CN114067931A - Asphalt mixture aggregate segregation prediction method - Google Patents

Asphalt mixture aggregate segregation prediction method Download PDF

Info

Publication number
CN114067931A
CN114067931A CN202111220850.9A CN202111220850A CN114067931A CN 114067931 A CN114067931 A CN 114067931A CN 202111220850 A CN202111220850 A CN 202111220850A CN 114067931 A CN114067931 A CN 114067931A
Authority
CN
China
Prior art keywords
aggregate
segregation
asphalt mixture
index
composite
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202111220850.9A
Other languages
Chinese (zh)
Other versions
CN114067931B (en
Inventor
栗培龙
宿金菲
宋法宽
孙胜飞
毕嘉宇
张万强
孙超
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Changan University
Original Assignee
Changan University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Changan University filed Critical Changan University
Priority to CN202111220850.9A priority Critical patent/CN114067931B/en
Publication of CN114067931A publication Critical patent/CN114067931A/en
Application granted granted Critical
Publication of CN114067931B publication Critical patent/CN114067931B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • G—PHYSICS
    • G16—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR SPECIFIC APPLICATION FIELDS
    • G16C—COMPUTATIONAL CHEMISTRY; CHEMOINFORMATICS; COMPUTATIONAL MATERIALS SCIENCE
    • G16C60/00—Computational materials science, i.e. ICT specially adapted for investigating the physical or chemical properties of materials or phenomena associated with their design, synthesis, processing, characterisation or utilisation
    • G—PHYSICS
    • G16—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR SPECIFIC APPLICATION FIELDS
    • G16C—COMPUTATIONAL CHEMISTRY; CHEMOINFORMATICS; COMPUTATIONAL MATERIALS SCIENCE
    • G16C10/00—Computational theoretical chemistry, i.e. ICT specially adapted for theoretical aspects of quantum chemistry, molecular mechanics, molecular dynamics or the like

Landscapes

  • Engineering & Computer Science (AREA)
  • Computing Systems (AREA)
  • Theoretical Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Bioinformatics & Cheminformatics (AREA)
  • Bioinformatics & Computational Biology (AREA)
  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Road Paving Structures (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)

Abstract

The invention relates to the field of road engineering, in particular to a method for prejudging aggregate segregation of an asphalt mixture, which comprises the following steps: step S1, establishing an aggregate segregation pre-judging model of the asphalt mixture; step S2, establishing an aggregate segregation evaluation standard of the asphalt mixture; step S3, calculating aggregate composite texture segregation tendency index STI of asphalt mixture to be predictedTXSTI (shallow Trench isolation) index of segregation tendency of composite edge angle with aggregateGAAnd comparing the segregation degree with the segregation evaluation standard of the asphalt mixture aggregate to pre-judge the segregation degree of the asphalt mixture aggregate. The invention judges whether the aggregate is isolated or not from the microscopic level, realizes the conversion of aggregate isolation from 'post evaluation' to 'pre-judgment', and further can perform advanced control on the aggregate isolation of the asphalt mixture.

