CN110174431A - A kind of Lignin modification silty clay frost resistance research method - Google Patents
A kind of Lignin modification silty clay frost resistance research method Download PDFInfo
- Publication number
- CN110174431A CN110174431A CN201910422376.4A CN201910422376A CN110174431A CN 110174431 A CN110174431 A CN 110174431A CN 201910422376 A CN201910422376 A CN 201910422376A CN 110174431 A CN110174431 A CN 110174431A
- Authority
- CN
- China
- Prior art keywords
- test
- silty clay
- lignin
- test specimen
- lignin modification
- 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.)
- Pending
Links
Classifications
-
- 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
-
- 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
- G01N25/16—Investigating or analyzing materials by the use of thermal means by investigating thermal coefficient of expansion
-
- 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
- G01N25/20—Investigating or analyzing materials by the use of thermal means by investigating the development of heat, i.e. calorimetry, e.g. by measuring specific heat, by measuring thermal conductivity
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/08—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/32—Investigating strength properties of solid materials by application of mechanical stress by applying repeated or pulsating forces
- G01N3/36—Investigating strength properties of solid materials by application of mechanical stress by applying repeated or pulsating forces generated by pneumatic or hydraulic means
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N5/00—Analysing materials by weighing, e.g. weighing small particles separated from a gas or liquid
- G01N5/02—Analysing materials by weighing, e.g. weighing small particles separated from a gas or liquid by absorbing or adsorbing components of a material and determining change of weight of the adsorbent, e.g. determining moisture content
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0001—Type of application of the stress
- G01N2203/0005—Repeated or cyclic
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0014—Type of force applied
- G01N2203/0016—Tensile or compressive
- G01N2203/0019—Compressive
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/003—Generation of the force
- G01N2203/0042—Pneumatic or hydraulic means
- G01N2203/0044—Pneumatic means
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Road Paving Structures (AREA)
Abstract
The invention discloses a kind of Lignin modification silty clay frost resistance research methods, include the following steps: that S1. air-dries silty clay, screen out little particle silty clay；S2. the silty clay after screening is adulterated together with lignin；S3. the silty clay sample of different lignin mixture proportions is stirred evenly, sealing infiltration 12h, static pressure method forming cylinder shape test specimen, then sealed thermostat constant humidity health carries out freezing and thawing test；S4. it will carry out repeating to load dynamic resilience modulus test through the test specimen before and after freezing and thawing test；S5. bearing-ratio test will be carried out through the test specimen before and after freezing and thawing test；S6. thermal coefficient test will be carried out through the test specimen before and after freezing and thawing test.Using Lignin modification silty clay frost resistance research method of the invention, the blank that pavement performance is studied under freeze-thaw cycles about cold area's industry byproduct Lignin modification cohesive soil has been filled up.
Description
Technical field
The present invention relates to Lignin modification silty clay performance study fields, and in particular to a kind of Lignin modification silty is glutinous
Native frost resistance research method.
Background technique
In seasonal freezing region, spring subgrade soils thaw, since the ice crystal of roadbed soil layer top accumulation melts,
Increase subgrade soils moisture content, silty clay drainability is poor in addition, the softening of roadbed upper layer, strength reduction.It is anti-in vehicular load
Under multiple effect, there is structural track in less serious case road surface, limits running speed, and severe one pavement cracking emits mud, the excessive mistake of subgrade deformation
Surely.
In recent years, the roadbed freeze-harm for finding that silty clay fills when the investigation of northern frore area road operation conditions is aobvious
It writes, Lignin modification silty clay is applied in cold area's subgrade engineering, needs to carry out exploration to its engineering properties and durability
Research, and the research at present for cold area's industry byproduct Lignin modification cohesive soil pavement performance under freeze-thaw cycles is fresh
It has been reported that, engineer application and effect assessment all extremely lack.
Summary of the invention
It is an object of the invention to overcome the deficiencies of the prior art and provide a kind of Lignin modification silty clay frost resistances to grind
Study carefully method.
The purpose of the present invention is achieved through the following technical solutions: a kind of Lignin modification silty clay frost resistance is ground
Study carefully method, includes the following steps:
S1. silty clay is air-dried, screens out little particle silty clay；
S2. the silty clay after screening is adulterated together with lignin；
S3. the silty clay sample of different lignin mixture proportions is stirred evenly, static pressure method forming cylinder shape test specimen is close
Constant temperature health is sealed, freezing and thawing test is then carried out；
S4. it will carry out repeating to load dynamic resilience modulus test through the test specimen before and after freezing and thawing test；
S5. bearing-ratio test will be carried out through the test specimen before and after freezing and thawing test；
S6. thermal coefficient test will be carried out through the test specimen before and after freezing and thawing test.
Preferably, in the S1, after silty clay is air-dried, via hole diameter is the sieve of 2mm, the silty after being screened
Clay.
