion coefficient gathered materials；εCollectionFor the strain gathered materials.D can be calculated by public formula (II) and public formula (III).To sum up, use
Evaluation methodology of the present invention can be for the type of different compounds and proportion of composing, and the size of joint base can simulate meter
Calculate, adjust the cross-sectional area of cylindric synapse, cryogenic property can be carried out by the dissimilar compound of road pavement targetedly
Test, to accomplish to be more nearly with road surface actual state, the current any Colophonium crack resistance at low-temperature evaluation of this point all cannot be done
Arrive.
After obtaining length d, Colophonium annulus cross-sectional area corresponding to Figure 13 middle conductor AD, then according to this face
The long-pending size determining cylindric synapse used, can obtain the diameter S of cylindrical synapse according to formula (I),
In formula, h represents the height of described cylindrical synapse；R1The outer shroud radius of the most swollen annulus described in expression；Described H represents
The height of described Colophonium annulus.In a preferred embodiment, the height h of described cylindrical synapse is equal to outside described cannelure
The difference of the outer shroud radius of ring radius and the most swollen described annulus.
Test on the external annulus of the cannelure that synapse is arranged on described base, obtain Colophonium annulus in ring crack with this
Ring crack temperature T corresponding during destructionFracWith ring crack intensity σFrac。
Use die trial size R herein1=30mm, R2=36mm, linear contractive quotiety calculates assumes αDrip=200 × 10-6, αCollection=
5×10-6, αNECR=0.5 × 10-6, by simultaneous formula (2.8), (2.9), d=32.2mm can be tried to achieve.Finally by calculating really
Fixed cylindric synapse a size of Φ 8mm × 6mm (h).
The loading process on actual road surface is made supposition a: PDrip=PCollection, Colophonium is equal with the interaction force gathered materials, and this ring
Split test and also meet PDrip=PNECR, i.e. the interaction force of Colophonium and the most swollen annulus is equal, then formula (2.10) and (2.11):
σDrip·ADrip=σCollection·ACollection=σNECR·ANECR (2.10)
I.e. εDrip·EDrip·ADrip=εCollection·ECollection·ACollection=εNECR·ENECR·ANECR (2.11)
In formula, EDripElastic modelling quantity for Colophonium；ECollectionFor the elastic modelling quantity gathered materials；ENECRElastic modelling quantity for the most swollen annulus.
The elastic strain that assuming gathers materials on road surface produces is equal with the microstrain of the most swollen annulus generation, i.e. εNECR=M
εCollection。
By the simultaneous equation, obtain ANECR, the cross-sectional area of the most swollen annulus, corresponding annulus height obtains test institute
The thickness of the most swollen corresponding annulus.
Analyzed by above, finally determine the most swollen annulus ring thickness a size of 2mm of this annular die trial, the chi of cylindric synapse
Very little for Φ 8mm × 6mm (h).
In sum, the present invention, by the strain at the detection temperature change value of temperature-fall period Colophonium and synapse, finally may be used
Obtain ring crack strain and the ring crack temperature of Colophonium annulus, and maximum corresponding when the strain of this ring crack can be ruptured with simulated roadway ruptures
Strain, it is also possible to obtain the fracture strength of the Colophonium of correspondence according to ring crack strain, low-temperature condition actual with paving mix is set up
Association, it is achieved the evaluation of the crack resistance at low-temperature of paving mix；For different mix type and proportion of composing, can adjust
The axial cross section area of whole synapse is tested with the cryogenic property of simulated roadway difference compound targetedly, can accomplish and road surface
Actual state is more nearly.