Description

Asphalt mixture aggregate segregation prediction method
Technical Field
The invention relates to the field of road engineering, in particular to a method for prejudging aggregate segregation of an asphalt mixture.
Background
Asphalt mixes are heterogeneous particulate materials composed of aggregates, asphalt binder and voids. The paving and compacting of the asphalt mixture are the processes of converting a particle system coated with asphalt from a loose flow state to a molding stable state through a metastable transition state. When aggregate is separated, the asphalt mixture is broken, so that the road pavement is damaged frequently and the durability is reduced.
Disclosure of Invention
The invention aims to provide a method for pre-judging aggregate segregation of an asphalt mixture, which is used for judging whether the aggregate is segregated or not from a microscopic level, so that the change of the aggregate segregation from 'post evaluation' to 'pre-judging' is realized, and the aggregate segregation of the asphalt mixture can be controlled in advance.
In order to achieve the purpose, the invention is realized by adopting the following technical scheme.
A method for predicting the segregation of asphalt mixture aggregates comprises the following steps:
step S1, establishing an aggregate segregation prediction model of the bituminous mixture, as shown in formula (1) and formula (2);
Figure BDA0003312527480000011
in the formula (1), STITXIs the index of segregation tendency of composite texture of asphalt mixture aggregate, CITXIs the composite texture index of the asphalt mixture,
Figure BDA0003312527480000012
the maximum value of the composite texture index of the asphalt mixture;
Figure BDA0003312527480000013
in the formula (2), STIGAIs the index of segregation tendency of composite edges and corners of the asphalt mixture aggregates,CIGAis the composite edge angle index of the asphalt mixture,
Figure BDA0003312527480000014
the maximum value of the composite edge angle index of the asphalt mixture;
step S2, establishing an aggregate segregation evaluation standard of the asphalt mixture;
aggregate composite grain segregation tendency index STI of asphalt mixtureTXWhen the value of (A) is 0-0.2, 0.2-0.25, 0.25-0.3, 0.3-0.35 and 0.35-1, the segregation degrees of the aggregates of the asphalt mixture are respectively corresponding to segregation of fine aggregates, no segregation, light segregation of coarse aggregates, medium segregation of coarse aggregates and heavy segregation of coarse aggregates; aggregate composite corner segregation tendency index STI of asphalt mixtureGAWhen the values of (A) are 0-0.6, 0.6-0.7, 0.7-0.8, 0.8-0.9 and 0.9-1, the segregation degrees of the aggregates of the asphalt mixture respectively correspond to segregation of fine aggregates, no segregation, light segregation of coarse aggregates, medium segregation of coarse aggregates and heavy segregation of coarse aggregates;
step S3, calculating aggregate composite texture segregation tendency index STI of asphalt mixture to be predictedTXSTI (shallow Trench isolation) index of segregation tendency of composite edge angle with aggregateGAAnd comparing the segregation degree with the segregation evaluation standard of the asphalt mixture aggregate to pre-judge the segregation degree of the asphalt mixture aggregate.
Compared with the prior art, the invention has the beneficial effects that: the aggregate segregation tendency prejudgment method is established by adopting the composite geometric characteristic parameters, whether the aggregates are segregated or not is judged from the microscopic level, the judgment of whether the aggregates are segregated or not is changed from 'post evaluation' to 'pre prejudgment', and the aim of controlling the segregation of the aggregates of the asphalt mixture in advance is fulfilled.
Drawings
The invention is described in further detail below with reference to the figures and specific embodiments.
FIG. 1 is a flow chart of a method for predicting aggregate segregation in bituminous mixtures according to the present invention;
FIG. 2 is a grading curve diagram of five bituminous mixtures in an example of the method for predicting segregation of bituminous mixture aggregates according to the present invention; the abscissa is the aperture of the sieve pore, and the ordinate is the passing rate of the sieve pore;
FIG. 3 is a composite shape index CI of five bituminous mixtures in an embodiment of the method for predicting aggregate segregation of bituminous mixtures according to the present inventionSPA plot of compaction energy index, CEI; the abscissa is the composite shape index CI of the asphalt mixtureSPThe ordinate is the compaction energy index CEI;
FIG. 4 is a composite texture index CI of five bituminous mixtures in an embodiment of the method for predicting aggregate segregation of bituminous mixtures according to the present inventionTXA plot of compaction energy index, CEI; the abscissa is the composite texture index CI of the asphalt mixtureTXThe ordinate is the compaction energy index CEI;
FIG. 5 shows the composite edge angle index CI of five asphalt mixtures in the embodiment of the method for predicting the aggregate segregation of the asphalt mixturesGAA plot of compaction energy index, CEI; the abscissa is the composite edge angle index CI of the asphalt mixtureGAThe ordinate is the compaction energy index CEI;
FIG. 6 is a composite shape index CI of five bituminous mixtures in an embodiment of the method for predicting aggregate segregation of bituminous mixtures according to the present inventionSPA relation graph with the damage times and the creep rate of the asphalt mixture; the abscissa is the composite shape index CI of the asphalt mixtureSPThe vertical coordinate from left to right respectively represents the damage times and creep rate of the asphalt mixture;
FIG. 7 is a composite texture index CI of five bituminous mixtures in an embodiment of the method for predicting aggregate segregation of bituminous mixtures according to the present inventionTXA relation graph with the damage times and the creep rate of the asphalt mixture; the abscissa is the composite texture index CI of the asphalt mixtureTXThe vertical coordinate from left to right respectively represents the damage times and creep rate of the asphalt mixture;
