ExperimentalInvestigationoftheTechnicalPerformancesof SRX

Research ArticleExperimental Investigation of the Technical Performances ofSRX-Stabilized Graded Macadam

Na Xu1 Zhongda Chen 1 Haijun Gao2 Dingming Dong2 Yongjun Wu3 Guanghui Lu4

and Zhifeng Chen5

1Key Laboratory for Special Area Highway Engineering of Ministry of Education Changrsquoan University Xirsquoan 710064 China2Yanrsquoan Highway Administration Bureau Yanrsquoan 716099 China3Weinan Traffic Bureau of Shaanxi Province Weinan 714000 China4Highway Survey and Design Institute of Zhoukou Zhoukou 466000 China5Henan Hongsheng Engineering Supervision Co Ltd Zhoukou 466000 China

Correspondence should be addressed to Zhongda Chen 2019021099chdeducn

Received 10 March 2021 Revised 18 August 2021 Accepted 25 August 2021 Published 14 September 2021

Academic Editor Jose Antonio Fonseca de Oliveira Correia

Copyright copy 2021 Na Xu et al +is is an open access article distributed under the Creative Commons Attribution License whichpermits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

+e technical performances of Solution Road RomixSoilfix- (SRX-) stabilized graded macadam (SSGM) are investigated topromote its application+e specimen curing conditions were proposed to improve the test efficiency by analyzing the influence ofcuring temperature on the unconfined compressive strength andmoisture content variation Moreover the mechanical properties(eg CBR strength and resilient modulus) and pavement performances (eg temperature shrinkage water stability and freezingstability) of SSGM were evaluated through laboratory tests +e results show that the recommended curing temperature in thedrying oven should be 100degCplusmn 2degC and the recommended curing time should not be less than 16 h Furthermore the CBRunconfined compressive and splitting strengths and resilient modulus of SSGM increase with the content of SRX stabilizer +etemperature shrinkage coefficient is approximately 15 of the cement-stabilized grading crushed stone +e dry-wet recoverystrength ratio is approximately 96 after four dry-wet cycles +e freeze-thaw recovery strength ratio is approximately 58 afterfive freeze-thaw cycles +e freezing stability of SSGM can be improved by increasing the content of SRX stabilizer +e technicalperformances of SSGM should fulfill the technical requirements

1 Introduction

Semirigid materials are widely used in the pavement base ofhigh-grade highways in China [1 2] Semirigid base withhigh strength and good slab property can effectively improvethe bearing capacity of asphalt pavements [3ndash5] Howeversimirigid base has its own insurmountable shortcomingseg dry shrinkage temperature shrinkage and reflectivecracking Moreover the stability durability and service lifeof the pavement structure are damaged due to the combinedeffect of load climate and moisture [6ndash9] In China theresearch and application of flexible bases have attracted theattentions from a considerable number of scholars [10ndash12]Common flexible bases mainly include asphalt-stabilizedmacadam base and graded macadam base [13ndash16]

Additionally Solution Road RomixSoilfix (SRX) used as anew road material has become a research hotspot amongflexible bases SRX is an organic copolymer solution com-prising a variety of special resins and organic additives SRX-stabilized graded macadam (SSGM) is a mixture of crushedstones and SRX A thin layer of organic mucosa is formed onthe surface of the crushed stone particles due to the evap-oration of light components and water [17] A strong layerformed by adhesion between the SRX and crushed stoneseffectively inhibits the formation of cracks in the structurallayer [18] +erefore SSGM with a strong flexible structurecan be effectively used to solve the problems of reflective andfatigue cracks in the base SSGM also has certain advantagesin application conditions technical quality constructiontechnology construction conditions and economic benefits

HindawiAdvances in Materials Science and EngineeringVolume 2021 Article ID 9959834 14 pageshttpsdoiorg10115520219959834

[19] In past decades many scholars have performed ex-tensive researches on its technical performance and con-ducted its exploratory applications in some countriesIyengar et al studied the SRX for application in highwaypavement base and analyzed the feasibility of SRX based onthe local engineering practice in Qatar [20] Scholten et alfound that the SRX-stabilized material can significantlyimprove the pavement performance and reduce the overallpavement thickness by comparing with ordinary semirigidbase asphalt pavement [21] Since 2008 SRX-stabilizedmaterials have been used in Beijing Guangdong ProvinceLiaoning Province and Sichuan Province in China Zhanget al studied and analyzed the mechanical properties ofSRX-stabilized base materials and the mechanical responseof asphalt pavement structures [22] It is found that SRX-stabilized materials used as pavement base have good fatigueresistance Meanwhile Du compared and analyzed theproperties of SRX-stabilized materials and inorganic binderstabilized materials It was proved that the SRX-stabilizedmaterials have advantages such as superior mechanicalproperties improvement of fatigue life and crack resistance[23]

+e abovementioned studies have promoted the de-velopment and application of SSGM However there arefew studies on the systematical investigation on themechanical properties and pavement performances ofSSGM Furthermore an appropriate curing conditionwith short test period for SSGM specimen is rarely re-ported For instance Romix International Ltd suggestedthat the curing condition of a SSGM specimen is asfollows (1) the specimen is cured in an oven at 50degC for 2days and then the specimen is dried in the sun for 7 daysagain (2) the specimen is directly cured in an oven at30degC for 10 days [19] However the above curing con-dition affects the experimental process and reduces theexperimental efficiency with the increase in the amount ofspecimens in the experiment

Hence this paper aims to explore the appropriate curingconditions of SSGM based on the effect of curing temper-ature and curing time on the formation of unconfinedcompressive strength and moisture content variationMeanwhile the mechanical properties and road perfor-mance of SSGM are evaluated to provide technical supportfor engineering applications

2 Test Materials

21 SRX Stabilizers and Graded Macadam +e raw mate-rials of SSGM comprise the SRX stabilizer aggregatesand water +e SRX stabilizer is obtained from RomixInternational Ltd and its technical performances arepresented in Table 1 Limestone aggregate produced inWeinan Shaanxi Province is selected as the aggregate+e technical performance of aggregate was testedaccording to Test Methods of Aggregate for HighwayEngineering (JTG E42ndash2005) [24] All indicators conformwith the relevant requirements listed in TechnicalGuidelines for Construction of Highway Roadbases (JTGTF20ndash2015) [25] as shown in Table 2

22 SSGM Mixture +e SSGM consists of aggregate SRXstabilizer and water +e aggregate gradation is obtainedbased on the multistage crowded skeleton determined by theprevious study of the research group +e gradation designmethods are as follows (1) the step-by-step filling theory isused to determine the gradation of coarse aggregates on thebasis of interference theory [26] (2) +e gradation of fineaggregates is determined by using I method according to themaximum density curve theory [27 28] (3) +e proportionof coarse aggregates and fine aggregates is rest with thedouble-optimum principle of dry density and unconfinedcompressive strength [29] +e composite gradation ispresented in Table 3 +e optimum moisture content andmaximum dry density of SSGM determined by the vibratorycompaction test (T0133ndash1993) in Test Method of Soils forHighway Engineering (JTG E40ndash2007) were 340 and247 gcm3 respectively [30] +e content of SRX stabilizerwas initially 025 05 075 and 1

3 Experimental Procedure

31 Curing Condition Test A cylindrical test specimen ofφ150mmtimes 150mm under the compaction of 98 wasformed by referring to the specification (T 0843ndash2009) inTest Methods of Materials Stabilized with Inorganic Bindersof Highway Engineering (JTG E51ndash2009) [31] +e SSGMspecimens were divided into ten groups Nine groups werecured in an oven at 30degC 50degC 65degC 80degC 90degC 95degC 100degC105degC and 110degC whereas the remaining group was curedunder natural conditions for 45 days (the test was performedin July 2019 the average temperature is 30degC)

+e curing time of nine groups of specimens was de-termined by recording the change of water content withtime +e methods were according to the Drying Method (T0801ndash2009) in Test Methods of Materials Stabilized withInorganic Binders of Highway Engineering (JTG E51ndash2009)[31] until the moisture content was zero indicating that allthe samples were completely dry Meanwhile the SSGMspecimen cured for 45 days under natural conditions wasselected as the benchmark while the strength of the specimenwas selected as the benchmark strength +e nine specimengroups were then tested for unconfined compressivestrength after they were cured in the oven

32 Mechanical Performance Test

321 California Bearing Ratio (CBR) Test CaliforniaBearing Ratio (CBR) is used to verify the bearing capacity ofSSGM +e CBR test (T0134ndash1993) was performed by theTest Method of Soils for Highway Engineering (JTGE40ndash2007) [30] A cylindrical test specimen of φ152mmtimes h170mm was formed under the given conditions as followsthe compaction of the specimens is 98 the moisturecontent and dry density are optimum and maximum re-spectively the contents of SRX stabilizer were 0 02505 075 and 1 +e cured specimens were soaked innormal temperature water for 96 h and then the CBR of thespecimens were measured under the most unfavorableconditions

2 Advances in Materials Science and Engineering

+e ratio of unit pressure to standard pressure was se-lected as the CBR value when the penetration of the ma-terials was 25mm as shown in Figure 1 +e CBR isexpressed by

CBR P

7000times 100 (1)

where CBR represents bearing ratio and P denotes unitpressure

322 Unconfined Compressive Strength and SplittingStrength Tests Unconfined compressive strength (UCS) isthe ultimate strength against the axial pressure under thegiven condition as follows the deformation rate remainsunchanged the specimen is continuously loaded withoutlateral pressure until it is damaged A cylindrical testspecimen of φ150mmtimes 150mm was molded by the com-paction of 98 +e contents of SRX stabilizer were 0025 05 075 and 1 +e UCS test (T 0805ndash1994)was performed by referring to Test Methods of MaterialsStabilized with Inorganic Binders of Highway Engineering(JTG E51ndash2009) [31] Figure 2 shows the unconfinedcompressive strength test [23] +e unconfined compressivestrength (R) is calculated using the following equation