Preferably, in the S2, by after screening silty clay and lignin according to lignin quality percentage be
0%, 2%, 4%, 6% ratio doping together, specimen molding density be optimum moisture content under the conditions of, maximum dry density
96%.
Preferably, in the S3, the freezing and thawing test includes the following steps:
S31. the sample after the powder clay of different lignin mixture proportions being added water and stirred uniformly is packed into hermetic bag, infiltration
12h；
S32. static pressure method shaping test piece is used, is put into Standard Curing case after sealable polyester film, is 20 DEG C in temperature, phase
Health 7d, 28d under the conditions of being 95% to humidity；
S33. the Lignin modification silty clay test specimen for completing health is put into high/low temperature alternation together with silty clay test specimen
In chamber, the freezing-thawing temperature of the high low temperature cycles test case is respectively -20 DEG C and 20 DEG C, and the freezing-thawing time is each
For 24 hours, Frozen-thawed cycled 10 times.
Preferably, in the S4, the load dynamic resilience modulus test that repeats is three axis repeated load tests, described
Three axis repeated load tests complete test using 30 universal testing-machine of DTS, are completed by the matched Testlab software of DTS 30
Data collection and analysis.
Preferably, in 30 universal testing-machine of DTS, confining pressure is air pressure-loading, haversine impulsive load, Loading frequency 10Hz,
Load time is 0.2s, and the load intermittent time is 0.8s；Each soil sample makes 3 parallel test specimens, each test specimen moisture content in test
With compactness control errors within 1%.
Preferably, in the S5, the bearing-ratio test includes the following steps:
S51. the quality of freeze thawing front and back each test specimen and cylinder is weighed；
S52. test specimen is put into frame, after the dial framework and dial gauge that install measurement swell increment, test specimen is placed into water
In slot, dial gauge initial reading is read, water is then added in sink, the water surface is higher by test specimen top surface 25mm or more；
S53. after test specimen impregnates 4 round the clock, percentage meter reading is read, test specimen is taken out from sink, pours out test specimen top surface
Water stands 15min, sheds the attachmentes such as frame, Loading Plate, weighing tank and test specimen quality；
S54. test specimen is placed on MQS-2 type pavement material intensity tester and carries out penetration test, meter record shift value and pressure
Force value；
S55. CBR, swell increment and water absorption are calculated.
Preferably, in the S54, when carrying out penetration test, inductive head, loading speed 1mm/ are loaded using 50kN
min。
Preferably, in the S6, the thermal coefficient test is completed using thermal conductivity factor instrument, instrument thermal conductivity measurement
Range: 0.005~500W/ (mK), precision: ± 3%, sensor uses polyimides overlay film, 1~2560s of testing time.
Preferably, the thermal conductivity factor instrument uses double helix sonde configuration, and double helix probe is sandwiched between two pieces of samples, and
Double helix probe temperature is established according to the resistance value size that measures of double helix probe to change with time relationship.
The beneficial effects of the present invention are:
1. silty clay surface of test piece has apparent crack, the improvement silty clay surface of lignin volume 2% after freeze thawing
There are small crack, and the improvement silty clay good integrity of lignin volume 4% and 6%, it has no crack, illustrates lignin
Incorporation effectively improves soil body freeze-thaw stability.
2. the dynamic resilience modulus test of Lignin modification silty clay the result shows that: before and after freeze thawing, Lignin modification powder
The dynamic resilience modulus of matter clay reduces with the increase of deviatoric stress, increases with the increase of confining pressure.Before freeze thawing, lignin
The modulus of resilience for improveing silty clay reduces as lignin volume increases.After freeze thawing, Lignin modification silty clay is returned
It plays modulus and increases as lignin volume increases, modulus of resilience percentage of decay reduces as lignin volume increases.It says
Bright lignin improves soil body frost resistance, but the excessively multipair soil strength of lignin volume is unfavorable.
3. the CBR test result of Lignin modification silty clay shows: Lignin modification soil CBR increases with lignin volume
Add, first increases and then decreases.After freeze thawing, the CBR of silty clay and Lignin modification silty clay reduces, but Lignin modification powder
It is smaller that the CBR of matter clay reduces amplitude.Before freeze thawing, Lignin modification soil expansion amount reduces as lignin volume increases.Freeze
After melting, the swell increment of Lignin modification soil increases as lignin volume increases.Before and after freeze thawing, Lignin modification silty clay
Water absorption with lignin volume increase and increase.Comprehensive analysis provides the cold best lignin of area's silty clay roadbed and mixes
Amount is 4%.
4. the conductivity test of Lignin modification silty clay the result shows that: the thermal coefficient of Lignin modification silty clay
Reduce as lignin volume increases, lignin mixes the soil body, reduces the conductivity of heat of the soil body, and to improving, frost resistance is advantageous.