FIG. 8 shows the composite edge angle index CI of five bituminous mixtures in the embodiment of the method for predicting aggregate segregation of bituminous mixturesGAA relation graph with the damage times and the creep rate of the asphalt mixture; the abscissa is the composite edge angle index CI of the asphalt mixtureGAThe vertical coordinate from left to right respectively represents the damage times and creep rate of the asphalt mixture;
FIG. 9 is a graph showing the relationship between the void ratio and the corresponding stripping times, rutting depth and stripping rate for five asphalt mixtures according to the embodiment of the method for pre-judging aggregate segregation of asphalt mixtures; the abscissa is the void ratio of the five asphalt mixtures, and the ordinate is the corresponding stripping times, rutting depth and stripping rate of the asphalt mixtures from left to right;
FIG. 10 shows the void contents and corresponding composite shape indexes CI of five asphalt mixtures in the embodiment of the method for predicting the segregation of the asphalt mixture aggregatesSPComposite texture index CITXAnd composite edge index CIGAA relationship diagram of (1); the abscissa is the void ratio of the asphalt mixture, and the ordinate is the composite shape index CI corresponding to the asphalt mixture from left to rightSPComposite texture index CITXAnd composite edge index CIGA；
FIG. 11 is a graph showing the tensile strengths R corresponding to five asphalt mixtures in the embodiment of the method for predicting the segregation of the asphalt mixture aggregatesTTensile strain at failure εTAnd a modulus of fracture stiffness STA comparison histogram of (2); the abscissa is the type of the asphalt mixture, and the ordinate is the tensile strength R corresponding to the asphalt mixture from left to rightTTensile strain at failure εTAnd a modulus of fracture stiffness ST。
Detailed Description
Embodiments of the present invention will be described in detail below with reference to examples, but it will be understood by those skilled in the art that the following examples are only illustrative of the present invention and should not be construed as limiting the scope of the present invention.
A method for predicting the segregation of asphalt mixture aggregates comprises the following steps:
step S1, establishing an aggregate segregation prediction model of the bituminous mixture, as shown in formula (1) and formula (2);
Figure BDA0003312527480000041
in the formula (1), STITXComposite texture segregation inclination for asphalt mixture aggregateExponential index, CITXIs the composite texture index of the asphalt mixture,
Figure BDA0003312527480000042
the maximum value of the composite texture index of the asphalt mixture;
Figure BDA0003312527480000043
in the formula (2), STIGAIs the index of segregation tendency of aggregate composite edges and corners of asphalt mixture, CIGAIs the composite edge angle index of the asphalt mixture,
Figure BDA0003312527480000044
the maximum value of the composite edge angle index of the asphalt mixture;
in particular, the composite texture index CI of the asphalt mixtureTXAs shown in formula (4);
Figure BDA0003312527480000045
in formula (4):
aicalculating the percent of the screen residue for the ith grade aggregate in the grading design;
n is the number of particle size steps of all aggregates in the grading design;
m is the grade number of the grain size of the coarse aggregate used in the grading design;
giis the bulk relative density of the i-th grade aggregate;
diis the average particle size of the i-th grade aggregate,
Figure BDA0003312527480000051
wherein P isi+1Mesh size for set i + 1;
Vwiis a weighted volume, V, of the aggregate particle shapeWi＝Vci×SPi+Vsi×(1-SPi) Wherein, cubic volume:
Figure BDA0003312527480000052
sphere volume:
Figure BDA0003312527480000053
SAwiis a weighted surface area of aggregate particle shape, SAWi＝SAci×SPi+SAsi×(1-SPi) Wherein, cubic surface area:
Figure BDA0003312527480000054
sphere surface area:
Figure BDA0003312527480000055
TXiis an index of surface texture;
GAithe edge angle gradient of the i-th grade aggregate;
specifically, the composite edge angle index CI of the asphalt mixtureGAAs shown in formula (5);
composite edge index CIGAAs shown in formula (5);
Figure BDA0003312527480000056
in formula (5):
aicalculating the percent of the screen residue for the ith grade aggregate in the grading design;
n is the number of particle size steps of all aggregates in the grading design;
m is the grade number of the grain size of the coarse aggregate used in the grading design;
giis the bulk relative density of the i-th grade aggregate;
diis the average particle size of the i-th grade aggregate,
Figure BDA0003312527480000061
wherein P isi+1Mesh size for set i + 1;
Vwiis a weighted volume of aggregate particle shape，VWi＝Vci×SPi+Vsi×(1-SPi) Wherein, cubic volume:
Figure BDA0003312527480000062
sphere volume:
Figure BDA0003312527480000063
GAithe edge angle gradient of the i-th grade aggregate;
m is the total mass of mineral aggregate;
in particular, the maximum value of the composite texture index of the asphalt mixture
Figure BDA0003312527480000065
Value of 2447.62397312175, maximum value of composite edge angle index of asphalt mixture
Figure BDA0003312527480000066
Has a value of 40008.2752815776.
Step S2, establishing an aggregate segregation evaluation standard of the asphalt mixture;
aggregate composite grain segregation tendency index STI of asphalt mixtureTXWhen the value of (A) is 0-0.2, 0.2-0.25, 0.25-0.3, 0.3-0.35 and 0.35-1, the segregation degrees of the aggregates of the asphalt mixture are respectively corresponding to segregation of fine aggregates, no segregation, light segregation of coarse aggregates, medium segregation of coarse aggregates and heavy segregation of coarse aggregates; aggregate composite corner segregation tendency index STI of asphalt mixtureGAWhen the values of (A) are 0-0.6, 0.6-0.7, 0.7-0.8, 0.8-0.9 and 0.9-1, the segregation degrees of the aggregates of the asphalt mixture respectively correspond to segregation of fine aggregates, no segregation, light segregation of coarse aggregates, medium segregation of coarse aggregates and heavy segregation of coarse aggregates; the asphalt mixture aggregate segregation evaluation criteria are shown in table 1.