R P

A (2)

where P is the maximum pressure when the specimen isdamaged and A is the cross-sectional area of the testspecimen A πD24 where D is the diameter of the testspecimen

Splitting strength is an indirect bending tensile strengthIt is also a maximum stress that the specimen can bear beforebreaking+e splitting strength test (T 0806ndash1994) should becarried out in accordance with Test Methods of MaterialsStabilized with Inorganic Binders of Highway Engineering(JTG E51ndash2009) [31] +e test specimen used in the splittingstrength test is the same as that of the unconfined

compressive strength test Meanwhile the SRX stabilizercontents of SSGMwere 025 05 075 and 1 Figure 3shows the apparatus of the splitting strength test +esplitting strength (r) is calculated using the followingequation

r 2p

πdh (3)

where p is the maximum pressure value when the testspecimen is damaged d is the diameter of the test specimenand h is the height of the test specimen

323 Compressive Modulus of the Resilience TestCompressive modulus of resilience test (T 0808ndash1994) wasperformed by referring to Test Methods of Materials Sta-bilized with Inorganic Binders of Highway Engineering (JTGE51ndash2009) [31] +e selected unit pressure was divided into4ndash6 levels as the stress value of each loading level +e test isused to determine the pressure that the material can bear inthe elastic range determined by the level-by-level loadingand unloading test +e measured compressive modulus ofresilience is used to characterize the mechanical propertiesof the specimen in the elastic stage +e testing equipmentused in the compressive modulus of resilience test is shownin Figure 4 +e compressive modulus of resilience (Ew) iscalculated using the following equation

Ew pH

l (4)

where P is the unit pressure H is the height of the testspecimen and l is the rebound deformation of the testspecimen (ie the difference between the load and unloadreading data)

33 Pavement Performance Test

331 Temperature Shrinkage Performance +e temperatureshrinkage test of thematerial was performed by using a testerof pavement material shrinkage deformation as shown inFigure 5 First the conditions required for the test in the hostmachine were set and the test specimen was inserted into theenvironment box for fixed installation +en the computerwas used to control the temperature in the environment box

Table 3 Aggregate gradationSize of sieves (mm) 315 19 95 475 236 06 0075Gradation () 100 64 47 36 28 175 75

Table 1 Technical performances of the SRX stabilizer

Index Solid amount () pH Viscosity (cps) Boiling point (degC) Proportion Flammability Water-solubleDetection value 2933 9 786 97 102 Nonflammable SolubleTechnical requirement 285ndash315 8ndash9 50ndash100 asymp100 gt1 Nonflammable Soluble

Table 2 Technical performances of the aggregate

Technical indicators () Test result Normative standard Test codeCrushing value 176 le22 T0316Acicular content 74 le18 T0312le0075mm particle content (water-washing) 09 le12 T0310Clay content of fine aggregates 21 le3 T0333Soft stone content 16 ＜3 T0320

Advances in Materials Science and Engineering 3

according to the setting conditions +e data were collectedby a displacement sensor and the received data signals weretransmitted to the computer through AD converter Finallythe data was automatically processed by the computer basedon the internal program +e results of temperatureshrinkage test were therefore obtained [32]

+e gradation of SSGM is presented in Table 3 andthe contents of SRX stabilizer were 025 05 075and 1 +e beam specimen of size 100 times100 times 400mm3

was molded by the compaction of 98 after standardcuring +e temperature ranges were divided into sixparts 40degCndash30degC 30degCndash20degC 20degCndash10degC 10degCndash0degC0degCndash minus10degC andminus10degCndash minus20degC Moreover the rate oftemperature change in each part was minus10degCh +en thespecimens were preserved in each temperature range for6 h under a constant temperature Meanwhile the in-terval of data acquisition was 5min +e specific steps aregiven as follows

(1) +e prepared beam test specimen was cured in anoven at 100degC until it was completely dry (Figure 6)

(2) Appropriate sizes of the glass specimens wereplaced on two square sides of the test specimen inorder to ensure the accuracy of the collected dataand then test specimens were placed into theenvironment box of the tester meanwhile thedisplacement sensor receiving bar above the en-vironment box was adjusted to its initial dis-placement Figure 7 shows the working diagram ofthe tester environment box

(3) +e test parameters and data acquisition conditionswere firstly set in the computer And then the teststarted when the temperature in the environmentbox rose to 40degC

+e displacement of each temperature range can becalculated ie the temperature shrinkage deformation ofthe test specimen (eg the temperature from Ti to Ti+ 1 andthe corresponding displacement values from εi to εi+ 1) +ecorresponding temperature shrinkage coefficient (αti) istherefore calculated using the following equation

αti εi+1 minus εi( 1113857

Ti+1 minus Ti( 1113857ΔεΔT

(5)

where ΔT is the temperature difference and Δε is thetemperature shrinkage corresponding to the temperaturerange

332 Water Stability Performance Water stability perfor-mance of SSGM was tested and evaluated through the dry-wet cycling test +e cylindrical test specimen of sizeφ150mmtimes 150mm was molded by the compaction of 98+e prepared test specimens according to the specificationswere divided into groups I II III and IV and each groupwas further divided into groups A and B [31] Groups I IIIII and IV were used for the first second third and fourthdry-wet cycling tests respectively

+e first group of specimens were taken as an exampleand the specific test steps were as follows +e unconfinedcompressive strength and splitting strength of group I-Awere tested after the standard curing +en the remainingspecimens were immersed in water for 24 h and the liquidlevel was kept at 2 cm higher than the specimens +ereafterthe unconfined compressive strength and splitting strengthof group I-B were tested +e remaining groups of thespecimens were cured under standard curing condition andthe following steps were similar to those of the first group+e unconfined compressive strength of specimen A of each

Figure 1 CBR test

Figure 2 Unconfined compressive strength test

Figure 3 Splitting strength test

Figure 4 Compressive modulus of resilience test


group was then tested Furthermore the unconfined com-pressive strength of specimen B was tested after immersionin water for 24 h

Meanwhile the softening coefficient and dry-wet re-covery strength ratio were used as indexes +e softeningcoefficient indicating the antiwater invasion ability of thematerials is defined as the ratio of wet strength to drystrength Furthermore the dry-wet recovery strength ratioexpressed as a percentage to reflect the strength recovery ofthe specimens after soaking and drying is defined as the ratioof the strength of immersed and redried specimens to that ofnonimmersed specimens

333 Freezing Stability Performance +e SSGM may bedamaged by freeze-thaw during service due to the obviousseasonal alternation in northern China [33] +e specimensused in the freeze-thaw cycling tests are the same as thoseused in the water stability performance test +e freeze-thawcycling tests are performed by referring to the test methodfor the freeze-thaw test of inorganic binders (T 0858ndash2009)in Test Methods of Materials Stabilized with Inorganic

Binders of Highway Engineering (JTG E51ndash2009) [31] +eprepared test specimens after standard curing were dividedinto six groups below I II III IV V and VI Each group wasseparated into part A and part B eg I-A and I-B A freeze-thaw cycle process is described as follows specimens werefirst soaked in water for 24 h specimens were then frozen atminus18degC for 16 h specimens were finally placed in a constanttemperature water tank at a temperature of 20degC for 8 h Sixgroups of specimens were used for five freeze-thaw cyclesPart A and part B were used to analyze the unconfinedcompressive strengths of the specimens after the freeze-thawprocess and standard curing under dry condition respec-tively +e specific test steps were as follows (1) the testspecimens were divided into twelve parts after the standardcuring ie I-A I-B II-A II-B III-A III-B IV-A IV-B V-AV-B VI-A and VI-B +e unconfined compressive strengthof group I-B was tested +en the unconfined compressivestrength of I-A was tested after the remaining specimenshave soaked in a constant temperature water tank for 24 h(2) +e water on the surface of the specimens was wiped offand then the specimens were frozen at minus18degC for 16 h af-terwards the specimens were placed in a constant tem-perature water tank at 20degC for 8 h the above process is thefirst freeze-thaw process (3) +e unconfined compressivestrengths of group II-A were measured after the first freeze-thaw cycle the unconfined compressive strengths of groupII-B were measured after the standard curing of the firstfreeze-thaw cycle (4) +e remaining four groups of speci-mens were used for the second third fourth and fifthfreeze-thaw cycles respectively (5) Each freeze-thaw cyclewas carried out by using the similar approach of the firstfreeze-thaw cycle

+e freeze-thaw coefficient and recovery strength ratioare the indexes for the freezing stability of SSGM+e freeze-thaw coefficient indicating the freezing resistance of theSSGM is defined as the ratio of freezing strength to drystrength +e freeze-thaw recovery strength ratio expressedas a percentage to reflect the recovery strength of the freeze-thaw redrying specimens is defined as the ratio of strength offreeze-thaw redrying specimens to the strength of non-immersed specimens

4 Results and Discussion

41CuringCondition +epurpose of the research on curingcondition is to accelerate the curing process of SSGMspecimens so as to shorten the curing time and improve thetest efficiency Improvement of the curing temperature is asuitable approach while the final strength is rarely affectedFinally a curing condition consisting of reasonable curingtemperature and curing time is taken as a standard curingcondition Figure 8 shows the unconfined compressivestrength and the change curve of curing time of SSGM underdifferent curing temperature conditions An increase in thecuring temperature will greatly reduce the curing time of thetest specimens of SSGM +e curing time is significantlyreduced from 10 d to 12 h when the curing temperature isincreased from 30degC to 110degC However the unconfinedcompressive strengths of the specimens under different