Thermal coefficient increases silty clay after freeze-thaw with Lignin modification silty clay.
Detailed description of the invention
Fig. 1 is silty clay and test specimen superficial appearance after the freeze thawing 7d of Lignin modification silty clay；
Test specimen superficial appearance after the freeze thawing 28d of Fig. 2 silty clay and Lignin modification silty clay；
Fig. 3 is crack spread scenarios after silty clay freeze thawing；
Fig. 4 is influence of the stress state to the modulus of resilience before the soil freeze thawing of health 7d Lignin modification；
Fig. 5 is influence of the stress state to the modulus of resilience after the soil freeze thawing of health 7d Lignin modification；
Fig. 6 is influence of the stress state to modulus pad value after the soil freeze thawing of health 7d Lignin modification；
Fig. 7 is influence of the stress state to the modulus of resilience before the soil freeze thawing of health 28d Lignin modification；
Fig. 8 is influence of the stress state to the modulus of resilience after the soil freeze thawing of health 28d Lignin modification；
Fig. 9 is influence of the stress state to modulus pad value after the soil freeze thawing of health 28d Lignin modification；
Figure 10 is health 7d conditioned soil dynamic resilience modulus and lignin volume relationship；
Figure 11 is health 28d conditioned soil dynamic resilience modulus and lignin volume relationship；
Figure 12 is Lignin modification soil modulus of resilience percentage of decay；
Figure 13 is influence of the freeze thawing to Lignin modification silty clay CBR value；
Figure 14 is influence of the freeze thawing to Lignin modification silty clay swell increment；
Figure 15 is influence of the freeze thawing to Lignin modification silty clay water absorption；
Figure 16 is Lignin modification soil thermal coefficient before and after health 7d freeze thawing；
Figure 17 is Lignin modification soil thermal coefficient before and after health 28d freeze thawing.
Specific embodiment
Technical solution of the present invention is described in further detail with reference to the accompanying drawing, but protection scope of the present invention is not limited to
It is as described below.
Embodiment
A kind of Lignin modification silty clay frost resistance research method, includes the following steps:
S1. silty clay is air-dried, via hole diameter is the sieve of 2mm, the silty clay after being screened；
S2. by after screening silty clay and lignin according to lignin quality percentage be 0%, 2%, 4%, 6%
Ratio adulterate together, specimen molding density be optimum moisture content under the conditions of, the 96% of maximum dry density；
S3. the silty clay sample of lignin mixture proportions different in S2 is stirred evenly, seals and infiltrate 12h, then
Carry out freezing and thawing test；The freezing and thawing test includes the following steps:
S31. the sample after sealing and infiltration is poured into punching block, using static pressure method shaping test piece, test specimen after molding is used
Sealable polyester film；
S32. the Lignin modification slity soil test specimen sealed is put into Standard Curing case, is 20 DEG C in temperature, relative humidity
Health 7d, 28d under the conditions of being 95%；
S33. the Lignin modification slity soil test specimen for completing health is put into the examination of high/low temperature alternation together with silty clay test specimen
In tryoff, the freezing-thawing temperature of the high low temperature cycles test case is respectively -20 DEG C and 20 DEG C, the freezing-thawing time respectively for 24 hours,
Frozen-thawed cycled 10 times.
S4. it will carry out repeating to load dynamic resilience modulus test through the sample before and after freezing and thawing test；Three axis repeat to add
Carry the method that test is the test subgrade soils dynamic resilience modulus received and applied extensively in the world, the fine grained soil made
Roadbed triaxial test loadingsequence table is as shown in table 1,
1. triaxial test loadingsequence table of table
Specifically, the three axis repeated load test completes test using 30 universal testing-machine of DTS, passes through DTS 30
Matched Testlab software data acquisition and analysis；In 30 universal testing-machine of DTS, confining pressure is air pressure-loading, haversine
Impulsive load, Loading frequency 10Hz, load time 0.2s, load intermittent time are 0.8s；Each soil sample makes 3 and puts down in test
Row test specimen, each test specimen moisture content and compactness control errors are within 1%.
S5. bearing-ratio test will be carried out through the sample before and after freezing and thawing test；The bearing-ratio test includes following step
It is rapid:
S51. the quality of freeze thawing front and back each test specimen and cylinder is weighed；
S52. test specimen is put into frame, after the dial framework and dial gauge that install measurement swell increment, test specimen is placed into water
In slot, dial gauge initial reading is read, water is then added in sink, the water surface is higher by test specimen top surface 25mm or more；
S53. after test specimen impregnates 4 round the clock, percentage meter reading is read, test specimen is taken out from sink, pours out test specimen top surface
Water stands 15min, sheds the attachmentes such as frame, Loading Plate, weighing tank and test specimen quality；
S54. test specimen is placed on MQS-2 type pavement material intensity tester and carries out penetration test, loaded and felt using 50kN
Answer head, loading speed 1mm/min, meter record shift value and pressure value；
S55. according to formula (T0134-2)~formula (T0134- in " highway earthwork test rule " (JTG E40-2007)
7) CBR, swell increment and water absorption, are calculated.