TABLE 1 evaluation criteria for aggregate segregation in bituminous mixtures
Figure BDA0003312527480000064
Figure BDA0003312527480000071
And dividing the specific numerical values of the dimensionless composite texture index and the dimensionless composite corner index according to the compaction characteristics of the segregation asphalt mixture and the pavement performance evaluation indexes to obtain an aggregate segregation evaluation standard table of the asphalt mixture, wherein the table is shown in table 1.
Step S3, calculating aggregate composite texture segregation tendency index STI of asphalt mixture to be predictedTXSTI (shallow Trench isolation) index of segregation tendency of composite edge angle with aggregateGAAnd comparing the segregation degree with the segregation evaluation standard of the asphalt mixture aggregate to pre-judge the segregation degree of the asphalt mixture aggregate.
The process for establishing the asphalt mixture aggregate segregation pre-judgment model comprises the following steps:
step 1, designing various asphalt mixtures with different segregation degrees.
Based on the AC-20 median asphalt mixture, 4.75mm and 9.5mm are used as key sieve holes, and a fine aggregate segregation asphalt mixture (F), a non-segregation asphalt mixture (N), a coarse aggregate light segregation asphalt mixture (L), a coarse aggregate medium segregation asphalt mixture (M) and a coarse aggregate heavy segregation asphalt mixture (H) are designed according to different grades, and the grading curve is shown in figure 1.
Step 2, calculating the composite geometric indexes of each asphalt mixture, including composite shape index CISPComposite texture index CITXAnd composite edge index CIGA。
Composite shape index CISPAs shown in formula (3);
Figure BDA0003312527480000072
in formula (3):
aicalculating the percent of the screen residue for the ith grade aggregate in the grading design;
n is the number of particle size steps of all aggregates in the grading design;
SPiis an index of the sphericity of the particles;
m is the grade number of the grain size of the coarse aggregate used in the grading design;
giis the bulk relative density of the i-th grade aggregate;
diis the average particle size of the i-th grade aggregate,
Figure BDA0003312527480000081
wherein P isi+1Mesh size for set i + 1;
Vwiis a weighted volume, V, of the aggregate particle shapeWi＝Vci×SPi+Vsi×(1-SPi) Wherein, cubic volume:
Figure BDA0003312527480000082
sphere volume:
Figure BDA0003312527480000083
Cwiis a weighted perimeter of aggregate particle shape, CWi＝Cci×SPi+Csi×(1-SPi) Wherein, the perimeter of the cube is:
Figure BDA0003312527480000084
sphere circumference:
Figure BDA0003312527480000085
composite texture index CITXAs shown in formula (4);
Figure BDA0003312527480000086
in formula (4):
aicalculating the percent of the screen residue for the ith grade aggregate in the grading design;
n is the number of particle size steps of all aggregates in the grading design;
m is the grade number of the grain size of the coarse aggregate used in the grading design;
giis the bulk relative density of the i-th grade aggregate;
diis the average particle size of the i-th grade aggregate,
Figure BDA0003312527480000087
wherein P isi+1Mesh size for set i + 1;
Vwiis a weighted volume, V, of the aggregate particle shapeWi＝Vci×SPi+Vsi×(1-SPi) Wherein, cubic volume:
Figure BDA0003312527480000091
sphere volume:
Figure BDA0003312527480000092
SAwiis a weighted surface area of aggregate particle shape, SAWi＝SAci×SPi+SAsi×(1-SPi) Wherein, cubic surface area:
Figure BDA0003312527480000093
sphere surface area:
Figure BDA0003312527480000094
TXiis an index of surface texture;
GAithe edge angle gradient of the i-th grade aggregate.
Composite edge index CIGAAs shown in formula (5);
Figure BDA0003312527480000095
in formula (5):
aicalculating the percent of the screen residue for the ith grade aggregate in the grading design;
n is the number of particle size steps of all aggregates in the grading design;
m is the grade number of the grain size of the coarse aggregate used in the grading design;
giis the bulk relative density of the i-th grade aggregate;
diis the average particle size of the i-th grade aggregate,
Figure BDA0003312527480000096
wherein P isi+1Mesh size for set i + 1;
Vwiis a weighted volume, V, of the aggregate particle shapeWi＝Vci×SPi+Vsi×(1-SPi) Wherein, cubic volume:
Figure BDA0003312527480000097
sphere volume:
Figure BDA0003312527480000098
GAithe edge angle gradient of the i-th grade aggregate;
m is the total mass of the mineral aggregate.
And 3, performing an asphalt mixture macroscopic performance test on the asphalt mixture with each segregation degree, wherein the test comprises a rotary compaction test, a water-soaked hamburger rut test and an indirect tensile test.
In a rotary compaction test, evaluating the compaction characteristics of the asphalt mixture through a compaction energy index CEI to obtain the compaction energy indexes CEI corresponding to five asphalt mixtures;
in a water-immersed hamburger rutting test, the high-temperature stability of the asphalt mixture is evaluated through the damage times and the creep rate when the rutting depth is close to 20mm, and the damage times and the creep rate corresponding to five kinds of asphalt mixtures are obtained; evaluating the water stability of the asphalt mixture according to the stripping times, the track depth and the stripping rate corresponding to the stripping points to obtain the rolling times, the track depth and the stripping rate corresponding to the five asphalt mixtures;
in the indirect tensile test, the tensile strength R is passedTTensile strain at failure εTAnd a modulus of fracture stiffness STTo evaluate asphalt mixesThe low-temperature crack resistance of the material is obtained, and the tensile strength R corresponding to the five asphalt mixtures is obtainedTTensile strain at failure εTAnd a modulus of fracture stiffness ST。
And 4, preferably selecting indexes for establishing an aggregate segregation pre-judgment model of the asphalt mixture: composite texture index CITXAnd composite edge index CIGA。
Substep 4.1, analyzing the relevance of the composite geometric indexes and the compaction characteristics of the five asphalt mixtures;