Figure 5 Pavement material shrinkage deformation tester

Figure 6 Isostatic pressure forming

Figure 7 Working of the tester environment box of the beamspecimen


curing temperatures are slightly different +e strengthdifference ratio is 15ndash30 by comparing the strength ofthe specimens cured under the given temperature and thestrength (ie 66MPa) of the specimens cured for 45 daysunder natural conditions Hence the unconfined com-pressive strengths of the specimens at different curingtemperatures are basically the same as those of specimenscured under natural conditions for 45 days +e curingtemperature has little effect on the strength of the specimenunder different temperature within a certain temperaturerange However an increase in the curing temperaturegreatly accelerates the curing process and increases thestrength of the specimen A very high curing temperaturecauses the materialsrsquo aging to a certain extent consideringthat SRX stabilizers are organic polymer compounds [17]+e curing temperature of the test specimens should begenerally no more than 100degC so as to reduce this adverseeffect and ensure the accuracy of the test results Further-more considering that lower curing temperature will in-crease the curing time and reduce the utilization rate of theequipment the curing temperature should be 100degCplusmn 2degC

+e moisture content water loss rate and the de-hydration rate of SSGM specimens were taken as theevaluation indexes to further determine the curing time+e variation law of those three indexes with the curingtime under the curing temperature of 100degC was analyzed+e test results are shown in Figures 9ndash11 Notably thewater loss rate is defined as the ratio of the differencebetween the moisture content of test specimen corre-sponding to an initial state and a certain time state to themoisture content of initial test specimen +e dehydra-tion rate is defined as the ratio of the difference in themoisture content of the test specimen corresponding to aprevious and a latter curing time to the curing time in-terval +e moisture content of the test specimen grad-ually decreased with an increase in the curing time undera curing temperature of 100degC Furthermore the waterloss rate gradually increased and the dehydration rategradually reduced In 0ndash2 h the dehydration rate of thetest specimen was the fastest and the water loss rate in0sim6 h was gt80 Afterwards the dehydration rate of thetest specimen started to slow down After 10 h the waterloss rate of the test specimen reached 968 and themoisture content reduced to 011 which was close tothe dry state At 16 h the moisture content of the testspecimen was close to 0 and the water loss rate was 100indicating that the test specimen was in the dry state Inaddition according to Figure 10 the water loss rate of thetest specimen has a good relationship with the curingtime +e regression equation is shown as follows

ω 00539t3

minus 19315t2

+ 2331t + 20182 R2

099481113872 1113873

(6)

where ω is the water loss rate of the test specimen and t is thecuring time

+e water loss rate of SSGM at any curing time could bedetermined using (6) When the water loss rate is 100 themoisture content of the test specimen is zero (ie dry state)and the curing time is 156 h Combining Figures 9ndash11 thecuring time is determined as 16 h In summary the rec-ommended curing conditions of SSGM are that the curingtemperature should be 100degCplusmn 2degC and the curing timeshould be ge16 h in the drying oven

42 Mechanical Performance

421 CBR Figure 12 shows the CBR values for the SSGMwith different SRX stabilizer contents +e CBR value in-creases with an increase in the SRX content +e CBR valueof SSGM is approximately 30 higher than ordinary gradedcrushed stone (ie the content is 0) under the content ofSRX stabilizer of 05 Moreover the CBR value of SSGMwith the content of SRX stabilizer of 10 increases sub-stantially from 446 to 692 compared with the ordinarygraded macadam It is obvious that the CBR value of SSGMsignificantly increases with the SRX stabilizer Moreover itsCBR value increases with an increase in the content of SRXstabilizer indicating that SSGM has good bearing capacity

30 50 65 80 90 95 100 105 110

e UCSCuring Time

Curing Temperature (degC)

Natural Conditions 66 MPa (1080 h)

0

50

100

150

200

250

Cur

ing

Tim

e (h)

62

63

64

65

66

67

68

Unc

onfin

ed C

ompr

essiv

e Str

engt

h (M

Pa)

Figure 8 Unconfined compressive strength at different curingtemperatures

2 4 6 8 10 12 14 160Curing Time (h)

0

1

2

3

4

Moi

sture

Con

tent

()

Figure 9 Change of moisture content with curing time


422 Unconfined Compressive Strength and SplittingStrength Figure 13 shows that the unconfined compressivestrength and splitting strength of SSGM gradually increase

with an increase in the SRX content However the growthrate of the above strength gradually decreases +e uncon-fined compressive strength increases from 252 to 471MPa(an increase of 869) with an increase in the content of SRXstabilizer from 025 to 10 Meanwhile the splittingstrength increases substantially from 015 to 031MPa (anincrease of 107) +us the strength of the graded brokenstone increased significantly due to the incorporation of theSRX stabilizer Under the condition of 05 SRX stabilizerthe unconfined compressive strength of SSGM is approxi-mately 164 times larger than that of graded gravel

423 Modulus of Resilience Top surface method was usedfor the compressive rebound modulus test Figure 14 showsthat the resilient modulus of SSGM increases with an in-crease in the SRX content However the increment graduallydecreases With an increase in the SRX content from 025to 10 the modulus of resilience increases from 692 to945MPa an increase of approximately 37 Meanwhile therebound modulus of SSGM is larger than that of ordinarygraded gravel Under the condition of 05 content theelastic modulus of SSGM is 814MPa which is approximately80 larger than the graded crushed stone indicating thatSSGM has good resistance to deformation

43 Pavement Performance

431 Temperature Shrinkage Performance Figure 15 showsthe variation of the temperature shrinkage coefficient fordifferent temperature ranges of SSGM Figure 16 shows themaximum average and minimum values of the temperatureshrinkage coefficient +e temperature shrinkage coefficientof SSGM increases slightly with an increase in SRX contentas shown in Figure 15 In the range of 0ndashminus10degC the SRXcontent has the greatest influence (approximately 22) onthe temperature shrinkage coefficient Meanwhile there is asignificant difference in the temperature shrinkage coeffi-cient eg the maximum and minimum of the temperatureshrinkage coefficient correspond to the temperature rangesof 0degndashminus10degC and 10ndash0degC respectively It is indicated that thetemperature change has a significant effect on the temper-ature shrinkage performance of SSGM Figure 16 shows thatthe average temperature shrinkage coefficient of SSGM is454ndash618times10minus6degC +e maximum temperature shrinkagecoefficient has a small value of 1234ndash1508times10minus6degC As theSRX stabilizer content increases there is a slight increase inthe average temperature shrinkage coefficient and themaximum temperature shrinkage coefficient increaseswhich indicates that SSGM has good temperature shrinkageperformance To fully analyze the temperature shrinkageproperties of SSGM the average temperature shrinkagecoefficient of SSGM and other road materials are presentedin Table 4

Table 4 shows that the temperature shrinkage coefficientof SSGM is much smaller than that of other road materialsCompared with cement-stabilized macadam the tempera-ture shrinkage coefficient of SSGM is approximately 15which indicates that SSGM has good temperature shrinkage

Measured ValuePrediction Curve

y = 00539x3 ndash 19315x2 + 2331x + 20182R2 = 09948

2 4 6 8 10 12 14 160Curing Time (h)

20

40

60

80

100

120

Wat

er L

oss R

ate (

)

0

Figure 10 Relationship between water loss rate and curing time

0~2 2~4 4~6 6~8 8~10 10~12 12~14 14~16Curing Time Interval (h)

0

02

04

06

08

Deh

ydra

tion

Rate

(h

)

Figure 11 Change of dehydration rate with curing time

0 025 05 075 1SRX content ()

0

200

400

600

800

CBR

()

Figure 12 Change law of CBR with SRX content


performance [34ndash37] +e reflective cracking of asphaltsurface caused by shrinkage cracks of semirigid base cantherefore be suppressed

432 Water Stability Performance It can be found that themechanical properties and temperature shrinkage perfor-mance of SSGM increase significantly when the content ofSRX stabilizer increases from 025 to 05 by referring tothe evaluation results of these properties However thementioned properties of SSGM increase gradually when theSRX stabilizer variation contents are 05ndash075 and075ndash1 but the increase degree is unobvious Highercontent of SRX stabilizer could induce great increase ofeconomic cost due to the engineering economy +e rec-ommended content of SRX stabilizer is therefore 05

Table 5 presents the results of the first dry-wet cyclingtest with compressive and splitting strengths Figure 17shows the comparison of the appearance of standard cur-ing specimens (ie before the first dry-wet cycle) with theappearance of the redried specimens after the fourth dry-wetcycle Figures 18 and 19 show the compressive strength afterfour dry-wet cycling tests

Table 5 shows that the softening coefficient of SSGMafter the first dry-wet cycle is approximately 55 while thecompressive strength loss is approximately 45 +estrength recovery ratio is 9836 after recuring and dryingwhich indicates that the strength was basically restored

As can be seen from the comparison of the specimenappearance shown in Figure 17 the surface of the specimensalmost remains intact after four dry-wet cycling testsFurthermore the weight loss of the specimens is almost zero+e results show that the structures of the specimens arebarely destroyed by dry-wet cycles

+e strengths of both immersed and redried speci-mens decrease with an increase in the dry-wet cyclingtimes as shown in Figures 18 and 19 Meanwhile thesoftening coefficient and dry-wet recovery strength ratioslightly decrease but the reductions of them are graduallynarrowed and the strength of redried specimens hasstabilized after the fourth dry-wet cycle After four dry-