Wherein, CBR test is the abbreviation of bearing-ratio test, and CBR is a kind of evaluation road proposed by California, USA Highway Administration Bureau
The index of sill bearing capacity, the test simulation roadbed filling are meeting compactness condition and are being in the least favorable impregnated by water
Under ambient conditions, the ability of the anti-local shear forces destruction of roadbed.
S6. thermal coefficient test will be carried out through the sample before and after freezing and thawing test；The thermal coefficient test, which uses, to be led
Hot coefficient instrument is completed, instrument thermal conductivity measurement range: 0.005~500W/ (mK), precision: ± 3%, sensor is using poly-
Acid imide overlay film, 1~2560s of testing time, thermal conductivity factor instrument use double helix sonde configuration, and double helix probe is sandwiched in two pieces of samples
Between product, and double helix probe temperature is established according to the resistance value size that measures of double helix probe and is changed with time relationship.
Wherein, the technical know-how based on transient state plate heat source, thermal conductivity factor instrument use double helix sonde configuration, the probe
Play the role of two during the test, it be both one be used to heat sample heat source and one be used to record temperature with
Time raised resistance value thermometer.Usually probe is to be arranged by 10 microns thick of nickel metal by bifilar helix, width, circle number
And its radius is all by sophisticated design.This helical structure is got up by external film material protection, on the one hand which mentions
For certain mechanical strength of popping one's head in, on the other hand guarantee electrical insulating property in use of popping one's head in.In the thermal coefficient of test material
When, the nickel spiral probe of envelope dress is sandwiched between two pieces of samples.Within the testing time, the change in resistance of probe will be recorded one by one
Get off, temperature experienced of popping one's head in changes over time relationship during the big mini system based on resistance value sets up test.According to difference
The thermal coefficient size of material, system will select different test parameters, comprising: output power, testing time and use are visited
The size etc. of head.
In the present embodiment,
In freezing and thawing test,
Test specimen superficial appearance after the freeze thawing of silty clay and Lignin modification silty clay, as shown in Figure 1, 2, 3, by Fig. 1,
2,3 it is found that silty clay test specimen is after unfreezing, and there are significant cracks on surface, and to vertically and horizontally developing.Lignin
There is also small cracks on the conditioned soil surface of volume 2%, but the conditioned soil surface of lignin volume 4% and 6% has no crack.
The appearance features of test specimen illustrate that lignin can improve silty clay roadbed freeze-thaw stability after freeze thawing.
It repeats in load dynamic resilience modulus test, the health 7d Lignin modification silty of different loadingsequences before and after freeze thawing
Clay dynamic resilience modulus test the results are shown in Table 2,
The 2. health 7d Lignin modification silty clay modulus of resilience of table tests table
As shown in Figure 4,5, before and after freeze thawing, under the premise of confining pressure is certain, the dynamic resilience of Lignin modification silty clay
Modulus reduces with the increase of deviatoric stress；Under the premise of deviatoric stress is certain, the dynamic of Lignin modification silty clay is returned
Modulus is played to increase with the increase of confining pressure.
As shown in fig. 6, under confining pressure certain condition, the dynamic resilience modulus pad value of Lignin modification silty clay with
The increase of deviatoric stress and reduce；Under deviatoric stress certain condition, the dynamic resilience modulus pad value of Lignin modification silty clay
Increase with the increase of confining pressure.
The health 28d Lignin modification silty clay dynamic resilience modulus test result of different loadingsequences is shown in front of and after freeze thawing
Table 3, to the dynamic resilience modulus test knot of Lignin modification silty clay under the different stress before and after unfreezing in table 3
Fruit carries out analysis and arrangement, and result is as shown in Figure 7,8, by Fig. 7,8 it is found that freeze thawing front and back, wooden under the premise of confining pressure is certain
The dynamic resilience modulus of element improvement silty clay reduces with the increase of deviatoric stress, under the premise of deviatoric stress is certain, wood
The dynamic resilience modulus of quality improvement silty clay increases with the increase of confining pressure.Stress state is wooden to 28d health
The dynamic resilience mould of the Lignin modification silty clay of the dynamic resilience modulus affecting laws and 7d health of element improvement silty clay
Measuring test result has good consistency.