referring to FIG. 3, it can be seen that the composite shape index CI of the five asphalt mixturesSPThe linear correlation with the compaction energy index CEI is poor;
referring to FIG. 4, it can be seen that the composite grain index CI for the five asphalt mixesTXThe compaction energy index CEI shows better linear correlation;
referring to FIG. 5, it can be seen that the composite edge angle index CI of the five asphalt mixturesGAShows better linear correlation with the compaction energy index CEI.
Substep 4.2, analyzing the relevance of the composite geometric indexes of the five asphalt mixtures and the high-temperature stability;
referring to FIG. 6, it can be seen that for a composite shape index CISPThe number of times of failure of the asphalt mixture is dependent on the composite shape index CI of the asphalt mixtureSPThe increase (i.e. the increase of the segregation degree of the asphalt mixture) of the asphalt mixture is a trend of increasing and then decreasing, and the creep rate of the asphalt mixture is along with the composite shape index CI of the asphalt mixtureSPThe increase of (i.e. the increase of the segregation degree of the asphalt mixture) is a trend of increasing after decreasing; and the damage times and creep rate of the asphalt mixture are both in the composite shape index CI of the coarse aggregate light segregation asphalt mixture (L)SPThe composite shape index CI of the asphalt mixture (L) with the coarse aggregate slightly separated and the peak value and the valley value are respectively reachedSPBetween 0.0185 and 0.019;
referring to FIG. 7, it can be seen that for a composite texture index CITXThe number of times of damage of the asphalt mixture is dependent on the asphalt mixture composite texture index CITXIncrease (i.e. segregation of asphalt mixture)The degree of aggravation) is increased and then decreased, and the creep rate of the asphalt mixture is CI along with the composite texture index of the asphalt mixtureTXThe increase of (i.e. the increase of the segregation degree of the asphalt mixture) is a trend of increasing after decreasing; and the damage times and the creep rate of the asphalt mixture are both in the composite texture index CI of the coarse aggregate light segregation asphalt mixture (L)TXA composite texture index CI of the asphalt mixture (L) with the coarse aggregate slightly segregated and reaching the peak value and the valley value respectivelyTXAt around 600;
referring to FIG. 8, it can be seen that for a composite edge index CIGAThe number of times of damage of the asphalt mixture is determined by the composite edge index CI of the asphalt mixtureGAThe increase (i.e. the increase of the segregation degree of the asphalt mixture) of the asphalt mixture is a trend of increasing firstly and then decreasing, and the creep rate of the asphalt mixture is along with the composite edge angle index CI of the asphalt mixtureGAThe increase of (i.e. the increase of the segregation degree of the asphalt mixture) is a trend of increasing after decreasing; and the damage times and the creep rate of the asphalt mixture are both in the composite edge angle index CI of the coarse aggregate light segregation asphalt mixture (L)GAThe composite edge angle index CI of the asphalt mixture (L) with the coarse aggregate slightly separated and the peak value and the valley value are respectively reachedGA26000 to 27000;
in summary, the coarse aggregate lightly segregated asphalt mix (L) has a composite texture index CI compared to the non-segregated asphalt mix (N)TXAnd composite edge index CIGALarger, but complex shape index CISPThe difference is not great, which indicates that the total number of the mineral aggregate particles of the coarse aggregate light segregation asphalt mixture (L) is equivalent to that of the non-segregation asphalt mixture (N), but the number of the large-particle-size coarse aggregates of the coarse aggregate light segregation asphalt mixture (L) is slightly larger; the asphalt mixture (L) with the coarse aggregate with the light segregation has stronger track deformation resistance compared with the asphalt mixture (N) without segregation, which shows that in the asphalt mixture, when the coarse aggregate is slightly segregated, the strength of a framework-bonding system formed by the interaction of the contact friction of mineral aggregate particles and the bonding lubrication effect of asphalt is the maximum.
Substep 4.3, analyzing the relevance of the composite geometric indexes of the five asphalt mixtures and the water stability;
referring to fig. 9, it can be seen that as the void fraction of the asphalt mixture increases, the number of exfoliation increases and then decreases, and the number of exfoliation of the coarse aggregate light segregation asphalt mixture (L) is the largest;
with the increase of the void ratio of the asphalt mixture, the depth of the track is in an overall rising trend; this is because, as the void fraction of the bituminous mixture increases, there is a compactable space between the mineral aggregates, which makes rutting more likely to form;
as the void fraction of the mix increases, the exfoliation rate exhibits a less regular tendency to change in the "M" type, and the exfoliation rate of the coarse aggregate light segregation mix (L) is minimal.
Referring to fig. 10, it can be seen that the asphalt porosity VV increases with the increase of the composite geometric index of the asphalt mixture, and the asphalt porosity VV and the composite texture index CI, respectivelyTXComposite edge and angle index CIGAHas better linear correlation.
To sum up, the void ratio VV of the coarse aggregate light segregation asphalt mixture (L) is at a medium level, the moisture of the coarse aggregate light segregation asphalt mixture (L) entering the structure is less than the coarse aggregate medium segregation asphalt mixture (M) and the coarse aggregate heavy segregation asphalt mixture (H), and the coarse aggregate light segregation asphalt mixture (L) contains a certain amount of coarse aggregates to form a stable skeleton structure, which can delay the peeling of the asphalt mixture under the coupling action of water and load, so the water stability of the coarse aggregate light segregation asphalt mixture (L) is the best.
Substep 4.4, analyzing the relevance of the composite geometric indexes of the five asphalt mixtures and the low-temperature crack resistance;