0 025 05 075 1SRX content ()

0

1

2

3

4

5

Unc

onfin

ed co

mpr

essiv

e str

engt

h (M

Pa)

(a)

025 05 075 1

Split

ting

stren

gth

(MPa

)

SRX content ()

0

005

01

015

02

025

03

035

(b)

Figure 13 Change law of mechanical strength with SRX content (a) Unconfined compressive strength (b) Splitting strength

0 025 05 075 1SRX content ()

0

200

400

600

800

1000

Mod

ulus

of r

esili

ence

(MPa

)

Figure 14 Change law of resilient modulus with SRX content

40 ~ 30 30 ~ 20 20 ~ 10 10 ~ 0 0~ -10 -10 ~ -20Temperature range (degC)

025SRX content

0500751

0

5

10

15

20

Tem

pera

ture

-shr

inka

ge co

effici

ent (

times10-6

degC)

Figure 15 Variation of temperature shrinkage coefficient withdifferent SRX stabilizer contents


wet cycling tests the dry-wet recovery strength ratio is964 ie the strength loss is small (approximately 4)+is indicates that the SSGM strength can be restored tothe strength of the last test by recuring +is is mainlybecause water intrusion temporarily softens the organicmucosa formed on the aggregate surface during the dry-wet cycling test reducing the bonding strength betweenSRX and the aggregate such that the structure is rarelydestroyed When the moisture is removed again thebonding strength between aggregates is perfectly re-stored +is shows that dry-wet cycling will not damageSSGM and it is reasonable and feasible to use the dry-wetrecovery strength ratio to evaluate water stability +eSSGM has good water stability performance on the basisof the comprehensive evaluation of softening coefficientand dry-wet recovery strength ratio However moreattention should be paid to drainage design in order tobetter develop the performance of materials due to thelow softening coefficient of SSGM

To sum up the strength of SSGM is barely reduced afterfour dry-wet cycle tests +e unconfined compressivestrengths of both the immersed and the redried specimensare basically unchanged after the third and fourth dry-wetcycle tests +is shows that the unconfined compressivestrength of SSGM specimens basically reaches a stable stateIt is therefore an optional strategy that the number of thedry-wet cycles is four +e dry-wet cycling test is performedbased on the given number of the dry-wet cycles

433 Freezing Stability Performance +e specimen used infreeze-thaw cycle tests is the same as that of dry-wet cycletests Table 6 lists the test results of the unconfined com-pressive strength and splitting strength after the first freeze-thaw cycle Figures 20 and 21 show the unconfined com-pressive strength of each freeze-thaw cycle Figure 22 showsthe comparison of the appearance of standard curingspecimens (ie before freeze-thaw cycle) and the redriedspecimens after the fifth freeze-thaw cycle

Table 6 shows that the freeze-thaw coefficient of SSGMafter the first freeze-thaw cycle is approximately 86 whichis mainly related to the strength reduction (approximately45) after immersion Moreover the freeze-thaw recoverystrength ratio after recuring is approximately 90 which issmaller than the dry-wet recovery strength ratio after thefirst dry-wet cycle however the strength after the firstfreeze-thaw cycle can be greatly recovered It can be seen thatthe freezing stability performance of SSGM is hardlyweakened after the first freeze-thaw cycle

As shown in Figures 20 and 21 with the number offreeze-thaw cycles increasing the strength of the SSGM thefreeze-thaw coefficient and the freeze-thaw recoverystrength ratios decreased continuously and gradually Afterfive freeze-thaw cycles the freeze-thaw coefficient is only51 and the freeze-thaw recovery strength ratio is ap-proximately 58 indicating that the strength loss is veryserious +e main reasons are as follows the bonding forcebetween SRX and the aggregate is reduced the organic

025 05 075 1SRX content ()

Maximum valueAverage valueMinimum value

0

4

8

12

16

Tem

pera

ture

-shr

inka

ge co

effici

ent (

times10-6

degC)

Figure 16 +e change law of temperature shrinkage coefficient with the content of SRX stabilizer

Table 4 Average temperature shrinkage coefficient of different road materials

TypeSSGM with different

contents Cementconcrete

Lime andgravel soil

Lime-fly ashconcrete

Skeleton-density cement-stabilized macadam

025 05 075 1Average temperature shrinkagecoefficient (times10ndash6degC) 456 503 571 618 967 156 566 375


mucous membrane formed on the aggregate surface isdamaged the structure of SSGM is destroyed the strength isnot completely recovered after recuring Freeze-thaw cyclescause permanent cumulative damage to SSGM +e damagedegree of freezing stability performance of SSGM increaseswith the number of freeze-thaw cycles

+e damage of the specimens is not obvious after fivefreeze-thaw cycles from the appearance of specimens pre-sented in Figure 22 +e edge and corner of the specimensare damaged slightly It can be seen that the spalling is notsignificant Considerable attention should be therefore paidtoward the antifreezing protection engineering in cold andfrozen areas to avoid the impact of freezing and thawing onthe freezing stability performance of SSGM structure layer

+e increase in the content of SRX stabilizer can improve thefreezing stability performance of SSGM Figure 23 shows theresults of the fifth freeze-thaw cycle test of SSGM withdifferent contents

As shown in Figure 23 the freeze-thaw coefficientsand recovery strength ratios increase to varying degreesas the SRX stabilizer content increases After five freeze-thaw cycles when the SRX stabilizer content increasesfrom 025 to 10 the freeze-thaw coefficient increasesfrom 416 to 684 an increase of 645 and the freeze-thaw recovery strength ratio increased from 477 to732 an increase of approximately 255 +e freeze-thaw stability was considerably improved which indi-cates that an increase in the SRX stabilizer content

Table 5 Water stability performance of SSGM

Indexes Strength of unsoakedspecimens (MPa)

Strength of soakedspecimens (MPa)

Softeningcoefficient ()

Strength of soaked andredried specimens

(MPa)

Lossstrength(MPa)

Recoverystrength ratio

()Compressivestrength 672 383 5699 661 011 9836

Splittingstrength 041 022 5366 040 001 9756

(a) (b)

Figure 17 Appearance of the test specimen (a) before and (b) after dry-wet cycling (a) Standard curing specimen (b) Specimen of thefourth dry-wet cycling test

UnsoakedSoakedSoaked and re-dried

3

4

5

6

7

8

Com

pres

sive s

tren

gth

(MPa

)

2 3 41Dry-wet cycling times

Figure 18 Compressive strength change law of different dry-wet cycles


increased the thickness of SRX organic mucosa formed onaggregate surface and the ability to resist freeze-thawdamage was strengthened +e increase in the SRX sta-bilizer content properly is therefore helpful to promoting

the freeze-thaw resistance of the SSGM base In cold andfrozen areas the content of the SRX stabilizer should beincreased appropriately to a recommended value of075

Soening coefficientDry-wet recovery strength ratio

52

53

54

55

56

57

Soe

ning

coeffi

cien

t (

)

96

965

97

975

98

985

99

Dry

-wet

reco

very

stre

ngth

ratio

()


Figure 19 Softening coefficient and dry-wet recovery strength ratio at different dry-wet cycles

Table 6 Freezing stability performance of SSGM after the first freeze-thaw cycle test

IndexesStrength ofimmersed

specimen (MPa)

Strength offreeze-thaw

specimen (MPa)

Freeze-thawcoefficient ()

Strength ofnonimmersed

specimen (MPa)

Strength ofredriedspecimen(MPa)

Lossstrength(MPa)


()

Compressivestrength 383 332 8668 672 604 068 8988

Splittingstrength 022 019 8636 041 036 005 8780

UnsoakedFreeze-thaw

SoakedFreeze-thaw and re-dried

1

2

3

4

5

6

7

8

Com

pres

sive s

tren

gth

(MPa

)

2 3 4 51Freeze-thaw cycling times

Figure 20 +e unconfined compressive strength of specimens under different freeze-thaw cycles


5 Conclusion

+is study focused on the investigation on the technicalperformances of SSGM +e curing conditions were first

developed +e CBR value strength resilient modulustemperature shrinkage performance water stability per-formance and freezing stability were then analyzed underdifferent contents of SRX stabilizer Furthermore a rea-sonable range of SRX stabilizer content was proposed +efollowing conclusions may be drawn

(1) +e effect of curing temperature on unconfinedcompressive strength of SSGM is insignificantFurther increase in curing temperature will havelittle effect on the final strength of SSGM even if thecuring temperature is 110degC However the increasein curing temperature can significantly accelerate thecuring process of SSGM in laboratory test +ecuring temperature of SSGM should be controlled toapproximately 100degC to avoid the aging of SRXstabilizer due to excessive temperature +e waterloss rate of the specimen gradually increases with anincrease in the curing time at a curing temperature of100degC +e curing time was 16 h when the moisturecontent is zero and the water loss rate is 100 +erecommended curing conditions of SSGM speci-mens are therefore as follows the curing temperatureshould be 100degCplusmn 2degC the curing time should not beless than 16 h in the drying oven

(2) SSGM has good mechanical performances As the SRXcontent increased the mechanical properties

Freeze-thaw coefficientFreeze-thaw recovery strength ratio

40

50

60

70

80

90

100

Free

ze-th

aw co

effici

ent (

)


50

60

70

80

90

Free

ze-th

aw re

cove

ry st

reng

th ra

tio (

)

Figure 21 Freeze-thaw coefficient and recovery strength under different freeze-thaw cycle ratios under different freeze-thaw cycles