To the dynamic resilience mould of Lignin modification silty clay under the different stress after Frozen-thawed cycled effect in table 3.4
It measures pad value and carries out analysis and arrangement, as shown in figure 9, as shown in Figure 9, under confining pressure certain condition, Lignin modification silty clay
Dynamic resilience modulus pad value reduce with the increase of deviatoric stress；Under deviatoric stress certain condition, Lignin modification silty
The dynamic resilience modulus pad value of clay increases with the increase of confining pressure.Lignin modification powder of the stress state to 28d health
The modulus pad value test result of the Lignin modification silty clay of the modulus pad value affecting laws and 7d health of matter clay has
There is good consistency.
The 3.4 health 28d Lignin modification silty clay modulus of resilience (MPa) of table
The test result under the conditions of roadbed average operation confining pressure 30kPa is chosen, Figure 10 and Figure 11 are depicted as.By Figure 10 (a),
11 (a) it is found that the dynamic resilience modulus of Lignin modification silty clay reduces as lignin volume increases before freeze thawing.
By Figure 10 (b) and Figure 11 (b) it is found that after undergoing 10 freeze thawing, Lignin modification silty clay increases with lignin volume
And increase, illustrate that lignin incorporation effectively inhibits the decaying of soil strength.
Different stress modulus of resilience attenuation results are averaged, then seek percentage of decay, the results are shown in Table 4 and Figure 12
It is shown,
4 Lignin modification soil modulus of resilience percentage of decay (%) of table
It is found that the incorporation of lignin effectively improves the frost resistance of silty clay, it is wooden as lignin volume increases
The modulus of resilience percentage of decay of element improvement silty clay is gradually reduced, shadow of the conditioned time to 6% conditioned soil of lignin volume
Sound is more significant.
Bearing-ratio test
Before and after freeze thawing, Lignin modification silty clay bearing-ratio test is as a result, be shown in Table 3.6, table 3.7, Figure 13
The CBR test result of Lignin modification silty clay before 3.6 freeze thawing of table
The CBR test result of Lignin modification silty clay after 3.7 freeze thawing of table
It is found that Lignin modification soil CBR value increases with lignin volume, first increases and then decreases.Before freeze thawing, lignin is mixed
The conditioned soil that amount is 2%, 4% and 6%, in health 7d, CBR increases 127%, 131.2%, 57.4%, in health 28d
When, CBR increases 134.4%, 143.2%, 66.7%.After freeze thawing, the CBR of silty clay and Lignin modification silty clay is equal
Reduce, but the CBR reduction amplitude of Lignin modification silty clay is smaller.After silty clay freeze thawing, CBR reduces 53%.It is wooden
The conditioned soil that plain volume is 2%, 4% and 6%, after health 7d freeze thawing, CBR reduces 29.9%, 9.3%, 8.2%, is supporting
After raw 28d freeze thawing, CBR reduces 21.4%, 7.8%, 10.1%.
Influence of the freeze thawing to Lignin modification silty clay swell increment
By table 3.6, table 3.7 and Figure 14 it is found that before freeze thawing, Lignin modification soil expansion amount with lignin volume increase and
Reduce.The conditioned soil that lignin volume is 2%, 4% and 6%, in health 7d, swell increment reduces 0.37%, 0.36%,
0.21%, in health 28d, swell increment reduces 0.27%, 0.29%, 0.3%.After freeze thawing, the expansion of Lignin modification soil
Amount increases as lignin volume increases.The conditioned soil that lignin volume is 2%, 4% and 6%, in health 7d, swell increment
0.79%, 0.85%, 0.88% is increased, in health 28d, swell increment increases 0.92%, 0.96%, 1.15%.Silty
After freeze-thaw, swell increment reduces 0.92% to clay.The conditioned soil that lignin volume is 2%, 4% and 6%, in health 7d freeze thawing
Afterwards, swell increment increases 0.23%, 0.29%, 0.17%；After health 28d freeze thawing, swell increment increases 0.26%,
0.33%, 0.53%.
Influence of the freeze thawing to Lignin modification silty clay water absorption
By table 3.6, table 3.7 and Figure 15 it is found that the water absorption of Lignin modification silty clay is with wooden before and after freeze thawing
Plain volume increases and increases.Before freeze thawing, the conditioned soil that lignin volume is 2%, 4% and 6%, in health 7d, water absorption increases
Big 42g, 48g, 64g, in health 28d, water absorption increases 37g, 54g, 74g.After freeze thawing, lignin volume be 2%,
4% and 6% conditioned soil, in health 7d, water absorption increases 74g, 90g, 117g, and in health 28d, water absorption is increased
38g,63g,89g.After freeze-thaw, water absorption increases, and silty clay increases for silty clay and Lignin modification silty clay
7g, the conditioned soil that lignin volume is 2%, 4% and 6%, in health 7d, water absorption increases 39g, 49g, 60g；In health
When 28d, water absorption increases 8g, 16g, 22g.