referring to FIG. 11, it can be seen that tensile strengths R of the remaining four asphalt mixtures except for the fine aggregate segregation asphalt mixture (F)TDecreasing with increasing segregation of the coarse aggregate.
Referring to fig. 10, it can be seen that the void ratio VV, the composite texture index CI of the coarse-aggregate medium-segregation asphalt mixture (M) and the coarse-aggregate heavy-segregation asphalt mixture (H)TXAnd composite edge index CIGAIs large; when composite texture index CITXAnd a composite edgeAngle index CIGAThe larger the size, the more coarse aggregate the asphalt mix, and the greater the reduction in fine aggregate of the asphalt mix, resulting in increased voids in the asphalt mix. Therefore, the expansion speed of the internal cracks of the coarse aggregate moderate segregation asphalt mixture (M) and the coarse aggregate heavy segregation asphalt mixture (H) is high;
composite texture index CI of fine aggregate segregation asphalt mixture (F)TXThe minimum indicates that the number of coarse aggregates of the fine aggregate segregation asphalt mixture (F) is the minimum, but the maximum number of fine aggregates causes a large number of contact points inside the fine aggregate segregation asphalt mixture (F), so that the transmission direction of stress is increased, and the stress dissipation is facilitated.
The coarse aggregate light segregation asphalt mixture (L) has more contact point decomposition stress, and the framework bonding strength can resist the external load action to the maximum extent, so the low-temperature crack resistance of the coarse aggregate light segregation asphalt mixture (L) is the best.
Comprehensive analysis shows that the low-temperature crack resistance of the compact mixture is better than that of the skeleton void type, and the low-temperature crack resistance of the coarse aggregate light segregation asphalt mixture (L) is the best. This is because, under the action of an axial load in an indirect tensile test, micro cracks first appear on the upper and lower surfaces of the asphalt mixture test piece, and a stress concentration phenomenon occurs at the tips of the micro cracks. When the stress meets more gaps in the transmission process, the microcracks can rapidly expand; when the mixture has fewer internal gaps and a dense structure, the stress transmission can meet continuous resistance so as to slow down the crack propagation speed.
Substep 4.5, finding out that the particle shape mainly influences the rotation speed of the particles, plays an auxiliary role in the edges and corners of the particles and the surface textures of the particles and has little influence on the macroscopic performance of the asphalt mixture according to the analysis; the contact state between particles is determined by the embedding and extruding of the edges and corners of the particles and the friction of the surface textures of the particles, so that the macroscopic performance of the asphalt mixture is influenced to a great extent; thus using a composite texture index CITXAnd composite edge index CIGAAnd establishing an aggregate segregation pre-judgment model.
Step 5, respectively carrying out composite texture index CI by adopting a maximum value calculation methodTXAnd compoundingEdge angle index CIGAAnd (3) carrying out normalization treatment, and respectively establishing models as shown in the formula (1) and the formula (2).
The maximum value of the composite texture index of the asphalt mixture is determined according to the general grading range of the upper layer and the middle layer recommended in the technical Specification for construction of asphalt road pavement
Figure BDA0003312527480000141
Maximum value of composite edge angle index of asphalt mixture
Figure BDA0003312527480000142
Taking a composite geometric index of SMA-20L; maximum value of composite texture index of asphalt mixture
Figure BDA0003312527480000143
The value of (A) is 2447.62397312175, the maximum value of the composite edge angle index of the asphalt mixture
Figure BDA0003312527480000144
40008.2752815776 is taken.
The effects of the present invention are further illustrated below in connection with the tests:
test step 1: selecting raw materials and mineral aggregate gradation.
In the test, limestone in some places in Shaanxi is adopted, main technical indexes of coarse aggregates and fine aggregates are measured according to the specification in road engineering aggregate test regulations (JTG E42-2005), and corresponding technical indexes of the materials are recorded through test tests, wherein the indexes are shown in Table 2.
TABLE 2 Main technical indexes of coarse and fine aggregates
Figure BDA0003312527480000145
Figure BDA0003312527480000151
4 grades were selected for the test, and the various grades are shown in Table 2.
TABLE 3 mesh passage (%) -of different gradation
Figure BDA0003312527480000152
Test step 2: calculating aggregate composite texture segregation tendency index STI of asphalt mixture under 4 gradesTXSTI (shallow Trench isolation) index of segregation tendency of composite edge angle with aggregateGAAnd pre-judging the aggregate segregation tendency of the asphalt mixture.
Aggregate composite texture segregation tendency index STI of 4 graded asphalt mixtures is calculatedTXSTI (shallow Trench isolation) index of segregation tendency of composite edge angle with aggregateGAAs shown in table 4.
TABLE 4 segregation tendency index of different gradation ore materials
Grading type S1 S2 S3 S4
STITX 0.153323 0.180296 0.16162 0.144464
STIGA 0.514258 0.600224 0.570886 0.564634
Comparing the segregation tendency index of the asphalt mixture under 4 grades with the segregation evaluation standard table of the asphalt mixture aggregate, the 4 grades of the asphalt mixture have the segregation tendency of the fine aggregate, but S2The fine aggregate segregation tendency of a type graded asphalt mix is relatively small.
Although the present invention has been described in detail in this specification with reference to specific embodiments and illustrative embodiments, it will be apparent to those skilled in the art that modifications and improvements can be made thereto based on the present invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.