(a) (b)

Figure 22 Appearance of test specimen (a) before and (b) after the freeze-thaw cycle (a) Standard curing specimen (b) Specimen after thefifth freeze-thaw cycle

025 05 075 1SRX content ()

Freeze-thaw coefficient

Freeze-thaw recovery strength ratio

0

20

40

60

80

Free

ze-th

aw co

effici

entf

reez

e-th

awre

cove

ry st

reng

th ra

tio (

)

Figure 23 Freeze-thaw coefficient and freeze-thaw recoverystrength ratio of different stabilizer contents


significantly improved When the SRX content was inthe range of 025ndash1 and increased by 025 theunconfined compressive strengths under the conditionof vibration forming were 52 15 and 7 higherthan the previous ones Furthermore the splittingstrengths increased by 47 18 and 19 while thecompressive resilient modulus increased by 18 12and 4 Moreover CBR increased by 14 11 and8 Meanwhile the growth range reduced as the SRXcontent increasedWhen the SRX content was 05 theCBR value unconfined compressive strength andmodulus of resilience of the SSGM were significantlyimproved compared with ordinary graded macadam

(3) +e pavement performances of SSGM were analyzedfrom three aspects (1) +e temperature shrinkagecoefficient varies greatly in different temperatureranges especially in the range of 0degCndashminus10degC (maximumtemperature shrinkage coefficient) and 10degCndash0degC(minimum temperature shrinkage coefficient) It isindicated that the temperature has a significant effect ontemperature shrinkage coefficient Additionally tem-perature shrinkage coefficient of SSGM ismuch smallerthan that of other pavement stabilized materials such ascement concrete lime and gravel soil lime-fly ashconcrete and skeleton-density cement-stabilized mac-adam so SRX has excellent temperature shrinkageresistance +e application of SSGM between asphaltlayer and semirigid base layer can therefore effectivelyrestrain reflective cracks in these pavements caused bythe shrinkage cracks in semirigid base (2) +e waterstability of SSGM is evaluated using softening coeffi-cient and dry-wet recovery strength ratio +e resultsshow that SSGM can effectively resist damage caused bydry-wet cycling +e invasion of water just reduces thestrength temporarily and has rare impact on the in-ternal structure of SSGM+e strength also can basicallyreturn to the original state when the specimen isredried It can be considered that SSGMhas good waterstability performance (3) +e freeze-thaw stability ofSSGM is characterized using the freeze-thaw coefficientand recovery strength ratio +e obtained freeze-thawcoefficient and recovery strength ratio are small whilethe recovery strength ratio is only approximately 58after five freeze-thaw cycles +e recovery strength ratioof 58 indicates that five freeze-thaw cycles cause se-rious damages to SSGM It is observed that an increasein the SRX content caused a significant improvement inthe freezing stability of the SRX through the contrasttest of strength of SSGM with different SRX stabilizercontent after five freeze-thaw cycles Increase in thestrength and stability of SSGM is considerably obviousunder the condition of 05ndash075 SRX content +estrength and bearing capacity of SSGM fulfill thetechnical requirements under the condition of 075SRX content

(4) +e reasonable content of SRX is determined bycomprehensively analyzing the effect of the content ofSRX stabilizer on mechanical properties and pavement

performances It is recommended that the SRX stabi-lizer content is 05 under common conditions and itscontent should be 075 in cold and frozen areas

(5) A certain understanding of technical performancesof SSGM is given in this paper but some extra worksneed to be further investigated For instance morerelevant properties tests should be conducted toprovide a better understanding of technical perfor-mances of SSGM Investigation on the application offield engineering regarding SSGM should be there-fore performed based on the above more relevantproperties tests and the properties tests preformed inthis paper In general more relevant properties testswill be first conducted and then field engineering isperformed to optimize the conclusions drawn in thispaper in future study

Data Availability

+e data and materials are included within the article

Conflicts of Interest

+e authors declare that they have no conflicts of interest

Acknowledgments

+e authors gratefully acknowledge the support of testconditions from Key Laboratory for Special Area HighwayEngineering of Ministry of Education

References

[1] A M Sha ldquoMaterial characteristics of semi-rigid baserdquo ChinaJournal of Highway and Transportation vol 21 no 1 pp 1ndash52008 in Chinese

[2] X Zhao A Sha and B Hong ldquoMechanical analysis of vaultedexpansion of semi-rigid baserdquo Journal of Highway andTransportation Research and Development vol 3 no 2pp 54ndash58 2008

[3] Q Xu J Bian and S Meng ldquoStudy of flexible base and semi-rigid base asphalt pavement performance under acceleratedloading facility (ALF)rdquo in Proceedings of Apt 08 Gird In-ternational Conference Madrid Spain October 2008

[4] L Q Hu Research on Structural Characteristic and Compo-nent Design Methods for Semi-Rigid Base Course MaterialChangrsquoan University Xirsquoan China 2004 in Chinese

[5] Z F Li G N Xu and X Y Guo ldquoAsphalt pavement structurewith semi-rigid base course based on cross-anisotropyrdquoJournal of Changrsquoan University (Natural Science Edition)vol 6 pp 21ndash24 2008 in Chinese

[6] S Ping L Jiang A Shen and X Liu ldquoResearch on adapt-ability of semi-rigid material as base course for long-life as-phalt pavementrdquo Journal of Highway and TransportationResearch and Development vol 4 no 2 pp 11ndash14 2010

[7] W G Wong Y Qun and K C P Wang ldquoPerformances ofasphalt-treated base and semi-rigid baserdquo HKIE Transactionsvol 10 no 3 pp 54ndash58 2003

[8] C F Yang H R Pi T Xiao and C Z Jin ldquoMechanicalresponse analysis of heavy traffic on semi-rigid base pavementperformancerdquo Applied Mechanics and Materials vol 97-98pp 146ndash150 2011


[9] J Zheng ldquoDesign guide for semirigid pavements in Chinabased on critical state of asphalt mixturerdquo Journal of Materialsin Civil Engineering vol 25 no 7 pp 899ndash906 2013

[10] G F Li C H Chen B F Jiang and L Y Su ldquoMechanicsanalysis of flexible base pavement structurerdquo Applied Me-chanics and Materials vol 580-583 pp 632ndash635 2014

[11] R B Ren H W Li and Z R Wang ldquoAnalysis of semi-rigidasphalt pavement with flexible base as a sandwich layerrdquo inProceedings of Selected Papers from the Geohunan Interna-tional Conference August 2009

[12] K A Khaled ldquoPerformance-based models for flexible pave-ment structural overlay designrdquo Journal of TransportationEngineering vol 131 no 2 pp 149ndash159 2005

[13] S Meng and X Huang ldquoStudy on optimum design of mixturefor asphalt pavement with flexible baserdquo Journal of Highwayand Transportation Research and Development vol 1 no 1pp 1ndash5 2006

[14] L Cao Z Dong and Y Tan ldquoDesign and performanceevaluation of cold recycled mixture with emulsified asphaltrdquoJournal of Highway and Transportation Research and Devel-opment vol 1 no 1 pp 15ndash22 2006

[15] C Guo N Wang H Ruan Q Shen and G Wang ldquoMe-chanical analysis of asphalt pavements with a graded crushedstone base under dynamic loadrdquo Journal of Highway andTransportation Research and Development vol 10 no 4pp 13ndash20 2016

[16] M Zhang L Wang and Y Zhou ldquoAsphalt pavementstructure analysis of the upper base of the graded crushedstonerdquo Journal of Shenyang Jianzhu University Natural Sci-ence vol 27 no 1 pp 64ndash69 2011 in Chinese

[17] L H He W Deng and H Z Zhu ldquoPropreties of SRX water-based polymer materialsrdquo Applied Chemical Industry vol 49no 4 pp 93ndash96 2008 in Chinese

[18] Y Zhang Y L Zhao and B Y Yu ldquo+e study on roadperformance and pavement structure analysis for the baselayer material stabilized by SRXrdquo Advanced Materials Re-search vol 594-597 pp 1402ndash1406 2012

[19] Romix International Ltd Design Criteria for Road WaterBased polymer (SRXndashVR Series) Flexible Road StructuresChina Communications Press Beijing China 2010 inChinese

[20] S R Iyengar E Masad A K Rodriguez and H S BazzildquoPavement subgrade stabilization using polymers charac-terization and performancerdquo Journal of Materials in CivilEngineering vol 25 no 4 pp 472ndash483 2013

[21] E J Scholten W Vonk and J Korenstra ldquoTowards greenpavements with novel class of SBS polymers for enhancedeffectiveness in bitumen and pavement performancerdquo In-ternational Journal of Pavement Research and Technologyvol 3 no 4 pp 216ndash222 2010

[22] M J Zhang Y L Zhao B Y Yu and P D Ou ldquoHydro-radical polymer stabilized base materials mechanics proper-ties and pavement structure analysisrdquo Journal of ShenyangJianzhu University Natural Science vol 28 no 6 pp 1030ndash1036 2012 in Chinese

[23] H X DuGe Experimental Study of Flexible Base Stabilized bySOILFIX Polymer Beijing Architecture University BeijingChina 2011 in Chinese

[24] China Communications Press JTG E42ndash2005 Test Methods ofAggregate for Highway Engineering China CommunicationsPress Beijing China 2005 in Chinese

[25] China Communications Press JTGT F20ndash2015 TechnicalGuidelines for Construction of Highway Roadbases ChinaCommunications Press Beijing China 2015 in Chinese

[26] X D Yang L Ma and Z Q Zhang ldquoEffect of particles size ofcoarse aggregate on stability of aggregate blendrdquo Journal ofXirsquoan University of Science and Technology vol 26 no 4pp 480ndash484 2006 in Chinese

[27] D Li Research on Graded Broken Stone Design Standard andDesign Method Based on Vibrating Compaction ChangrsquoanUniversity Xirsquoan China 2013 in Chinese

[28] J L Zhang Study on the Test of Vibratory Compaction forCement Stabilized Gravel Changrsquoan University Xirsquoan China2008 in Chinese

[29] Y Jiang J Xue and Z Chen ldquoInfluence of volumetricproperty on mechanical properties of vertical vibrationcompacted asphalt mixturerdquo Construction and BuildingMaterials vol 135 pp 612ndash621 2017

[30] China Communications Press JTG E40ndash2007 Test Method ofSoils for Highway Engineering China Communications PressBeijing China 2007 in Chinese

[31] China Communications Press JTG E51ndash2009 Test Methods ofMaterials Stabilized with Inorganic Binders for Highway En-gineering China Communications Press Beijing China 2009in Chinese

[32] Q Hu andM Sha ldquoResearch on influence factor in semi-rigidbase course material temperature shrinkage coefficient testusing strain gaugerdquo Journal of Highway and TransportationResearch and Development vol 2 no 2 pp 12ndash15 2007

[33] C Wang Z Fan and C Li ldquoPreparation and engineeringproperties of low-viscosity epoxy grouting materials modifiedwith silicone for microcrack repairrdquo Construction andBuilding Materials vol 290 Article ID 123270 2021

[34] P Jitsangiam and H Nikraz ldquoMechanical behaviours ofhydrated cement treated crushed rock base as a road basematerial in Western Australiardquo International Journal ofPavement Engineering vol 10 no 1 pp 39ndash47 2009

[35] Y Wang and X Sun ldquoResearch on the shrinkage performanceof cement-stabilized baserdquo Advanced Materials Researchvol 905 pp 292ndash295 2014

[36] Y J Yingjun Jiang L W Liwei Li J L Jiaolong RenY S Yinshan Xu and Y Yi Zhang ldquoPerformances of cement-stabilized macadam with multilevel dense built-in gradingstructure gradationrdquo in Proceedings of International Confer-ence on Electric Technology amp Civil Engineering April 2011

[37] J Cheng Z Xu and Z Sun ldquoTrial research on cement-sta-bilized macadam anti-crack evaluation coefficient based onenvironment and loadrdquo Journal of Highway and Trans-portation Research and Development vol 4 no 1 pp 7ndash112009


[19] In past decades many scholars have performed ex-tensive researches on its technical performance and con-ducted its exploratory applications in some countriesIyengar et al studied the SRX for application in highwaypavement base and analyzed the feasibility of SRX based onthe local engineering practice in Qatar [20] Scholten et alfound that the SRX-stabilized material can significantlyimprove the pavement performance and reduce the overallpavement thickness by comparing with ordinary semirigidbase asphalt pavement [21] Since 2008 SRX-stabilizedmaterials have been used in Beijing Guangdong ProvinceLiaoning Province and Sichuan Province in China Zhanget al studied and analyzed the mechanical properties ofSRX-stabilized base materials and the mechanical responseof asphalt pavement structures [22] It is found that SRX-stabilized materials used as pavement base have good fatigueresistance Meanwhile Du compared and analyzed theproperties of SRX-stabilized materials and inorganic binderstabilized materials It was proved that the SRX-stabilizedmaterials have advantages such as superior mechanicalproperties improvement of fatigue life and crack resistance[23]

+e abovementioned studies have promoted the de-velopment and application of SSGM However there arefew studies on the systematical investigation on themechanical properties and pavement performances ofSSGM Furthermore an appropriate curing conditionwith short test period for SSGM specimen is rarely re-ported For instance Romix International Ltd suggestedthat the curing condition of a SSGM specimen is asfollows (1) the specimen is cured in an oven at 50degC for 2days and then the specimen is dried in the sun for 7 daysagain (2) the specimen is directly cured in an oven at30degC for 10 days [19] However the above curing con-dition affects the experimental process and reduces theexperimental efficiency with the increase in the amount ofspecimens in the experiment

Hence this paper aims to explore the appropriate curingconditions of SSGM based on the effect of curing temper-ature and curing time on the formation of unconfinedcompressive strength and moisture content variationMeanwhile the mechanical properties and road perfor-mance of SSGM are evaluated to provide technical supportfor engineering applications

2 Test Materials

21 SRX Stabilizers and Graded Macadam +e raw mate-rials of SSGM comprise the SRX stabilizer aggregatesand water +e SRX stabilizer is obtained from RomixInternational Ltd and its technical performances arepresented in Table 1 Limestone aggregate produced inWeinan Shaanxi Province is selected as the aggregate+e technical performance of aggregate was testedaccording to Test Methods of Aggregate for HighwayEngineering (JTG E42ndash2005) [24] All indicators conformwith the relevant requirements listed in TechnicalGuidelines for Construction of Highway Roadbases (JTGTF20ndash2015) [25] as shown in Table 2

22 SSGM Mixture +e SSGM consists of aggregate SRXstabilizer and water +e aggregate gradation is obtainedbased on the multistage crowded skeleton determined by theprevious study of the research group +e gradation designmethods are as follows (1) the step-by-step filling theory isused to determine the gradation of coarse aggregates on thebasis of interference theory [26] (2) +e gradation of fineaggregates is determined by using I method according to themaximum density curve theory [27 28] (3) +e proportionof coarse aggregates and fine aggregates is rest with thedouble-optimum principle of dry density and unconfinedcompressive strength [29] +e composite gradation ispresented in Table 3 +e optimum moisture content andmaximum dry density of SSGM determined by the vibratorycompaction test (T0133ndash1993) in Test Method of Soils forHighway Engineering (JTG E40ndash2007) were 340 and247 gcm3 respectively [30] +e content of SRX stabilizerwas initially 025 05 075 and 1

3 Experimental Procedure

31 Curing Condition Test A cylindrical test specimen ofφ150mmtimes 150mm under the compaction of 98 wasformed by referring to the specification (T 0843ndash2009) inTest Methods of Materials Stabilized with Inorganic Bindersof Highway Engineering (JTG E51ndash2009) [31] +e SSGMspecimens were divided into ten groups Nine groups werecured in an oven at 30degC 50degC 65degC 80degC 90degC 95degC 100degC105degC and 110degC whereas the remaining group was curedunder natural conditions for 45 days (the test was performedin July 2019 the average temperature is 30degC)

+e curing time of nine groups of specimens was de-termined by recording the change of water content withtime +e methods were according to the Drying Method (T0801ndash2009) in Test Methods of Materials Stabilized withInorganic Binders of Highway Engineering (JTG E51ndash2009)[31] until the moisture content was zero indicating that allthe samples were completely dry Meanwhile the SSGMspecimen cured for 45 days under natural conditions wasselected as the benchmark while the strength of the specimenwas selected as the benchmark strength +e nine specimengroups were then tested for unconfined compressivestrength after they were cured in the oven

32 Mechanical Performance Test

321 California Bearing Ratio (CBR) Test CaliforniaBearing Ratio (CBR) is used to verify the bearing capacity ofSSGM +e CBR test (T0134ndash1993) was performed by theTest Method of Soils for Highway Engineering (JTGE40ndash2007) [30] A cylindrical test specimen of φ152mmtimes h170mm was formed under the given conditions as followsthe compaction of the specimens is 98 the moisturecontent and dry density are optimum and maximum re-spectively the contents of SRX stabilizer were 0 02505 075 and 1 +e cured specimens were soaked innormal temperature water for 96 h and then the CBR of thespecimens were measured under the most unfavorableconditions



CBR P

7000times 100 (1)



R P

A (2)




r 2p

πdh (3)



Ew pH

l (4)



















(5)




Figure 1 CBR test


















ω 00539t3

minus 19315t2

+ 2331t + 20182 R2

099481113872 1113873

(6)





30 50 65 80 90 95 100 105 110

e UCSCuring Time



0

50

100

150

200

250

Cur

ing

Tim

e (h)

62

63

64

65

66

67

68

Unc

onfin

ed C

ompr

essiv

e Str

engt

h (M

Pa)


2 4 6 8 10 12 14 160Curing Time (h)

0

1

2

3

4

Moi

sture

Con

tent

()










y = 00539x3 ndash 19315x2 + 2331x + 20182R2 = 09948

2 4 6 8 10 12 14 160Curing Time (h)

20

40

60

80

100

120

Wat

er L

oss R

ate (

)

0



0

02

04

06

08

Deh

ydra

tion

Rate

(h

)


0 025 05 075 1SRX content ()

0

200

400

600

800

CBR

()









0 025 05 075 1SRX content ()

0

1

2

3

4

5

Unc

onfin

ed co

mpr

essiv

e str

engt

h (M

Pa)

(a)

025 05 075 1

Split

ting

stren

gth

(MPa

)

SRX content ()

0

005

01

015

02

025

03

035

(b)


0 025 05 075 1SRX content ()

0

200

400

600

800

1000

Mod

ulus

of r

esili

ence

(MPa

)



025SRX content

0500751

0

5

10

15

20

Tem

pera

ture

-shr

inka

ge co

effici

ent (

times10-6

degC)








025 05 075 1SRX content ()


0

4

8

12

16

Tem

pera

ture

-shr

inka

ge co

effici

ent (

times10-6

degC)





Lime andgravel soil














(MPa)

Lossstrength(MPa)




(a) (b)



3

4

5

6

7

8

Com

pres

sive s

tren

gth

(MPa

)







52

53

54

55

56

57

Soe

ning

coeffi

cien

t (

)

96

965

97

975

98

985

99

Dry

-wet

reco

very

stre

ngth

ratio

()





specimen (MPa)


specimen (MPa)



specimen (MPa)


Lossstrength(MPa)


()



UnsoakedFreeze-thaw


1

2

3

4

5

6

7

8

Com

pres

sive s

tren

gth

(MPa

)




5 Conclusion






40

50

60

70

80

90

100

Free

ze-th

aw co

effici

ent (

)


50

60

70

80

90

Free

ze-th

aw re

cove

ry st

reng

th ra

tio (

)


(a) (b)


025 05 075 1SRX content ()



0

20

40

60

80

Free

ze-th

aw co

effici

entf

reez

e-th

awre

cove

ry st

reng

th ra

tio (

)








Data Availability




Acknowledgments


References









































CBR P

7000times 100 (1)



R P

A (2)




r 2p

πdh (3)



Ew pH

l (4)



















(5)




Figure 1 CBR test


















ω 00539t3

minus 19315t2

+ 2331t + 20182 R2

099481113872 1113873

(6)





30 50 65 80 90 95 100 105 110

e UCSCuring Time



0

50

100

150

200

250

Cur

ing

Tim

e (h)

62

63

64

65

66

67

68

Unc

onfin

ed C

ompr

essiv

e Str

engt

h (M

Pa)


2 4 6 8 10 12 14 160Curing Time (h)

0

1

2

3

4

Moi

sture

Con

tent

()










y = 00539x3 ndash 19315x2 + 2331x + 20182R2 = 09948

2 4 6 8 10 12 14 160Curing Time (h)

20

40

60

80

100

120

Wat

er L

oss R

ate (

)

0



0

02

04

06

08

Deh

ydra

tion

Rate

(h

)


0 025 05 075 1SRX content ()

0

200

400

600

800

CBR

()









0 025 05 075 1SRX content ()

0

1

2

3

4

5

Unc

onfin

ed co

mpr

essiv

e str

engt

h (M

Pa)

(a)

025 05 075 1

Split

ting

stren

gth

(MPa

)

SRX content ()

0

005

01

015

02

025

03

035

(b)


0 025 05 075 1SRX content ()

0

200

400

600

800

1000

Mod

ulus

of r

esili

ence

(MPa

)



025SRX content

0500751

0

5

10

15

20

Tem

pera

ture

-shr

inka

ge co

effici

ent (

times10-6

degC)








025 05 075 1SRX content ()


0

4

8

12

16

Tem

pera

ture

-shr

inka

ge co

effici

ent (

times10-6

degC)





Lime andgravel soil














(MPa)

Lossstrength(MPa)




(a) (b)



3

4

5

6

7

8

Com

pres

sive s

tren

gth

(MPa

)







52

53

54

55

56

57

Soe

ning

coeffi

cien

t (

)

96

965

97

975

98

985

99

Dry

-wet

reco

very

stre

ngth

ratio

()





specimen (MPa)


specimen (MPa)



specimen (MPa)


Lossstrength(MPa)


()



UnsoakedFreeze-thaw


1

2

3

4

5

6

7

8

Com

pres

sive s

tren

gth

(MPa

)




5 Conclusion






40

50

60

70

80

90

100

Free

ze-th

aw co

effici

ent (

)


50

60

70

80

90

Free

ze-th

aw re

cove

ry st

reng

th ra

tio (

)


(a) (b)


025 05 075 1SRX content ()



0

20

40

60

80

Free

ze-th

aw co

effici

entf

reez

e-th

awre

cove

ry st

reng

th ra

tio (

)








Data Availability




Acknowledgments


References

















































(5)




Figure 1 CBR test


















ω 00539t3

minus 19315t2

+ 2331t + 20182 R2

099481113872 1113873

(6)





30 50 65 80 90 95 100 105 110

e UCSCuring Time



0

50

100

150

200

250

Cur

ing

Tim

e (h)

62

63

64

65

66

67

68

Unc

onfin

ed C

ompr

essiv

e Str

engt

h (M

Pa)


2 4 6 8 10 12 14 160Curing Time (h)

0

1

2

3

4

Moi

sture

Con

tent

()










y = 00539x3 ndash 19315x2 + 2331x + 20182R2 = 09948

2 4 6 8 10 12 14 160Curing Time (h)

20

40

60

80

100

120

Wat

er L

oss R

ate (

)

0



0

02

04

06

08

Deh

ydra

tion

Rate

(h

)


0 025 05 075 1SRX content ()

0

200

400

600

800

CBR

()









0 025 05 075 1SRX content ()

0

1

2

3

4

5

Unc

onfin

ed co

mpr

essiv

e str

engt

h (M

Pa)

(a)

025 05 075 1

Split

ting

stren

gth

(MPa

)

SRX content ()

0

005

01

015

02

025

03

035

(b)


0 025 05 075 1SRX content ()

0

200

400

600

800

1000

Mod

ulus

of r

esili

ence

(MPa

)



025SRX content

0500751

0

5

10

15

20

Tem

pera

ture

-shr

inka

ge co

effici

ent (

times10-6

degC)








025 05 075 1SRX content ()


0

4

8

12

16

Tem

pera

ture

-shr

inka

ge co

effici

ent (

times10-6

degC)





Lime andgravel soil














(MPa)

Lossstrength(MPa)




(a) (b)



3

4

5

6

7

8

Com

pres

sive s

tren

gth

(MPa

)







52

53

54

55

56

57

Soe

ning

coeffi

cien

t (

)

96

965

97

975

98

985

99

Dry

-wet

reco

very

stre

ngth

ratio

()





specimen (MPa)


specimen (MPa)



specimen (MPa)


Lossstrength(MPa)


()



UnsoakedFreeze-thaw


1

2

3

4

5

6

7

8

Com

pres

sive s

tren

gth

(MPa

)




5 Conclusion






40

50

60

70

80

90

100

Free

ze-th

aw co

effici

ent (

)


50

60

70

80

90

Free

ze-th

aw re

cove

ry st

reng

th ra

tio (

)


(a) (b)


025 05 075 1SRX content ()



0

20

40

60

80

Free

ze-th

aw co

effici

entf

reez

e-th

awre

cove

ry st

reng

th ra

tio (

)








Data Availability




Acknowledgments


References





















































ω 00539t3

minus 19315t2

+ 2331t + 20182 R2

099481113872 1113873

(6)





30 50 65 80 90 95 100 105 110

e UCSCuring Time



0

50

100

150

200

250

Cur

ing

Tim

e (h)

62

63

64

65

66

67

68

Unc

onfin

ed C

ompr

essiv

e Str

engt

h (M

Pa)


2 4 6 8 10 12 14 160Curing Time (h)

0

1

2

3

4

Moi

sture

Con

tent

()










y = 00539x3 ndash 19315x2 + 2331x + 20182R2 = 09948

2 4 6 8 10 12 14 160Curing Time (h)

20

40

60

80

100

120

Wat

er L

oss R

ate (

)

0



0

02

04

06

08

Deh

ydra

tion

Rate

(h

)


0 025 05 075 1SRX content ()

0

200

400

600

800

CBR

()









0 025 05 075 1SRX content ()

0

1

2

3

4

5

Unc

onfin

ed co

mpr

essiv

e str

engt

h (M

Pa)

(a)

025 05 075 1

Split

ting

stren

gth

(MPa

)

SRX content ()

0

005

01

015

02

025

03

035

(b)


0 025 05 075 1SRX content ()

0

200

400

600

800

1000

Mod

ulus

of r

esili

ence

(MPa

)



025SRX content

0500751

0

5

10

15

20

Tem

pera

ture

-shr

inka

ge co

effici

ent (

times10-6

degC)








025 05 075 1SRX content ()


0

4

8

12

16

Tem

pera

ture

-shr

inka

ge co

effici

ent (

times10-6

degC)





Lime andgravel soil














(MPa)

Lossstrength(MPa)




(a) (b)



3

4

5

6

7

8

Com

pres

sive s

tren

gth

(MPa

)







52

53

54

55

56

57

Soe

ning

coeffi

cien

t (

)

96

965

97

975

98

985

99

Dry

-wet

reco

very

stre

ngth

ratio

()





specimen (MPa)


specimen (MPa)



specimen (MPa)


Lossstrength(MPa)


()



UnsoakedFreeze-thaw


1

2

3

4

5

6

7

8

Com

pres

sive s

tren

gth

(MPa

)




5 Conclusion






40

50

60

70

80

90

100

Free

ze-th

aw co

effici

ent (

)


50

60

70

80

90

Free

ze-th

aw re

cove

ry st

reng

th ra

tio (

)


(a) (b)


025 05 075 1SRX content ()



0

20

40

60

80

Free

ze-th

aw co

effici

entf

reez

e-th

awre

cove

ry st

reng

th ra

tio (

)








Data Availability




Acknowledgments


References










































ω 00539t3

minus 19315t2

+ 2331t + 20182 R2

099481113872 1113873

(6)





30 50 65 80 90 95 100 105 110

e UCSCuring Time



0

50

100

150

200

250

Cur

ing

Tim

e (h)

62

63

64

65

66

67

68

Unc

onfin

ed C

ompr

essiv

e Str

engt

h (M

Pa)


2 4 6 8 10 12 14 160Curing Time (h)

0

1

2

3

4

Moi

sture

Con

tent

()










y = 00539x3 ndash 19315x2 + 2331x + 20182R2 = 09948

2 4 6 8 10 12 14 160Curing Time (h)

20

40

60

80

100

120

Wat

er L

oss R

ate (

)

0



0

02

04

06

08

Deh

ydra

tion

Rate

(h

)


0 025 05 075 1SRX content ()

0

200

400

600

800

CBR

()









0 025 05 075 1SRX content ()

0

1

2

3

4

5

Unc

onfin

ed co

mpr

essiv

e str

engt

h (M

Pa)

(a)

025 05 075 1

Split

ting

stren

gth

(MPa

)

SRX content ()

0

005

01

015

02

025

03

035

(b)


0 025 05 075 1SRX content ()

0

200

400

600

800

1000

Mod

ulus

of r

esili

ence

(MPa

)



025SRX content

0500751

0

5

10

15

20

Tem

pera

ture

-shr

inka

ge co

effici

ent (

times10-6

degC)








025 05 075 1SRX content ()


0

4

8

12

16

Tem

pera

ture

-shr

inka

ge co

effici

ent (

times10-6

degC)





Lime andgravel soil














(MPa)

Lossstrength(MPa)




(a) (b)



3

4

5

6

7

8

Com

pres

sive s

tren

gth

(MPa

)







52

53

54

55

56

57

Soe

ning

coeffi

cien

t (

)

96

965

97

975

98

985

99

Dry

-wet

reco

very

stre

ngth

ratio

()





specimen (MPa)


specimen (MPa)



specimen (MPa)


Lossstrength(MPa)


()



UnsoakedFreeze-thaw


1

2

3

4

5

6

7

8

Com

pres

sive s

tren

gth

(MPa

)




5 Conclusion






40

50

60

70

80

90

100

Free

ze-th

aw co

effici

ent (

)


50

60

70

80

90

Free

ze-th

aw re

cove

ry st

reng

th ra

tio (

)


(a) (b)


025 05 075 1SRX content ()



0

20

40

60

80

Free

ze-th

aw co

effici

entf

reez

e-th

awre

cove

ry st

reng

th ra

tio (

)








Data Availability




Acknowledgments


References















































y = 00539x3 ndash 19315x2 + 2331x + 20182R2 = 09948

2 4 6 8 10 12 14 160Curing Time (h)

20

40

60

80

100

120

Wat

er L

oss R

ate (

)

0



0

02

04

06

08

Deh

ydra

tion

Rate

(h

)


0 025 05 075 1SRX content ()

0

200

400

600

800

CBR

()









0 025 05 075 1SRX content ()

0

1

2

3

4

5

Unc

onfin

ed co

mpr

essiv

e str

engt

h (M

Pa)

(a)

025 05 075 1

Split

ting

stren

gth

(MPa

)

SRX content ()

0

005

01

015

02

025

03

035

(b)


0 025 05 075 1SRX content ()

0

200

400

600

800

1000

Mod

ulus

of r

esili

ence

(MPa

)



025SRX content

0500751

0

5

10

15

20

Tem

pera

ture

-shr

inka

ge co

effici

ent (

times10-6

degC)








025 05 075 1SRX content ()


0

4

8

12

16

Tem

pera

ture

-shr

inka

ge co

effici

ent (

times10-6

degC)





Lime andgravel soil














(MPa)

Lossstrength(MPa)




(a) (b)



3

4

5

6

7

8

Com

pres

sive s

tren

gth

(MPa

)







52

53

54

55

56

57

Soe

ning

coeffi

cien

t (

)

96

965

97

975

98

985

99

Dry

-wet

reco

very

stre

ngth

ratio

()





specimen (MPa)


specimen (MPa)



specimen (MPa)


Lossstrength(MPa)


()



UnsoakedFreeze-thaw


1

2

3

4

5

6

7

8

Com

pres

sive s

tren

gth

(MPa

)




5 Conclusion






40

50

60

70

80

90

100

Free

ze-th

aw co

effici

ent (

)


50

60

70

80

90

Free

ze-th

aw re

cove

ry st

reng

th ra

tio (

)


(a) (b)


025 05 075 1SRX content ()



0

20

40

60

80

Free

ze-th

aw co

effici

entf

reez

e-th

awre

cove

ry st

reng

th ra

tio (

)








Data Availability




Acknowledgments


References














































0 025 05 075 1SRX content ()

0

1

2

3

4

5

Unc

onfin

ed co

mpr

essiv

e str

engt

h (M

Pa)

(a)

025 05 075 1

Split

ting

stren

gth

(MPa

)

SRX content ()

0

005

01

015

02

025

03

035

(b)


0 025 05 075 1SRX content ()

0

200

400

600

800

1000

Mod

ulus

of r

esili

ence

(MPa

)



025SRX content

0500751

0

5

10

15

20

Tem

pera

ture

-shr

inka

ge co

effici

ent (

times10-6

degC)








025 05 075 1SRX content ()


0

4

8

12

16

Tem

pera

ture

-shr

inka

ge co

effici

ent (

times10-6

degC)





Lime andgravel soil














(MPa)

Lossstrength(MPa)




(a) (b)



3

4

5

6

7

8

Com

pres

sive s

tren

gth

(MPa

)







52

53

54

55

56

57

Soe

ning

coeffi

cien

t (

)

96

965

97

975

98

985

99

Dry

-wet

reco

very

stre

ngth

ratio

()





specimen (MPa)


specimen (MPa)



specimen (MPa)


Lossstrength(MPa)


()



UnsoakedFreeze-thaw


1

2

3

4

5

6

7

8

Com

pres

sive s

tren

gth

(MPa

)




5 Conclusion






40

50

60

70

80

90

100

Free

ze-th

aw co

effici

ent (

)


50

60

70

80

90

Free

ze-th

aw re

cove

ry st

reng

th ra

tio (

)


(a) (b)


025 05 075 1SRX content ()



0

20

40

60

80

Free

ze-th

aw co

effici

entf

reez

e-th

awre

cove

ry st

reng

th ra

tio (

)








Data Availability




Acknowledgments


References













































025 05 075 1SRX content ()


0

4

8

12

16

Tem

pera

ture

-shr

inka

ge co

effici

ent (

times10-6

degC)





Lime andgravel soil














(MPa)

Lossstrength(MPa)




(a) (b)



3

4

5

6

7

8

Com

pres

sive s

tren

gth

(MPa

)







52

53

54

55

56

57

Soe

ning

coeffi

cien

t (

)

96

965

97

975

98

985

99

Dry

-wet

reco

very

stre

ngth

ratio

()





specimen (MPa)


specimen (MPa)



specimen (MPa)


Lossstrength(MPa)


()



UnsoakedFreeze-thaw


1

2

3

4

5

6

7

8

Com

pres

sive s

tren

gth

(MPa

)




5 Conclusion






40

50

60

70

80

90

100

Free

ze-th

aw co

effici

ent (

)


50

60

70

80

90

Free

ze-th

aw re

cove

ry st

reng

th ra

tio (

)


(a) (b)


025 05 075 1SRX content ()



0

20

40

60

80

Free

ze-th

aw co

effici

entf

reez

e-th

awre

cove

ry st

reng

th ra

tio (

)








Data Availability




Acknowledgments


References

















































(MPa)

Lossstrength(MPa)




(a) (b)



3

4

5

6

7

8

Com

pres

sive s

tren

gth

(MPa

)







52

53

54

55

56

57

Soe

ning

coeffi

cien

t (

)

96

965

97

975

98

985

99

Dry

-wet

reco

very

stre

ngth

ratio

()





specimen (MPa)


specimen (MPa)



specimen (MPa)


Lossstrength(MPa)


()



UnsoakedFreeze-thaw


1

2

3

4

5

6

7

8

Com

pres

sive s

tren

gth

(MPa

)




5 Conclusion






40

50

60

70

80

90

100

Free

ze-th

aw co

effici

ent (

)


50

60

70

80

90

Free

ze-th

aw re

cove

ry st

reng

th ra

tio (

)


(a) (b)


025 05 075 1SRX content ()



0

20

40

60

80

Free

ze-th

aw co

effici

entf

reez

e-th

awre

cove

ry st

reng

th ra

tio (

)








Data Availability




Acknowledgments


References











































52

53

54

55

56

57

Soe

ning

coeffi

cien

t (

)

96

965

97

975

98

985

99

Dry

-wet

reco

very

stre

ngth

ratio

()





specimen (MPa)


specimen (MPa)



specimen (MPa)


Lossstrength(MPa)


()



UnsoakedFreeze-thaw


1

2

3

4

5

6

7

8

Com

pres

sive s

tren

gth

(MPa

)




5 Conclusion






40

50

60

70

80

90

100

Free

ze-th

aw co

effici

ent (

)


50

60

70

80

90

Free

ze-th

aw re

cove

ry st

reng

th ra

tio (

)


(a) (b)


025 05 075 1SRX content ()



0

20

40

60

80

Free

ze-th

aw co

effici

entf

reez

e-th

awre

cove

ry st

reng

th ra

tio (

)








Data Availability




Acknowledgments


References








































5 Conclusion






40

50

60

70

80

90

100

Free

ze-th

aw co

effici

ent (

)


50

60

70

80

90

Free

ze-th

aw re

cove

ry st

reng

th ra

tio (

)


(a) (b)


025 05 075 1SRX content ()



0

20

40

60

80

Free

ze-th

aw co

effici

entf

reez

e-th

awre

cove

ry st

reng

th ra

tio (

)








Data Availability




Acknowledgments


References













































Data Availability




Acknowledgments


References






































































Documents

ExperimentalInvestigationoftheTechnicalPerformancesof SRX