Bearing-ratio test the result shows that, silty clay CBR before and after unfreezing is smaller, is not able to satisfy " highway subgrade
Design specification " in the minimum technical indicator of roadbed filling requirement.Analyze Lignin modification silty clay freeze thawing front and back CBR, expansion
Measuring can obtain with the changing rule of water absorption, and the best lignin volume of area's silty clay roadbed of trembling with fear is 4%.
Conductivity test
Silty clay and Lignin modification silty clay Measured Results of Thermal Conductivity as a result, be shown in Table 3.8~3.9, Figure 16,17, by
Table 3.8, table 3.9, Figure 16 and Figure 17 are it is found that before and after freeze thawing, and the thermal coefficient of Lignin modification silty clay is with lignin
Volume increases and reduces.Before freeze thawing, the conditioned soil that lignin volume is 2%, 4% and 6%, in health 7d, power 150W item
Thermal coefficient is measured under part and reduces 2.93%, 9.05%, 14%, is measured thermal coefficient under the conditions of power 180W and is reduced
0.08%, 8.42%, 13.76%；In health 28d, measured under the conditions of power 150W thermal coefficient reduce 2.51%,
5.2%, thermal coefficient, which is measured, under the conditions of 15.93%, power 180W reduces 2.09%, 4.42%, 13.18%.After freeze thawing, wood
The conditioned soil that quality volume is 2%, 4% and 6% measures thermal coefficient under the conditions of power 150W and reduces in health 7d
3.01%, thermal coefficient, which is measured, under the conditions of 4.72%, 16.02%, power 180W reduces 2.51%, 3.24%, 15.37%；
In health 28d, thermal coefficient is measured under the conditions of power 150W and reduces 3.17%, 5.85%, 12.76%, power 180W item
Thermal coefficient is measured under part reduces 2.99%, 6.55%, 12.22%.Silty clay is freezing with Lignin modification silty clay
Melt rear thermal coefficient to increase, silty clay measures thermal coefficient under the conditions of power 150W and increases 3.1%, in power 180W
Under the conditions of measure thermal coefficient and increase 3.09%.The conditioned soil that lignin volume is 2%, 4% and 6%, in health 7d, function
Thermal coefficient is measured under the conditions of rate 150W and increases 3.02%, 8.02%, 0.68%, measures thermal coefficient under the conditions of power 180W
Reduce 0.58%, 8.93%, 1.16%；In health 28d, thermal coefficient is measured under the conditions of power 150W and is increased
2.41%, thermal coefficient, which is measured, under the conditions of 2.39%, 6.98%, power 180W reduces 2.13%, 0.79%, 4.23%.
3.8 health 7d Lignin modification silty clay thermal coefficient (W/mK) of table
3.9 health 28d Lignin modification silty clay thermal coefficient (W/mK) of table
Study Lignin modification silty clay anti-freezing property through the invention, show: lignin incorporation effectively improves soil
Body freeze-thaw stability；Lignin improves soil body frost resistance, but the excessively multipair soil strength of lignin volume is unfavorable；The area Chu Han silty
The best lignin volume of clay roadbed is 4%；Thermal coefficient increases silty clay after freeze-thaw with Lignin modification silty clay
Add, provide theoretical foundation in silty clay improvement as lignin, compensates for wooden for cold area's industry byproduct at present
Element improvement cohesive soil research of pavement performance under freeze-thaw cycles be rarely reported and its engineer application and effect assessment all
The defect extremely lacked.
The above is only a preferred embodiment of the present invention, it should be understood that the present invention is not limited to described herein
Form should not be regarded as an exclusion of other examples, and can be used for other combinations, modifications, and environments, and can be at this
In the text contemplated scope, modifications can be made through the above teachings or related fields of technology or knowledge.And those skilled in the art institute into
Capable modifications and changes do not depart from the spirit and scope of the present invention, then all should be in the protection scope of appended claims of the present invention
It is interior.
Claims (10)
1. a kind of Lignin modification silty clay frost resistance research method, characterized by the following steps:
S1. silty clay is air-dried, screens out little particle silty clay；
S2. the silty clay after screening is adulterated together with lignin；
S3. the silty clay sample of different lignin mixture proportions is stirred evenly, static pressure method forming cylinder shape test specimen, sealing is permanent
Then warm health carries out freezing and thawing test；
S4. it will carry out repeating to load dynamic resilience modulus test through the test specimen before and after freezing and thawing test；
S5. bearing-ratio test will be carried out through the test specimen before and after freezing and thawing test；
S6. thermal coefficient test will be carried out through the test specimen before and after freezing and thawing test.
2. a kind of Lignin modification silty clay frost resistance research method according to claim 1, it is characterised in that: in institute
It states in S1, after silty clay is air-dried, via hole diameter is the sieve of 2mm, the silty clay after being screened.