Claims (4)

1. The method for prejudging the aggregate segregation of the asphalt mixture is characterized by comprising the following steps of:
step S1, establishing an aggregate segregation prediction model of the bituminous mixture, as shown in formula (1) and formula (2);
Figure FDA0003312527470000011
in the formula (1), STITXIs the index of segregation tendency of composite texture of asphalt mixture aggregate, CITXIs the composite texture index of the asphalt mixture,
Figure FDA0003312527470000012
the maximum value of the composite texture index of the asphalt mixture;
Figure FDA0003312527470000013
in the formula (2), STIGAIs the index of segregation tendency of aggregate composite edges and corners of asphalt mixture, CIGAIs the composite edge angle index of the asphalt mixture,
Figure FDA0003312527470000014
the maximum value of the composite edge angle index of the asphalt mixture;
step S2, establishing an aggregate segregation evaluation standard of the asphalt mixture;
aggregate composite grain segregation tendency index STI of asphalt mixtureTXWhen the value of (A) is 0-0.2, 0.2-0.25, 0.25-0.3, 0.3-0.35 and 0.35-1, the segregation degrees of the aggregates of the asphalt mixture are respectively corresponding to segregation of fine aggregates, no segregation, light segregation of coarse aggregates, medium segregation of coarse aggregates and heavy segregation of coarse aggregates; aggregate composite corner segregation tendency index STI of asphalt mixtureGAWhen the values of (A) are 0-0.6, 0.6-0.7, 0.7-0.8, 0.8-0.9 and 0.9-1, the segregation degrees of the aggregates of the asphalt mixture respectively correspond to segregation of fine aggregates, no segregation, light segregation of coarse aggregates, medium segregation of coarse aggregates and heavy segregation of coarse aggregates;
step S3, calculating aggregate composite texture segregation tendency index STI of asphalt mixture to be predictedTXSTI (shallow Trench isolation) index of segregation tendency of composite edge angle with aggregateGAAnd comparing the segregation degree with the segregation evaluation standard of the asphalt mixture aggregate to pre-judge the segregation degree of the asphalt mixture aggregate.
2. The asphalt mixture aggregate segregation prediction method according to claim 1, characterized in that the asphalt mixture composite texture index CI in step S1TXThe calculation method is shown as the formula (4);
Figure FDA0003312527470000021
in formula (4):
aicalculating the percent of the screen residue for the ith grade aggregate in the grading design;
n is the number of particle size steps of all aggregates in the grading design;
m is the grade number of the grain size of the coarse aggregate used in the grading design;
giis the bulk relative density of the i-th grade aggregate;
diis the average particle size of the i-th grade aggregate,
Figure FDA0003312527470000022
wherein P isi+1Mesh size for set i + 1;
Vwiis a weighted volume, V, of the aggregate particle shapeWi＝Vci×SPi+Vsi×(1-SPi) Wherein, cubic volume:
Figure FDA0003312527470000023
sphere volume:
Figure FDA0003312527470000024
SAwiis a weighted surface area of aggregate particle shape, SAWi＝SAci×SPi+SAsi×(1-SPi) Wherein, cubic surface area:
Figure FDA0003312527470000025
sphere surface area:
Figure FDA0003312527470000026
TXiis an index of surface texture;
GAithe edge angle gradient of the i-th grade aggregate.
3. The asphalt mixture aggregate segregation prediction method according to claim 1, characterized in that the composite edge angle index CI of the asphalt mixture in step S1GAThe calculation method is shown as the formula (5);
Figure FDA0003312527470000027
in formula (5):
aicalculating the percent of the screen residue for the ith grade aggregate in the grading design;
n is the number of particle size steps of all aggregates in the grading design;
m is the grade number of the grain size of the coarse aggregate used in the grading design;
giis the bulk relative density of the i-th grade aggregate;
diis the average particle size of the i-th grade aggregate,
Figure FDA0003312527470000031
wherein P isi+1Mesh size for set i + 1;
Vwiis a weighted volume, V, of the aggregate particle shapeWi＝Vci×SPi+Vsi×(1-SPi) Wherein, cubic volume:
Figure FDA0003312527470000032
sphere volume:
Figure FDA0003312527470000033
GAithe edge angle gradient of the i-th grade aggregate;
m is the total mass of the mineral aggregate.
4. The asphalt mixture aggregate segregation prediction method according to claim 1, characterized in that the maximum value of the composite texture index of the asphalt mixture in step S1
Figure FDA0003312527470000034
Maximum value of composite edge angle index of asphalt mixture
Figure FDA0003312527470000035
In particular, the maximum value of the composite texture index of the asphalt mixture
Figure FDA0003312527470000036
Value of 2447.62397312175, maximum value of composite edge angle index of asphalt mixture
Figure FDA0003312527470000037
Has a value of 40008.2752815776.
CN202111220850.9A 2021-10-20 2021-10-20 Asphalt mixture aggregate segregation pre-judging method Active CN114067931B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202111220850.9A CN114067931B (en) 2021-10-20 2021-10-20 Asphalt mixture aggregate segregation pre-judging method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202111220850.9A CN114067931B (en) 2021-10-20 2021-10-20 Asphalt mixture aggregate segregation pre-judging method