Three, the contrast of the most swollen annulus ring crack test of different materials:
Prepare base as above and the most swollen annulus, in the present embodiment, select respectively quartz glass, invar alloy and
Pottery is as the material of the most swollen annulus, in the medial wall uniform application lubrication of the lateral wall of the most swollen described annulus and described cannelure
Agent；Selecting 8 kinds of different Colophoniumes, be divided into three groups according to the material of the most swollen annulus of difference and test, heated asphalt one is little respectively
Time, pour into respectively in the annular space of base as above and the formation of the most swollen annulus, cool down molding, obtain 8 kinds of different pitches
The Colophonium annulus that material obtains, the medial wall of the most swollen annulus described in relative with described synapse arranges strain transducer,
At the circular central of base, temperature sensor is set, then the Colophonium low temperature that Colophonium annulus, the most swollen annulus and base form is resisted
Fragility energy evaluation structure is put in material height temperature tester, keeps 30min at 0 DEG C, then lowers the temperature straight with the speed of 10 DEG C/h
Rupture to Colophonium annulus, test and record the ring crack temperature of each Colophonium annulus, rupture warm with the TSRST of 8 kinds of asphalt materials respectively
Degree carries out correlation analysis, obtains experimental result such as Figure 14, Figure 15 and Figure 16, the most swollen annulus pictorial diagram such as Fig. 3 of different materials,
The bitumen samples ring crack temperature of difference three kinds of materials of gained and the correlation analysis result of TSRST breaking temperature.According to Figure 14, figure
The analysis result of 15 and Figure 16, the evaluation methodology gained ring crack temperature that the present invention provides and TSRST breaking temperature have preferably
Dependency, and use silica glass material gained dependency best, and compare pottery, invar alloy material, quartz glass
Linear expansion coefficient α is minimum, asphalt material can be made quickly to rupture, and test error is low.Final contrast determines, override selects
The most swollen annulus of quartz glass is used to test.The breaking temperature obtained according to test and strain data, draw strain with temperature
Change curve, such as Figure 17, the jump strain value in figure is the instantaneous strain that when bitumen samples ruptures, the most swollen annulus is born, by
Formula (3.1) stress-strain relation can obtain,
FThe most swollen annulus=εStrain jump value×EThe most swollen annulus×AThe most swollen annulus (3.1)
In formula: FThe most swollen annulusFor temperature action power suffered on fracture moment the most swollen annulus, unit is N；
εStrain jump valueFor the jump strain value making the most swollen annulus produce because of asphalt material fracture, unit is μ ε；
EThe most swollen annulusFor the elastic modelling quantity of the most swollen annulus, (quartz glass material, takes E=7.5 × 1010Pa), unit is Pa；
AThe most swollen annulusCross-sectional area (A=6.0 × 10 in test for the most swollen annulus-5m2), unit is m2。
Owing to testing the lubrication of smearing of front lubricant, drawing of bitumen samples generation between bitumen samples and the most swollen annulus
Power is equal to the most swollen annulus pressure, and both are active force and counteracting force, i.e. FThe most swollen annulus=FDrip.Therefore, bitumen samples is disconnected
Split stress to be calculated as follows:
In formula: FDripFor temperature action power suffered on the most swollen annulus, unit is N；
ADripFor cross-sectional area (A=1.2 × 10 in test at asphalt binder sample synapse-4m2), unit is m2。
σDripIt is required ring crack intensity σFrac, the temperature of corresponding strain projection is ring crack temperature index TFrac。
Four, the ring crack temperature test under different pitches difference rate of temperature fall:
Select these five kinds of asphalt materials of 110#+5%SBS, 110#, 90#+5%SBS, 90#, 70# respectively according to difference respectively
Cooling rate (1 DEG C/h, 5 DEG C/h, 10 DEG C/h, 20 DEG C/h, 30 DEG C/h) carry out ring crack evaluation of the present invention, select quartz
Glass, as the most swollen annulus material, is selected steel base material, is obtained ring crack temperature TFracAnd the experimental result of standard deviation SD
As shown in table 1 and Figure 18.By the experimental result of table 1 it can be seen that to five kinds of Colophoniumes respectively with 1 DEG C/h, 5 DEG C/h, 10 DEG C/h, 20
DEG C/h, the speed of 30 DEG C/h lowers the temperature, same bitumen difference rate of temperature fall maximum temperature difference 3.6 DEG C (90#+5%), minimum temperature
2.1 DEG C (70#), the difference between the ring crack temperature value measured is less；The standard deviation of 5 kinds of rate of temperature fall is compared, 10 DEG C/h's
The SD average of rate of temperature fall is relatively small, has and preferably tests repeatability.
Ring crack temperature test result under table 1 different pitches difference rate of temperature fall
Claims (10)
1. the evaluation methodology of a Colophonium crack resistance at low-temperature, it is characterised in that comprise the following steps:
S1: take or prepare base and the most swollen annulus, has a cannelure in the middle of described base, the most swollen described annulus closely surrounds institute
Stating on the internal ring wall of cannelure, described base is provided with a synapse on the external annulus of described cannelure, and described synapse is that level sets
The cylindrical synapse being placed on the external annulus of described cannelure；
S2: heated asphalt, poured into described in annular space between the most swollen annulus and described cannelure external annulus, be cooled to
Type, obtains Colophonium annulus；
S3: cooling, until the fracture of described Colophonium annulus, detects and records temperature value and the most swollen annulus in the position of corresponding synapse
Instantaneous strain value.
The evaluation methodology of Colophonium crack resistance at low-temperature the most according to claim 1, it is characterised in that described S1 and S2 it
Between be additionally included in described in the step of medial wall uniform application lubricant of the lateral wall of the most swollen annulus and described cannelure.
The evaluation methodology of Colophonium crack resistance at low-temperature the most according to claim 1, it is characterised in that the concrete step of described S3
Suddenly it is: on the medial wall of the most swollen annulus described in relative with described synapse, strain transducer is set, base arranges temperature
Sensor, puts in heat sink by base, the most swollen annulus together with described Colophonium annulus, preheating, then controls cooling dress
Put and lower the temperature with steady rate, until the fracture of described Colophonium annulus, detect and record temperature value and the most swollen annulus in corresponding synapse
The instantaneous strain value of position.
The evaluation methodology of Colophonium crack resistance at low-temperature the most according to claim 3, it is characterised in that also include after described S3
S4: the instantaneous strain value that drafting detection obtains varies with temperature curve, when instantaneous strain value occurs to jump, corresponding temperature value is
For the temperature during fracture of asphalt material, i.e. ring crack temperature.
The evaluation methodology of Colophonium crack resistance at low-temperature the most according to claim 1, it is characterised in that described cylindrical is dashed forward
The diameter touched can determine according to public formula (I):
In formula, S represents the diameter of described cylindrical synapse, and h represents the height of described cylindrical synapse；R1The most swollen circle described in expression
The outer shroud radius of ring；Described H represents the height of described Colophonium annulus；D determines according to public formula (II):
In formula, αDripLinear expansion coefficient for Colophonium；αNECRLinear expansion coefficient for the most swollen annulus；Δ T is cooling extent；R1For institute
State the outer shroud radius of the most swollen annulus；R2Outer shroud radius for described Colophonium annulus；In formula, parameter εADetermined by public formula (III):
εA=(αDrip+M·αCollection) Δ T M εCollection (III)
In formula, Δ T is cooling extent；αDripLinear expansion coefficient for Colophonium；M is the length ratio gathering materials one-dimensional with Colophonium；αCollectionFor collection
The linear expansion coefficient of material；εCollectionFor the strain gathered materials.
The evaluation methodology of Colophonium crack resistance at low-temperature the most according to claim 1, it is characterised in that the most swollen described annulus
Linear expansion coefficient≤5 × 10-6mm/mm/℃。
The evaluation methodology of Colophonium crack resistance at low-temperature the most according to claim 1, it is characterised in that the most swollen described annulus
Material is any one in quartz glass, invar alloy, pottery and steel.
The evaluation methodology of Colophonium crack resistance at low-temperature the most according to claim 1, it is characterised in that the most swollen described annulus
Material is quartz glass.
The evaluation methodology of Colophonium crack resistance at low-temperature the most according to claim 1, it is characterised in that the material of described base
For any one in steel, ferrum, aluminum.
The evaluation methodology of Colophonium crack resistance at low-temperature the most according to claim 1, it is characterised in that the fall in described S3
Temperature velocity interval is 1～30 DEG C/h.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4335613A (en) * | 1979-10-10 | 1982-06-22 | Vaisala Oy | Apparatus for indicating the freezing of the surface of an asphalt road, paved runway, or the like |
| JP2002082102A (en) * | 2000-09-05 | 2002-03-22 | Kajima Corp | Low-temperature crack evaluating system and method |
| CN1719223A (en) * | 2005-07-27 | 2006-01-11 | 马骉 | Low temperature fracture testing instrument of asphalt mixed material |
| CN2932367Y (en) * | 2005-07-27 | 2007-08-08 | 马骉 | Asphalt mixture low-temperature breaking tester |
| CN202110107U (en) * | 2011-05-20 | 2012-01-11 | 长沙亚星数控技术有限公司 | Bituminous mixture low-temperature frozen breakage testing machine |
| CN202562817U (en) * | 2012-04-28 | 2012-11-28 | 邢台路桥建设总公司 | Expansion instrument for measuring stress absorbability of asphalt mixture under negative pressure |
| CN202735336U (en) * | 2012-07-25 | 2013-02-13 | 甘肃省交通规划勘察设计院有限责任公司 | Device for testing anti-cracking performance of asphalt at low temperature |
-
2016
- 2016-05-31 CN CN201610377177.2A patent/CN106018463B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4335613A (en) * | 1979-10-10 | 1982-06-22 | Vaisala Oy | Apparatus for indicating the freezing of the surface of an asphalt road, paved runway, or the like |
| JP2002082102A (en) * | 2000-09-05 | 2002-03-22 | Kajima Corp | Low-temperature crack evaluating system and method |
| CN1719223A (en) * | 2005-07-27 | 2006-01-11 | 马骉 | Low temperature fracture testing instrument of asphalt mixed material |
| CN2932367Y (en) * | 2005-07-27 | 2007-08-08 | 马骉 | Asphalt mixture low-temperature breaking tester |
| CN202110107U (en) * | 2011-05-20 | 2012-01-11 | 长沙亚星数控技术有限公司 | Bituminous mixture low-temperature frozen breakage testing machine |
| CN202562817U (en) * | 2012-04-28 | 2012-11-28 | 邢台路桥建设总公司 | Expansion instrument for measuring stress absorbability of asphalt mixture under negative pressure |
| CN202735336U (en) * | 2012-07-25 | 2013-02-13 | 甘肃省交通规划勘察设计院有限责任公司 | Device for testing anti-cracking performance of asphalt at low temperature |
Non-Patent Citations (1)
| Title |
|---|
| 郝培文登: "《沥青混合料低温约束温度应力试验研究》", 《石油沥青》 * |
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