3. a kind of Lignin modification silty clay frost resistance research method according to claim 1, it is characterised in that: in institute
State in S2, by after screening silty clay and lignin according to lignin quality percentage be 0%, 2%, 4%, 6% ratio
Doping together, specimen molding density be optimum moisture content under the conditions of, the 96% of maximum dry density.
4. a kind of Lignin modification silty clay frost resistance research method according to claim 1, it is characterised in that: in institute
It states in S3, the freezing and thawing test includes the following steps:
S31. the sample after the powder clay of different lignin mixture proportions being added water and stirred uniformly is packed into hermetic bag, infiltrates 12h；
S32. static pressure method shaping test piece is used, is put into Standard Curing case after sealable polyester film, is 20 DEG C in temperature, it is relatively wet
Degree is health 7d, 28d under the conditions of 95%；
S33. the Lignin modification slity soil test specimen for completing health is put into high low temperature cycles test case together with silty clay test specimen
Interior, the freezing-thawing temperature of the high low temperature cycles test case is respectively -20 DEG C and 20 DEG C, the freezing-thawing time respectively for 24 hours, freeze thawing
Circulation 10 times.
5. a kind of Lignin modification silty clay frost resistance research method according to claim 1, it is characterised in that: in institute
It states in S4, the load dynamic resilience modulus test that repeats is three axis repeated load tests, and the three axis repeated load test is adopted
It completes to test with DTS30 universal testing-machine, passes through the matched Testlab software data acquisition of DTS30 and analysis.
6. a kind of Lignin modification silty clay frost resistance research method according to claim 5, it is characterised in that:
In DTS30 universal testing-machine, confining pressure is air pressure-loading, haversine impulsive load, Loading frequency 10Hz, load time 0.2s,
The load intermittent time is 0.8s；Each soil sample makes 3 parallel test specimens, each test specimen moisture content and compactness control errors in test
Within 1%.
7. a kind of Lignin modification silty clay frost resistance research method according to claim 1, it is characterised in that: in institute
It states in S5, the bearing-ratio test includes the following steps:
S51. the quality of freeze thawing front and back each test specimen and cylinder is weighed；
S52. test specimen is put into frame, after the dial framework and dial gauge that install measurement swell increment, test specimen is placed into sink,
Dial gauge initial reading is read, water is then added in sink, the water surface is higher by test specimen top surface 25mm or more；
S53. after test specimen impregnates 4 round the clock, percentage meter reading is read, test specimen is taken out from sink, pours out the water of test specimen top surface, it is quiet
15min is set, the attachmentes such as frame, Loading Plate, weighing tank and test specimen quality are shed；
S54. test specimen is placed on MQS-2 type pavement material intensity tester and carries out penetration test, record shift value and pressure value；
S55. CBR, swell increment and water absorption are calculated.
8. a kind of Lignin modification silty clay frost resistance research method according to claim 7, it is characterised in that: in institute
It states in S54, when carrying out penetration test, inductive head, loading speed 1mm/min is loaded using 50kN.
9. a kind of Lignin modification silty clay frost resistance research method according to claim 1, it is characterised in that: in institute
It states in S6, the thermal coefficient test is completed using thermal conductivity factor instrument, instrument thermal conductivity measurement range: 0.005~500W/
(mK), precision: ± 3%, sensor uses polyimides overlay film, 1~2560s of testing time.
10. a kind of Lignin modification silty clay frost resistance research method according to claim 9, it is characterised in that: institute
Thermal conductivity factor instrument is stated using double helix sonde configuration, double helix probe is sandwiched between two pieces of samples, and is popped one's head in and surveyed according to double helix
Resistance value size establish double helix probe temperature and change with time relationship.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910422376.4A CN110174431A (en) | 2019-05-21 | 2019-05-21 | A kind of Lignin modification silty clay frost resistance research method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910422376.4A CN110174431A (en) | 2019-05-21 | 2019-05-21 | A kind of Lignin modification silty clay frost resistance research method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110174431A true CN110174431A (en) | 2019-08-27 |
Family
ID=67691747
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910422376.4A Pending CN110174431A (en) | 2019-05-21 | 2019-05-21 | A kind of Lignin modification silty clay frost resistance research method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110174431A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113533410A (en) * | 2021-07-09 | 2021-10-22 | 长沙理工大学 | Method for estimating permanent deformation of road foundation soil under freeze-thaw cycle |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20030103547A1 (en) * | 2001-11-19 | 2003-06-05 | Energy Absorption Systems, Inc. | Roadway freezing point monitoring system and method |
| CN101923085A (en) * | 2010-07-06 | 2010-12-22 | 中交第二公路勘察设计研究院有限公司 | Multifunctional road soil roadbed freezing and thawing circulating test device |
| CN105136652A (en) * | 2015-08-22 | 2015-12-09 | 浙江鑫宙竹基复合材料科技有限公司 | Frost heaving adaptability test method of bamboo composite pressure tube under freeze-thawing cycle |
| CN106706701A (en) * | 2016-12-27 | 2017-05-24 | 中国科学院理化技术研究所 | Device for measuring heat conductivity coefficient of powder on basis of transient plane heat source method |
| CN109342250A (en) * | 2018-12-10 | 2019-02-15 | 南华大学 | A kind of test method of lime improvement silty clay freezing and thawing performance |
-
2019
- 2019-05-21 CN CN201910422376.4A patent/CN110174431A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20030103547A1 (en) * | 2001-11-19 | 2003-06-05 | Energy Absorption Systems, Inc. | Roadway freezing point monitoring system and method |
| CN101923085A (en) * | 2010-07-06 | 2010-12-22 | 中交第二公路勘察设计研究院有限公司 | Multifunctional road soil roadbed freezing and thawing circulating test device |
| CN105136652A (en) * | 2015-08-22 | 2015-12-09 | 浙江鑫宙竹基复合材料科技有限公司 | Frost heaving adaptability test method of bamboo composite pressure tube under freeze-thawing cycle |
| CN106706701A (en) * | 2016-12-27 | 2017-05-24 | 中国科学院理化技术研究所 | Device for measuring heat conductivity coefficient of powder on basis of transient plane heat source method |
| CN109342250A (en) * | 2018-12-10 | 2019-02-15 | 南华大学 | A kind of test method of lime improvement silty clay freezing and thawing performance |
Non-Patent Citations (2)
| Title |
|---|
| 张涛: "基于工业副产品木质素的粉土固化改良技术与工程应用研究", 《中国博士学位论文全文数据库 工程科技Ⅱ辑》 * |
| 朱福: "松嫩平原季冻区低路堤石灰土加固机理及应用研究", 《中国博士学位论文全文数据库 工程科技Ⅱ辑》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113533410A (en) * | 2021-07-09 | 2021-10-22 | 长沙理工大学 | Method for estimating permanent deformation of road foundation soil under freeze-thaw cycle |
| CN113533410B (en) * | 2021-07-09 | 2022-05-31 | 长沙理工大学 | Method for estimating permanent deformation of road foundation soil under freeze-thaw cycle |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Çokça et al. | Shear strength-suction relationship of compacted Ankara clay | |
| Ceratti et al. | Seasonal variations of a subgrade soil resilient modulus in southern Brazil | |
| Tian et al. | Experimental and analytical investigation of the dynamic behavior of granular base course materials used for China's high-speed railways subjected to freeze-thaw cycles | |
| CN110174431A (en) | A kind of Lignin modification silty clay frost resistance research method | |
| Qian et al. | Experimental and modeling study of water-retention behavior of fine-grained soils with dual-porosity structures | |
| Hu et al. | Effect of wetting-drying cycles on mechanical behaviour and electrical resistivity of unsaturated subgrade soil | |
| CN106769475A (en) | A kind of method for evaluating semi-rigid sub-base material frost resistance using dynamic compression rebound modulu | |
| Luo et al. | Effect of freeze–thaw temperature and number of cycles on the physical and mechanical properties of marble | |
| Lee et al. | Effect of artificial cementation on cone tip resistance and small strain shear modulus of sand | |
| Wang et al. | Water absorption/dehydration by NMR and mechanical response for weakly cemented mudstones subjected to different humidity conditions | |
| CN113433292A (en) | System and method for testing evolution of microstructure of discrete sample under freeze-thaw cycle action | |
| Sarsby et al. | Bedding error in triaxial tests on granular media | |
| Trani et al. | Use of impedance probe for estimation of porosity changes in saturated granular filters under cyclic loading: calibration and application | |
| Kiyota et al. | Effects of sample disturbance on small strain characteristics and liquefaction properties of Holocene and Pleistocene sandy soils | |
| Åhnberg | Effects of back pressure and strain rate used in triaxial testing of stabilized organic soils and clays | |
| CN105910929A (en) | Method for testing long-term road application characteristics of soft rock filling material | |
| Rinaldi et al. | Effect of cement and saturation on the stress-strain behavior of a silty clay | |
| Dafalla | The influence of placement conditions on the swelling of variable clays | |
| Payan et al. | Characterization of small-strain shear modulus of sands subjected to anisotropic states of stress | |
| Miller et al. | Iowa borehole shear testing in unsaturated soil | |
| Nagaraj et al. | An improved k o-stress method of determining liquid limit of soils | |
| Tai et al. | Thermal conductivity of Toyoura sand at various moisture and stress conditions | |
| Taylor et al. | New density normalization approach for evaluation of the cyclic resistance of silts | |
| Bardanis et al. | Soil-water characteristic curves and evolution of the tensile and unconfined compression strength of drying slurried soils | |
| Saarenketo et al. | Suction and deformation properties of base course aggregates |
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 | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20190827 |