Publications (2)

Publication Number Publication Date
CN114067931A true CN114067931A (en) 2022-02-18
CN114067931B CN114067931B (en) 2024-08-16

Family

ID=80235231

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202111220850.9A Active CN114067931B (en) 2021-10-20 2021-10-20 Asphalt mixture aggregate segregation pre-judging method

Country Status (1)

Country Link
CN (1) CN114067931B (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013056642A1 (en) * 2011-10-17 2013-04-25 交通运输部公路科学研究所 Method for determining composition of coarse-grain, high-modulus asphalt concrete with interlocking structure
CN106680158A (en) * 2017-01-09 2017-05-17 山东大学 Asphalt mixture separation degree estimation method and device
CN106950120A (en) * 2017-02-16 2017-07-14 浙江大学 A kind of asphalt mixture gradation optimization method under virtual state
US20190292735A1 (en) * 2017-02-14 2019-09-26 William B. Coe Apparatus and method for preparing asphalt and aggregate mixture

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013056642A1 (en) * 2011-10-17 2013-04-25 交通运输部公路科学研究所 Method for determining composition of coarse-grain, high-modulus asphalt concrete with interlocking structure
CN106680158A (en) * 2017-01-09 2017-05-17 山东大学 Asphalt mixture separation degree estimation method and device
US20190292735A1 (en) * 2017-02-14 2019-09-26 William B. Coe Apparatus and method for preparing asphalt and aggregate mixture
CN106950120A (en) * 2017-02-16 2017-07-14 浙江大学 A kind of asphalt mixture gradation optimization method under virtual state

Also Published As

Publication number Publication date
CN114067931B (en) 2024-08-16

Similar Documents

Publication Publication Date Title
WO2013056642A1 (en) Method for determining composition of coarse-grain, high-modulus asphalt concrete with interlocking structure
CN112765782B (en) Design method of high-performance ultrathin asphalt wearing layer
Ling et al. Using recycled waste tyres in concrete paving blocks
CN107679352B (en) Asphalt pavement bearing layer material design method based on structural function requirements
CN111423156B (en) Anti-rutting drainage ultrathin overlay asphalt mixture and preparation method thereof
CN101265053A (en) Asphalt-enriched discontinuous gradation rubber asphalt mixture
CN111785338A (en) Grading method, system, medium and equipment suitable for regenerated asphalt mixture
CN114180884A (en) Gradation design method for framework dense ultrathin overlay asphalt mixture
CN107129227A (en) A kind of preparation method of pavement of road or airfield pavement paving structure
CN1583387A (en) Methods for gradating and inspecting coarse aggregate for asphalt concrete
Zhou et al. Study on mesostructure and stress–strain characteristics of pervious concrete with different aggregate sizes
CN101736675A (en) Forming method of cold regeneration upper substrates on damaged pavement and cold regeneration material combined structure
CN103485255B (en) A kind of Optimization Design of micro-surfacing mixture match ratio
Song et al. Effect of pore characteristics on sound absorption ability of permeable pavement materials
CN114067931A (en) Asphalt mixture aggregate segregation prediction method
CN109020338B (en) Design method of cement-stabilized iron-like tailing sand base material
CN113582641A (en) Inorganic mixture prepared from construction waste recycled aggregate and preparation method thereof
CN110489923B (en) Method for estimating plastic strain of graded broken stone mixture under repeated loading effect
Li et al. Stress analysis and optimization of coarse aggregate of large stone porous asphalt mixture based on discrete element method
Xu et al. Performance Investigation and Internal-Structure Analysis of Polyurethane Bonded Mixture on Highway Steel Bridge
CN114400055B (en) Framework-stable and segregation-resistant asphalt mixture grading design method
CN107572896B (en) A kind of AC-20 modified asphalt mixture design method based on pavement performance
CN111351691B (en) Method for evaluating anti-rutting performance of asphalt mixture
CN115017573B (en) Airport pavement SMA grading design method
CN114707320A (en) Design method for asphalt mixture mix proportion of high-temperature environment road in desert area

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant